Bone Scan Research Articles

#1950 Burosumab activity on osteomalacia—a TIO case report

Abstract Background and Aims Tumor-Induced Osteomalacia (TIO) is a rare paraneoplastic disorder caused by a tumor (PMT), usually of small size and benign, secreting FGF23. FGF23 suppresses the reabsorption of phosphate and the synthesis of 1,25(OH)2 vitamin D in the proximal tubular cells of the kidney; consequently, affected patients develop hypophosphatemia and osteomalacia, resulting in bone pain and pathological fractures. The treatment of choice is the surgical resection of the tumor, but when the latter is not detected or cannot be removed, phosphate salts and active vitamin D can be employed to improve TIO symptoms. Burosumab, a monoclonal antibody directed against FGF23 introduced for the treatment of X-linked hypophosphatemic rickets, has recently been tested for the treatment of TIO non-surgical patients with encouraging results, even if few data are currently available. Method Starting from January 2021, a 56M patient affected by TIO without identified PMT has been treated with burosumab at the dosage of 1 mg/kg s.c. every 4 weeks. Results Before the introduction of burosumab, his blood exams showed hypophosphatemia (1.9 mg/dL), low 1,25(OH)2 vitamin D levels (15 pg/mL) and hyperparathyroidism (81 pg/mL) secondary to previous administrations of phosphate salts. He also reported widespread bone pain, suspect of multiple fractures and pseudofractures, confirmed by whole skeleton bone scintigraphy (BS) as numerous areas of pathological accumulation in the ribs, sacrum, bilateral femur, right proximal tibia, sternoclavicular joint and vertebral bodies. After the initiation of burosumab, serum phosphate, PTH and 1,25(OH)2 vitamin D levels gradually normalized. The patient also reported an improvement in bone pain, and later BS described a notable and continuous reduction in pathological accumulations, which almost completely disappeared after 24 months, confirming the absence of new fractures and the improvement of existing ones. Conclusion Therefore, burosumab is suggested as an alternative treatment for non-surgical TIO patients, especially since, unlike conventional therapy with phosphate salts and active vitamin D, its therapeutic action seems to contribute to the further improvement of osteomalacia.

True-Positive 18F-Flotufolastat Lesions in Patients with Prostate Cancer Recurrence with Baseline-Negative Conventional Imaging: Results from the Prospective, Phase 3, Multicenter SPOTLIGHT Study.

18F-rhPSMA-7.3 (18F-flotufolastat) is a high-affinity prostate-specific membrane antigen-targeted diagnostic radiopharmaceutical for PET imaging in patients with prostate cancer. Here, we report findings from the SPOTLIGHT study (NCT04186845), assessing the performance of 18F-flotufolastat PET/CT for identifying prostate-specific membrane antigen-positive lesions confirmed by standard of truth (SoT) in men with biochemical recurrence of prostate cancer and negative conventional imaging at baseline. Methods: Men with biochemical recurrence received 296 MBq of 18F-flotufolastat intravenously and then underwent PET/CT 50-70 min later. 18F-flotufolastat PET/CT findings were evaluated by 3 masked central readers and verified using histopathology or follow-up confirmatory imaging (CT, MRI, bone scan, or 18F-fluciclovine PET/CT) as the SoT. The present analysis evaluated all patients who had negative conventional imaging at baseline, underwent 18F-flotufolastat PET/CT, and had SoT verification by histopathology or follow-up confirmatory imaging to report detection rate (DR), which is the number of patients with at least 1 PET-positive lesion, divided by the number of evaluable patients, and verified DR (VDR), which is the proportion of patients with at least 1 true-positive lesion as verified by SoT, of all patients scanned (PET-positive and PET-negative scans). DR and VDR were calculated and stratified according to prior therapy. Majority read data (agreement between ≥2 readers) are reported. Results: In total, 171 patients with negative baseline conventional imaging and SoT by histopathology or post-PET confirmatory imaging were evaluated. By majority read, the overall 18F-flotufolastat DR among these patients was 95% (163/171; 95% CI, 91.0%-98.0%), and 110 of 171 of these patients had at least 1 true-positive lesion identified (VDR, 64%; 95% CI, 56.7%-71.5%). In the postprostatectomy group (133/171), 8.3% of patients had at least 1 true-positive lesion in the prostate bed, 28% in pelvic lymph nodes, and 35% in other sites. Among those who had received radiotherapy (36/171), 50% of patients had true-positive detections in the prostate, 8.3% in pelvic lymph nodes, and 36% in other sites. Conclusion: 18F-flotufolastat frequently identified true-positive prostate cancer lesions in patients with negative conventional imaging. 18F-flotufolastat may help to better define sites of disease recurrence and inform salvage therapy decisions than does conventional imaging, potentially leading to improved outcomes.

MRI and SPECT/CT demonstrate, with low certainty of evidence, the highest diagnostic accuracy for aseptic knee arthroplasty loosening: A systematic comparative diagnostic test review and meta-analysis.

The purpose of this study was to evaluate and compare the diagnostic accuracy of modalities used to aid the diagnosis of aseptic knee arthroplasty loosening. A comparative diagnostic test accuracy systematic review and meta-analysis was conducted following the Cochrane and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, EMBASEand Cochrane databases were searched for original articles evaluating diagnostic modalities up to March 2024. Included studies compared the modality (index test) to the intraoperative finding as reference test. The QUADAS-C (Quality Assessment of Diagnostic Accuracy Studies-Comparative)tool was used to assess the quality of the included studies. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was used to evaluate the certainty of evidence. Level of evidence was evaluated using the Oxford Levels of Evidence tool. The primary outcome wasthe summary of diagnostic accuracy metrics for each modality as demonstrated by a summary receiver-operating characteristic (SROC) curve. The search yielded 467 articles. Of these, 14 articles were included. These 14 articles evaluated a total of five different diagnostic modalities: bone scintigraphy (three studies, 146 cases), 18-fluorodeoxyglucose positron emission tomography(two studies, 50 cases), single-photon emission computed tomography combined with computed tomography (SPECT/CT) (seven studies, 371 cases), radionuclide arthrogram (three studies, 196 cases)and magnetic resonance imaging (MRI) (one study, 116 cases). Nine studies exhibited a high risk of bias in patient selection, and all studies showed a high risk of bias related to the reference test. The majority of the included studies were classified as Level III evidence, leading to an overall low level of certainty in the evidence. The most accurate tests, as demonstrated by the SROC analysis, were MRI and SPECT/CT, with sensitivities ranging from 0.00 to 1.00 and 0.33 to 1.00 and specificities between 0.31-1.00 and 0.00-1.00, respectively. This review and meta-analysis evaluated available diagnostic modalities to aid the diagnosis of knee arthroplasty loosening and based on a low certainty of evidence suggests that MRI and SPECT/CT are currently the most accurate modalities available to aid the diagnosis of aseptic loosening of knee arthroplasty components. Level III.

WHEN AND WHERE DOES A CARRIER OF HEREDITARY TRANSTHYRETIN AMYLOIDOSIS (ILE88LEU) SHOW THE FIRST SIGNS OF THE DISEASE? DIAGNOSTIC CHALLENGES OF A NOT ONLY CARDIOGENIC MUTATION

Abstract We present the case of a 58–year–old man with a familiar history (mother affected) positive for ATTR–v (Ile88Leu) amyloidosis. The mother initially had a pure cardiac phenotype and was firstly treated with tafamidis, but progression of the disease to the nervous system warranted a switch to patisiran. Our patient carried the Ile88Leu mutation and had a medical history notable for surgically treated left carpal tunnel syndrome (CTS) and untreated right CTS. Furthermore, he was affected by systemic arterial hypertension and was a habitual smoker. He has been followed at our Institution since 2018. His first echocardiogram showed normal left ventricular ejection fraction (LVEF 65%), mild hypertrophy (anterior septum: 12 mm), and borderline values of GLS (– 16%) without any specific pattern. Further exams were executed: Bone scintigraphy (BS): negative (Perugini score 0); Coronary artery ct scan: moderate stenosis of proximal LAD; Neurologic evaluation: no signs of peripheral neuropathy. The clinical picture remained unaltered in 2020 and 2021. However, during November 2022 the patient developed atrial fibrillation (AF) and presented to the ED for dyspnea and palpitations. Electrical cardioversion was performed with success but subsequent recurrences warranted AF ablation in April 2023. At that moment, the patient was re–evaluated. Basal ECG did not show any significant alteration (FIg.1)This time, echocardiogram showed mild worsening of hypertrophy (13 mm septum), GLS – 16% with apical sparing pattern, no other major variations (Fig.2). BS was repeated and revealed grade 1 Perugini score (Fig.3). Hence, a series of clinical question arose: Should we begin a specific treatment or is the disease in an excessively early stage that does not warrant treatment? Is AF linked to concomitant arterial hypertension or might it be an early marker of disease? We questioned the usefulness of endomyocardial biopsy in this specific setting. In this case, we repeated electromyography that showed mild axonal sensitive–motor polyneuropathy. Finally, we concluded for initial signs of systemic amyloidosis ATTR–v (Ile88Leu) type with mixed phenotype (neurological+cardiac). The neurological involvement allowed us to start a gene–silencer (Patisiran). In conclusion, a periodic neurological evaluation is necessary and has crucial therapeutic implications in all genotypes. Indeed, there is increasing evidence that Ile88Leu is a not only cardiogenic mutation.

TAFAMIDIS FOR TREATMENT OF TRANSTHYRETIN CARDIAC AMYLOIDOSIS: A REAL WORLD EXPERIENCE

Abstract Background A regional network for cardiac amyloidosis (CA) was created in 2019 with the aim of enhancing disease awareness among physicians and favoring appropriate access to innovative diagnostic tools/therapies. The network includes all 14 Cardiology Departments and outpatient clinics from 5 Local Health Units. Therapies for variant (ATTR–v) and wild–type (ATTR–wt) CA have recently become available in Italy. Selected centres with expertise in cardiomyopathies were identified to prescribe new modifying disease drugs. Tafamidis is the first medication approved for the treatment of ATTR–C. The landmark ATTRACT trial showed a reduction in cardiovascular mortality and cardiovascular–related hospitalization in patients treated with tafamidis compared to placebo. From October 2021 tafamidis can be prescribed in Italy according to AIFA criteria (only NYHA I/II patients eligible). The aim of our study is to present the experience of our Network in prescribing tafamidis and to compare the clinical baselibe characteristics of our population and the ATTRACT trial population. Methods Thanks to our network , 189 patients with ATTR–CA were referred to our Center. 58 ATTR patients were treated with tafamidis according to AIFA criteria, while 5 patients with variant–TTR and neuropathy received patisiran iv. The causes of exclusion from tafamidis therapy are shown in figure 1. We prospectively collected all the patientst treated with tafamidis from January 2022 until November 2023. All the data about clinical characteristics, laboratoy findings ECG, echo, bone scintigraphy and concomitant treatment were collected during routin follow–up visits anc compared to those of ATTRACT trial population. Results The main findings of our study are summarized in Table (fig,2) The age of our population was similar to that of the patients enrolled in the ATTR–ACT trial (75,94 ± 11.4 vs. 74,5±7.2, P = 0.21). Of note, our population does not include patients in NYHA class III as the AIFA prescriptive criteria exclude these patients from treatment in Italy. this implies a substantial difference in the distribution of the NYHA class compared to the attract population (p = 0.001). The outcome of our patient was excellent, the drug was well tolerated. Conclusions: Implementing specific clinical network provided excellent results, allowing a precise phenotype/genotype characterization and favoring appropriate access to specific disease–modifying drugs.

PREVALENCE OF WILD–TYPE TRANSTHYRETIN CARDIAC AMYLOIDOSIS IN ELDERLY SUBJECTS FROM THE GENERAL POPULATION

Abstract Background Wild–type transthyretin cardiac amyloidosis (ATTRwt–CA) affects older adults, and is currently considered as a rare disorder. Objective We investigated for the first time the prevalence of ATTRwt–CA in elderly individuals from the general population. Methods General practitioners from Pisa, Italy, proposed a screening for ATTRwt–CA to all their patients aged 65–90 years, until 1,000 accepted. The following red flags were searched: interventricular septal thickness ≥12 mm, any echocardiographic, ECG or clinical hallmark of CA, or high sensitivity–troponin T ≥14 ng/L. Individuals with at least one red flag (n=346) were asked to undergo the search for a monoclonal protein and bone scintigraphy, and 216 accepted. Results Four patients received a non–invasive diagnosis of ATTRwt–CA. All complained of dyspnoea on moderate effort. A woman and a man aged 79 and 85 years, respectively, showed an intense cardiac tracer uptake (grade 3), left ventricular (LV) wall thickening, grade 2 to 3 diastolic dysfunction, and N–terminal pro–B–type natriuretic peptide (NT–proBNP) >1,000 ng/L. Two other patients (a man aged 74 years and a woman aged 83 years) showed a grade 2 uptake, an increased LV septal thickness, but preserved diastolic function, and NT–proBNP <300 ng/L. The prevalence of ATTR–CA in subjects ≥65 years was calculated as 0.46% (i.e., 4 out of the 870 subjects completing the screening, namely 654 not meeting the criteria for Step 2 and 216 progressing to Step 2). Conclusions ATTRwt–CA has a prevalence of 0.46% in elderly subjects from the general population.

Anatomical variations of Koerner's septum: a computed tomography-based, single-centered study.

Koerner's septum (KS) is a bony plate located at the junction of the petrous and squamous parts of the temporal bone. The reported prevalence of KS varied between studies. KS variations are associated with various pathologies and pose difficulties during surgeries. The study aims to determine the KS frequency in Omani patients and analyze its association with sex and side. The present study investigated the KS topography in 344 computed tomography (CT) scans of normal temporal bones of adult Omani patients at Sultan Qaboos University Hospital. The presence of KS and its parts (complete or incomplete), as well as its thickness at three anatomical landmarks were recorded. Additionally, sex and laterality differences in KS parameters were analyzed using a Chi-square test. The overall frequency of KS among Omani subjects was 39.5%. The complete KS was observed only in 14% of cases. The thickness of KS was 0.78 ± 0.21 mm, 0.93 ± 0.28 mm and 0.78 ± 0.21 mm at the head of the malleus (HM), the superior semicircular canal (SSC) and the tympanic sinus (TS), respectively (p<0.01). KS was present most constantly at the level of HM (64.7%), followed by SSC (57.4%), and less constantly at the level of TS (49.3%). KS frequency was similar in both males than females (41.9% vs 37.3%), with statistically insignificant difference (p = 0.38). No side differences were observed concerning KS frequency (p = 0.955). The KS frequency in Omani subjects within the range of previously reported studies. It is incomplete in most of the cases and constantly present at the level of HM. Its thickness is more at the level of SSC.

Abstract PO5-05-13: Clinical utility of whole body low dose computed tomography for detecting bone metastasis in breast cancer patients: A cross sectional study

Abstract Clinical utility of Whole Body Low Dose CT scan for detecting bone metastasis in Breast cancer patients: A cross sectional study Background: Skeletal scintigraphy (Bone scan) is the imaging of choice to detect bone metastasis in locally advanced and metastatic breast cancer patients. Nuclear medicine facilities are however limited in their availability. As an alternative diagnostic modality to bone scan, we studied the diagnostic capability of Whole-Body Low Dose CT (WBLDCT) scan for detection of bone metastasis in these patients. Materials and Method: This cross-sectional study was conducted from November 2021 to May 2023 at a tertiary healthcare center in India with an aim to study the clinical applicability of whole-body low dose computed tomography scan for detecting bone metastasis in patients with breast cancer. Breast cancer patients with primary tumor measuring 5cm or more, pathologically proven axillary lymph node metastasis, Stage III/IV disease, symptoms attributable to metastasis and suspected disease recurrence were included. All patients underwent WBLDCT and Bone scan within a period of about 2 weeks. WBLDCT was done during the same time as conventional dose CT scan was being done as part of metastatic workup. WBLDCT acquisition protocol was set in CT scan machine by modulating the technical parameters like Care dose 4D-automated, Care kV semi, rotation time &amp; noise index. The image analysis was performed by Radiologist and Nuclear medicine experts in a blinded fashion. Data was recorded in MS Excel sheet. Sensitivity, specificity, positive and negative predicative value, and concordance rates were calculated using SPSS software ver 25.0. Agreement amongst WBLDCT and Bone scan was calculated using Inter-rater agreement. p value &amp;lt; 0.05 was taken as significant. Results: 110 patients were enrolled in this study. The mean age of participants was 48.5 years and three fourth had stage III disease at presentation. Estrogen receptor positive disease was seen in 43.64% participants while 30% were triple negative. Her2neu positive disease was seen in 27.27% patients. Bone scan couldn’t be done in 03 patients who deferred treatment (these had no bone metastasis on WBLDCT). Both bone scan and WBLDCT detected bone metastasis in 19 patients. Bone scan picked up additional metastasis in three patients which were missed on WBLDCT. WBLDCT detected bone metastasis additionally in three patients which were not detected on Bone scan. Multiple lesions were most seen in vertebrae in 38.5% and 28.6% on bone scan and WBLDCT respectively. The sensitivity and specificity of WBLDCT for detection of bone metastasis was 86.36% and 96.47% respectively. The concordance rate between Bone scan and WBLDCT scan was 94.39% with an Inter-rater Kappa(k) quotient for agreement of 0.828 (p&amp;lt; 0.0001). Conclusion: WBLDCT scan has comparable diagnostic capability to skeletal scintigraphy in detecting bone metastasis in breast cancer and may be a useful alternative specially in resource limited settings. Table 1: Sensitivity, specificity, positive predictive value and negative predictive value of WBLDCT for detection of metastasis Variables Values Sensitivity (95% CI) 86.36% Specificity (95% CI) 96.47% AUC (95% CI) 0.91 Positive Predictive Value (95% CI) 86.36% Negative Predictive Value (95% CI) 96.47% Diagnostic accuracy 94.39% Inter-rater agreement (kappa) 0.828 Citation Format: Lipton Mitra, Suhani Suhani, Ankur Goyal, Rakesh Kumar, Mohit Joshi, Hemanga Bhattacharjee, Haresh KP, Raju Sharma, Rajinder Parshad. Clinical utility of whole body low dose computed tomography for detecting bone metastasis in breast cancer patients: A cross sectional study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-05-13.

Abstract PO4-07-11: FDG-PET is superior to bone scintigraphy for the detection of bone metastases in breast cancer patients

Abstract Background: Bone is the commonest site for metastases in breast cancer patients, with up to 44% of patients having bone as their sole site of metastatic disease. Patients are at increased risk of morbidity from skeletal related events (SRE) from bone metastases due to pathological fractures and spinal cord compression. Early diagnosis is crucial so that bone modifying agents can be used to prevent SREs and other agents such as CDK4/6 inhibitors can be considered. Bone scintigraphy is the most widely performed first investigation for patients at high risk or symptomatic from bone metastases. Methods: We performed a meta-analysis comparing FDG-PET and bone scintigraphy using PubMed, Science Direct, and Embase for the literature search. 1009 patients were included in the study. Data for 2 × 2 contigency tables was selected and QUADAS-2 was used for quality assessment. Diagnostic accuracy was performed using Graph pad Prism 9.5.1 and R studio 2022. Pooled sensitivity and specificity of FDG-PET/CT was 96.6% (95% CI=91.5%-98.7%) and 96.8% (95% CI=82.1%-99.5%) respectively. Respective results for BS were 88.3% (95% CI=79.8%-93.5%) and 81.3% (95% CI=63.1%-91.7%). Sensitivity and specificity of FDG-PET/CT was significantly higher than BS (P=0.0063, P= 0.0068, respectively). The diagnostic odds ratio and area under ROC curve were significantly higher for FDG-PET/CT than BS (654.36 vs 35.24, and 0.980 vs 0.877, respectively). Conclusion: FDG-PET is superior to bone scinitigaphy for the detection of bone metastases in breast cancer.The benefits of replacing BS with FDG-PET/CT are evident. However othere technologies such as DW-MRI should be considered. Large multicentre prospective trials with strict FDG-PET/CT imaging protocols compared to DW-MRI both for disease detection and monitoring of response are required to strengthen the evidence in this field, to help inform imaging guidelines and best practices in the future. Newer technologies such as [18F]estradiol (FES)-PET and [18F]GE-226 for HER2 expression also warrant further investigation in ER positive and HER2 positive breast cancer. Citation Format: Laura Kenny, Maisher Tin-U. FDG-PET is superior to bone scintigraphy for the detection of bone metastases in breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-07-11.

Abstract PS05-04: [89Zr]Trastuzumab-PET/MRI to Characterize HER2+ Breast Cancer: A Quantitative Approach on Tumor Heterogeneity

Abstract Introduction: Molecular imaging of human epidermal receptor 2 (HER2) aims to overcome limitations of traditional HER2 assessment through biopsy, including invasiveness and inability to detect intra and inter-tumoral spatial heterogeneity. Prior human studies suggest that [89Zr]Trastuzumab-positron emission tomography (PET) imaging can effectively differentiate HER2 lesions (Dehdashti et al, Breast Cancer Res. Treat. 2018). Commonly, CT complements PET for anatomical reference, however, integrating MRI enables the sensitivity of soft-tissue contrast required for anatomic and morphological breast imaging and can provide for quantitative multiparametric characterization. Diffusion weighted-MRI (DW-MRI) contributes to tumor characterization by assessing intratumoral cellularity via the apparent diffusion coefficient (ADC), and can be combined with molecular expression from HER2-PET. We present preliminary results in 13 patients with HER2 PET/MRI to define tumor and normal tissue imaging metrics. Methods: A phase II clinical trial assessing the feasibility of [89Zr]trastuzumab-PET with simultaneous quantitative DW-MRI to enhance understanding of tumor heterogeneity in patients with HER2-positive metastatic breast cancer. 13 patients (ages 40-70; mean 60) with HER2-positive breast cancer based on prior biopsy underwent whole-body [89Zr]trastuzumab-PET/MR imaging (5 ± 1 days post-injection of radiopharmaceutical) during the course of HER2-directed therapy. Normal organ and tumor regions of interest (ROI) were identified on concurrently acquired whole-body T1-weighted MRI for ADC (cellularity) and standardized uptake value (SUV, PET uptake) mean quantification. Tumor presence was confirmed via bone scintigraphy, FDG-PET/CT, or contrast-enhanced MRI. Non-parametric T-tests compared lesions to normal organs. Lesions greater than 30 mm in diameter underwent multiparametric intratumoral habitat analysis. Using the median HER2 values, tumors were evaluated for heterogeneity of high and low HER2 expression in conjunction with ADC. Long-term treatment response evaluation is ongoing. Results: Mean [89Zr]trastuzumab uptake, SUV, and ADC values for normal tissue were summarized in Table 1. All tumors demonstrated higher overall uptake of [89Zr]trastuzumab (bone: p=0.019, brain: p=0.014, breast: p=0.069, juxtapulmonary: p=0.026) and increased ADCmean values (bone: p=0.002, brain: p=0.5, breast: p=0.03, juxtapulmonary: p=0.037), in comparison to matched normal organs. Notably, one of five patients with a breast lesion, who completely responded to HER2 targeted therapy, exhibited the highest breast lesion SUVmean. Brain and lymph node lesions demonstrated intratumoral heterogeneity of HER2 expression. Conclusion: Our study demonstrates the potential value of quantitative MRI along with molecular imaging to characterize metastatic HER2+ breast cancer and evaluate intratumoral heterogeneity. We underscore the importance of standardizing processing techniques and contribute to this effort by summarizing [89Zr]trastuzumab uptake and cellularity values of normal physiological uptake. Higher SUVmean and ADC mean values observed in lesions, compared to normal tissue, highlight their potential roles in intratumoral classification. While studies have shown the utility of [89 Zr]trastuzumab-PET/CT, our findings demonstrate that integrated DW-MRI can aid in tumor classification. Table 1: Physiological 89Zr-Trastuzumab Uptake (SUVmean) and Apparent Diffusion Coefficient (ADCmean) in Healthy Tissues Citation Format: Ameer Mansur, Moozhan Nikpanah, Johnathan McConathy, Erica Stringer-Reasor, Gabrielle Rocque, Ahmed Elkhanany, Katia Khoury, Nusrat Jahan, Suzanne Lapi, Anna Sorace. [89Zr]Trastuzumab-PET/MRI to Characterize HER2+ Breast Cancer: A Quantitative Approach on Tumor Heterogeneity [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS05-04.

Abstract PO5-07-11: Use of 64Cu-DOTA trastuzumab -PET to predict response to trastuzumab-deruxtecan (TDXd) in patients with metastatic disease to the brain: Study in Progress

Abstract Background: We have utilized 64Cu-DOTA trastuzumab-PET imaging in patients with advanced breast cancer. In our experience, uptake on 64Cu-DOTA trastuzumab-PET correlated with the qualitative assessment of HER2 by IHC. In women treated with the antibody-drug conjugate (ADC), ado-trastuzumab emtansine (TDM1), we identified a threshold level of 64Cu-DOTA trastuzumab-PET uptake that predicted for lack of response to TDM1. As patients are living longer with advanced breast cancer, the incidence of brain metastasis has increased. The ADC, trastuzumab-deruxtecan (T-DXd) has demonstrated activity in patients with metastatic HER2 positive breast cancer with brain metastases. The DESTINY 04 trial included patients with HER2 1+ and 2+ disease and demonstrated superior survival compared to standard of care. It is not feasible to biopsy all brain metastases to determine tumor markers. Given the increased incidence of brain metastases in this population and the efficacy of T-DXd in patients with HER2+ metastatic disease to the brain, we initiated a study of 64Cu-DOTA trastuzumab-PET/MRI of the brain prior to institution of T-Dxd. Endpoints Primary: 1. 64Cu-DOTA-trastuzumab PET-CT will identify tumor heterogeneity of trastuzumab uptake in women with metastatic breast cancers. 2. The degree of uptake of 64Cu-DOTA-trastuzumab PET-CT will predict for response to Enhertu. Secondary: 1. Uptake of 64Cu-DOTA-trastuzumab PET-CT will be predictive of response duration to Enhertu. Eligibility: Patients must have documented recurrent breast cancer that is HER2 1+, 2+ or 3+, evidence of brain metastases by CT or MRI of the brain and are candidate for treatment with trastuzumab-deruxtecan. The CNS disease must be stable and not in need of intervention. Methods: Prior to treatment staging workups includes pathologic review of HER2 status, disease staging with 18FDG-PET or CT of the chest/abdomen/pelvis and bone scan, and 64Cu-DOTA-trastuzumab PET/MRI of the brain. After initiation of T-Dxd, MRI of the brain is repeated every 6 weeks for the first 24 weeks and every 9 weeks thereafter. Progress: We have enrolled 1 patients to date, received PET and dynamic contrast-enhanced MRI. Four lesions were analyzed in this patient. The mean values of Ktrans (volumetric perfusion to tumor, s−1) in these lesions near a prior resection cavity were 0.210 s−1, indicating sufficient perfusion for ADC uptake. Corresponding to this perfusion data, the mean SUVmax of these lesions on the 64Cu-DOTA-trastuzumab PET scans was 5.38. Citation Format: Joanne Mortimer, Kofi Poku, Jessica Liu, Russell Rockne, Chen Bihong, Ryan Woodall, Vikram Adhikarla. Use of 64Cu-DOTA trastuzumab -PET to predict response to trastuzumab-deruxtecan (TDXd) in patients with metastatic disease to the brain: Study in Progress [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-07-11.

Abstract PO1-20-07: Valosin-containing protein (VCP)/p97: A novel breast cancer susceptibility gene?

Abstract Introduction: Mutations in the valosin-containing protein (VCP, also known as p97) gene are associated with autosomal dominant inclusion-body myopathy with early-onset Paget disease and frontotemporal dementia. VCP is an ATPase that subserves a variety of cellular functions, prominently, organelle biogenesis and ubiquitin-dependent protein degradation. Recently, VCP has also been shown to physically interact with BRCA1 and is postulated to orchestrate the response to DNA double-strand breaks, a critical molecular prelude to homologous recombination DNA repair. Moreover, VCP is also involved in the removal of trapped poly [ADP-ribose] polymerase 1 (PARP1) from chromatin and may play a key role in the response of tumor cells to PARP inhibitors. Whether VCP acts as a breast cancer predisposition gene is currently unknown. These observations raise speculation as to whether pathologic variation in VCP may predispose to breast cancer. Case Description: A 45-year-old female presented with early-age, locally advanced invasive ductal carcinoma, grade 2, ER &amp;lt; 1%, PR 10%, HER2 IHC 3+, FISH ratio 5.4. The patient completed 6 cycles of neoadjuvant PTH and was surgically downstaged to ypT1bN1a at the time of her left mastectomy. She declined adjuvant radiation. She received 1 dose of trastuzumab emtansine which was discontinued due to intolerance and transitioned to complete 1 year of adjuvant trastuzumab and pertuzumab. Her medical history is significant for inclusion body myopathy with Paget disease of bone and/or frontotemporal dementia, which was diagnosed at age 36 after presenting with proximal muscle weakness. Bone scan was consistent with Paget’s disease and neurocognitive testing did not identify any abnormalities. Diagnosis was confirmed via whole genome germline sequencing which identified a pathogenic variant in VCP [c.463C &amp;gt;G (p.Arg155Gly)]. Germline resequencing of 155 known cancer predisposition genes did not identify any pathogenic variants. Whole exome genomic analysis of the patient’s breast cancer revealed an elevated homologous recombination score ( &amp;gt; 42), consistent with molecularly important role of VCP in homologous recombination breast cancer DNA repair. The patient’s family history is significant for muscular dystrophy in multiple family members on her paternal side, each of whom was deceased prior to age 60. Her paternal half-sister has both inclusion body myopathy and breast cancer, and her paternal cousin was diagnosed with breast cancer at age 46 (unknown genetic testing for each). No history of cancer on her maternal side. Discussion: This case raises the intriguing question of whether the VCP gene represents a heretofore unrecognized breast cancer predisposition gene. Further investigation into the role of VCP in tumorigenesis is warranted, and additional population studies are necessary to confirm VCP’s role in breast cancer predisposition. Given that cancers with homologous recombination deficiencies benefit from PARP inhibitors and VCP is involved in the function of the PARP1 protein, patients with mutations in the VCP gene may benefit from PARP inhibition. Citation Format: Alexis LeVee, Duveen Sturgeon, Joanne Mortimer, Kevin McDonnell. Valosin-containing protein (VCP)/p97: A novel breast cancer susceptibility gene? [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-20-07.

Abstract PO4-19-06: Phase II study of a PARP inhibitor, talazoparib, in HER2- metastatic breast cancer with a somatic BRCA1/2 mutation present in cell-free DNA or tumor tissue genotyping

Abstract Background: PARP inhibitors improve both progression free survival (PFS) and patient quality of life in germline BRCA1/2 mutant metastatic breast cancer (MBC), which accounts for 5-10% of breast cancer, leading to their approval in this setting. We have previously shown that a subset of patients with MBC who are not germline BRCA1/2 carriers may harbor pathogenic somatic BRCA1/2 mutations that are identified by cell-free DNA and/or tumor tissue genotyping. In our prior work, we developed a circulating tumor cell culture from a patient with MBC harboring a pathogenic somatic BRCA1 mutation, and demonstrated that a PARP inhibitor induced cell growth inhibition similar to germline BRCA1/2 mutant cultures. Thus, we hypothesize that a PARP inhibitor may be effective in treating somatic BRCA1/2 mutant MBC. In this clinical trial, we are studying the efficacy of a PARP inhibitor in somatic BRCA1/2 mutant MBC. Our work may help expand the clinical application of PARP inhibitors in MBC. Trial Design: This phase II investigator-initiated clinical trial is enrolling 30 patients with MBC who have a pathogenic somatic BRCA1/2 mutation identified by a CLIA certified cell-free DNA and/or tumor tissue genotyping assay. Patients are treated with the PARP inhibitor talazoparib 1 mg/day until progression of disease. Imaging (CT chest, abdomen and pelvis, and bone scan) occurs for disease assessment at baseline and every 3 months. Cell-free DNA is collected at baseline and then monthly to evaluate changes in the genomic environment. Patients also undergo the Cancer Risk B (CR-B) assay, a novel flow variant assay to identify double-strand break repair mutations in circulating blood cells, at baseline. Eligibility Criteria: Patients must have MBC with a pathogenic somatic BRCA1/2 mutation identified in a cell-free DNA and/or tumor tissue genotyping assay, with pathogenicity confirmed by a genetics counselor using validated genomic databases such as ClinVar. Patients may have triple-negative (receipt of at least 1 prior chemotherapy) or hormone receptor positive/HER2- MBC (receipt of at least 1 prior hormone therapy). Patients must not be known germline BRCA1/2 carriers. Any number of prior therapies including a prior platinum (in absence of progressive disease on a platinum) are allowed, but patients should not have received a prior PARP inhibitor. Patients must have adequate organ function and performance status. Specific Aims: The primary aim is to determine PFS (RECIST 1.1). Secondary aims include determining the objective response rate and toxicity (NCI CTCAE v 5.0). Exploratory aims include evaluating serial changes in BRCA1/2 mutant allelic frequency in cell-free DNA, understanding the impact of BRCA1/2 reversion mutations in cell-free DNA, comparing pre- and post-treatment cell-free DNA results to understand changes in the genomic environment, studying the CR-B assay positivity rate, and correlating these biomarker analyses with treatment response. Statistical Methods: This study has 81% power to demonstrate that the 12-week PFS is 53% or higher. In contrast, there is a 4% (alpha) probability of concluding that the 12-week PFS is ≥ 53% if the true 12-week PFS is 30% or lower. If 14 or more of 30 total patients achieve PFS &amp;gt; 12 weeks, the null hypothesis (12-week PFS ≤ 30%) will be rejected. Present accrual and target accrual: This study (NCT03990896) is open at Massachusetts General Hospital, MD Anderson, University of California San Francisco, Emory, Northwestern, and Vanderbilt. As of 7/2023, 14/30 patients are enrolled. Funding: This study is funded by a Pfizer ASPIRE award and Conquer Cancer Foundation of ASCO–Breast Cancer Research Foundation- Career Development Award. Contact information: Neelima Vidula, MD, Massachusetts General Hospital, nvidula@mgh.harvard.edu. Citation Format: Neelima Vidula, Senthil Damodaran, Manali Bhave, Hope Rugo, Ami N. Shah, Erica Blouch, Nathan Royce Ruffle-Deignan, Ogadinma Ogbenna, Lisa E. Flaum, Massimo Cristofanilli, Joseph Sparano, Harry Ostrer, Vandana Abramson, Nora Horick, Aditya Bardia. Phase II study of a PARP inhibitor, talazoparib, in HER2- metastatic breast cancer with a somatic BRCA1/2 mutation present in cell-free DNA or tumor tissue genotyping [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-19-06.

Abstract PO4-02-07: Prevalence of distant metastases in High-Risk Operable Breast Cancer (HROBC) pT1-2 N2a orhigher at diagnosis

Abstract Introduction: Current standard guidelines do not recommend a routine staging workup in early breast cancer as incidence of de novo metastasis is only 1-2%. Some of these patients are found to have a higher axillary nodal burden after surgery. This prospective study evaluated the incidence of distant metastases in clinically high-risk operable breast cancer (HROBC) who have a higher nodal burden on histopathological report after surgery. The intent was to detect presence of subclinical distant disease that may have an impact on treatment offered and outcome. Currently, there is no compelling data to support a routine metastatic workup in these patients. Methodology: A single-centre study approved by Institutional Ethics Committee was carried out enrolling early breast cancer patients with high nodal burden (four or more axillary nodes positive) after definitive surgery. The HROBC group was defined as early breast cancer patients with pT1/2, N2a/N3 stage on surgical histopathology. They underwent a comprehensive metastatic workup, including ultrasound abdomen, bone scan, and CT scan (thorax-abdomen-pelvis) or PET scan before starting their adjuvant treatment. Burden of distant disease was classified into oligometastatic (M1o) or polymetastatic disease (M1p). The adjuvant treatment intent was redefined as curative or palliative based on the distant disease burden and treatment was modified accordingly. Result: The study accrued 100 HROBC women with pT1-2, pN2a-3 stage disease during 2015-2018 operated upfront for early breast cancer cT1-2 N0-1, of which 97 were included in final analysis. The 3 excluded patients had their surgery elsewhere with clinical diagnosis of early breast cancer with histopathology indicating heavy nodal burden; 2 of them had T3 tumor and 1 had cN3 disease and were deemed a higher stage and would anyway warrant a metastatic work-up and hence were ineligible for the study. Forty percent women were premenopausal, 54 (55.6%) had pN2a disease and 43 (44.4%) had pN3. Staging investigations identified distant metastatic disease (M1) in 8 of 97 women (8.24%). Interestingly, 5 of them had oligometastatic (M1o) disease (5.15%) and 3 had polymetastatic (M1p) disease (3.09%). Between the 2 nodal groups, no specific distribution of M1o or M1p disease was observed, but the pickup rate of overall distant disease was higher in pN3 (11.4%) as against N2a (5.6%) patients p=NS. The most common sites of metastases observed was bone (5/8) followed by liver (3/8). There was no correlation with ER, PgR or HER2neu status and extent of distant disease. The patients with M1o disease, completed their adjuvant treatment as planned along with treatment of oligometastatic sites. Only 3.09% patients who were detected with M1p disease, were treated with a palliative systemic therapy. Conclusion: Early detection of metastatic disease, M1o and M1p, in clinical HROBC could lead to improved treatment strategies. The findings have the possibility to optimize management of high-risk early breast cancer as a separate clinical entity, requiring staging post hoc after primary surgery, for adequate resource stratification and better outcomes, especially in those with 10 or more axillary nodes positive for metastases. This subset may get identified in the TNM classification for better understanding and management. Citation Format: Vani Parmar, Naveena Kumar AN, Basila Ameer Ali, Nita Nair, Shalaka Joshi, Purvi Thakkar, Garvit Chitkara, Varsha Gaikwad, Vaibhav Vanmali, Shabina Siddique, Palak Popat, Sneha Shah, Sangeeta Desai, Tanuja Shet, Meenakshi Thakur, Venkatesh Rangarajan, Rajendra Badwe. Prevalence of distant metastases in High-Risk Operable Breast Cancer (HROBC) pT1-2 N2a orhigher at diagnosis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-02-07.

Abstract PO4-20-11: Excellent Response to Trastuzumab Deruxtecan in “HER-2 Low” Leptomeningeal Breast Cancer and Diagnostic and Monitoring Utility of CNSide Assay

Abstract A 72-year-old female presented to the emergency department with sudden onset of imbalance and cognitive decline. Two years ago, she was diagnosed with stage III estrogen receptor (ER) positive, progesterone receptor (PR) negative and human epidermal growth factor receptor 2 (HER2) negative (immunohistochemistry score: 0) invasive breast cancer. She subsequently underwent lumpectomy, adjuvant radiation and chemotherapy. She had been taking adjuvant letrozole at the time of presentation. Magnetic resonance imaging (MRI) of the brain showed obstructive hydrocephalus without any parenchymal lesion or leptomeningeal enhancement. MRI of spine, computerized tomography of chest/abdomen/pelvis and bone scan were unrevealing except a left adrenal mass which was equivocal for metastasis. Cerebrospinal fluid (CSF) analysis showed rare malignant cells. Based on the morphology of malignant cells and the patient’s prior history of breast cancer, the diagnosis of leptomeningeal disease with breast primary was made. There were insufficient cells for additional studies. CNSide, a microfluidic platform that uses antibody capture method to detect CSF tumor cells, showed 4678 tumor cells per milliliter (ml) of CSF. Immunocytochemistry of these cells showed that the cells were ER negative (criterion: &amp;lt; 2.6% ER positive cells) and programmed cell death ligand 1 (PD-L1) negative (criterion: &amp;lt; 3.4% PD-L1 positive cells). Fluorescence in situ hybridization (FISH) testing showed 22% of tumor cells with HER2 amplification (either HER2 to CEP17 ratio &amp;gt;/= 2.0 or HER2 copy number &amp;gt;/= 6). She underwent ventriculoperitoneal (VP) shunt placement with complete recovery of her neurological symptoms. Five weeks later, she was started on trastuzumab deruxtecan (T-DXd) mainly because of the HER2 FISH results from CNSide. She did not receive central nervous system(CNS) irradiation due to complete resolution of neurological symptoms with VP shunt placement. After two cycles of T-DXd, MRI brain showed mild leptomeningeal enhancement along bilateral superior cerebellar sulci. Positron emission tomography/computed tomography(PET/CT) scan showed a new sclerotic rib focus, thought to represent treatment response. It also showed decrease in size of the adrenal mass. The adrenal mass was hypermetabolic on PET, consistent with malignancy. CSF cytology was negative, while CSF tumor cell count significantly reduced to 6.72 cells/ml using CNSide. There were no new neurological symptoms. Despite MRI brain findings, she was continued on T-DXd given overall favorable clinical, radiological and CSF data. After 7th cycle of T-DXd, repeat CSF cytology continued to remain negative, CNSide CSF tumor cell count decreased further to 6.27 cells/ml, MRI brain showed interval resolution of prior leptomeningeal enhancement, CT scan showed further decrease in size of the adrenal mass (baseline 5.4cm to 3cm), stable rib sclerotic lesion and no additional metastatic lesion. To date, she has undergone eight cycles of T-DXd which has effectively controlled her disease for a period of seven months. She has not needed VP shunt revision and continues to do well. To our knowledge, this is the first case demonstrating the activity of T-DXd against CSF tumor cells where a small subset exhibited HER2 amplification. This case also highlights the benefits of using advanced and highly sensitive CSF assays to diagnose and surveil leptomeningeal disease and to assess HER2 signaling. This case is well-timed especially in the era of next-generation, CNS penetrating, potent HER2-directed antibody-drug conjugate like T-DXd which can mount antitumor activity even with minimal HER2 expression in tumors. Citation Format: Sarah Stanford, Zeni Kharel, Lauryn Hemminger, Tyler Schmidt, Sara Hardy, Jason Zittel, Nimish Mohile, Ajay Dhakal. Excellent Response to Trastuzumab Deruxtecan in “HER-2 Low” Leptomeningeal Breast Cancer and Diagnostic and Monitoring Utility of CNSide Assay [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-20-11.

Abstract PO5-20-06: Paraneoplastic cerebellar degeneration in anti-Yo antibody and HER2-positive metastatic breast carcinoma

Abstract Paraneoplastic cerebellar degeneration (PCD) in the context of breast carcinoma affects less than 1% of patients. In most cases, breast cancer diagnosis follows several months or even years after the onset of neurological symptoms. The first association between PCD and occult gynecologic cancers (breast or ovarian) was identified in 1938 with the discovery of antibodies directed against cytoplasmic antigens of Purkinje cells (“anti-Yo antibodies”). Since then, evidence has grown significantly to support anti-Yo antibodies as excellent diagnostic markers of PCD with underlying gynecologic and breast carcinoma. This case study evaluates a 57-year-old female who initially presented with headache and subacute cerebellar ataxia. Her symptoms progressed over a period of three months with multiple falls, onset of speech difficulties, and diplopia. She also reported 30-pound weight loss, which she attributed to dieting and starting semaglutide. Magnetic resonance imaging (MRI) of the brain and spine were unremarkable and autoimmune workup was normal. Cerebral spinal fluid (CSF) and serum studies demonstrated positive anti-Yo antibodies. Computed tomography (CT) of the abdomen and pelvis showed an enlarged left axillary lymph node concerning for metastatic disease with a 1.2cm focus of asymmetric density in the central inferior left breast parenchyma. Diagnostic mammogram one year prior was reportedly normal. Ataxia symptoms improved after a course of empiric intravenous immunoglobulins and steroids. Ultrasound-guided biopsy of the left axillary lymph node revealed metastatic mammary carcinoma: estrogen and progesterone receptor negative and human epidermal growth factor receptor 2 (HER2)-positive, cT0N2aM0, ypTxN1aM0, stage IIIa (AJCC 8th edition). She underwent further metastatic workup, including repeat CSF studies and MRI. MRI of the spine was remarkable for multiple hemangiomas throughout the cervical, thoracic, and lumbar spine, with subsequent unremarkable bone scan. MRI of the abdomen was remarkable for right hepatic lobe hemangioma and a right adrenal nodule. CSF studies showed no sign of metastases. After multidisciplinary discussion, TCHP (docetaxel, carboplatin, trastuzumab, and pertuzumab) neoadjuvant therapy was initiated and repeat imaging demonstrated favorable treatment response with a shrinking axillary mass; no primary breast mass was identified. The patient underwent left sentinel lymph node biopsy with a positive frozen section intraoperative for invasive cancer, therefore proceeded with left axillary lymph node dissection. She was offered a mastectomy but elected for only axillary surgery. Pathology revealed 1 of 14 lymph nodes were positive for metastatic ductal carcinoma. She remains in a rehabilitation center and her ataxia is improving, but her functional status remains below baseline. She is undergoing radiation to whole breast and regional lymph nodes. With this case, we aim to continue to build upon the limited base of the exceedingly rare presentation of breast cancer-associated paraneoplastic syndrome. In addition, several studies and case reports have demonstrated a strong correlation between HER2 overexpression and anti-Yo associated PCD. As we continue to diagnose and monitor breast cancer patients, we could consider starting to screen for anti-Yo antibodies in HER2-positive patients to gain insight into a patient’s prognosis and development of PCD. Citation Format: You Kim, Alison Coogan, Andrea Madrigrano. Paraneoplastic cerebellar degeneration in anti-Yo antibody and HER2-positive metastatic breast carcinoma [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-20-06.

Abstract PO1-12-02: Impact of Discontinuation of Denosumab on Bone Health in Breast Cancer Patients

Abstract Denosumab (Dmab), an inhibitor of osteoclast activity and proliferation is approved for treatment of women on aromatase inhibitor (AI) therapy for early breast cancer (60 mg Q 6-months) and metastatic disease (120 mg Q 4-weeks) to protect against bone loss and prevention of skeletal-related events (SREs). 60 mg given twice a year has shown fracture reduction, especially in women on aromatase inhibitor therapy, and recent data supports benefits in disease free survival, bone-metastasis free-survival and overall survival with Dmab in early breast cancer. It appears superior in reduction of SREs versus zoledronic acid (ZA) in established skeletal metastatic disease; thus, a preferred choice in the oncology setting. In the osteoporosis setting, withdrawal of Dmab therapy leads to a “rebound” increase of bone resorption, rapid bone loss and potential vertebral fractures. Increased risk of spontaneous and multiple vertebral fractures has been seen in this patient population. To prevent this, after discontinuation of Dmab, the addition of another anti-resorptive such as ZA is initiated. Dmab withdrawal events are uncommonly reported in patients with metastatic skeletal disease due to generally poor prognosis. Dmab given as 120 mg/month in this setting may need to be curtailed for a variety of indications including hypocalcemia, major dental procedures, osteonecrosis of the jaw or atypical femoral fracture. In the oncologic setting, it is unclear if discontinuation of Dmab will lead to rebound bone resorption or increased incidence of fractures. We describe the case is of a 32-year-old woman with a history of T2N3M1, oligometastatic breast cancer (solitary bone metastases at L1, biopsy-proven) that was ER/PR/HER2 positive. She was treated with neoadjuvant trastuzumab, pertuzumab, taxotere and carboplatin followed by bilateral mastectomy, and radiation to chest wall and L1. She received total estrogen blockade initially with GnRH-agonist and exemestane and ultimately bilateral salpingo-oophorectomy plus exemestane. She continues pertuzumab and trastuzumab (80 treatments to date) for the past 5 years and denosumab 120 mg/month for 14 treatments and then every 3 months, 20 total treatments. Development of hip pain (regular runner) and concern for atypical fracture vs metastatic disease led to bone scan and PET/CT. Metastatic disease was ruled out and stress reaction was diagnosed. Dmab therapy was discontinued with monitoring of her metabolic bone turnover. 1 year after her last Dmab injection, bone turnover markers began to increase and ultimately demonstrated a very significant “rebound phenomenon.” Subsequently, a single dose of 120 mg denosumab decreased bone markers to previously low levels which remain low on routine monitoring, table below. In future, ZA will be initiated and continued on a yearly basis. Dmab has replaced ZA in managing bone health in breast cancer patients. Many oncologists use this without the assistance of bone health endocrinologists, who are an integral part of our cancer center. Bone modifying agents are often discontinued without consideration of the negative impact this may have. As this is a major survivorship issue, we document this case with literature review, to raise awareness for oncologists prescribing these medications. Citation Format: Susan Tannenbaum, Alvaro Alvarez Soto, Pamela Taxel. Impact of Discontinuation of Denosumab on Bone Health in Breast Cancer Patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-12-02.

Role of 99mTc-HMDP Bone Scintigraphy in the Management of Neurogenic Para- Osteo-Arthropathies (NAOP)

Neurogenic para-osteo-arthropathies (NAOP) are characterized by ectopic juxta-articular peri- or para-osseous ossifications. Diagnosis of these conditions is often delayed. They are frequently associated with central neurological disorders and are rarely observed in cases of peripheral neuropathy. Bone scintigraphy is crucial for determining the maturity of the ossification, optimizing surgical interventions, and preventing recurrence.

Role of Ga68 Prostate-Specific Membrane Antigen Positron Emission Tomography-Computed Tomography in Prostate Cancer Imaging

AbstractThe introduction of prostate-specific membrane antigen (PSMA) in clinical practice has revolutionized the evaluation of biochemical recurrence (BCR) of prostate cancer after curative-intent treatment. The high expression of this glycoprotein in prostate cancer cells makes PSMA imaging superior to the current conventional staging methods, namely bone scanning and computed tomography. The high capability of PSMA imaging for identifying very small previously undetected lesions has been widely demonstrated in the literature, leading to a rethinking of patient management by treating physicians. The usual and predictable patterns of spread in prostate cancer are still more prevalent, such as spread to pelvic lymph nodes and bone metastasis, but different patterns of disease spread are becoming more commonly recognized with higher reliability because PSMA imaging allows the detection of more usual and unusual lesions than conventional imaging. The expanding use of PSMA positron emission tomography (PET) has also revealed PSMA ligand uptake in diverse nonprostatic diseases, which raised questions about the specificity of this imaging modality. It is important for the reading physician to recognize and understand the usual disease spread, the most prevalent unusual sites of relapse, and the nonprostatic conditions which are PSMA avid not only to heighten the relevancy of reports but also to improve imaging consultancy in multispecialty oncologic practice. This article aims to brief the role of PSMA PET in the initial staging of multitude of clinical scenarios, BCR, castration-resistant prostate cancer, usual and unusual patterns of recurrence and metastatic spread diagnosed with PSMA PET, normal variants, pitfalls, and nonprostatic disorders showing PSMA expression.

Erythrocytosis: Diagnosis and investigation.

An absolute erythrocytosis is present when the red cell mass is greater than 125% of the predicted. This is suspected when the hemoglobin or hematocrit is above the normal range. An erythrocytosis can be classified as primary or secondary and congenital or acquired. The commonest primary acquired disorder is polycythemia vera. The diagnostic criteria for PV have evolved over time and this is the main diagnosis managed in hematology clinics. There are a variety of rare congenital causes both primary and secondary. In particular in young patients and/or those with a family history a congenital cause is suspected. There remains a larger cohort with acquired erythrocytosis mainly with non-hematological pathology. In order to explore for a cause of erythrocytosis, measurement of the erythropoietin level is a first step. A low erythropoietin level indicates a primary cause and a normal or elevated level indicates a secondary etiology. Further investigation is then dictated by initial findings and includes mutational testing with PCR and NGS for those in whom a congenital cause is suspected. Following this possibly bone marrow biopsy, scans, and further investigation as indicated by history and initial findings. Investigation is directed toward the identification of those with a hematological disorder which would be best managed following guidelines in hematology clinics and referral elsewhere in those for whom there are non-hematological reasons for the elevated hemoglobin.