Clinical Positron Emission Tomography/Computed Tomography: Quarter-Century Transformation of Prostate Cancer Molecular Imaging.

Although positron emission tomography/computed tomography (PET/CT) underwent rapid growth during the last quarter-century, becoming a new standard-of-care for imaging most cancer types, CT and bone scan remained the gold standard for patients with prostate cancer. This occurred as 2-fluorine-18-fluoro-2-deoxy-d-glucose was perceived to have a limited role owing to low sensitivity in many patients. A resurgence of interest occurred with the use of fluorine-18-sodium-fluoride PET/CT as a replacement for bone scintigraphy, and then choline, fluciclovine, and dihydrotestosterone (DHT) PET/CT as prostate "specific" radiotracers. The last decade, however, has seen a true revolution with the meteoric rise of prostate-specific membrane antigen PET/CT.

Correlation of current myocardial perfusion imaging and previous coronary angiography to avert the need for repeat intervention - A case report.

INTRODUCTION: Evaluation of chest pain in an individual with prior coronary artery bypass graft (CABG) procedures can be complex. Stress myocardial perfusion imaging (MPI) demonstrates reasonable sensitivity for detection of ischemia following bypass grafting [1] but often requires multi-modality imaging correlation for knowledge of graft anatomy. CASE AND OUTCOME: We describe the findings of a reversible perfusion defect on myocardial perfusion scintigraphy in a person post-CABG. This was interpreted in combination with findings of coronary angiography, thereby identifying ischemia in a native un-grafted vessel territory and influencing management strategy. DISCUSSION: Myocardial perfusion scintigraphy is a sensitive technique for evaluation of inducible ischemia. It provides information on the extent and severity of ischemia. Integrating the knowledge of changes on coronary angiography with MPI provides a comprehensive picture that can guide management decisions, as in our case. CONCLUSION: Correlation of structural and functional imaging findings may be extremely helpful for management of patients with myocardial ischemia post-CABG.

Safety of Lutetium-177 prostate-specific membrane antigen-617 (PSMA-617) radioligand therapy in the setting of severe renal impairment: a case report and literature review.

Reported here is a case of rapidly progressive metastatic castration-resistant prostate cancer treated with [177Lu]Lu-PSMA-617 in the setting of severe renal impairment and impending ureteric obstruction. PSMA is expressed on renal tubular cells, raising the possibility of radiation-induced nephrotoxicity, and this level of renal impairment would typically exclude the patient from [177Lu]Lu-PSMA-617 therapy. Multidisciplinary input, individualized dosimetry, and patient-specific dose reduction were used to ensure the cumulative dose to the kidneys remained within acceptable limits. He was initially planned for treatment with six cycles of [177Lu]Lu-PSMA-617. However, he had an excellent response to therapy following four cycles of treatment and the last two cycles were omitted. He has been followed for 1-year posttherapy without evidence of disease recurrence. No acute or chronic nephrotoxicity was observed. This case report highlights the utility of [177Lu]Lu-PSMA-617 therapy in severe renal impairment and provides evidence of relative safety in patients who would otherwise not be considered candidates for therapy.

This report presents a case of a man with aggressive metastatic prostate cancer who received [¹⁷⁷Lu]Lu-PSMA-617 therapy, despite having severely reduced kidney function and worsening ureter obstruction. This treatment could have potential side effects on kidney function, but the medical team used a personalized approach to reduce patient risk. The man was initially planned to have six cycles of therapy, but his excellent response to treatment after four cycles meant the last two cycles were not given. The man has been followed for 1 year after treatment and has not experienced any worsening kidney function. This case shows the safe and effective use of [¹⁷⁷Lu]Lu-PSMA-617 therapy in a patient with severely reduced kidney function who would not normally qualify for this treatment.

Meningeal Relapse of Neuroblastoma-Utility of 68Ga-DOTATOC PET/CT for Detection.

ABSTRACT: In treatment of metastatic neuroblastoma, the central nervous system seems to act as a sanctuary leading to often unexpected relapse of disease. We present a case of neuroblastoma treated with chemotherapy and autologous stem cell transplantation only to relapse in central nervous system with meningeal metastases visualized on 68Ga-DOTATOC imaging.

Rare Involvement of Thyroid Cartilage and Thyroid Gland by Multiple Myeloma on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Multiple myeloma commonly involves the skeleton. Extraosseous disease is sometimes noticed involving various organs. We present a very unusual site of myeloma involvement in the thyroid gland and thyroid cartilage.

Unusual Case of Metastatic Intracranial Hemangiopericytoma and Emphasis on Role of 68Ga-PSMA PET in Imaging.

We present a 53 year old woman initially diagnosed as hemangiopericytoma in the posterior fossa on the right side post excision with immunohistochemistry staining for CD34 being positive. Presently, the patient had difficulty in walking due to back pain and pain in left arm. Imaging with F-FDG PET showed low glucose avidity in disease sites but Ga-PSMA PET unequivocally demonstrated multiple skeletal and liver metastases with intense PSMA avidity. Patient received palliative radiotherapy to bone metastasis and was planned for chemotherapy. This report adds to the list of applications of Ga PSMA PET and a possible theranostic target.

Utility of 68Ga-PSMA-11 PET/CT in Imaging of Glioma-A Pilot Study.

BACKGROUND: Imaging of gliomas remains challenging. The aim of the study was to assess the feasibility of using Ga-PSMA-11 PET/CT for imaging gliomas. METHODS: Fifteen patients with glioma from 2 centers were included in the study. Ten patients were treated cases of glioblastoma with suspected recurrence. Two patients were sent for assessing the nature (primary lesion/metastasis) of space-occupying lesion in the brain; 3 patients were imaged immediately after surgery and before radiotherapy. Target-to-background ratios (TBR) for the brain lesions were calculated using contralateral cerebellar uptake as background. RESULTS: Among the 10 cases with suspected recurrence, scan was positive in 9, subsequent surgery was done, and histopathology proved it to be true recurrence. In the scan-negative case on follow-up, no evidence of disease could be made clinically or radiologically. Among the other cases the presence or absence of disease could be unequivocally identified on the Ga-PSMA-11 brain scan and correlated with the histopathology or other imaging. Apart from the visual assessment quantitative assessment of the lesions with TBR also showed a significantly high TBR value for those with true disease compared with those with no disease. CONCLUSIONS: In the evaluation of gliomas, Ga-PSMA-11 PET/CT brain imaging is a potentially useful imaging tool. The use of Ga-PSMA-11 brain PET/CT in evaluation of recurrent glioma seems promising. Absence of physiological uptake of Ga-PSMA-11 in the normal brain parenchyma results in high TBR values and consequently better visualization of glioma lesions.

Trails on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Leading to Diagnosis of Testicular Adrenal Rest Tumor.

Testicular adrenal rest tumors (TARTs) are secondary to hypertrophy of adrenal rest cells in the rete testis in settings of hypersecretion of androgens. We present a case of congenital adrenal hyperplasia with TART with clues to the diagnosis on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). To the best of our knowledge, this is the first reported case on the role of 18F-FDG PET/CT in TART.

Disease- and Treatment-related Complication on F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Oncology Practice: A Pictorial Review.

F-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is routinely performed in oncology patients for various indications including staging, restaging, recurrence detection, and treatment response evaluation. Many disease- and treatment-related complications can be incidentally detected on PET/CT, which may be due to the complication of radiotherapy, chemotherapy, intervention, or primary tumor itself. Some of these complications could be life threatening and need urgent intervention. Therefore, these incidental findings should be recognized on PET/CT and immediately informed to the treating physicians if required urgent intervention.

Usefulness of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in dermatofibrosarcoma protuberans on treatment with imatinib.

Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive tumor with distant metastases being unusual. We present a case of metastatic DFSP treated with imatinib showing complete metabolic response to treatment.

Incidentally Detected Mediastinal Vascular Anatomical Variants on PET-CT: A Pictorial Essay.

Positron emission tomography with computed tomography (PET-CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET-CT, along with a review of associated literature.

Favourable outcomes of (177)Lu-octreotate peptide receptor chemoradionuclide therapy in patients with FDG-avid neuroendocrine tumours.

PURPOSE: Increased glycolytic activity on FDG PET/CT defines a subgroup of patients with metastatic gastroenteropancreatic neuroendocrine tumour (NET) with a poor prognosis. A limited range of systemic treatment options exist for more aggressive NET. The role of peptide receptor chemoradionuclide therapy (PRCRT) in such patients is, however, unclear. This retrospective study assessed the outcomes of patients with FDG-avid NET treated with PRCRT. METHODS: Clinical, biochemical and imaging response was assessed after completion of induction treatment of PRCRT with 5-fluorouracil in 52 patients selected for treatment on the basis of somatostatin-receptor imaging without spatially discordant FDG-avid disease. Of the cohort, 67% had received prior chemotherapy. Overall survival (OS) and progression-free survival (PFS) were also analysed. RESULTS: PRCRT was well tolerated with negligible grade 3/4 toxicities. After a median follow-up period of 36 months, the median OS was not achieved with a median PFS of 48 months. At 3 months after completion of PRCRT 2% of patients showed a complete anatomical response, 28% a partial response, 68% stable disease, and only 2% progression. On FDG PET/CT, 27% achieved a complete metabolic response during the follow-up period. A biochemical response (>25% fall in chromogranin-A levels) was seen in 45%. CONCLUSION: PRCRT is an effective treatment in patients with FDG-avid NET, even in patients who have failed conventional therapies. Given apparently higher response rates than with alternative therapeutic options and low toxicity, further research is needed to establish whether PRCRT should be used as a first-line treatment modality in this patient population.

"Metabolic signature" of the lesions on F18-fluoro-deoxyglucose positron emission tomography: A clue to the underlying pathology.

Increase in glycolytic pathway, forms one of the major adaptations in various cancer types. This can be imaged using (18)F-fluoro-deoxyglucose positron emission tomography/computed tomography (FDG PET). The intensity of FDG avidity is an indirect marker of the grade of the tumor. We present a case where FDG PET demonstrated a known chondrosarcoma and two other incidental lesions. The intensity of avidity in each of the lesions was grossly incongruent from the chondrosarcoma and further investigation proved the lesions to be two distinct primary malignancies, pathologically different from the known chondrosarcoma. We present the case to highlight the fact that the grade of FDG avidity is a clue to the pathological nature of the lesion and should always be considered while interpreting PET images.

Role of fluorodeoxyglucose positron emission tomography/computed tomography in diagnostic evaluation of carcinoma urinary bladder: comparison with computed tomography.

Bladder carcinoma is the most frequent tumor of the urinary tract and accounts 7% of all malignancies in men and 2% of all malignancies in women. This retrospective study was carried out to assess the diagnostic utility of F18-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the imaging evaluation of bladder carcinoma. Seventy-seven consecutive patients diagnosed to have carcinoma urinary bladder referred for F18-FDG PET/CT were included in this study. Thirty-four patients were for initial staging after transurethral biopsy and remaining 43 patients were for restaging. All patients also underwent CT scan of the abdomen and pelvis. PET/CT findings were correlated with diagnostic CT scan and histopathological findings. In 30 of the 34 patients for initial staging, both PET/CT and CT confirmed the primary lesion in the bladder. Histopathology report was available in 23 patients. Lymph nodes FDG uptake reported to be metastatic in 10/23 patients while CT detected lymph node metastasis in 12 patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy have been calculated to be 87.5%, 80%, 70%, 92%, 82% for PET/CT and 66%, 57%, 50%, 72%, 60% for CT respectively. PET/CT detected metastatic disease in 8 patients whereas CT detected in 4 patients. Of the 43 patients for restaging, local recurrence was detected in 24 patients on both PET/CT and CT. Histopathology report was available in 17 patients. Sensitivity, specificity, PPV, NPV and accuracy were 85%, 60%, 60%, 85%, 70% for PET/CT and 80%, 50%, 40%, 85%, 58% for CT respectively. Nineteen patients were detected to have metastatic disease by PET/CT, whereas CT detected metastases in 11 patients. F-18 FDG PET/CT is a very useful modality in pre-operative staging and monitoring after surgery, chemotherapy or radiotherapy of patients with carcinoma urinary bladder.

F-18 fluorodeoxyglucose positron emission tomography/computed tomography in a rare case of recurrent malignant mixed mullerian tumor.

We report a case of 66-year-old female with previous history of histopathologically proven. Malignant mixed mullerain tumor of the uterus in whom positron emission tomography/computed tomography (CT) done for characterization of soft tissue lesion in pelvis noticed on CT, showed extensive recurrent disease in the pelvis with pulmonary metastases.