99mTc Bone Research Articles

Frequency of Positive Findings on MRI of The Patients Diagnosed with Vertebral Metastases on Bone Scintigraphy

Objective: The present study is conducted with the aim to compare the bone scan and MRI findings for detecting spinal metastasis in our local population. Study design and duration: This cross sectional study was conducted at Radiology Department of Pakistan Institute of medical Sciences, Islamabad from May 2019-May 2020. Material and Methods: Total 30patients with confirmed diagnosis of cancer who were suspected for spinal metastasis on Tc-99m bone scan and sent for radiologic workup for confirm diagnosis of s pine lesions were enrolled. MRI was performed on 1.5-tesla system using standard protocol. Spine was divided into four regions: cervical, thoracic, lumber and sacral regions. Region-wise bone metastasis were analyzed and compared for bone scan and MRI. Interpretations were considered concordant if both reports showed positive for metastatic lesions, while discordant if readings differ. Results: 63.3% of the study population were female. Mean age of the enrolled patients was 59.3±14.9 years. All the lesions of cervical region were concordant. Most of the discordance for MRI was noted for lumbar region, where 7 patients were reported as negative who were positive on bone scan. In case of bone scintigraphy, 2 patients were discordant for thoracic region who were positive on MRI. Conclusion: Very low discordance rate exists among MRI and bone scan. MRI is an effective imaging tool for detection of spinal metastasis with added benefits of no radiation dose to the patient and wider availability as compare to the bone scintigraphy.

A scanning focus nuclear microscope with multi-pinhole collimation

Microscopic nuclear imaging down to spatial resolutions of a few hundred microns can already be achieved using low-energy gamma emitters (e.g. 125I, ∼30 keV) and a basic single micro-pinhole gamma camera. This has been applied to in vivo mouse thyroid imaging, for example. For clinically used radionuclides such as 99mTc, this approach fails due to penetration of the higher-energy gamma photons through the pinhole edges. To overcome these resolution degradation effects, we propose a new imaging approach: scanning focus nuclear microscopy (SFNM). We assess SFNM using Monte Carlo simulations for clinically used isotopes. SFNM is based on the use of a 2D scanning stage with a focused multi-pinhole collimator containing 42 pinholes with narrow pinhole aperture opening angles to reduce photon penetration. All projections of different positions are used to iteratively reconstruct a three-dimensional image from which synthetic planar images are generated. SFNM imaging was tested using a digital Derenzo resolution phantom and a mouse ankle joint phantom containing 99mTc (140 keV). The planar images were compared with those obtained using a single-pinhole collimator, either with matched pinhole diameter or with matched sensitivity. The simulation results showed an achievable 99mTc image resolution of 0.04 mm and detailed 99mTc bone images of a mouse ankle with SFNM. SFNM has strong advantages over single-pinhole imaging in terms of spatial resolution.

Lipoma arborescence of knee joint in an adolescent male patient: a case report

<p>A very uncommon benign synovial membrane tumor is called lipoma arborescens. It often affects a single articulation, the knee. Despite a conventional imaging assessment, the lesion’s histological analysis is still required for the ultimate diagnosis. A 15-year-old boy attended the outpatient clinic of the Lahore General Hospital Lahore, Pakistan with pain and swelling in his left knee that had been steadily worsening over the previous 4 years. There were no concomitant prodromal symptoms, and the swelling was soft and non-tender while also inhibiting knee flexion. Soft tissue shadows were observed on radiographs. A large amount of subarticular erosion in the nearby tibial and femoral condyle was caused by the frond-like proliferation of fatty synovium, according to magnetic resonance imaging. Only the left knee joint showed focused areas of unusually elevated radionuclide uptake during the Technetium (Tc99m) bone scan. After an open synovectomy, the specimen underwent histological analysis, which revealed villiform fatty tissue, a hallmark of Lipoma arborescens coated by somewhat thicker synovium. Although infrequent, open synovectomy is currently the preferred course of treatment for lipoma arborescens, which should be taken into account when making a differential diagnosis of knee diseases. Approximately 3 months after surgery, the patient underwent his most recent follow-up and was asymptomatic with a small amount of joint effusion.</p>

Comparison of 18-FDG SUV Value with Bone Scintigraphy Findings in Diagnosed Cases of Malignancy with Sclerotic Bony Metastasis

Objective: To determine the correlation of 18F-FDG SUV value with bone scintigraphy findings, i.e. uptake of Tc-99m in diagnosed cases of malignancy with sclerotic bone metastasis.
 Study Design: Prospective longitudinal study.
 Place and Duration of Study: Armed Forces Institute of Radiology and Imaging, Rawalpindi Pakistan, from Sep 2020 to Mar 2021.
 Methodology: This study included 30 patients of age 18 to 80 years who had sclerotic bone metastasis as confirmed in histopathology. All patients underwent whole-body PET/CT scanning to evaluate sclerotic bone metastasis and determined 18-FDG SUV after 5MBq/kg body weight of 18-FDG was injected. After two weeks of PET/CT scan, Tc-99m bone scintigraphy was carried out, and SUV of Tc-99m was determined after 20-25mCi technetium-99 methylene disphosphonate was injected, and the correlation was assessed between SUV of 18-FDG and Tc-99m.
 Results: The mean 18-FDG SUVmax and mean Tc-99m SUVmax, were, 21.31±8.77g/ml and 15.29±6.49g/ml respectively.21(70%) lesions on 18-FDG PET/CT and 8(26.7%) on Tc-99m bone scintigraphy were metastatic in bones. 18-FDG SUV on PET/CET and Tc-99m SUV on bone scintigraphy correlated positively with each other, and this correlation was found to be statistically significant (r=0.491, p=0.006).
 Conclusion: 18-FDG SUV PET/CT significantly correlated with Tc-99m SUV on bone scintigraphy and helped detect metastatic lesions earlier and modulate treatment response.Keywords: Bone metastasis, Bone scintigraphy, 18-FDG PET/CT, Tc-99m SUV.

Intra-individual comparison of 18F-sodium fluoride PET–CT and 99mTc bone scintigraphy with SPECT in patients with prostate cancer or breast cancer at high risk for skeletal metastases (MITNEC-A1): a multicentre, phase 3 trial

Detection of skeletal metastases in patients with prostate cancer or breast cancer remains a major clinical challenge. We aimed to compare the diagnostic performance of 99mTc-methylene diphosphonate (99mTc-MDP) single-photon emission CT (SPECT) and 18F-sodium fluoride (18F-NaF) PET-CT for the detection of osseous metastases in patients with high-risk prostate or breast cancer. MITNEC-A1 was a prospective, multicentre, single-cohort, phase 3 trial conducted in ten hospitals across Canada. Patients aged 18 years or older with breast or prostate cancer with a WHO performance status of 0-2 and with high risk or clinical suspicion for bone metastasis, but without previously documented bone involvement, were eligible. 18F-NaF PET-CT and 99mTc-MDP SPECT were done within 14 days of each other for each participant. Two independent reviewers interpreted each modality without knowledge of other imaging findings. The primary endpoint was the overall accuracy of 99mTc-MDP SPECT and 18F-NaF PET-CT scans for the detection of bone metastases in the per-protocol population. A combination of histopathological, clinical, and imaging follow-up for up to 24 months was used as the reference standard to assess the imaging results. Safety was assessed in all enrolled participants. This study is registered with ClinicalTrials.gov, NCT01930812, and is complete. Between July 11, 2014, and March 3, 2017, 290 patients were screened, 288 of whom were enrolled (64 participants with breast cancer and 224 with prostate cancer). 261 participants underwent both 18F-NaF PET-CT and 99mTc-MDP SPECT and completed the required follow-up for statistical analysis. Median follow-up was 735 days (IQR 727-750). Based on the reference methods used, 109 (42%) of 261 patients had bone metastases. In the patient-based analysis, 18F-NaF PET-CT was more accurate than 99mTc-MDP SPECT (84·3% [95% CI 79·9-88·7] vs 77·4% [72·3-82·5], difference 6·9% [95% CI 1·3-12·5]; p=0·016). No adverse events were reported for the 288 patients recruited. 18F-NaF has the potential to displace 99mTc-MDP as the bone imaging radiopharmaceutical of choice in patients with high-risk prostate or breast cancer. Canadian Institutes of Health Research.

Impact of CT tube-voltage and bone density on the quantitative assessment of tracer uptake in Tc-99m bone SPECT/CT: A phantom study

PurposeTo evaluate the effect of computed tomography (CT) tube voltage and CT density for CT-based attenuation correction (CTAC) on quantification of tracer uptake in single photon emission computed tomography (SPECT)/CT. MethodsA cylindrical phantom contained 7 cylinders with diameter of 30 mm. The central cylinder and background part were filled with 17 kBq/ml of 99mTc-pertechnetate solution. Of the remaining 6 cylinders, one cylinder was filled with water and 5 cylinders were filled with each own different concentration of K2HPO4 solution (120, 275, 450, 666, and 960 mg/cm3) to simulate different bone densities. The 6 cylinders also contained 99mTc-pertechnetate solution with the same radioactivity concentration (207 kBq/ml). CT scans were performed with 4 different tube voltages of 80, 100, 120, and 140 kVp for CTAC. The radioactivity concentration in the 6 cylinders were measured on the SPECT images processed with 4 different attenuation coefficient maps derived from each tube voltage of CT images. ResultsCompared with the water cylinder without K2HPO4 solution, the measured radioactivity of the highest density cylinder (K2HPO4 solution concentration: 960 mg/cm3) was found to be overestimated by 3.3 % and 4.3 %, respectively, when the tube voltage was 120 kVp and 140 kVp (p = 0.022). The use of low-tube voltage, such as 80 kVp, has improved the quantitative accuracy of bone SPECT/CT. ConclusionsSPECT quantitative evaluation of tracers in high-density objects tends to overestimate as tube voltage for CTAC increases. However, the overestimation in quantitative SPECT/CT evaluation in simulated bone area is less than 5% at most.

Recurrence rate after radical prostatectomy following primary staging of high-risk prostate cancer with 68Ga-PSMA PET/CT

Background Accurate primary staging is one of the most important issues for initial management of prostate cancer (PCa) patients to perform an optimal selection of patients for curative intended treatment. 68Ga-Prostate-Specific-Membrane-Antigen (PSMA) PET/CT was found superior to conventional imaging both for detection of recurrence after curative intended treatment and for primary staging. We studied the recurrence rate after radical prostatectomy in high-risk PCa patients primary staged with 68Ga-PSMA PET/CT compared with conventional imaging. Material and methods The study included 247 D’Amico high-risk PCa patients treated with radical prostatectomy (RP) after primary staging with 68Ga-PSMA PET/CT and a reference group of 137 high-risk patients with RP after conventional imaging (99mTc bone scintigraphy and CT). Recurrence rates were assessed by Cox regression and Kaplan-Meier analysis. Results The 5-year recurrence-free survival rate was 71.1% in the 68Ga-PSMA PET/CT cohort compared with 56.4% in the conventional imaging cohort. Primary staging by 68Ga-PSMA PET/CT reduced biochemical recurrence (BCR) risk by 42% (HR = 0.58 (0.41–0.83), p = .004). Conclusion The present data could indicate a lower recurrence rate after RP following primary staging with 68Ga-PSMA PET/CT compared to conventional imaging, likely due to improved selection of patients for surgery.

S2212 A Rare Systemic Illness Presenting With Fever and Abdomen Pain

Introduction: Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytic disease. ECD can practically involve any organ system in the body with common organs involved being skeletal system, cardiovascular system and the central nervous system. Rarely, other organs like breast, liver, spleen, kidney, testis and thyroid glands were reported to be involved. Case Description/Methods: A 51-year-old female presented to our emergency with fever and left upper quadrant pain abdomen of 10 days. Historically, she was symptomatic for last 3 years with complaints of intermittent fever, knee joints pain, polyuria, nocturia and polydipsia. Contrast enhanced computer tomography (CECT) chest and abdomen showed bilateral pleural and pericardial effusion, thrombosis in splenic vein and right portal vein, splenic infarct, bilateral urothelial thickening with perinephric fat stranding, soft tissue thickening around the aorta and asymmetrical bulky adrenals. PET-CT revealed Flouro-deoxyglucose (FDG) avid ill-defined lesion in the pericardium which was extending into the inter-atrial and atrioventricular septum and FDG avid asymmetrical mural thickening of aorta extending from ascending thoracic aorta up to the infrarenal abdominal aorta. There was presence of bulky tail of pancreas, bulky left adrenal, lytic lesions involving left femoral head, right sacrum and mandible, FDG avid lesions involving meninges, sella and cranial venous sinuses. Tc-99m bone scan showed increased tracer uptake in maxilla, mandible, bilateral forearm bones, bilateral femurs and bilateral tibia. PET guided biopsy from the lytic bone lesion in the right sacrum showed presence of cluster of atypical histiocytes with occasional multinucleated Touton type giant cells. The cells also showed granular cytoplasmic positivity for BRAFV600E, confirming the diagnosis of Erdheim Chester disease (ECD). She was initiated on oral vemurafenib, BRAF inhibitor, at a dose of 240mg twice a day. Discussion: ECD presenting with splenic infarct has not been described previously. A thorough evaluation and targeted biopsy confirmed the diagnosis. BRAFV600E is the most common mutation noted in these patients, seen in nearly 60% of the patients and the patients with BRAF mutations respond well to vemurafenib, a kinase domain inhibitor of mutant BRAF. Here in, we report a patient of ECD who presented with multisite venous thrombosis and splenic infarct, a rare manifestation of ECD, who was treated successfully with vemurafenib.

Necrotising Otitis Externa: An Overview Of Imaging Modalities.

Necrotising Otitis Externa (NOE) has often posed some challenges in view of diagnosis and management by clinicians. One such challenge is the appropriate and timely use of imaging techniques, since its use is critical not only in diagnosis but also determining the extent and resolution of the disease. Hence, doctors in both primary and secondary health care need to be familiar with presenting symptoms, while specialists need to be appraised of advances in imagining techniques in management of NOE. Whilst there is a general consensus amongst clinicians on some aspects of management of NOE, there is very limited consensus on the use of imaging modalities. There is no single modality of imaging that can provide a complete picture of diagnosis, disease progression and resolution. There are some advantages and limitation of each methodology, which indicate that a multi-modal imaging technique at particular stages of the disease may provide better management outcomes. However, further research in this area is required, as there is not yet an established 'gold standard' for imaging in NOE.

Central Skull Base Osteomyelitis: Multimodality Imaging and Clinical Findings from a Large Indian Cohort.

Central or atypical skull base osteomyelitis (CSBO) often presents with severe unrelenting headache and progressive mono or polyneuritis cranialis. MRI and CT are used as initial imaging techniques but have a poor specificity and sensitivity. To analyze our cohort of CSBO. Over a 5-year period [2015-2020], we retrospectively analyzed the records of all patients with CSBO who had undergone a 3T MRI Brain, MR angiography, regional FDG PET-CT, and skeletal scintigraphy with 99mTc MDP/SPECT-CT. Surgical biopsy specimens were sent for bacterial and fungal cultures. In total, 17 patients with CSBO were identified. Typically, 88% of patients presented with severe unilateral headache. All patients had at least a cranial mono or polyneuritis. The majority of patients were diabetic [64%]. MRI was normal in 42% of patients, whereas PET-CT and with 99mTc MDP scan and SPECT-CT were abnormal in all patients. Our series of CSBO showed a 40% mortality rate with significant morbidity and relentless progression. Patients required repeated PET CT and bone scans to detect regression of disease activity. The average duration of IV therapy ranged from 3 weeks to 9 months and oral therapy for around 2-3 months. Cure was defined after taking into account the original diagnosis, symptom resolution, and concordant reduction of tissue uptake on PET CT and 99mTc bone scan. The combination of MRI, FDG PET CT, and 99mTc bone scan with concurrent SPECT CT was able to detect disease and disease progression in all patients.

The roof step cut: A novel technique for bony reconstruction of acetabular roof deficiency during total hip replacement.

Objectives This study aims to present a new technique, the roof step cut (RSC), for acetabular augmentation of hip dysplasia.Patients and methods Between December 2008 and March 2020, we applied the RSC technique in a total of 48 hips of 41 patients (2 males, 39 females; mean age: 50.1±9.5 years; range, 30 to 75 years) with Hartofilakidis type A, B, C hip dysplasia. The RSC technique uses a L-shaped graft cut from the femoral head. The graft is partially inside the acetabulum and partially on the lateral aspect of the ilium. It is fixed with two screws at a 45° angle allowing simultaneous distalization and lateral covering of the cementless cup. Follow-up was done at six weeks, three months, and annually thereafter using standard pelvis anteroposterior X-ray and function scores. The 99mTc bone scintigraphy examination was also performed at around two weeks, six months, and 12 months postoperatively to evaluate the healing process of the graft.Results The mean follow-up time was 59.6±25.6 (range, 12 to 109) months. No significant center-edge angle changes and no contiguous radiolucent zones at the boneprosthesis interface were observed at the final follow-up. The single-photon emission tomography (SPECT) showed the activity of the bone graft gradually increased after surgery and became almost the same as the reference area after 12 months. Functional evaluation showed a significant improvement after the operation. No complication directly related to the technique was observed.Conclusion In the short-term follow-up, the RSC technique is a reliable procedure for acetabular augmentation of hip dysplasia, providing enough coverage for the cementless cup and assuring proper stability.

747 IS 99MTC BONE SCINTIGRAPHY NECESSARY IN THE PREOPERATIVE WORKUP FOR PATIENTS WITH POTENTIALLY RESECTABLE ESOPHAGEAL SQUAMOUS CELL CANCER?

Abstract 99mTc bone scintigraphy(BS) is still the most widely used method to evaluate bone metastasis in China. The aim of this study was to investigate the necessity of the 99mTc bone scintigraphy in the preoperative workup for patients with potentially resectable esophageal squamous cell cancer (ESCC,cT1-4aN0–3). Methods This was a prospective cross-section clinical trial (ChiCTR1800020304). There were a total of 471 patients who were diagnosed ESCC in Thoracic Surgery Clinic from October 2018 to September 2020. Of these 471 patients, 385 patients with cT1-4aN0–3 who were potentially candidates for surgical resection were consecutively enrolled into the study. BS was performed preoperatively. The treatment strategy could be changed if the bone metastasis was confirmed. The primary endpoint was the incidence rate of the treatment regimen being changed because of bone metastasis. The secondary endpoint was the rate of positive BS findings. Results In all 385 patients, there are only 2(0.5%) patients changed their treatment regimen because of bone metastasis proved by BS. The rate of positive BS findings is 1%. The number of patients with false positive and false negative was 2(0.5%) and 2 (0.5%), respectively. The BS diagnostic performance for bone metastasis was as follows: sensitivity, 50%; specificity, 99.5%; positive predictive value, 50%; negative predictive value, 99.5% and accuracy, 99.0%. There were no significant difference of bone metastasis among the Age, Sex, Tumor location and Clinical stage. Conclusion 99mTc bone scintigraphy is unnecessary in the preoperative workup for patients with potentially resectable esophageal squamous cell cancer.

Clinical characteristics and outcomes of Langerhans cell histiocytosis at a single institution in Thailand: a 20-year retrospective study.

Langerhans cell histiocytosis (LCH) is a rare disease characterized by the various systems involved and clinical manifestations with a wide range of symptoms. To describe clinical characteristics, imaging, treatment, and outcomes of pediatric LCH at Phramongkutklao Hospital, Bangkok, Thailand. We conducted a 20-year retrospective review of the medical records of patients diagnosed with LCH from birth to 21 years old from January 1, 1997, to December 31, 2016. In all, 14 patients with median age of 2.5 years were studied. Six (43%) patients had single-system (SS) LCH. Five patients (63%) with multisystem (MS) LCH (n = 8. 57%) had risk-organ involvement (RO+). All patients had plain X-ray imaging of their skull with 11 (79%) showing abnormal findings. Tc-99m bone imaging and fluorodeoxyglucose F18 (FDG) positron emission tomography (PET)-computed tomography (CT) demonstrated abnormal findings in 8 (89%) and 4 (29%) patients, respectively. The 5-year event-free survival (EFS) for patients with RO+ MS-LCH was less than that for those without risk-organ involvement (RO-) MS-LCH and SS-LCH (20% vs. 100%, P = 0.005). Hematological dysfunction, hypoalbuminemia, and conjugated hyperbilirubinemia may be worse prognostic factors for RO+ MS-LCH. FDG-PET-CT might have a greater accuracy to detect LCH disease than conventional plain X-ray and Tc-99m bone imaging. RO+ MS-LCH has been encountered with relapse and poor outcomes. Hematopoietic involvement, hypoalbuminemia, and conjugated hyperbilirubinemia may be worse prognostic factors for RO+ MS-LCH.

P55-6 Encorafenib for Erdheim-Chester disease harboring the BRAFV600E mutation

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis harboring the BRAFV600E mutation in about 50% of patients. Use of BRAF inhibitor for BRAF-mutated ECD was one of the representative practices of precision medicine. FDA approved vemurafenib for BRAF-mutated ECD, and dabrafenib and encorafenib in addition to vemurafenib for BRAF-mutated melanoma. Though there have been some cases reported of use of dabrafenib for BRAF-mutated ECD, there has never been reported of use of encorafenib. Here we report the first treatment of encorafenib for BRAF-mutated ECD, which showed dramatic efficacy. An 81-year-old female was admitted to our hospital because of dyspnea. CT scanning revealed pericardial effusion, and perinephric soft tissue thickening. 99mTc bone scintigraphy showed bilateral symmetric osteosclerosis of bones of the legs. Her respiratory symptom was resolved by aspiration of pericardial effusion. We suspected of ECD based on specific clinical findings and followed up her in the outpatient setting. Two years later, she presented to our hospital because of dyspnea and a headache. FDG-PET/CT revealed pleural effusion in addition to the findings described above. MRI of the head showed a mass compressing the brainstem. Pleural specimens revealed pathological findings of ECD. NGS identified the BRAFV600E mutation. After obtaining the ethics committee approval, she started to receive encorafenib 100mg once daily. After three months, MRI of the head showed a 30% reduction in size of the mass, and FDG-PET/CT revealed partial metabolic response. Adverse events of encorafenib were Grade2 hand-foot syndrome and Grade1 alopecia. Recently, a framework of precision medicine has been actively constructed in Japan. However, genetic testing of BRAF mutation and use of BRAF inhibitor for ECD is not covered by the Japanese insurance system. We hope clinical utility of testing comprehensive target genes and using target drugs is possible for rare diseases in Japan.

Denosumab Induced Severe Prolonged Hypocalcemia in Metastatic Prostate Cancer

Background: Denosumab is a RANK-l inhibitor that, in addition to the treatment of osteoporosis, is used in patients with advanced cancer and metastatic bone disease to prevent skeletal-related events. Although denosumab is generally safe and effective, it can cause hypocalcemia which in some patients can be severe and life threatening. We present a case of severe prolonged hypocalcemia after a single dose of denosumab in a patient with metastatic prostate cancer. Case: A 78-year-old male with a past medical history of stage 4 prostate cancer on antiandrogen treatment with GnRH antagonist presented with severe hypocalcemia. Physical exam revealed a blood pressure 125/80 mm Hg, pulse 115 per min and weight 135 lb with negative Chvostek’s and Trousseau’s signs. The electrocardiogram showed supraventricular tachycardia with prolonged QTc interval of 503 ms (<430 ms). Labs showed serum calcium 4.9mg/dL (8.5–10.5), albumin 2.5g/dL (3.6–5.1), corrected calcium 5.7 mg/dL, ionized serum calcium 0.64mmol/L (1.05–1.3), creatinine 1.10mg/dL (0.7–1.2), eGFR >60, phosphorus 2.0mg/dL (2.5–4.5), magnesium 1.9 mg/dL (1.6–2.6), 25-OH vitamin D 29.7 ng/mL (30–100), 1,25 dihydroxy vitamin D 174 pg/mL (18–64), iPTH 244.0 pg/mL (11–68) and PSA 1860 ng/mL. Three weeks prior to presentation, the patient received 120 mg of subcutaneous denosumab. Pre-treatment serum calcium was 9.2 mg/dL (8.5–10.5), and Tc-99m bone scan showed multiple osteoblastic osseous metastatic lesions involving both axial and appendicular skeleton. The patient was diagnosed with denosumab-induced severe hypocalcemia and started on intravenous (IV) calcium gluconate infusion, oral phosphate 250 mg twice daily, and ergocalciferol 50,000 IU twice weekly. He required IV calcium gluconate up to 10 g per day in addition to oral calcium carbonate 2 g t.i.d. for 2 weeks to resolve hypocalcemia and normalize QTc interval. Patient was discharged to nursing home on calcium carbonate 2 g q.i.d. with IV calcium gluconate as needed to keep corrected calcium >8.0 mg/dL. After discharge he required up to 4 g of IV calcium and 8 g of oral calcium per day. Unfortunately, he presented again with severe hypocalcemia 5 weeks after discharge. In addition to current regimen of oral and IV calcium boluses, low dose calcitriol was started. We were only able to maintain his serum calcium>8.0 mg/dL by administering high daily dose of oral calcium carbonate 8 g /day and calcitriol 2 mcg daily. Due to poor prognosis, he was transitioned to hospice care and died 2 weeks later. Discussion: There are not many case reports on severe prolonged hypocalcemia secondary to denosumab in cancer patients but normal kidney function. Our patient remained on high dose of calcium even 101 days after denosumab administration. Reference: 1. Milat F et al. Prolonged hypocalcemia following denosumab therapy in metastatic hormone refractory prostate cancer. Bone. 2013 Aug 1;55(2):305–8.

F-18 fluorocholine positron emission tomography- computed tomography in initial staging and recurrence evaluation of prostate carcinoma: A prospective comparative study with diffusion-weighted magnetic resonance imaging and whole-body skeletal scintigraphy.

Prostate cancer (PCa) is one of the major causes of death due to cancer in men. Conventional imaging modalities such as magnetic resonance imaging (MRI) provide locoregional status, but fall short in identifying distant metastasis. C-11 choline F-18 fluorocholine (F-18 FCH) has been shown to be useful in imaging of PCa. The present prospective study evaluates and compares the role of F-18 FCH positron emission tomography–computed tomography (PET-CT) with locoregional MRI and whole-body bone scintigraphy in PCa patients for initial staging and recurrence evaluation. This study included a total of 50 patients. Tc-99m skeletal scintigraphy, F-18 FCH PET-CT, and diffusion-weighted MRI of the pelvic region were performed within a span of 2–3 weeks of each other, in random order. For the primary site, core biopsy findings of the lesion were considered as gold standard. The kappa test was used to measure agreement between bone scintigraphy, F-18 FCH, and MRI. For comparing Tc-99m bone scintigraphy, F-18 FCH, and MRI, McNemar's test was applied. F-18 FCH PET-CT and MRI were able to detect primary lesion in all initial staging patients. The sensitivity and specificity of F-18 FCH PET-CT versus MRI were found to be 92.8% versus 89.2% and 100 versus 80%, respectively, for the recurrence at the primary site. A total of 55 bony lesions at distant sites were detected on F-18 FCH PET-CT in comparison to 43 bone lesions on whole-body bone scintigraphy. F-18 FCH PET/CT also detected additional lung lesions in 2 patients and abdominal lymph nodes in 12 patients. F-18 FCH PET-CT could detect primary lesions, local metastasis, bone metastasis, and distant metastasis in a single study and is also a useful modality in recurrence evaluation in PCa patients.

A Prospective Study Comparing the Role of 18 FDG PET-CT with Contrast-Enhanced Computed Tomography and Tc99m Bone Scan for Staging Locally Advanced Breast Cancer

Locally advanced breast cancer (LABC) patients require an accurate staging of the disease to rule out distant metastases. Various imaging investigations are used to stage LABC patients. The present study is a prospective comparison of conventional imaging (CI) with fusion positron-emission tomography and computed tomography (PET-CT) scans in the staging of LABC patients. Seventy-three consecutive LABC patients presenting to the breast cancer clinic of the tertiary care cancer institute were included in the study. All patients underwent contrast-enhanced computed tomography, Tv99m bone scintigraphy, and fusion PET-CT. Histology of the metastatic site was confirmed wherever possible. The disparity between the two imaging findings was compared. Doubtful lesions were observed clinically for at least 2 years to confirm their nature. PET-CT detected a higher number of lymph nodes in the axilla, internal mammary, and supraclavicular region as compared to CI. PET-CT upstaged 36.98% and downstaged 5.4% of the patients respectively leading to a change in the management in 30.13% of the patients. Sensitivity, specificity, positive predictive value, and negative predictive value of CI and PET-CT were 71.87%, 87.80%, 82.14%, and 80%, and 90.90%, 90%, 88.23%, and 92.30% respectively. PET-CT was more accurate in staging the LABC patients as compared to CI. PET-CT is more accurate then contrast-enhanced CT and bone scintigraphy for staging locally advanced breast carcinoma patients. It can replace multiple organ-directed imaging in staging breast cancer. It can provide accurate staging of the disease so that patients can be prognosticated and can be directed to the most appropriate treatment plans.

Is 99m Tc bone scintigraphy necessary in the preoperative workup for patients with cT1N0 subsolid lung cancer? A prospective multicenter cohort study.

Background 99mTc bone scintigraphy (BS) is still the most common approach for the evaluation of bone metastasis in China. The purpose of this study was to investigate the necessity of BS as part of a routine preoperative workup for patients with cT1N0 subsolid lung cancer.MethodsThis was a prospective multicenter clinical trial (NCT03689439). Patients with cT1N0 subsolid nodules who were candidates for surgical resection were consecutively enrolled into the study. BS was performed preoperatively. The surgical plan could be changed if a positive result was detected. The primary endpoint was the incidence rate of the surgical plan being changed because of positive BS results. The secondary endpoint was the rate of positive BS findings and the rate of related complications.ResultsFrom November 2018 to July 2019, 691 patients were enrolled into the study. None of the patients had positive BS results and no surgical plans were changed by BS findings. There were 222 male and 469 female patients. The average age was 54.8 ± 3.7 years old. The average tumor diameter was 14.9 ± 4.2 mm. There were 282 patients with pure GGO nodules and 409 with part‐solid nodules. A total of 470 patients had a single nodule, while 221 patients had multifocal lesions. The number of patients whose pathological diagnosis was invasive adenocarcinoma, minimally invasive adenocarcinoma, adenocarcinoma in situ and mucinous adenocarcinoma was 357, 293, 32 and nine, respectively. The number of patients who underwent lobectomy, segmentectomy and wedge resection was 234, 199 and 258, respectively.Conclusions 99mTc bone scintigraphy is unnecessary in the preoperative workup for patients with cT1N0 subsolid lung cancer.Key pointsSignificant findings of the studyIn this prospective study of 691 patients with cT1N0 subsolid lung cancer, no surgical plans were affected by positive bone scan findings.What this study addsWe suggest physicians consider canceling BS from preoperative workup for cT1 subsolid lung cancer patients.Clinical trial registry number: NCT03689439.

Self-inflicted finger cold injury leading to amputation: Report of a case.

A cold injury can result in devastating outcomes, leading to significant morbidity and loss of distal extremities. Amputations are common after severe frostbite injuries with delayed presentation, often mediated by post-injury arterial thrombosis. Ischemic injuries are managed according to the ischemia time. The most controversial aspect of treating a salvage injury is the time of surgical intervention, which used to be based on the previous management dogma freeze in January, amputate in July. Recently, the paradigm has shifted to early surgical management if the level of viability of the deep structure can be ascertained using 99mTc pertechnetate scintigraphy (99mTc bone scans). We present a case of a finger amputation resulting from a cold injury secondary to a crush injury.

A novel artificial intelligence biomarker: Validation of the automated bone scan index (aBSI) in veterans with metastatic prostate cancer.

e17507 Background: Prostate cancer commonly metastasizes to the bone and is associated with reduced survival, pathologic fractures and bone pain. The assessment of bone lesions is made with the technetium Tc99m(99mTc) bone scan, which relies on the subjective interpretation of radiologists and has a wide interobserver variability. There is an unmet need for a more objective and quantifiable measurement tool. Progenics Pharmaceuticals has introduced an automated bone scan index (aBSI), which employs artificial intelligence to quantify skeletal tumor burden. The automated bone scan index has been prospectively validated and is reproducible in large Phase III studies. The aBSI was validated by our study in the Veteran population at the West LA VA Medical Center. Methods: The first positive technetium 99 Tc99m bone scans of veterans diagnosed with metastatic, castration-sensitive prostate cancer were evaluated. Since 2011, a total of 107 evaluable patient bone scans were studied (n = 107). Patients with visceral metastases were excluded to evaluate only those with skeletal metastases. An automated bone scan index (aBSI) was generated for each scan using the Progenics Pharmaceuticals’ artificial intelligence platform. Multivariate analysis of aBSI with overall survival, prostate cancer specific survival, time from diagnosis to first positive bone scan, age at diagnosis, ethnicity, and Gleason score was assessed. Results: The study demonstrated a wide range of aBSI values (Range 0-16.84). Values calculated above the Median aBSI value (1.0) were prognostic for Overall Survival (p = 0.0009) and Prostate Cancer-Specific Survival (p = 0.0011). Patients in the highest quartile of aBSI values (range 5.2-16.84) showed a statistically significant Prostate Cancer-Specific Mortality (p = 0.0300) when compared to the lowest two quartiles (Range 0-1.07). The time from diagnosis to the first positive Tc99m bone scan statistically correlated with aBSI values (p = 0.0016). Multivariate analysis using Cox regression was utilized in the final statistical analysis of prostate cancer-specific mortality and overall survival. Conclusions: The automated Bone Scan Index provides a quantifiable and validated artificial intelligence biomarker to address an unmet need among metastatic prostate cancer patients. This tool was validated among Veterans, a pertinent population that is commonly affected by metastatic prostate cancer.