Sharjeel Usmani

Objective: ¹⁷⁷Lu-PSMA-617 radioligand therapy (RLT) is an established treatment for metastatic castration-resistant prostate cancer (mCRPC). Its predominant renal clearance pathway raises concerns about safety and dosimetry in patients with underlying renal disease. Such patients are typically excluded from clinical trials, leaving a significant evidence gap in clinical practice. The aim of this study is to describe our experience with ¹⁷⁷Lu-PSMA-617 RLT in mCRPC patients presenting with complex pre-existing renal conditions, including end-stage renal disease on hemodialysis, renal transplant, chronic kidney disease, severely reduced glomerular filtration rate, obstructed kidneys, and solitary kidney. Methods: We retrospectively reviewed cases of mCRPC patients with significant renal comorbidity treated with ¹⁷⁷Lu-PSMA-617 at our institution. Patient demographics, renal function parameters, treatment adaptations, dosimetric data, PSA response, and renal safety outcomes were recorded for each case. Results: Six patients with distinct renal conditions were identified. All patients received at least 2 cycles of ¹⁷⁷Lu-PSMA-617. PSA responses (≥50% decline) were observed in 4/6 patients (67%), ranging from 37% to 99.9% across the cohort. Renal function remained stable or improved in most cases, with individualized dosimetry and multidisciplinary management enabling safe administration. No patient required permanent cessation of therapy due to acute renal toxicity. Conclusions: With careful patient selection, individualized dosimetry, multidisciplinary input, and close renal monitoring, ¹⁷⁷Lu-PSMA-617 RLT can be administered safely in mCRPC patients with complex renal disease. These cases highlight the need for prospective data and consensus guidelines for this underserved population.

Glioblastoma multiforme (GBM) is the most common brain tumor in the adult population, and it is characterized by poor prognosis; thus, new treatment strategies are strongly needed. Precision medicine is a rapidly growing field in oncology that identifies specific molecular features of tumor cells and allows theranostic strategies (combining diagnosis and therapy). In nuclear medicine, prostate-specific membrane antigen (PSMA) represents an interesting molecular target in theranostics, considering its involvement in the neoangiogenesis of many kinds of tumors, including GBM. In this narrative review, we performed a web-based literature search to explore the current evidence regarding PSMA-targeted nuclear medicine theranostics in GBM, highlighting diagnostic applications, therapeutic potential, and future clinical perspectives.

Accurate target delineation is critical for radiotherapy (RT) planning in intracranial meningiomas, particularly in complex anatomical regions such as the skull base or in postoperative settings. Meningiomas characteristically overexpress somatostatin receptor subtype-2 (SSTR2), allowing high-contrast molecular imaging with ⁶⁸Ga-DOTA-TOC PET/CT. This study evaluated the impact of integrating SSTR-PET with conventional imaging on RT target delineation in patients with intracranial meningiomas. In this single-center observational study, 25 consecutive patients with intracranial meningioma undergoing radiotherapy planning underwent MRI and ⁶⁸Ga-DOTA-TOC PET/CT. Gross tumor volumes were delineated using MRI alone and PET-fused CT images. PET-derived biological tumor volume (BTV) was generated using a 40% SUVmax threshold. Semiquantitative PET parameters, SUVmax and tumor-to-background ratio (TBR), were recorded. Changes in GTV delineation following PET integration were analyzed. ⁶⁸Ga-DOTA-TOC PET demonstrated intense SSTR expression (SUVmax 14.19 ± 10.88; TBRmax 83.48 ± 76.18) and precisely delineated tumor margins. PET identified osseous involvement in 40% of patients compared with 16% detected on MRI alone and revealed additional nonadjacent disease sites in 28% of cases. PET-based GTVs were significantly smaller than MRI-based volumes (12.01 ± 12.77 cm³ vs. 20.02 ± 18.71 cm³, p = 0.012). Integration of PET resulted in clinically relevant contour modification (> 5%) in 17 of 20 evaluable patients, including bone-specific adjustments in 12. ⁶⁸Ga-DOTA-TOC PET/CT demonstrated complementary value in radiotherapy planning for intracranial meningiomas, producing systematic geometric modifications in target volumes, with more frequent osseous involvement detection compared to MRI alone. These hypothesis-generating findings require validation in larger prospective multicenter studies with long-term clinical outcome endpoints before routine clinical adoption.

⁶⁸ Ga-FAPI PET/CT has emerged as a promising molecular imaging modality targeting cancer-associated fibroblasts, rather than tumor cells. We report a novel physiological uptake pattern on ⁶⁸ Ga-FAPI PET/CT in a 56-year-old woman with newly diagnosed invasive lobular carcinoma of the right breast undergoing staging. ⁶⁸ Ga-FAPI PET/CT demonstrated intense tracer uptake in the primary right breast tumor and a right level I axillary lymph node, consistent with FAPI expression in the primary malignancy and suspicious nodal involvement. In addition, bilateral linear, rope-like tracer uptake extending from the uterus through the inguinal canals along the round ligaments was observed, creating an “Alien Antenna” appearance. Recognition of this physiological uptake pattern is essential to avoid misinterpretation as peritoneal or metastatic disease.

Immune Checkpoint Inhibitor-associated Periaortitis Detected on 18F-FDG PET/CT: A Rare Case of Nivolumab Toxicity - Molecular Imaging and Radionuclide Therapy

Objectives: This study aimed to evaluate the diagnostic yield and complications associated with computed tomography (CT)-guided transthoracic core-needle biopsy (CNB) of lung lesions and to identify factors influencing biopsy outcomes. Methods: This retrospective study included patients who underwent CT-guided CNB of lung lesions at Sultan Qaboos Comprehensive Cancer Care & Research Centre, University Medical City, Muscat, Oman, from November 2021 to December 2024. Patients were categorised as either having undiagnosed lung masses/nodules or suspected pulmonary metastases from known malignancies. Biopsies were performed using an 18-gauge coaxial needle, following standard protocols. Diagnostic yield, sample adequacy for molecular analysis and complications were analysed using descriptive statistics and Chi-squared or Fisher's exact tests. Results: A total of 105 patients were included. Diagnostic yield of CT-guided CNB was 81.9% (n = 86) with malignancy confirmed in 72.4% of cases. Diagnostic yield significantly correlated with lesion size with increasing accuracy for lesions >2.1 cm compared to those <1 cm (93.9% versus 55%; P = 0.003). Lesion morphology, localisation, positron emission tomography guidance and patient demographics had no significant effects statistically. Complications in 28.8% of patients were largely pneumothorax (21.2%), followed by haemoptysis (8.7%) and haemothorax (1.9%). Smaller lesions (5 cm) had higher rates of complications (P = 0.007 and P = 0.080, respectively). Conclusion: CT-guided lung biopsy demonstrated high diagnostic yield with acceptable rates of complications. Lesion depth and size had significant impacts on diagnostic success and occurrence of complications. These results support that CT-guided CNB is a safe and reliable diagnostic procedure for lung lesions, especially when lung lesions are superficially located and solid.

Fibroblast activation protein inhibitor (FAPI) PET/CT has emerged as an investigational alternative which targets cancer-associated fibroblasts, abundant in the ILC tumor stroma. This narrative review synthesizes emerging evidence on radiolabeled FAPI PET/CT in ILC and highlights potential advantages, limitations, and research gaps. A purposive literature search of SCOPUS, PubMed/MEDLINE, and Web of Science up to August 2025 identified 10 clinical publications, including three prospective studies, two retrospective comparisons, and five case reports; mixed-cohort studies were included when ILC-specific findings were extractable. Across these small, heterogeneous early studies, gallium-68 FAPI PET/CT consistently demonstrated higher tumor uptake and greater lesion conspicuity than ¹⁸ F-FDG PET/CT in several ILC-relevant scenarios, particularly infiltrative soft-tissue metastases, peritoneal and serosal involvement, and sclerotic osseous lesions. Comparative studies also reported identification of additional multifocal or multicentric primary foci and greater nodal involvement, while case reports described enhanced visualization of gastric, orbital, peritoneal, and ovarian metastases, sites often inconspicuous on ¹⁸ F-FDG PET/CT. Despite these promising findings, available evidence remains limited, predominantly observational, and lacks lesion-level histopathologic confirmation, standardized imaging protocols, and data on management impact or patient outcomes. Overall, early results suggest that gallium-68 FAPI PET/CT may offer improved lesion conspicuity in selected ILC settings; however, these observations remain hypothesis generating. Larger, multicentre prospective studies with standardized acquisition parameters, rigorous lesion validation, and clinically meaningful endpoints are required to establish the diagnostic and therapeutic relevance of FAPI PET/CT and determine whether it has a role in the routine clinical evaluation of ILC.

Oncocytoma is a benign renal tumor, composed of oncocytic cells that are rich in mitochondria. Despite being benign, oncocytomas may show increased uptake on ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which can lead to false-positive interpretations. We report the case of a 66-year-old female with breast cancer presented with a huge left breast mass with matted axillary lymph nodes referred for ¹⁸ F-FDG PET/CT for staging. ¹⁸ F-FDG PET/CT show large hypermetabolic fungating lobulated mass in the outer quadrant of left breast (primary tumor) and ¹⁸ F-FDG avid ipsilateral metastatic left axillary and left internal lymph nodes. In addition, a large ¹⁸ F-FDG avid right renal mass is noted. Finding is suspicious for renal primary versus metastatic. Biopsy showed oncocytoma. Renal oncocytomas may show moderate-to-intense ¹⁸ F-FDG uptake, which is typically associated with malignant lesions, leading to diagnostic confusion. ¹⁸ F-FDG avid renal lesions must be interpreted cautiously. Multimodality imaging and histopathological correlation remains the gold standard.

We report the case of a 47-year-old woman who presented with left inguinal swelling; the biopsy of which showed high-grade serous adenocarcinoma. ⁶⁸ Ga-FAPI PET/CT revealed a tracer-avid lesion in the left adnexal region and an enlarged left inguinal nodal mass (site of biopsy). Multiple focal lesions were also seen at the hepatic dome, along the falciform ligament and at the right lateral abdominal wall, suspicious for peritoneal/metastatic deposits. The patient received 3 cycles of neoadjuvant chemotherapy, followed by interval debulking surgery. Tumor was seen in the left fallopian tube, but not in the ovaries. ⁶⁸ Ga-FAPI PET/CT provides better lesion localization due to a higher tumor-to-background ratio.

Unveiling the Diagnostic Mystery: 18F-FDG PET and Bone Scan Negative in Bone Metastases of Lobular Breast Cancer: A Case Report - Molecular Imaging and Radionuclide Therapy