Positron Emission Tomography-computed Tomography Scan Research Articles

Long-Term Outcomes in Radioiodine-Resistant Follicular Cell-Derived Thyroid Cancers Treated with [177Lu]Lu-DOTAGA.FAPi Dimer Therapy.

Aim: The study aimed to analyze the long-term outcomes of [177Lu]Lu-DOTAGA.FAPi dimer therapy in individuals diagnosed with radioiodine-resistant (RAI-R) follicular cell-derived thyroid cancer. Materials and Methods: In this retrospective study, 73 patients with RAI-R follicular thyroid carcinoma who had undergone multiple lines of previous treatments were included. Following [68Ga]Ga-DOTA.SA.FAPi positron emission tomography-computed tomography scan, among the 73 patients, 65 received [177Lu]Lu-DOTAGA.FAPi dimer monotherapy with a median activity of 5.5 GBq per cycle at 8-week intervals. The remaining eight patients underwent tandem [177Lu]Lu/[225Ac]Ac-DOTAGA.FAPi dimer therapy, consisting of a median of two cycles of [177Lu]Lu-DOTAGA.FAPi dimer followed by one cycle of [225Ac]Ac-DOTAGA.FAPi dimer, also at 8-week intervals. The primary endpoint included progression-free survival (PFS) and overall survival (OS). Secondary endpoints included PERCIST criteria response assessment and safety assessment according to Common Terminology Criteria for Adverse Events (V5.0). Results: We enrolled 37 female and 36 male patients, with a mean age of 54.3 years (range: 27 - 80 years). The patients received a median cumulative activity of 22.2 GBq (range, 4 GBq-55.5 GBq) of [177Lu]Lu-DOTAGA-FAPi dimer over one to nine cycles, with a median of three cycles. Among 73 patients, 20 died and 16 deaths were due to thyroid cancer. Nineteen patients experienced disease progression, with an estimated median PFS of 29 months [CI 14-34 months]. The estimated median OS was 32 months [CI 21-40 months]. Four patients (5.4%) encountered grade III anemia, primarily linked to bone metastasis in three cases and neck tumor mass bleed in one. Grade III thrombocytopenia occurred in three patients (4%). No grade III renal or hepatotoxicity was observed. Conclusion: In this study, [177Lu]Lu-DOTAGA.FAPi dimer therapy showed promising safety and efficacy in aggressive, radioiodine-resistant thyroid cancer, achieving a median PFS and OS of 29 and 32 months, respectively, with manageable adverse events. Confirmation of our findings is needed from prospective clinical trials comparing [177Lu]Lu-DOTAGA.FAPi dimer therapy to other treatments.

Tumor burden quantified by Soluble B-Cell Maturation Antigen and Metabolic Tumor Volume determine myeloma CAR-T outcomes.

Chimeric antigen receptor T-cell (CAR-T) therapy has emerged as a breakthrough treatment for relapsed and refractory multiple myeloma (RRMM). However, these products are complex to deliver and alternative options are now available. Identifying biomarkers that can predict therapeutic outcomes is crucial for optimizing patient selection. There is a paucity of data evaluating the utility of both serum soluble B-cell maturation antigen (sBCMA) levels and metabolic tumor volume (MTV) at baseline in patients with RRMM undergoing CAR-T therapy. We identified a cohort of 183 patients with available serum to measure sBCMA and/or pre-treatment MTV, derived from positron emission tomography-computed tomography (PET-CT) scans obtained per standard of care. Expectedly, high pre-treatment levels of sBCMA correlated with other established markers of tumor burden (e.g., bone marrow plasma cells/BMPCs, beta2 microglobulin) and inflammation, and were highly prognostic for CAR-T related toxicities and inferior progression free survival (PFS). High MTV values were also associated with shorter PFS and inferior overall survival (OS). The poor correlation observed between these two measures prompted evaluation of those with discordant results, identifying that those with low sBCMA and high MTV frequently had low/absent BCMA expression on plasma cells and suboptimal response. Our findings highlight the potential utility of sBCMA and MTV to facilitate more personalized treatment strategies in the management of RRMM eligible for BCMA directed CAR-T.

An unusual case of primary pulmonary synovial sarcoma

BackgroundAn extremely rare intrathoracic tumour that typically affects young adults is primary pulmonary synovial sarcoma. It manifests as a big intrathoracic mass without involvement of the bone or mediastinal region. Tumour biopsy, immunostaining and histologic analysis can assist in determining the kind of tumour.Case presentationWe present a case of a 25-year-old male with complaints of breathlessness and chest pain for a month. On radiological imaging, he was found to have mass in upper and middle zones of right hemithorax. For confirmation of diagnosis, the patient underwent ultrasound-guided biopsy of the lesion and histopathologhical examination (HPE) of the lesion. The histopathological features were suggestive of a rare type of lung malignancy. For further diagnosis regarding type of malignancy, immunohistochemical staining of the lesion was done with the help of with specific immunological markers, which confirmed the diagnosis of monophasic pulmonary sarcoma. On PET (positron emission tomography) CT (computed tomography) scan, there were no features suggestive of distant metastasis especially in extremities which confirmed the diagnosis of primary pulmonary synovial sarcoma. Patient was started on chemotherapy regimen of ifosfamide and doxorubicin after oncologist’s opinion but was lost to follow up after 3rd cycle of chemotherapy.ConclusionsPrimary pulmonary synovial sarcoma is an extremely uncommon tumour in young adults as lung metastases from other sources mainly extremities are more common. Diagnosis of such rare tumour requires histopathological examination along with immunohistochemical staining of the lung lesions. A multimodal strategy of treatment involving resection, chemotherapy and radiation is used for the treatment of such tumours.

Pericardial Tamponade Two Years after Central Venous Catheter Implantation in a Patient with Breast Cancer: A Case Report

We report a rare and diagnostically challenging case of pericardial tamponade in a breast cancer patient, treated two years earlier. Echocardiogram and an enhanced computed tomography (CT) scan revealed a large mass in the right pericardium with indistinct borders. A positron emission tomography-computed tomography (PET-CT) scan showed no uptake of fluorine-18 fluorodeoxyglucose (18F-GDP) by the mass. Cardiac magnetic resonance imaging (MRI) with late gadolinium enhancement confirmed no signal enhancement within the mass and a clear border, decisively ruling out malignancy. This case highlights the importance of late gadolinium enhancement in this diagnostically challenging case and explores the pericardial tamponade development mechanism.

Highlights of the 2024 ASCO Annual Meeting: radiotherapy of head and neck cancer

At the 2024 Annual Meeting of the American Society of Clinical Oncology (ASCO), several important studies on radiotherapy for head and neck squamous cell carcinoma (HNSCC) were presented. There were two Chinese phaseIII trials on treatment escalation for locally advanced nasopharyngeal carcinoma: adjuvant immune checkpoint inhibition with camrelizumab after induction chemotherapy and cisplatin-based chemoradiotherapy (RCT) in the DIPPER trial reached the primary endpoint of improved event-free survival (EFS) but did not improve overall survival (OS). Simultaneous and adjuvant administration of the angiogenesis inhibitor endostar in addition to cisplatin-based RCT for locally advanced nasopharyngeal carcinoma led to asignificant improvement in progression-free survival (PFS) and OS. Another major focus was on treatment optimization and deintensification for oropharyngeal cancer (OPC): using intensity-modulated proton therapy (IMPT), aphaseIII trial demonstrated noninferiority in definitive RCT for OPC compared to photon-based intensity-modulated radiotherapy (IMRT). In adjuvant treatment of human papillomavirus-positive (HPV+) OPC, the long-term results of the E3311 phaseII study confirmed that individually deintensified radiotherapy is feasible. Lee etal. showed with the results of aphaseII study that HPV+ OPC might be treatable with chemoradiotherapy to atotal dose of only 30 Gy if no hypoxia is detected in the 18F‑fluoromisonidazole positron-emission tomography-computed tomography (F-MISO-PET) scan. Both the deintensified treatment of HPV+ OPC as well as additive immune checkpoint and angiogenesis inhibition in chemoradiotherapy of nasopharyngeal carcinoma require further studies before they can be recommended in clinical practice.

Can the presence of aortic or coronary artery calcifications in the standard of care baseline CT or PET-CT scan of patients with Hodgkin or non-Hodgkin lymphoma be used as a predictor of MACE?

Abstract Background Major adverse cardiovascular events (MACE), commonly defined as acute myocardial infarction, acute coronary syndrome/ischemic heart disease requiring revascularization, stroke, and heart failure, represent a significant cause of mortality among patients with cancer. With increased rates of both cancer and cancer survivorship, the identification of new predictive markers for the development of MACE in this population is crucial for implementing effective preventive and risk-mitigation strategies. Purpose To determine whether the presence of calcifications in the coronary arteries (CAC) or aorta (CA) of lymphoma patients, as reported in standard-of-care PET-CT (Positron Emission Tomography-Computed Tomography) or chest CT (Computed Tomography) scan, can predict the occurrence of MACE. Methods A Retrospective analysis was conducted on a cohort of patients diagnosed with Hodgkin or non-Hodgkin lymphoma and treated with anthracycline-based chemotherapy. Patients were diagnosed from January 1, 2013, and followed through to June 30, 2023. The reference point for the study was the radiologist’s report of the PET-CT or chest CT conducted before the initiation of anthracycline therapy. Patients who did not undergo a PET-CT or CT before the start of treatment, and/or developed MACE before treatment initiation were excluded. Univariate and multivariate adjusted Cox regression models were employed to assess whether the presence of CA and CAC was associated with the development of MACE. Associations with outcomes were evaluated using the Kaplan-Meier method and Cox regression. Results 326 patients were included with a mean age of 55 years (range: 52-60), predominantly male 201 (61%) and white 314 (96%), CAC was reported in 75 patients (23%) and CA in 18 (6%). In the univariate regression model, a statistically significant association was found between the presence of both CA and CAC with the risk of MACE. CAC showed a stronger association with the development of MACE than CA (HR: 3.7 [1-7.9], p=0.0005 vs HR: 2.9 [1- 8.5], p=0.050). In multivariable analysis CAC emerged as the strongest predictor of MACE (HR: 2.9 [1.3 – 6.4], p=0.01), after accounting for hypertension, diabetes, dyslipidemia, and GFR <60 (Table 1), while the association with CA attenuated (HR: 2.01 [0.7-6.5], p=0.2010) and was no longer significant (Table 2). Conclusion CAC in the standard-of-care PET/-CT scans was a predictor of MACE in lymphoma patients treated with anthracyclines, while the association with CA weakened in multivariable analyses and was likely underpowered given the small number of patients with CA. If replicated, this finding warrants closer surveillance of this group of patients and can be considered as a non-invasive cardiovascular risk marker.

Heterotopic High-Grade Salivary duct Carcinoma Likely Arising within Cervical Lymph Nodes

Abstract Introduction/Objective Salivary duct carcinoma arising in heterotopic salivary gland tissue is an extremely rare occurrence, with less than five cases reported in the literature. We present a unique case of heterotopic high-grade salivary duct carcinoma likely arising within cervical lymph nodes. Methods/Case Report A 56-year-old male presented with enlarged cervical lymph nodes for few months. Physical examination was unremarkable. Computerized tomography (CT) scan of head and neck showed two enlarged level 1B lymph nodes, measuring 1.0 and 1.4 cm, with unremarkable salivary glands. Patient had left cervical level II lymph node biopsy that showed metastatic poorly differentiated carcinoma. Immunohistochemically, the tumor cells were positive for GATA3, cytokeratin 903, androgen receptor, p16 (variable nonspecific), and were negative for TTF-1, p40, p63, ER, PR and NKX3.1, favoring salivary gland ductal carcinoma. Positron emission tomography (PET) CT scan showed a hypermetabolic left submandibular gland and level 2A lymph nodes. Subsequently, the patient underwent left modified radical neck dissection. Sectioning of the submandibular gland revealed no discrete lesions. Multiple, firm to rubbery lymph nodes ranging from 0.4 cm to 2.3 cm, with tan-pink cut surfaces were identified. Microscopic examination showed normal submandibular salivary gland parenchyma. However, eight out of nineteen lymph nodes were positive for metastatic high-grade salivary duct carcinoma comprising tumor cells forming nests and cords with ample eosinophilic cytoplasm, pleomorphic round to oval nuclei and numerous mitotic figures. Several benign and malignant lymph nodes in levels I, II and IV showed heterotopic salivary gland tissue. Immunohistochemical stains for androgen receptor and p40 were positive and negative respectively, supported the final diagnosis of high-grade salivary duct carcinoma. Results (if a Case Study enter NA) NA Conclusion Given the absence of carcinoma in the completely sampled submandibular gland, the origin of the intra- nodal tumor deposits was most likely to be heterotopic salivary gland tissue. This case emphasizes the importance of meticulous pathological sampling required for definitive diagnosis.

Optic neuritis in Rosai Dorfman disease.

A 55-year-old man while being evaluated for unexplained weight loss was found to have multiple metabolically active lymph nodes on positron emission tomography-computed tomography (PET-CT)scan, and biopsy from right axillary lymph node demonstrated multiple histiocytes with emperipolesis with S100 positivity, consistent with Rosai-Dorfman disease.

Exceptional sustained long-term complete response to Tepotinib in a MET-amplified advanced intrahepatic biliary tract cancer failing Durvalumab plus Cisplatin and Gemcitabine.

Biliary tract cancers (BTCs) are a diverse group of malignancies with varied genetic backgrounds. The prevalence of intrahepatic cholangiocarcinoma (iCC) is increasing, particularly in Western countries. Despite advancements in treatments, the prognosis for BTC remains poor. Recent molecular profiling has revealed that up to 40% of iCC cases have targetable genetic alterations. MET amplification, although rare, presents a significant target for therapy. A 25-year-old female with a history of ulcerative colitis presented with shoulder pain and a positron emission tomography-computed tomography (PET-CT) scan revealed an enlarged liver and multiple metastases. Histopathological analysis diagnosed poorly differentiated adenocarcinoma. First-line therapy with Cisplatin, Gemcitabine, and Durvalumab resulted in disease progression. Molecular profiling identified a TP53 mutation and MET amplification. Based on these findings, Tepotinib was initiated. Tepotinib treatment led to a significant reduction in tumor size and normalization of CA 19-9 levels within 2 months, achieving a complete metabolic remission lasting up to 17 months. The treatment was well tolerated with minimal side effects. MET-amplified BTCs are exceedingly rare, and evidence for targeted treatment is limited. This case demonstrates the efficacy of Tepotinib in a young patient with MET-amplified iCC, showing a long-term response and suggesting a potential new standard treatment option for this molecularly defined entity. This case also highlights the aggressive nature of MET-amplified tumors and the need for targeted second-line therapies. Tepotinib showed remarkable efficacy in treating MET-amplified intrahepatic cholangiocarcinoma, underscoring the importance of molecular profiling in BTCs and suggesting a potential new therapeutic approach for this rare cancer subtype.

Effect of a Single-Session Mindfulness-Based Swinging Technique (MBST) Intervention on Emotional Distress in Cancer Patients Undergoing PET-CT Scan: A Randomized Controlled Trial.

Introduction: Undergoing complex diagnostic investigation of positron emission tomography-computed tomography (PET-CT) scans is associated with high levels of distress, fear, and anxiety in oncological patients. This study evaluated the effects of a single 20-min session of an innovative mindfulness-based swinging technique (MBST) intervention on emotional distress in cancer patients scheduled for PET-CT scans. Material and Methods: Adult cancer patients undergoing PET-CT scans (n = 57) were assigned to the intervention group (n = 27) or the control group (n = 30). The emotion thermometer (ET) was used to measure distress, anxiety, depression, anger, and need for help at baseline and after the PET-CT scan. Participants in the intervention group received a 5-min psycho-education followed by listening to an audio recording of the MBST intervention just before their PET-CT scan. The session included mindfulness-based visualization, imaginary swinging activity, and synchronized breathing. The control group participants received brief 5-min counseling. Results: There was a statistically significant reduction in distress (p < 0.001), anxiety (p < 0.001), depression (p < 0.001), anger (p = 0.002), and need for help (p < 0.001) in the intervention group compared with the control group. Safety: None of the participants reported adverse events caused by the MBST intervention. The intervention was well accepted by the participants. However, n = 3 participants could not complete the intervention due to mind wandering, inability to focus, difficulty complying with the guided instructions, falling asleep, and physical discomfort unrelated to the intervention. Conclusion: The findings suggest the potential role of MBST intervention in mitigating emotional distress in patients undergoing complex diagnostic imaging procedures. Integrating this with conventional care in nuclear medicine settings can provide patient-centered care that addresses their unmet requirements. There is a need for further validation with a larger sample size. Clinical Trial Registration Number: CTRI/2023/04/051243 (Registered prospectively on 03/04/2023).

Vinblastine-Induced Posterior Reversible Encephalopathy Syndrome in Pediatric Hodgkin Lymphoma

AbstractPosterior reversible encephalopathy syndrome (PRES) is a critical care scenario seen with several etiologies. We report a pediatric case of Hodgkin lymphoma presenting with paraneoplastic features of nephrotic syndrome (NS). Diagnosis was confirmed with positron emission tomography-computed tomography scan and immunohistochemistry of the tissue biopsy. Remission for NS was achieved within a week of starting chemotherapy (ABVD–adriamycin, bleomycin, vinblastine, and dacarbazine). After the second cycle, he developed headache, seizures, and hypertension, requiring intensive care management. Magnetic resonance imaging brain was suggestive of PRES. The condition was managed with antihypertensives, antiepileptics, and supportive care. Considering all the risk factors for PRES including the drug, vinblastine, further chemotherapy was administered with only ABD regimen. The child attained complete remission after six cycles of chemotherapy and did not have any further episodes of hypertension or seizures. This case highlights the rare complication of vinblastine in a complicated lymphoid malignancy.

FDG PET Scan in Cutaneous Rosai–Dorfman–Destombes Disease

Rosai–Dorfman–Destombes (RDD) disease is also called as sinus histiocytosis and is characterized by enlarged lymph nodes and previously called as non-Langerhans cell histiocytosis. Based on pathologic, molecular, and genetic features, RDD disease has been classified into sporadic noncutaneous (classical nodal, extranodal, neoplasia associated, and autoimmune associated), familial (H syndrome, autoimmune lymphoproliferative syndrome related, and familial NOS), and cutaneous subtypes. Cutaneous RDD disease is not associated with lymphadenopathy or visceral organ involvement. The disease is usually localized and has relatively better long-term prognosis. Presented here is a case of indurated plaque-like skin lesions over the abdomen. 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography scan revealed FDG avid cutaneous–subcutaneous soft-tissue lesions. Histology confirmed the diagnosis of cutaneous RDD disease.

Predicting non-small cell lung cancer lymph node metastasis: integrating ctDNA mutation/methylation profiling with positron emission tomography-computed tomography (PET-CT) scan: protocol for a prospective clinical trial (LUNon-invasive Study).

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases and remains a leading cause of cancer-related death. Lymph node metastasis (LNM) significantly affects recurrence, survival rates, and treatment options. While lymph node sampling is standard for surgically removing operable NSCLC, it can lead to complications. Positron emission tomography-computed tomography (PET-CT) helps assess preoperative LNM despite false positive or negative rates. Additionally, circulating tumor DNA (ctDNA) detects minimal residual disease with high sensitivity and specificity. Whether ctDNA can predict LNM in operable NSCLC remains uncertain. Our goal is to develop a precise model for predicting NSCLC LNM using non-invasive ctDNA/methylation profiling combined with PET-CT imaging. This is a prospective study conducted in three stages. We will enroll patients with clinical stage I-IIIB [8th tumor, node, metastasis (TNM) staging] NSCLC requiring lobectomy plus lymph node sampling/dissection. The distribution of clinical stages in the enrolled population is as follows: clinical stage cN0 (n=100) and cN1/cN2 (n=100). During Stage 1, we will establish LNMs-specific ctDNA methylation signatures and compare negative predictive value (NPV) rates of LNMs using preoperative blood ctDNA somatic mutation/methylation alone or combined with PET-CT across different groups. For Stage 2, we will compare detection rates between ctDNA somatic mutation/methylation profiles alone or combined with PET-CT and traditional mediastinoscopy/endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). As for Stage 3, ctDNA-free interval (CFI) and disease-free survival between systematic lymph node presence and absence in patients will be compared with preoperative negative ctDNA profiling and/or PET-CT. In Stage 3, patients will be followed up for 5 years to collect recurrence and survival data. Post-surgery follow-up ctDNA tests will be conducted every 3 months for the first 2 years, every 6 months for years 3-4, and annually in year five. Demographics and baseline data will be summarized with mean, standard deviation, median, max, and min values. Tests will include t-tests, Welch/Behren-Fisher test, and Wilcoxon rank-sum test for continuous variables. Categorical data will be presented as counts/percentages and compared using χ2 test or Fisher's exact test. By utilizing preoperative ctDNA/methylation profiling in conjunction with PET-CT, this study is expected to yield substantial evidence for accurately predicting LNM before surgery. This will help inform surgeons in selecting the appropriate intraoperative lymph node dissection strategy for operable NSCLC patients. This study is registered on www.clinicaltrials.gov (NCT06358222).

The Relationship Between Nodal Metastases and Primary Location in Stage I Non-Small Cell Lung Cancer

IntroductionThis study examines the relationship between location of the primary tumor and specific nodal metastases in clinical stage 1 non-small cell lung cancer (NSCLC) patients undergoing lobectomy. MethodsWe retrospectively analyzed all lobectomies performed at a single institution, between January 2005 and December 2019, for clinical stage I NSCLC patients. Patients selected for this study were clinically node negative (cN0) by positron emission tomography-computed tomography scan and selectively by endobronchial ultrasound or mediastinoscopy. Cases of postoperative pathologic nodal upstaging were identified among these patients. For each patient upstaged, the specific lymph node stations found to be positive were recorded. Descriptive statistics, chi-squared tests, and Fisher's exact test were utilized to identify independent risk factors for upstaging to specific N1 and N2 lymph node stations. All clinical and pathologic staging information was retrospectively normalized to the International Association for the Study of Lung Cancer 8th Edition TNM Classification. ResultsThe research cohort included 645 patients. The mean age was 68 years (standard deviation ± 9.2), 54% were female, and 88% were White, 11% Black, and 1% other. Twelve percent (n = 75) were upstaged from cN0 to pN1 or pN2 upon final pathologic examination: 41 to pN1 (54.7%) and 34 to pN2 (45.3%). The primary tumor location with the highest rate of nodal upstaging was the left upper lobe (LUL) (12.8%). Tumors in the right middle lobe had the lowest rate of unsuspected nodal metastases (8.8%). Out of all upstaged patients, there were no positive level eight lymph nodes, and only 1 patient with a positive level nine lymph node. Lymph node levels five and six were only positive in LUL primary tumors, a relationship that approached statistical significance (P = 0.0797). No patients with a LUL primary tumor had a positive level seven lymph node. Upstaging at station 12 was significantly associated with the location of the primary tumor, occurring less often in tumors originating in the right upper lobe in comparison to other lobes (P = 0.0288). ConclusionsWe identified relationships between the location of a primary tumor and specific nodal upstaging in patients with clinical stage I NSCLC who undergo lobectomy. We found the following: 1) only 1 patient had a positive level eight or nine lymph node out of 645 patients; 2) only LUL primary tumors demonstrated upstaging to level five or six lymph nodes; and 3) right upper lobe tumors were significantly less likely to be associated with a positive level 12 lymph node.

Integrating myocardial metabolic imaging and stress myocardial contrast echocardiography to improve the diagnosis of coronary microvascular diseases in rabbits.

Persistent challenges associated with misdiagnosis and underdiagnosis of coronary microvascular disease (CMVD) necessitate the exploration of noninvasive imaging techniques to enhance diagnostic accuracy. Therefore, we aimed to integrate multimodal imaging approaches to achieve a higher diagnostic rate for CMVD using high-quality myocardial metabolism imaging (MMI) and myocardial contrast echocardiography (MCE). This combination diagnostic strategy may help address the urgent need for improved CMVD diagnosis. In this study, we established five distinct pretreatment groups, each consisting of nine male rabbit: a fasted group, a nonfasted group, a sugar load group, an acipimox group, and a combination group of nonfasted rabbits administered insulin. Moreover, positron emission tomography-computed tomography (PET/CT) scan windows were established at 30-, 60-, and 90-minute intervals. We developed 10 CMVD models and conducted a diagnosis of CMVD through an integrated analysis of MMI and MCE, including image acquisition and processing. For each heart segment, we calculated the standardized uptake value (SUV) based on body weight (SUVbw), as well as certain ratios of SUV including SUV of the heart (SUVheart) to that of the liver (SUVliver) and SUVheart to SUV of the lung (SUVlung). Additionally, we obtained three coronary SUVbw uptake values. To clarify the relationship between SUVbw uptake values and echocardiographic parameters of the myocardial contrast agent more thoroughly, we conducted a comprehensive analysis across different pretreatment protocols. Receiver operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic accuracy of each parameter in the context of CMVD. In the context of MMI, the nonfasted-plus-insulin group, as observed during the 60-minute examination, exhibited a noteworthy total 18F-fluorodeoxyglucose (18F-FDG) uptake of 47.44±6.53 g/mL, which was found to be statistically different from the other groups. To ascertain the reliability of the results, two double-blind investigators independently assessed the data and achieved a good level of agreement, according to the intraclass correlation coefficient (ICC) (0.957). The SUVbw of the nonfasted-plus-insulin group exhibited a moderate correlation with the microvascular blood flow reserve (MBFR) parameters derived from the MCE examination, as evidenced by a r value of 0.686. For the diagnosis of CMVD disease, the diagnostic accuracy of the combined diagnostic method [area under the curve (AUC) =0.789; 95% confidence interval (CI): 0.705-0.873] was significantly higher than that of the MBFR (AUC =0.697; 95% CI: 0.597-0.797) and SUVbw (AUC =0.715; 95% CI: 0.622-0.807) methods (P<0.05). Our study demonstrated the feasibility of a simple premedication approach involving free feeding and intravenous insulin in producing high-quality gated heart 18F-FDG PET/CT images in adult male New Zealand white rabbits. This technique holds considerable potential for ischemic heart disease research in rabbits and can enhance CMVD diagnosis via the comprehensive assessment of myocardial metabolism and perfusion.

Machine learning-based estimation of patient body weight from radiation dose metrics in computed tomography.

Currently, precise patient body weight (BW) at the time of diagnostic imaging cannot always be used for radiation dose management. Various methods have been explored to address this issue, including the application of deep learning to medical imaging and BW estimation using scan parameters. This study develops and evaluates machine learning-based BW prediction models using 11 features related to radiation dose obtained from computed tomography (CT) scans. A dataset was obtained from 3996 patients who underwent positron emission tomography CT scans, and training and test sets were established. Dose metrics and descriptive data were automatically calculated from the CT images or obtained from Digital Imaging and Communications in Medicine metadata. Seven machine-learning models and three simple regression models were employed to predict BW using features such as effective diameter (ED), water equivalent diameter (WED), and mean milliampere-seconds. The mean absolute error (MAE) and correlation coefficient between the estimated BW and the actual BW obtained from each BW prediction model were calculated. Our results found that the highest accuracy was obtained using a light gradient-boosting machine model, which had an MAE of 1.99kg and a strong positive correlation between estimated and actual BW (ρ=0.972). The model demonstrated significant predictive power, with 73% of patients falling within a±5% error range. WED emerged as the most relevant dose metric for BW estimation, followed by ED and sex. The proposed machine-learning approach is superior to existing methods, with high accuracy and applicability to radiation dose management. The model's reliance on universal dose metrics that are accessible through radiation dose management software enhances its practicality. In conclusion, this study presents a robust approach for BW estimation based on CT imaging that can potentially improve radiation dose management practices in clinical settings.

PET-CT-guided, symptom-based, patient-initiated surveillance versus clinical follow-up in head neck cancer patients (PETNECK2): study protocol for a multicentre feasibility study and non-inferiority, randomised, phase III trial

BackgroundApproximately 40% of treated head and neck cancer (HNC) patients develop recurrence. The risk of recurrence declines with time from treatment. Current guidelines recommend clinical follow-up every two months for the first two years after treatment, with reducing intensity over the next three years. However, evidence for the effectiveness of these regimes in detecting recurrence is lacking, with calls for more flexible, patient-centred follow-up strategies.MethodsPETNECK2 is a UK-based multi-centre programme examining a new paradigm of follow-up, using positron emission tomography-computed tomography (PET-CT)-guided, symptom-based, patient-initiated surveillance. This paradigm is being tested in a unblinded, non-inferiority, phase III, randomised controlled trial (RCT). Patients with HNC, one year after completing curative intent treatment, with no clinical symptoms or signs of loco-regional or distant metastasis will be randomised using a 1:1 allocation ratio to either regular scheduled follow-up, or to PET-CT guided, patient-initiated follow-up. Patients at a low risk of recurrence (negative PET-CT) will receive a face-to-face education session along with an Information and Support (I&S) resource package to monitor symptoms and be in control of initiating an urgent appointment when required. The primary outcome of the RCT is overall survival. The RCT also has an in-built pilot, a nested QuinteT Recruitment Intervention (QRI), and a nested mixed-methods study on patient experience and fear of cancer recurrence (FCR). An initial, single-arm feasibility study has been completed which determined the acceptability of the patient-initiated surveillance intervention, the completion rates of baseline questionnaires, and optimised the I&S resource prior to implementation in the RCT.DiscussionWe hypothesise that combining an additional 12-month post-treatment PET-CT scan and I&S resource will both identify patients with asymptomatic recurrence and identify those at low risk of future recurrence who will be empowered to monitor their symptoms and seek early clinical follow-up when recurrence is suspected. This change to a patient-centred model of care may have effects on both quality of life and fear of cancer recurrence.Trial registrationISRCTN: 13,709,798; 15-Oct-2021.

Design, Synthesis, and Biological Evaluation of Novel Nonsteroidal 18F-Labeled PET Probes Specifically Targeting Estrogen Receptor α.

The estrogen receptor α positive (ERα+) subtype represents nearly 70% of all breast cancers (BCs), which seriously threaten women's health. Positron emission computed tomography (PET) characterizes its superiority in detecting the recurrence and metastasis of BC. In this article, an array of novel PET probes ([18F]R-1, [18F]R-2, [18F]R-3, and [18F]R-4) targeting ERα based on the tetrahydropyridinyl indole scaffold were developed. Among them, [18F]R-3 and [18F]R-4 showed good target specificity toward ERα and could distinguish MCF-7 (ERα+) and MDA-MB-231 (ERα-) tumors efficiently. Especially, [18F]R-3 could differentiate the ERα positive/negative tumors successfully with a higher tumor-to-muscle uptake ratio (T/M) than that of [18F]R-4. The radioactivity of [18F]R-3 in the MCF-7 tumor was 5.24 ± 0.84%ID/mL and its T/M ratio was 2.49 ± 0.62 at 25 min postinjection, which might be the optimal imaging time point in PET scanning. On the contrary, [18F]R-3 did not accumulate in the MDA-MB-231 tumor at all. The autoradiography analysis of [18F]R-3 on the MCF-7 tumor-bearing mice model was consistent with the PET imaging results. [18F]R-3 exhibited the pharmacokinetic property of rapid distribution and slow clearance, making it suitable for use as a diagnostic PET probe. Overall, [18F]R-3 was capable of serving as a PET radiotracer to delineate the ERα+ tumor and was worthy of further exploitation.

Development of a novel methodology to assess response to lymphoma treatment in real-world data.

e19081 Background: Innovation in the use of real-world data (RWD) for regulatory purposes is an important provision of 21st Century Cures Act. Numerous initiatives to enhance RWD methodologies in oncology drug development are ongoing, including evaluation of treatment response assessment to support effectiveness research. Blinded independent central review (BICR) standardizes response assessment in clinical trials, and corresponding RWD methodologies are needed. This study assess feasibility of BICR using RWD, and evaluates a novel, standardized treatment response methodology among patients with diffuse large B-cell lymphoma (DLBCL). Methods: A retrospective multisite chart review identified adult patients with DLBCL treated with first-line chemoimmunotherapy in US (01JAN2015-31DEC2022). Clinical data, including physician-reported response, were abstracted from medical charts and positron emission tomography-computed tomography (PET-CT) reports at treatment initiation and first response assessment. Lugano 2014 criteria, such as standardized uptake value (SUV) and Deauville score, were extracted and converted to an algorithm (rwLugano). Absence of normal tissue SUV in PET-CT reports was addressed using published values for background, mediastinum, and liver to facilitate a real-world Deauville (rwDeauville) score for rwLugano classification. PET-CTs underwent deidentified digital image transfer for BICR using Lugano 2014 criteria by two lymphoma radiologists. Descriptive analyses assessed BICR feasibility and completeness of rwLugano data elements. Results: Six oncology practices, comprising 77 physicians, abstracted medical records and PET-CT reports for 185 patients. PET-CT scans were available for BICR for 174/185 (94%) patients (41% female, mean age 66 years). BICR discordance for Deauville score at baseline and initial response occurred in 7% (12/174) and 29% (50/174), respectively. For response assessment per Lugano, BICR discordance occurred in 9% (16/174), and were further adjudicated by a third party. Lugano discordance was often related to interpretation of marrow activity and/or new disease sites, highlighting variability in lymphoma treatment response assessment. Medical record review found Deauville score charted for 97 (56%) patients at baseline and 145 (83%) at first response. Tumor SUV was complete (174/174, 100%) at baseline and for all patients (63/63, 100%) not charted as CR at first response. Thus, 29 patients (17%) required calculation of rwDeauville at first response, providing data to calculate rwLugano for all patients in the final cohort (174/174, 100%). Conclusions: This study suggests BICR, though resource intensive, can be performed, and the component measures necessary to assess response per Lugano criteria can be obtained using RWD. Accordingly, rwLugano warrants further analysis for concordance with BICR- and physician-reported response.

Tumor metabolic activity is associated with subcutaneous adipose tissue radiodensity and survival in non-small cell lung cancer

BackgroundCachexia-associated body composition alterations and tumor metabolic activity are both associated with survival of cancer patients. Recently, subcutaneous adipose tissue properties have emerged as particularly prognostic body composition features. We hypothesized that tumors with higher metabolic activity instigate cachexia related peripheral metabolic alterations, and investigated whether tumor metabolic activity is associated with body composition and survival in patients with non-small cell lung cancer (NSCLC), focusing on subcutaneous adipose tissue. MethodsA retrospective analysis was performed on a cohort of 173 patients with NSCLC. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans obtained before treatment were used to analyze tumor metabolic activity (standardized uptake value (SUV) and SUV normalized by lean body mass (SUL)) as well as body composition variables (subcutaneous and visceral adipose tissue radiodensity (SAT /VAT radiodensity) and area; skeletal muscle radiodensity (SM radiodensity) and area). Subjects were divided into groups with high or low SAT radiodensity based on Youden Index of Receiver Operator Characteristics (ROC). Associations between tumor metabolic activity, body composition variables, and survival were analyzed by Mann-Whitney tests, Cox regression, and Kaplan-Meier analysis. ResultsThe overall prevalence of high SAT radiodensity was 50.9% (88/173). Patients with high SAT radiodensity had shorter survival compared with patients with low SAT radiodensity (mean: 45.3 vs. 50.5 months, p=0.026). High SAT radiodensity was independently associated with shorter overall survival (multivariate Cox regression HR=1.061, 95% CI: 1.022-1.101, p=0.002). SAT radiodensity also correlated with tumor metabolic activity (SULpeak rs=0.421, p=0.029; SUVpeak rs=0.370, p=0.048). In contrast, the cross-sectional areas of SM, SAT, and VAT were not associated with tumor metabolic activity or survival. ConclusionHigher SAT radiodensity is associated with higher tumor metabolic activity and shorter survival in patients with NSCLC. This may suggest that tumors with higher metabolic activity induce subcutaneous adipose tissue alterations such as decreased lipid density, increased fibrosis, or browning.