Nuclear Medicine

177Lu-DOTATATE PRRT in Japanese NENs: strong efficacy and manageable toxicity

In this multicenter Japanese series, 422 patients with unresectable or recurrent NENs received 177Lu-DOTATATE PRRT across 33 institutions. The objective response rate was 37.6%, with higher responses in pancreatic (45.2%) and hindgut (40.7%) primaries. Median progression-free survival was 21.4 months, and 75% of functional tumors had marked hormonal symptom improvement. Better outcomes were associated with pancreas or hindgut primaries, Krenning score 4, lower liver tumor burden, smaller liver metastases, lower Ki-67, and somatostatin analog co-therapy. Grade ≥3 adverse events were uncommon, with hematologic toxicity in 18% and renal toxicity in fewer than 1% of patients. 1

PET/CT-guided microwave ablation of colorectal liver metastases with real-time margin and biopsy assessment

This single-center prospective trial evaluated PET/CT-guided microwave ablation for 104 colorectal liver metastases in 77 patients. Intraprocedural workflow combined minimal ablation margin measurements, FDG-PET assessment, and rapid cytology with viability staining from ablation-center and margin biopsies. Immediate reablation was performed in 14% of lesions based on insufficient margin, residual PET avidity, or viable tumor on rapid assessment. Lesions with minimal ablation margin greater than 5 mm had substantially reduced local tumor progression risk, with no progression when margins exceeded 10 mm. Participants with biopsy-proven complete ablation and margins greater than 5 mm had low 1–3 year cumulative local progression rates. 2

Nuclear imaging to monitor infection treatment response and outcomes

This review outlines how SPECT and PET can quantify infection burden and monitor treatment response beyond conventional clinical and radiologic markers. It emphasizes that nuclear imaging can distinguish active infection from sterile inflammation, improving early assessment of therapeutic efficacy. The article summarizes applications across diverse infectious diseases and highlights promising novel radiopharmaceuticals for targeted pathogen or immune imaging. It also discusses imaging-based response criteria and protocols that could standardize follow-up and better predict clinical outcomes. 3

68Ga-FAPI PET/CT identifies psoriasis patients at higher risk of psoriatic arthritis

In this prospective study, 45 psoriasis patients with arthralgia underwent 68Ga-FAPI PET/CT and longitudinal follow-up. Eighty-two percent were FAPI positive, with uptake most frequent in large joints and mechanically stressed entheseal sites. FAPI uptake was associated with higher BMI, higher disease activity, low-grade synovial hyperplasia, entheseal Power Doppler signal, and concomitant osteoarthritis. FAPI-positive patients had a higher risk of progressing to psoriatic arthritis than FAPI-negative patients, with nearly half of FAPI-positive individuals converting. These data suggest fibroblast activation imaging may help identify high-risk psoriasis patients before overt psoriatic arthritis develops. 4