Efficacy and Safety of Actinium-225 Prostate-Specific Membrane Antigen Radioligand Therapy in Metastatic Prostate Cancer: A Systematic Review and Metanalysis.

BACKGROUND: Actinium-225 (Ac-225) labelled PSMA RLT has been tested recently in metastatic castration-resistant prostate cancer (mCRPC), with encouraging results. Ac-225, being an alpha emitter, is expected to have higher efficacy and fewer side effects compared to the beta-emitters such as Lutetium-177. We have performed a meta-analysis to assess the therapeutic responses, survival effects, and significant side effects of Ac-225 PSMA RLT in patients with mCRPC. METHODOLOGY: Systematic literature search was carried out from five electronic databases PubMed/MEDLINE, SCOPUS, EMBASE, Web of Science, and Cochrane Library until March 2021. Eight studies were found to be eligible for this metanalysis. RESULTS: Eight studies with 226 patients were analyzed in this metanalysis. 81% (95% CI 73-89) patients had a decline in PSA levels. 60% of the patients showed more than 50% PSA decline. Two studies assessed survival effects of radioligand naïve patients compared to patients who had received Lu-PSMA therapy previously and the pooled HR for radioligand naïve patients is 0.22. The most common toxicity reported was xerostomia in 167 patients out of 226 patients (73.9%, 95% CI 67.6-79.5%); however, most of them were confined to grade I and II levels. Other reported side effects include hematologic toxicity and nephrotoxicity. CONCLUSION: Ac-PSMA RLT is a safe and potentially effective treatment option for patients with mCRPC.

Prognostic significance of extramedullary disease (EMD) detected on pre-transplant 18F-FDG PET/CT in patients with multiple myeloma: Results of PIPET-M trial.

Background: It is difficult to prognosticate the post-Autologous Stem Cell Transplant (ASCT) responses in multiple myeloma (MM) with the currently available prognostication models. 18F-FDGPET/CT has numerous advantages to prognosticate the post-transplant responses by assessing extramedullary disease (EMD) in addition to the extent of active disease. We aimed at identifying the prognostic value of EMD in predicting progression-free survival (PFS) and overall survival (OS). Methods: This is a single centre prospective study from western India during a study period of 2014-2022 (with a median follow-up of patients of 6 years). All ASCT patients underwent 18F-FDG-PET/CT as part of pre-transplant workup. The conditioning and treatment protocols were not modified based on PET/CT findings. EMD on PET/CT was correlated with pre-transplant biochemical markers and post-ASCT survival/ progression (as defined by revised IMWG criteria). Statistical analysis was done using SPSS ver. 20. Results: Patients with pre-ASCT EMD had a hazard-ratio for post-transplant all-cause mortality of 5.46 (p-0.045). Pre-transplant ß2M and LDH were significantly higher in patients with EMD (p-0.036). The 6-year median OS in patients with and without EMD were 57.1%, and 80.6% respectively. Kaplan-Meier analysis showed poorer OS in patients with EMD χ2 (1-0.496, p-0.481). There was no significant difference in clinical or biochemical EFS among patients with EMD. Conclusion: EMD detected on 18F-FDG-PET/CT has a higher hazard for mortality and is significantly correlated with pre-transplant higher ß2M and LDH levels. Thus, EMD by pre-transplant 18F-FDG-PET/CT has a significant prognostic role.

Effectiveness of Convalescent Plasma Therapy in the Treatment of Moderate to Severe COVID 19 Patients: A Systematic Review and Meta-Analysis.

Though Convalescent plasma therapy (CPT) is being used for management of COVID-19, the evidence is still equivocal. So, we carried out this study to evaluate the currently available data to provide evidence about CPT in COVD-19 patients. RCTs and observational studies with sample size with more than 5 were included in the analysis. Out of 196 studies, 12 studies were selected for systematic review and meta-analysis was carried out for 6 studies having a control arm. For dichotomous values, risk ratio (RR) and 95% confidence interval was expressed. MAIN OUTCOMES: All-cause mortality, clinical improvement by day 7 and viral detection by day 7 were the defined outcome measures before starting of data extraction. RESULT: For 6 studies (2 RCTs and 4 observational studies) with 474 patients, the overall pooled RR for all-cause mortality was 0.61 (95%CI: 0.37 to 0.99. P= 0.04). Only RCTs and only observational studies for all-cause mortality showed pooled RR of 0.60 (95% CI: 0.33 to 1.10, P=0.10) and 0.48 (95% CI: 0.17 to 1.36, P= 0.17) respectively. There was risk of bias in the studies due to randomization process and confounding. Sensitivity analysis was carried out only for observational studies. The overall pooled RR for clinical improvement by day 7 and viral detection by day 7 were 1.12 (95%CI: 0.96 to 1.31, P=0.16) and 0.19 (95%CI: 0.09 to 0.60, P < 0.0001). CONCLUSION AND RELEVANCE: Though the review suggests modest utility of CPT in reducing all-cause mortality, improving clinical outcome, and early viral clearance, it should be interpreted cautiously.

Role of PSMA-targeted PET-CT in renal cell carcinoma: a systematic review and meta-analysis.

Fluoro-deoxy glucose positron emission tomography/computed tomography (PET/CT), the workhorse of nuclear medicine, has limited utility for renal cell carcinoma (RCC), particularly clear cell variant. Thus, various other tracers have been tried for evaluation of RCC. One of the most promising targets for radiotracers is prostate-specific membrane antigen (PSMA) expressed in abundance in carcinoma-associated neo-vasculature. Thus, we tried to review and analyse the role of PSMA-targeted PET/CT in evaluation of RCC. Databases like PubMed, EMBASE and SCOPUS were searched for original studies published on PSMA-targeted PET/CT in RCC till 30 September 2023. Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) checklist was used to assess the included studies. Pooled sensitivity and specificity were calculated and represented with 95% confidence intervals (95%CI). Heterogeneity in the studies was assessed by I-square index. Pooled sensitivity and specificity of PSMA-targeted PET/CT for detection of local disease estimates were 87.2% (95%CI: 77-94%) and 100% (95%CI: 92.9-100%), respectively. Pooled sensitivity and specificity for detection of local recurrent disease are 100% (95%CI: 71.5-100%) and 100% (95%CI: 89.4-100%), respectively. Pooled sensitivity and specificity for detection of metastatic disease are 92% (95%CI: 86.2-96%) and 96.9% (95%CI: 83.8-99.9%), respectively. Pooled sensitivity of PSMA-targeted PET/CT for detection of clear cell renal cell carcinoma (ccRCC) and non-ccRCC are 94.7% (95%CI: 88-98.3%) and 75% (95%CI: 35-96.8%), respectively. PSMA-targeted PET-CT demonstrated better diagnostic efficacy for the detection of recurrent RCC. Whilst for staging RCC, it had higher specificity but lower sensitivity. Thus, it can serve as a non-invasive adjuvant tool to conventional imaging in the evaluation of staging of RCC, particularly clear cell variant.

Uncommon Site of Metastasis: A Case Report of Breast Carcinoma Spreading to the Pancreas.

The metastatic lesions to pancreas are reported in various malignancies. However, pancreatic metastasis from breast cancer is rare and difficult to diagnose due to nonspecific symptoms and imaging findings. At the time of diagnosis, there may already be an associated widespread metastasis. In this case report, a woman in her forties with a history of breast cancer was found to have widespread metastases, including in the pancreas. The patient was treated with chemotherapy and hormonal therapy.

Diagnostic Performance of FAPI PET/CT vs. 18F-FDG PET/CT in Evaluation of Liver Tumors: A Systematic Review and Meta-analysis.

Objectives: Primary liver tumors constitute one of the most common tumors. These are aggressive tumors with poor survival. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), most commonly used functional imaging, shows limited tracer retention and poor tumor to background ratios (TBR). Novel 68Ga-fibroblast-activation-protein inhibitor (FAPI) PET/CT has shown better tracer uptake and detection efficacy in liver tumors. However, most of the available literature is limited to single center studies with limited number of patients. So, we tried to review and analyze the head-to-head comparison of 18F-FDG PET/CT and 68Ga-FAPI PET/CT in evaluation of liver tumors. Methods: Literature available on head to head comparison of diagnostic accuracy of 18F-FDG PET/CT and 68Ga-FAPI PET/CT was searched in databases like PubMed, SCOPUS, EMBASE and Google Scholar for published original studies till April 2023. The relevant studies were selected and assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies-2 checklist. A random-effect model was used for calculating pooled sensitivity and specificity. They were represented with 95% confidence intervals (95% CI) and demonstrated in Forest plots. I-square statistic was used to assess heterogeneity in the studies. Results: Pooled sensitivity and specificity of FAPI PET/CT and 18F-FDG PET/CT for detection of primary liver tumors was 94.3% (95% CI: 90.6-96.8%); 89.3% (95% CI: 71.8-97.7%) and 56.1% (95% CI: 49.7-62.5%); 96.4% (95% CI: 81.7-99.9%) respectively. Pooled sensitivity for detection of extrahepatic metastatic disease was 92.2% (range: 88.1-100%; 95% CI: 87.8-95.4%) and 72.4% (range: 69.8-76.5; 95% CI: 65.9-78.2%) respectively. Also, the maximum standardized uptake value (SUVmax) and TBR were higher for FAPI PET/CT than 18F-FDG PET/CT in the included studies. Conclusion: Overall, FAPI PET/CT showed higher sensitivity for detection of liver tumors with better SUVmax and TBR than 18F-FDG PET/CT.

Incidental Detection of Myocardial Ischemia on Whole-Body PET/CT in a Patient With Carcinoma Lung.

ABSTRACT: 18 F-FDG PET/CT being a whole-body technique can detect multiple other critical nononcological findings. Various cardiac disorders identified incidentally on 18 F-FDG have been reported to help in timely management and improve overall patient care. We hereby present one such case where 18 F-FDG PET/CT performed for a workup of carcinoma lung revealed abnormal myocardial FDG uptake in the anteroseptal and apical region, which raised suspicion of myocardial ischemia such as hot spot imaging. On coronary angiography, coronary artery disease was detected and subsequently managed.

Rare Case of Primary Leiomyosarcoma of Bone - Findings on 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Primary leiomyosarcoma of bone (PLB) is a rare tumor, constituting <0.7% of all primary bone malignancies. It is clinically aggressive with heterogeneous presentation and a dismal prognosis. The most common presentation is pain with swelling and pathological fracture at times. Limited literature is available on PLB and only about 150 cases have been reported to date with only a few case reports defining the utility of 18F-fluorodeoxyglucose (18-F FDG) positron emission tomography/computed tomography (PET-CT) in its management. We hereby present a case of primary leiomyosarcoma of the right distal femur and the role of FDG-PET-CT in its management.

Incidental 68Ga-PSMA Uptake in the Benign Enchondroma-A Rare Finding on 68Ga-PSMA PET/CT.

ABSTRACT: 68Ga-PSMA (prostate-specific membrane antigen)-HBED-CC (N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid) PET/CT is the new advancement in oncological imaging. However, false-positive uptake can be seen in benign lesions on 68Ga-PSMA PET/CT. We describe a rare case of intense 68Ga-PSMA uptake in an enchondroma confirmed on MRI.

Radioiodine Uptake at Suture Site Granuloma Mimicking Neck Node Metastasis on 131 I Whole-Body Iodine Scintigraphy.

ABSTRACT: Differentiated thyroid carcinoma constitutes over 90% of all thyroid cancers. The standard treatment approach involves total or near-total thyroidectomy with or without neck dissection followed by 131 I whole-body scintigraphy (WBS) to detect local or distant metastases. Radioiodine offers high sensitivity and specificity for detection of metastatic disease in well differentiated thyroid carcinoma. However, despite its high accuracy, 131 I WBS demonstrates false-positive results, mostly at inflammatory or infective site. These false-positive radioiodine accumulation can lead to misdiagnosis and unwarranted radioiodine treatment. This case presents localization of 131 I to the suture site granuloma leading to false-positive results on 131 I WBS.

Incidence of exclusive extrapelvic skeletal metastasis in prostate carcinoma on bone scintigraphy.

BACKGROUND: Bone is one of the common sites of metastasis from prostate carcinoma. Bone scintigraphy (BS) is one of the most sensitive imaging modalities currently used for bone metastatic work-up. Skeletal metastasis in prostate carcinoma commonly involves pelvic bones but rarely involves extrapelvic-extraspinal sites. AIM: To retrospectively analyze the BS data to determine the pattern of skeletal metastases in the prostate carcinoma. METHODS: This retrospective observational study involves patients with biopsy-proven prostate carcinoma referred for BS for staging assessment. Patients with abnormal BS were evaluated for the pattern of skeletal involvement and data were presented in descriptive format in the form of percentages. RESULTS: A total of 150 patients with biopsy-proven prostate cancer who were referred for staging were included in the study. Thirteen of 150 patients (8.67%) had no abnormal uptake on planar images, ruling out metastatic disease. Twenty-four patients (16%) had heterogeneous uptake in the spine with distribution characteristic of degenerative disease and no scan pattern of metastatic disease. Thirty patients (20%) had multifocal uptake involving both pelvic and extra pelvic bones on planar images typical for skeletal metastasis and were considered metastatic. Eighty-three out of 150 patients (55.3%) had increased tracer uptake, which was indeterminate, thus, single photon emission computed tomography-computed tomography (SPECT-CT) was acquired, which showed 51 with metastatic disease, 31 benign lesions, and one indeterminate finding. Seven of 150 patients had exclusive pelvic bone uptake, which was found to be metastatic in 4/7 patients in SPECT-CT. Fifty six out of 150 patients showed exclusive extrapelvic tracer uptake, of which only 3 had vertebral metastatic disease. None of the patients with increased uptake exclusively in the extrapelvic-extraspinal location was metastatic. CONCLUSION: The incidence of exclusive extrapelvic skeletal metastatic disease in prostate carcinoma is 2% (excluding one patient with indeterminate findings). Further, none of the patients in the current study had exclusive extrapelvic-extraspinal metastasis. Thus, exclusive extrapelvic-extraspinal focal abnormality on planar BS carries a very low probability of metastatic disease and hence, further imaging or SPECT-CT can be safely avoided in such cases.

An Incidentally Detected Case of Atypical Bronchial Carcinoid on Stress Myocardial Perfusion SPECT/CT.

Myocardial perfusion imaging is primarily done to look for stress-induced perfusion defects in patients suspected of having coronary artery disease. However, the rotating raw images can provide significant information on the surrounding structures. The lungs lie near the heart, and any abnormality showing increased uptake can be seen on myocardial perfusion imaging. We report the case of a 52-y-old man with a history of diabetes for the previous 5 y, who presented to the cardiology outpatient department because of occasional chest pain and dyspnea. Electrocardiography and echocardiography showed no significant abnormality. The patient was referred to the nuclear medicine department for stress-induced myocardial perfusion scintigraphy. The raw 99mTc-sestamibi images showed abnormal uptake in the hilar region of the right lung, which, on subsequent investigations, was diagnosed as atypical bronchial carcinoid tumor.

Recurrent Renal Cell Carcinoma Presenting as Port-Site Metastases, Detected on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

The incidence of port-site metastases (PSMs) varies with the tumor type with adenocarcinoma having a high incidence. However, it is rarely seen in urological malignancies and more so in renal cell carcinoma (RCC). We hereby describe one such case of PSM after laparoscopic radical nephrectomy for RCC, which was detected on 18F-fluorodeoxyglucose positron emission tomography-computed tomography.

Small Chyle Leak Localized on Lymphoscintigraphy with Single-Photon Emission Computed Tomography-Computed Tomography.

Chylothorax refers to the accumulation of triglyceride-rich fluid (chyle) within the pleural space. We described a case of spontaneous chylothorax in an infant. Lymphoscintigraphy was performed with 99 m-Tc sulfur colloid which showed tracer accumulation into thoracic cavity, and single-photon emission computed tomography/CT (SPECT/CT) revealed leak in the thoracic duct at D8 vertebral level as the cause. We, thus, emphasize the role of lymphoscintigraphy with SPECT/CT in identification of cause and guiding the management of chylothorax, especially when surgical treatment is planned.

Uterine Metastasis Presenting as Abnormal Uterine Bleeding in a Case of Primary Breast Cancer Identified on 18F-FDG PET/CT.

Metastases to the female genital tract are rare, especially from extragenital primaries. The most common extragenital sites associated with genital metastasis are the gastrointestinal tract (37.6%) followed by the breast (34.9%). It is crucial to differentiate primary from metastatic involvement of the uterus for appropriate patient management. We present one such case of endometrial metastasis in a patient who presented clinically with abnormal uterine bleeding and was diagnosed with primary breast cancer via 18F-FDG PET/CT.

Emerging role of bone scintigraphy single-photon emission computed tomography/computed tomography in foot pain management.

Foot and ankle joints being weight-bearing joints are commonly subjected to wear and tear and are prone to traumatic and other pathologies. Most of these foot and ankle pathologies present with pain. The diagnosis of pathology and localization of pain generators is difficult owing to the complex anatomy of the foot and similar clinical presentation. This makes the management of foot pain clinically challenging. Conventional anatomical imaging modalities are commonly employed for evaluation of any anatomical defect; however, these modalities often fail to describe the functional significance of the anatomical lesions, especially in presence of multiple lesions which is common in ankle and foot; however, hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) by virtue of its dual modalities, that is, highly sensitive functional imaging and highly specific anatomical imaging can serve as a problem-solving tool in patient management. This review attempts to describe the role of hybrid SPECT/CT in overcoming the limitation of conventional imaging and describes its potential application in the management of foot and ankle pain.

Rare Case of Phyllodes Tumor of Breast with Cardiac and Pancreatic Metastases: Findings on 18F-FDG PET/CT.

Phyllodes tumor (PT) represents a rare type of breast tumor arising from the stromal component rather than the epithelium. Metastatic spread occurs hematogenously, with lung, bone, brain, and liver being the most common sites. We present the 18F-FDG PET/CT scan of one such case of phyllodes tumor showing cardiac and pancreatic metastases, which are an extremely rare occurrence.

Steroid-Induced Activated White Adipose Tissue Detected on 18F-FDG PET/CT.

White adipose tissue (WAT) usually shows negligible 18F-FDG uptake due to negligible glucose utilization. However, corticosteroids alter the biodistribution of 18F-FDG and increase uptake in WAT. Here, we present a case of diffusely increased 18F-FDG uptake in WAT secondary to high-dose corticosteroid therapy for nephrotic syndrome.

Acute Myeloid Leukemia following Radioactive Iodine Therapy for Metastatic Follicular Carcinoma of the Thyroid.

Radioactive iodine (RAI) therapy is widely used and has an important role in the management of hyperthyroidism and thyroid malignancies. The development of acute or chronic leukemia is a very rare complication of RAI therapy. We report a case of metastatic Follicular thyroid cancer (FTC) who underwent total thyroidectomy followed by treatment with a cumulative dose of 1600 mCi of RAI (for 4 years) and by palliative radiotherapy for L4 spinal metastasis, later on, developed acute myeloid leukemia. Thus, all patients with thyroid carcinoma treated with RAI should undergo periodic hematological examinations irrespective of RAI dose.

False-Positive Radioiodine Uptake in the Cervix in a Patient with Thyroid Cancer.

Radioactive iodine (RAI) accumulation is commonly used for the detection of metastatic disease posttotal thyroidectomy. However, false-positive results have been reported due to abnormal RAI accumulation in some benign pathologies apart from metastatic sites. Here, we present one such case where false-positive I-131 uptake in the pelvis which localized to the cervix and was attributed to menstruation.