Prostate specific membrane antigen (PSMA) over-expression is a hallmark of prostate adenocarcinoma and many PSMA targeting positron emission tomography (PET) radiopharmaceuticals have been developed over the last decade. The role of 68Ga-PSMA-11 PET-computed tomography (CT) is well established in staging and biochemical recurrence of PCa, with growing interest and evidence regarding its utility in suspected prostate cancer.

Background and Aim: Serum prostate-specific-antigen (PSA) guided systematic transrectal ultrasound (TRUS)-guided biopsies are known to have a low predictive value in detection of primary prostate carcinomas (PCa). Our aim was to evaluate the accuracy of gallium-68 (Ga-68) prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) for the detection of PCa with serum PSA <50 ng/ml. Patients and Methods: We retrospective analyzed prebiopsy Ga-68 PSMA PET/CT's of all patients with suspected PCa from October 2019 to March 2020. Several quantitative clinical and PET/CT variables were compared in benign and malignant groups and assessed for significance using an independent t-test. Diagnostic performance of PSMA PET/CT for detection of cancer was evaluated and compared with the diagnostic performance of cancer risk predicting calculator (European Randomized Study for Screening of Prostate Cancer [ERSPC3]). The standard of reference was 12-core TRUS-guided biopsies. Results: Sixty-four patients were included with mean age 70 years (range 48–94 years); mean PSA 15.67 ng/ml (range 1.74–44), mean PSA density 0.32 ng/ml² (range 0.01–0.99) and mean prostate volume 54.55 cc (range 16.5–182). 64% (n = 41/64) patients had benign histology and 36% (n = 23/64) had carcinoma. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PSMA PET/CT for detecting PCa reported using the prostate cancer molecular imaging standardized evaluation (PROMISE) was 74%, 92%, 85%, 86%, and 86%, respectively. Mean prostate maximum standardized uptake value (SUVmax) was significantly higher in PCa versus Benign lesions (19.56 ± 18.11 vs. 4.21 ± 1.5, P = 0.00001), in patients with PSA >20 ng/ml versus PSA <20 ng/ml (19.1 ± 20.6 vs. 6.01 ± 5.4, P-0.0052), and in patients with Gleason's score (GS) score >7 versus GS ≤7 (28.1 ± 20.3 vs. 10.2 ± 8.9, P-0.010). SUVmax cutoff value of 5.6 on PSMA PET/CT showed a sensitivity of 95% and specificity of 90.9% (area under the curve 0.990, P < 0.0001). Conclusion: Ga-68 PSMA PET/CT can differentiate benign and malignant lesions of the prostate with very high accuracy and when used alongside with ERSPC3 calculator and magnetic resonance imaging, could potentially reduce painful and often unnecessary prostate biopsies.

Purpose of the Study: Gallium (Ga)-68-DOTA peptides targeting somatostatin receptors have been assessed as a valuable tool in neuroendocrine tumor imaging using positron emission tomography. However, at the moment, a specific monograph in the European Pharmacopoeia (Ph. Eur.) does exist only for Ga-68-edotreotide (DOTATOC) injection. Here, we report on the validation process of Ga-68-DOTA-Tyr3-octreotate (DOTATATE) cassette-based production and quality control (QC). Materials and Methods: Preparation of Ga-68-DOTATATE was performed according to the current European Union-good manufacturing practices, the current good radiopharmacy practice, the Ph. Eur., and the guidelines on validation of analytical methods for radiopharmaceuticals. Process was validated via three consecutive production runs to ensure that the methods are reproducible and reliable in routine use. The QC tests for Ga-68-DOTATATE were radiochemical purity (RCP – high-pressure liquid chromatography [HPLC]), radiochemical impurities ⁶⁸Ga³⁺ (HPLC and instant thin layer chromatography [ITLC]), chemical purity (HPLC and gas chromatography [GC]), pH (pH-strips), radionuclidic purity (principal γ-photon), germanium-breakthrough (⁶⁸Ge-content), Ga-68 half-life (γ-ray spectrometry), and sterility/endotoxin assay. Results: Radiolabeling procedure of Ga-68-DOTATATE fits all the applicable Ph. Eur. specifications. RCP measured via ITLC was >99% in the three validation batches. HPLC-measured RCP resulted 99.45%, 99.78%, and 99.75%. Germanium-breakthrough was far below the recommended level established in the Ph. Eur. Ga-68-DOTATOC injection (#2482). Residual ethanol tested with GC was less than 10%. All the batches were tested for endotoxin content, which always resulted lower than 17.5 EU/ml. All preparations passed the sterility tests. pH of the final product was 7 in all samples. Conclusion: Ga-68-DOTATATE fulfilled all the pre-set QCs and release criteria in the batches considered for this validation study. The results demonstrated a batch-to-batch reproducibility, ensuring that synthesis process leads to the expected final product in terms of yield, quality, reliability, safety, and efficacy.

Aims: Actinium-225 (²²⁵Ac) labeled prostate-specific membrane antigen (PSMA)-617 is a novel treatment modality in the management of metastatic castration-resistant prostate cancer (mCRPC). The present study was conducted to assess the impact of ²²⁵Ac-PSMA-617 therapy on the quality-of-life of patients with heavily pretreated mCRPC using the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy-Prostate Symptom Index-17 (NCCN-FACT-FPSI-17) questionnaire. Materials and Methods: This was a retrospective single-center study where data of consecutive heavily pretreated mCRPC patients treated with ²²⁵Ac-PSMA-617 from January 2019 to February 2020, was collected and analyzed for the biochemical response, quality-of-life outcomes and treatment-related toxicity. Results: Eleven heavily pretreated mCRPC patients received a median cumulative dose of 8.3 MBq (interquartile range [IQR] 5.6–20.4 MBq) ²²⁵Ac-PSMA-617 over 1–4 cycles. 5/11 patients (46%) showed a ≥50% decline in Prostate Specific Antigen (PSA), while stable values and PSA progression were observed in 3/11 (27%) patients each. Pre- and post-therapy NCCN-FACT-FPSI-17 questionnaires revealed statistically significant improvement in the total FPSI score (P = 0.003) as well as the disease-related symptoms-physical (P = 0.004) and disease-related symptoms-emotional (P = 0.046) subscores. Among the physical symptoms, significant improvement was noted with respect to pain, difficulty in urination, bone pain, fatigue, and restriction in physical activity. No significant change was noted in the treatment side-effects subscore. Of the treatment-related adverse effects, Grade 3 dryness of the mouth, anemia, and nephrotoxicity was observed in 1/11 patients (9%) each and Grade 3 thrombocytopenia in 2/11 patients (18%). Conclusion: Health-related quality-of-life of the mCRPC patients improved significantly with²²⁵Ac-PSMA-617 despite extensive pretreatment and advanced nature of the disease.

Background: Death due to cardiovascular disease is a major concern in the field of noncommunicable disease. Assessment of cardiovascular risk score using Framingham score and WHO/ISH score is a noninvasive, easier method of predicting the adverse cardiovascular event in the general population. Aims and Objectives: The aim of the study was to assess the cardiovascular risk using Framingham score and WHO/ISH in women undergoing stress myocardial perfusion imaging (MPI) and comparison with scan-predicted risk. Materials and Methods: Adult females with suspected coronary artery disease referred to the department of nuclear medicine for 2 months were included in the study. Data pertaining to the risk score assessment were collected, and the risk scores were calculated. Subsequently, the patients underwent scheduled Tc-99m methoxy-isobutyl-isonitrile myocardial stress imaging, and scan-predicted risks were calculated. Then, the risk score of Framingham and WHO/ISH methods were compared with stress myocardial perfusion score using Cohen's kappa statistic. Results: The mean age of the sample was 52 years (standard deviation: 11). Framingham and WHO/ISH risk scores predicted low, intermediate, and high risk in 62.2%, 28.9%, and 8.9% and 68.9%, 22.1%, and 8.89% of the population. The two scoring methods showed moderate agreement (κ =0.59). However, the scores showed only slight and fair agreement, respectively, with risk predicted by stress MPI. Conclusion: Although the risk scores have been shown to benefit in screening general population, they may not perform well in symptomatic patients with suspected angina. Out of the two methods, WHO/ISH fares better than Framingham score in this population.

Aim: Liver volume measurement is a mandatory test before measure liver surgeries and transplantation. We aimed a study on the difference in volume measurement and radiation dose to an anthropomorphic liver phantom using high-dose and low-dose diagnostic computed tomography (CT). Materials and Methods: Several measurements of the manual total volume measurement done on an anthropomorphic liver phantom mounted with thermoluminescent dosimeter. We exposed the phantom with diagnostic CT, low-dose CT, and a low-dose CT with copper filter. Results: Phantom underwent ten scanning for each exposure. There was no significant difference in the total volume measurement in comparison to the phantom volume. The volume of phantom measured by low-dose CT, low-dose CT with copper phantom, and high-dose CT were 1869 ± 18 cm³, 1852 ± 24 cm³, and 1908 ± 12 cm³, (P = 0.3), respectively. However, the radiation dose delivered was significantly different (1.54 mGy, 0.77 mGy, and 5.84 mGy [P = 0.001], respectively). Conclusion: Total liver volume measurement provides essential clinical information in several clinical conditions. We recommended that the volume measured by a low-dose CT has an excellent correlation with the diagnostic quality CT and should be a routine in the routine clinical practice. CT volumetry achieves the same result while using very less radiation exposure. It may also be used with functional imaging to give complete information.

Background: Traumatic brain injury (TBI) is a critical health problem with various comorbidities and socioeconomic consequences. Tending to increase in recent decades, TBI results in more cases of consciousness disorders including vegetative state (VS)/minimally conscious state (MCS). However, no definite or effective treatment still exists for these conditions. The aim of this article is to study the effects of zolpidem in patients with VS caused by TBI by using brain perfusion single-photon emission computed tomography (SPECT). Materials and Methods: This was a prospective clinical trial on a cohort of patients with VS. We evaluated the TBI database to find VS/MCS patients, between the ages of 20 and 65 years. We received written consent from their family members prior to enrollment and compared their clinical status and brain perfusion SPECT prior and after 2 weeks of zolpidem therapy. Results: Among the 12 patients included in this study, six patients changed to MCS after 2 weeks. Comparison of their motor score, revealed a statistically significant difference (2.08 vs. 3.75, P = 0.007, respectively). None of the quantitative or qualitative brain perfusion parameters showed any differences after zolpidem therapy. However, the perfusion pattern, with focal or multifocal cortical defects, was significantly more prevalent in the responder group (five patients vs. one patient, P = 0.015). Conclusion: Zolpidem therapy may improve consciousness levels and motor function in a considerable portion of VS patients with TBI. This study showed that the presence of focal brain perfusion defect can predict response to zolpidem.

Aim: Radionuclide imaging and therapies produce radioactive liquid waste that may lead to significant radiation exposure to the general public. The study aims to assess the radiation exposure rate to public sewerage from a modified delay tank facility. We shall also evaluate the exposure rates and overall radioactivity at several points. Materials and Methods: After having appropriate permission from the AERB, we measured the radiation exposure from the radionuclide therapy ward. Ward has three isolation beds and a single delay and decay tank of a capacity of 7500 liters. Effluents from the delay tank are processed at the filtration plant of the institute and subsequently released in the public sewerage. We obtained samples from several sites to determine discharged radioactivity. Results: A total of 38 patients received 129.4 ± 42 mCi (Range 40- 200) radioiodine therapy during the study. Discharge of the tanks was done two times during the study. The radioactivity discharges into aeration plant were 89.2 and 71.2 mCi that correspond to 440.05 and 351 MBq/m3, respectively. This was diluted by the aeration tank (6 million liters). Finally, at the discharge time, the radioactivity in the discharge was 1.6 and 1.5 MBq/m3, respectively. The highest exposure rates were 14 μSv/h near the delay tank, which rapidly decreased on moving to the surrounding. Conclusion: Our study indicates that the addition of the dilution method and close monitoring may significantly reduce the radiation exposure and overall radioactivity release from the facility. Old facilities that do not have space to add up the tank capacity may get a benefit from it. A small change in the practice, such as admitting patients alternate months or providing extra decay time for radioactive waste, may lead to a cost-effective alternative.

Adult cases of congenital arteriovenous malformation (AVM) of the mediastinum are extremely rare, and because of their varied clinical presentations, they pose a diagnostic challenge. There is no reported association of pulmonary AVM and papillary thyroid carcinoma. We describe a 38-year-old female with a large right lung AVM, multinodular goiter, and high serum thyroglobulin (Tg) with papillary thyroid carcinoma. The lung mass was believed to represent a pulmonary metastatic deposit due to high Tg value. Whole body I-131 scan and FDG PETMR imaging were performed as part of the workup.

Fibroids are rare in postmenopausal females. Torsion of pedunculated uterine fibroid is also a very rare occurrence in elderly females. We report a rare case of an 84-year-old multiparous, postmenopausal female, a treated case of non-Hodgkin's lymphoma, presenting with a large abdominal mass. The comparative positron emission tomography/computed tomography scan study of the patient revealed that a new mass in the abdomen and pelvis connected with the left adnexa with a pedicle and previously seen fibroid was not visualized on the present scan, thus raising suspicion of torsion of subserosal fibroid. Histopathology confirmed the diagnosis of fibroid.

Parathyroid carcinoma (PC) is a rare endocrine carcinoma. It is one of the rare causes for primary hyperparathyroidism. It is very uncommon in individuals with secondary or tertiary hyperparathyroidism. We report a rare case of 53-year-old male, a known case of chronic kidney disease on dialysis, who presented with fatigue and muscle cramps. Lab reports revealed elevated parathyroid hormone (PTH) and serum calcium levels. ^99mTc-Sestamibi single-photon-emission computed tomography/computed tomography scintigraphy showed 4 foci of increased tracer uptake with retention, suggestive of parathyroid adenomas, including two ectopic foci in the mediastinum. At surgery, the enlarged bilateral superior, left inferior parathyroid gland, and two calcified left superior mediastinal lesions were removed. Histopathology revealed parathyroid adenomas in the right superior, left inferior, supernumerary ectopic left superior mediastinum lesion and PC in the left superior parathyroid lesion. Intraoperative serum PTH became normal, and the patient is asymptomatic now.

Schistosomiasis is a helminthic infection acquired through direct contact with contaminated fresh water. To the best of our knowledge, this is the first case pulmonary of schistosomias is evaluated with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) reported in the literature. Functional imaging with ¹⁸F-FDG PET/CT may help in the diagnosis of schistosomiasis, leading to a correct definition of the disease extension.

Positron emission tomography/computed tomography (PET/CT) scanner is a state-of-art imaging device. Susceptibility of PET scanner in fluctuation environmental condition is known. Hence, every vendor prescribes the optimal conditions such as temperature and humidity to maintain the equipment in its best condition. In a hot summer day, we faced an unexpected long duration power failure in our department after administration of F-18 fluorodeoxyglucose to one of our patients. As air condition was not working in our department, temperature in the machine room went far beyond the prescribed level. As we had already injected the patient, we decided to perform PET scan of that patient in the existing condition in the machine room. When we reviewed the scan, we identified significant count loss in the image, which raised doubt in our mind. We discussed with our colleague and decided to perform a daily quality assurance (DQA) test to assess the condition of the equipment in high temperature. On DQA scan, we spotted several changes in the uniformity plot as well as energy plot. Following to that, the system was shut down completely till the main supply was restored successfully, and room temperature and humidity was restored to normal in machine room and console room. After several hours of restoration of normal condition in console and machine room, PET/CT equipment was restarted, and the DQA was repeated. On review, we found the restoration of normal DQA graph. We conclude that the sudden increase in temperature and humidity in PET/CT equipment room affects the performance of scanner which reflects as count deficit in the image. This impairment in the image quality may be because of bismuth germanate crystal, photomultiplier tubes, and associated electronics.

Langerhans cell histiocytosis (LCH) is a disease of unknown pathogenesis characterized by the accumulation of Langerhans cells which show immunopositivity for S-100 and CD1a. LCH with skeletal muscle involvement has been rarely described in literature. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is an important tool in identifying the sites of involvement in LCH. We present a rare case of muscle invasive LCH where ¹⁸F-FDG PET/CT showed involvement of multiple other sites such as the liver, bones, bone marrow, and possibly the thyroid gland in our case. Further, the current case also shows that liver involvement by LCH (possibly fibrotic phase) can be negative on PET but show lesions on CT.

Synovial sarcomas are aggressive soft-tissue tumors with the propensity for metastases at presentation or later course of disease. The most common site of metastases is lung, followed by lymph node and bone. It rarely metastasizes to the liver and to the brain. Breast metastases from extramammary tissue are extremely rare, more so from synovial sarcoma. ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET/CT) plays a very important role in diagnosing occult metastasis in sarcomas. Histopathological diagnosis and translocation studies are important to confirm the diagnosis. We present a case of synovial sarcoma who underwent¹⁸FDG PET/CT which showed occult metastasis to the breast.

Perivascular epithelioid cell tumors (PEComas) are a rare variety of mesenchymal tumors composed of distinctive cells that show a focal association with blood vessel walls and usually express melanocytic and smooth muscle markers. We present a case of 38-year-old male, diagnosed with PEComa of the pelvic cavity who underwent serial ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography scans for the assessment of response to the chemotherapeutic combination of irinotecan and temozolomide.

Extragastrointestinal stromal tumors (EGISTs) are rare mesenchymal tumors occurring outside the gastrointestinal tracts that have similar histological and immunohistochemical characteristics similar to those of gastrointestinal stromal tumors. EGISTs involving the urinary bladder are extremely rare tumors with very few reports mentioned in the literature. We present a case of a 48-year-old man, known case of biopsy-proven EGIST of the urinary bladder that presented with recurrence after partial cystectomy and ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography scans documenting the response assessment of the recurrent tumor to imatinib.

Intramedullary spinal cord metastases (SCMs) are extremely rare. Here, we report a case of a 60-year-old man with a history of right nonsmall cell lung cancer treated by concomitant radiochemotherapy who complained, 9 months after treatment completion, of chest pain, breath shortness, and more recently back pain. An ¹⁸F-FDG PET/CT was performed as part of the restaging process and showed a hypermetabolic mass of the right lung in addition to ipsilateral mediastinal hypermetabolic lymph nodes. There was also an FDG avid lesion of thoracic spinal cord at the T11–T12 level consistent with SCM as confirmed by MRI.

T-cell acute lymphoblastic leukemia (ALL) is hematological malignancy with a propensity to involve extramedullary organs. We present the case of a 7-year-old child who was diagnosed with disease free from ALL for 1 year and then developed fever. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography revealed extramedullary infiltration of ALL in lungs, pancreas, kidneys, bone, muscles, and subcutaneous tissues.

We report a case of an elderly male who has undergone right radical nephrectomy for renal cell carcinoma (RCC). Six months later, he presented with gradually progressive low backache and mild lower limb weakness. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET-CT) was done that revealed a suspected area of mild metabolic activity in the spinal cords at the L1–L2 vertebral level. Magnetic resonance imaging revealed intramedullary spinal cord metastasis (ISCM). Solitary ICSM is a rare presentation of RCC on FDG PET-CT, and only a few case reports exist in the literature. This case highlights that adequate clinical history and careful examination of the PET images may reveal it.

Hemangiomas are extremely rare tumors of the heart that may present with pericardial effusion, dyspnea, chest discomfort, palpitations, or syncope. Few published reports have highlighted the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET-CT) in the evaluation of cardiac lesions. We report a case demonstrating the utility of ¹⁸F-FDG PET-CT in a young man who presented with gross pericardial effusion and suspicion of metastatic carcinoma on fluid cytology.

Malignant transformation Paget's disease of bone to sarcoma is relatively rare, occurring in approximately 1% of these patients. Although few clinical and imaging findings may help in prediction of malignant transformation, most of them are nonspecific. We describe a case of carcinoma vocal cord and Paget's disease of bone with sarcomatous transformation, where ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography–computed tomography was helpful in accurate diagnosis by demonstrating differential intense FDG uptake in transformed areas of pagetic bone and also FDG-avid osteoblastic pulmonary metastasis.

Thymic carcinoma is a rare thymic epithelial cancer which is not only locally invasive but also highly aggressive disease. The prognosis for this cancer is poor and the surgery remains the mainstay of treatment. Thymic carcinomas have been shown to metastasize to the lymph nodes, lung, and liver. A 63-year old male who was successfully treated for thymic cancer in 2015, presented with metastatic disease recurrence to the spinal cord. We share interesting images of the spinal cord lesions as well as pituitary metastases that were incidentally detected on restaging 18F-fluorodeoxyglucose positron emission tomography-computed tomography.

The recent WHO classification of gliomas has incorporated molecular markers such as isocitrate dehydrogenase (IDH) mutation and 1p/19q co-deletion into the ambit of morphological diagnosis, and 18F-fluoro-ethyl-tyrosine (¹⁸F-FET) positron emission tomography (PET) has shown its utility in noninvasive glioma grading and prognosis. Both dynamic and static FET PET parameters may assist in predicting the IDH mutational status, but time to peak derived from dynamic data may be a better predictor for IDH status. We present a case of left frontal lobe lesion suggestive of high-grade glioma on magnetic resonance imaging and static ¹⁸F-FET PET images, however, dynamic FET image was suggestive of low-grade IDH1-mutated glioma which was later confirmed on histology and immunohistochemistry.

Peritoneal dialysis (PD) was commonly used renal replacement therapy for treating end-stage renal failure patients leading to various infectious and mechanical complications. We present a case of a 50-year-old female patient who presented with reduced dialysate return and abdominal wall edema following continuous ambulatory PD. Peritoneal scintigraphy done on suspicion of dialysate leak shows tracer accumulation in the anterior abdominal wall below the insertion of the peritoneal catheter.

Somatostatin cell surface receptors are expressed on the peritumoral vessels of various benign and malignant neoplasms including angiofibromas. Positive initial uptake on positron emission tomography-computed tomography (PET/CT) imaging with ⁶⁸Ga-labeled DOTANOC is noted in a patient with juvenile nasal angiofibroma (JNA), and the same is noted to be absent following complete surgical excision. Functional ⁶⁸Ga-DOTANOC PET/CT may be an early useful tool for JNA residual/recurrence identification and precise postoperative surveillance.

A 9-year-old male patient, with an ultrasonography diagnosis of horseshoe kidney condition, was referred to our hospital for recurrent urinary tract infection. He was submitted to ^99mTc-diethylenetriamine pentaacetic acid sequential scintigraphy that demonstrated urine stasis in the calyces of both kidneys and was also suggestive for 8-shaped right-to-left crossed-fused renal ectopia. A subsequently performed ^99mTc-dimercaptosuccinic acid scan confirmed the diagnosis of crossed renal ectopia, also disclosing, through single-photon emission computed tomography (SPECT) acquisition, cortical uptake defects in both kidneys, and indicative of renal scarring due to recurrent pyelonephritis. Combined scintigraphy and appropriate technological approaches (SPECT/3D volume rendering) may be useful in selected patients with congenital anomalies.