PSMA-PET/CT is a suitable replacement for conventional imaging in the primary staging of PCa. The aim of this retrospective study was to assess the correlation between parameters discovered by PSMA PET/CT in primary staging and either prostate histopathology (pT) findings or PSMA-IHC expression in a cohort of biopsy-proven high-risk PCa candidates for surgery. Clinical information (age, iPSA-value, and grading group) and PSMA-PET/CT parameters (SUVmax, PSMA tumor volume [PSMA-TV], and total lesion [PSMA-TL]) were compared with pT (including histologic pattern, Gleason grade, and lymphovascular invasion [LVI]) and PSMA-IHC features, including visual quantification (VS) with a four-tiered score (0 = negative, 1+ = weak, 2+ = moderate, 3+ = strong), growth pattern (infiltrative vs expansive), and visual pattern (cytoplasmic vs membranous). In total, 44 patients were enrolled, with a median age of 67 (IQR 57-77); the median iPSA was 9.4 ng/dL (IQR 12.5-6.0). One patient (3%) was grading group (GG) 3, 27/44 (61%) were GG4, and 16/44 (36%) were GG5. PSMA-PET/CT detection rate for the presence of primary prostate cancer was 100%. Fused/poorly formed Gleason grade 4 features were predominant (22/44–50%); a cribriform pattern was present in 18/44 (41%) and acinar in 4/44 (9%). We found that lower PSMA-TVs were mostly related to acinar, while higher PSMA-TVs correlated with a higher probability to have a cribriform pattern (p-value 0.04). LVI was present in 21/44(48%) patients. We found that higher PSMA-TV and PSMA-TL are predictive of LVI p-value 0.002 and p-value 0.01, respectively. There was no correlation between PET-parameters and perineural invasion (PNI), probably because this was present in almost all the patients. Moreover, patients with high PSMA-TL values displayed the highest PSMA-IHC expression (VS3+) with a membranous pattern. In conclusion, PSMA-TV and PSMA-TL are predictors of a cribriform pattern and LVI. These conditions are mostly related to higher aggressiveness and worse outcomes.

Nonmelanoma skin cancer (NMSC) occurs in photoexposed areas and is frequent in the elderly population. Surgical excision remains the treatment of choice whenever feasible. However, alternative approaches are clinically important for patients who are unsuitable for surgery. This study evaluated the efficacy and safety of ¹⁸⁸Re epidermal radionuclide therapy (¹⁸⁸Re-ERT) for local disease control in NMSCs deemed inoperable. Methods: In total, 124 consecutive patients (79 men, 45 women; mean age, 81 y [range, 49-94 y]) with histologic confirmation of NMSC were treated with ¹⁸⁸Re-ERT, with 181 lesions treated. Efficacy was evaluated 6 mo after ¹⁸⁸Re-ERT with videodermoscopy and biopsy. Follow-up was performed at 12, 18, 24, and 36 mo. Relapses were confirmed histologically. Safety was assessed on the basis of CTCAE version 5.0. Results: Lesion characteristics included surface area (mean, 6.0 cm²; range, 1-34 cm²), thickness (mean, 1.2 mm; range, 0.2-3.0 mm), volume (mean, 0.85 cm³; range, 0.05-7.7 cm³). Locations include the H area (102 lesions), scalp (39 lesions), extremities (24 lesions), and thorax (16 lesions). Histology confirmed 104 basal cell carcinoma; 71 squamous cell carcinoma, and 6 basosquamous carcinoma. Mean administered dose to the lesion was 51 Gy, the mean dose to the deepest point of cancer invasion was 25 Gy, and the mean treatment duration was 90 min. No patient reported pain during or after the treatment. Overall, 165 of 181 lesions (91.1%) were relapse-free at 36 mo. Relapses occurred in 16 patients as follows: 6 at 6 mo, 3 at 12 mo, 2 at 18 mo, 3 at 24 mo, and 2 at 36 mo. Lesions less than 8 cm² demonstrated a relapse rate of 1.4% at 6 mo. Larger lesion area volumes were significantly associated with relapse. Early adverse skin reactions classified according to CTCAE version as G1 (minimal skin changes, faint erythema, or dry desquamation) or G2 (moderate erythema, patchy moist desquamation, and edema) were observed in 165 of 181 lesions (91.1%) and resolved within a mean time of 32 d; G3 skin reactions (severe skin changes without pain) were present in 16 lesions, lasting up to 8-12 wk. Conclusion: ¹⁸⁸Re-ERT showed high efficacy with a relapse-free rate of 91.1% at 36 mo. Larger lesions were associated with an increased risk of relapse. Adverse events were generally mild, resolving within 32 d. These results support ¹⁸⁸Re-ERT as a safe and effective alternative for patients with inoperable NMSC.