Clinical Nuclear Medicine

Current Issue Highlights

Amyloid PET Changes During Lecanemab Treatment in Patients With and Without Amyloid-related Imaging Abnormalities
December 2026
Lecanemab reduces cerebral amyloid-β burden in Alzheimer disease, but whether amyloid-related imaging abnormalities (ARIA) are associated with greater amyloid clearance remains unclear. We report 3 patients with comparable clinical backgrounds and similar baseline cognitive performance who underwent amyloid-β PET before and after lecanemab treatment. Quantitative analysis using Centiloid showed a greater reduction in amyloid burden in the patient who developed ARIA than in the 2 patients without ARIA. These observations suggest ARIA may be associated with more pronounced treatment-related amyloid clearance, warranting further investigation in larger cohorts.
FDG Uptake Extending From the Dorsal Root Ganglion to the Sciatic Nerve After Herpes Zoster
December 2026
A woman in her 50s receiving paclitaxel, carboplatin, and pembrolizumab for recurrent cervical cancer developed herpes zoster and received antiviral therapy. ¹⁸F-FDG PET/CT performed 22 days after zoster onset, when the skin lesions had crusted, demonstrated continuous uptake extending from the left L5 dorsal root ganglion to the sciatic nerve. To our knowledge, this is the first reported case of FDG PET findings indicating ganglioneuritis extending from the dorsal root ganglion to a peripheral nerve after herpes zoster. Recognition of this pattern is important in patients receiving chemoimmunotherapy because it may mimic immune-related neuritis or perineural tumor spread.
¹⁷⁷Lu-PSMA Therapy in Recurrent High-Grade Glioma
December 2026
Purpose:
Patients with recurrent high-grade glioma have poor prognosis and limited treatment options. This pilot study evaluated the feasibility and potential clinical benefit of ¹⁷⁷Lu-PSMA therapy in this patient population.
Patients and Methods:
Eligible patients were selected for treatment based on positive ⁶⁸Ga-PSMA-PET findings. ¹⁷⁷Lu-PSMA (7.4 GBq/200 mCi) was administered at 6–8-week intervals and continued as long as well-tolerated. The safety, tolerability, and efficacy of ¹⁷⁷Lu-PSMA were assessed in each treatment cycle using PET/MRI, SPECT/CT, blood tests, neurological tests, and patient-reported outcome measures.
Results:
Ten patients were enrolled (WHO grade 4 glioblastoma, n=6; WHO grade 4 astrocytoma, n=1; WHO grade 3 astrocytoma, n=3). ⁶⁸Ga-PSMA-PET before treatment demonstrated tumor uptake in 9 patients (median SUV_max: 6.4, IQR: 4.2–9.0). Six patients received treatment (20 cycles total; range: 1–7 per patient). Median absorbed dose per cycle was 0.9 Gy (IQR: 0.8–1.1) for tumors, 2.6 Gy (IQR: 1.9–3.2) for kidneys, and 1.7 Gy (IQR: 1.5–2.2) for parotid glands. No CTCAE grade 3–4 toxicities occurred. The most common patient-reported symptoms were fatigue, transient xerostomia, and nausea. Median survival from treatment initiation was 187 days (range: 87–756) and the median progression-free survival was 45 days (range: 41–335). MRI (RANO 2.0) demonstrated stable disease in half of the patients during all or part of the treatment course.
Conclusions:
¹⁷⁷Lu-PSMA therapy was feasible and well-tolerated. Radiologic stabilization was observed in a subset of patients, but strategies to increase tumor dose delivery may be needed to improve efficacy.
A Head-to-Head Comparison of Detection Rate and Tumor Uptake of FAPI, PSMA, and FDG PET/CT in Newly Diagnosed High-risk Prostate Cancer
December 2026
Purpose:
This study was designed to investigate the detection rate and tumor uptake of ¹⁸F-AlF-NOTA-De-FAPI PET/CT in newly diagnosed high-risk prostate cancer (PCa), compared with ⁶⁸Ga-PSMA-11 and ¹⁸F-FDG PET/CT.
Patients and Methods:
This study enrolled 48 patients with biopsy-diagnosed, treatment-naive high-risk PCa who underwent ¹⁸F-AlF-NOTA-De-FAPI, ⁶⁸Ga-PSMA-11, and ¹⁸F-FDG PET/CT between April and December 2024. A head-to-head comparison of detection rate and tumor uptake was performed among the 3 tracers. In addition, ¹⁸F-AlF-NOTA-De-FAPI and ⁶⁸Ga-PSMA-11 dual-tracer PET was used to characterize the imaging phenotypes of each lesion and interlesional heterogeneity.
Results:
A total of 477 lesions were detected by the 3 PET tracers. ⁶⁸Ga-PSMA-11 exhibited the highest overall detection rate (96.4%), followed by ¹⁸F-AlF-NOTA-De-FAPI (81.1%) and ¹⁸F-FDG (66.0%). A total of 17 ⁶⁸Ga-PSMA-11-negative lesions were identified in 8 patients, all of which were detected by ¹⁸F-AlF-NOTA-De-FAPI, whereas only 12 were detected by ¹⁸F-FDG. Combined ⁶⁸Ga-PSMA-11 and ¹⁸F-AlF-NOTA-De-FAPI PET identified all lesions detected by triple-tracer PET. Based on relative tracer dominance of dual-tracer PET, patients were classified as PSMA-dominant (n=23), FAPI-dominant (n=5), or mixed phenotype (n=20). The mixed phenotype with marked interlesional heterogeneity might be associated with more advanced clinical characteristics, with a higher proportion of metastatic disease and a greater metastatic burden.
Conclusions:
¹⁸F-AlF-NOTA-De-FAPI is a promising PET tracer for newly diagnosed high-risk PCa. It may improve the detection rate of ⁶⁸Ga-PSMA-11-negative lesions and provide complementary information that could reflect interlesional heterogeneity. The clinical value of combining ¹⁸F-AlF-NOTA-De-FAPI and ⁶⁸Ga-PSMA-11 PET requires further validation in larger prospective cohorts.
^¹⁷⁷Lu-PSMA Radioligand Therapy in Metastatic Castration-resistant Prostate Cancer With Complex Renal Conditions
December 2026
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.
Blood Pool and Late-phase 3D-ring CZT SPECT/CT in Painful Os Peroneum Syndrome
December 2026
A 52-year-old woman was referred for chronic left lateral foot pain, with suspicion of a stress fracture. ^99mTc-HDP bone scintigraphy using a new 3D-ring CZT system (StarGuide) was performed. Bloodpool and late-phase SPECT/CT demonstrated increased uptake in foci corresponding to the os peroneum, suggestive of painful os peroneum syndrome (POPS). Our case highlights the potential of this new generation of 3D-ring CZT SPECT/CT systems to identify POPS, as early diagnosis remains crucial for adequate management.

Latest Articles

Primary Brain Sarcoma Presented on FDG PET/CT
Clinical Nuclear Medicine. November 12, 2026
A 62-year-old man had dizziness and dysarthria for 4 months and limited mobility of the left upper extremity for 1 month. An outside enhanced MR showed a space-occupying lesion in the right frontal lobe. Since the patient had pancreaticoduodenectomy, gastrostomy, and jejunostomy 8.5 years ago for poorly differentiated adenocarcinoma of the small intestine, brain metastasis was suspected. FDG PET/CT demonstrated increased FDG activity in the right frontal lobe lesion, but no FDG-avid lesion was found in other parts of the body. Following surgical resection, histopathology examination indicated sarcoma. The patient underwent brain radiotherapy afterward.
Intense Focal Renal ¹⁸F-MFBG Uptake Attributable to Radiation in a Pediatric Patient With Neuroblastoma
Clinical Nuclear Medicine. November 12, 2026
A 9-year-old boy with neuroblastoma was enrolled in a clinical trial. After radiotherapy to the primary tumor site, ¹⁸F-MFBG PET/CT was performed 2 months later. No abnormal radiotracer accumulation suggestive of metastatic disease was identified. However, focal intense ¹⁸F-MFBG uptake was observed in the upper pole of the left kidney, within the previously irradiated field. No structural renal lesion was identified on cross-sectional imaging, and no evidence of renal tumor was found during 12 months of clinical and imaging follow-up. This case illustrates that intense localized renal ¹⁸F-MFBG uptake may result from radiation and should be recognized as a potential pitfall in post-radiotherapy ¹⁸F-MFBG PET/CT interpretation.
Scapular Gouty Tophus Mimicking Malignancy on ¹⁸F-FDG PET/CT in a Patient Without Prior Gout History
Clinical Nuclear Medicine. November 12, 2026
A gouty tophus found in the scapula is exceedingly rare. Here, we report on a 62-year-old asymptomatic woman with no history of gout or hyperuricemia who was incidentally found on chest CT screening to have a localized osteolytic lesion in the left scapula. ¹⁸F-FDG PET/CT demonstrated abnormally increased FDG uptake within this lesion, concerning for a neoplasm. Subsequent biopsy confirmed a gouty tophus, a rare mimic of malignancy in this location.

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Clinical Nuclear Medicine

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