Introduction: This study aims to assess ⁶⁸Ga-Trivehexin PET/CT for detecting hyperfunctioning parathyroid tissue in comparison to [^99mTc]Tc-MIBI scintigraphy-SPECT/CT (MIBI scan) in patients with primary hyperparathyroidism (PHPT). Methods: The cohort comprised 13 patients diagnosed with PHPT based on biochemical analyses, including serum calcium, phosphorus, and parathyroid hormone (PTH) levels. Each participant underwent cervical ultrasonography, MIBI scan, and ⁶⁸Ga-Trivehexin PET/CT imaging. Complementary 4D-CT and [¹⁸F]fluorocholine PET/CT were conducted in 7 patients. Ten lesions of 7 patients underwent PTH wash-out (WO) procedure. ⁶⁸Ga-Trivehexin PET/CT findings were compared with other modalities and PTH-WO results. Results: Ten patients had sporadic PHPT, while 3 were diagnosed with MEN-1 syndrome-associated PHPT. One patient did not have any identifiable parathyroid lesion across the imaging modalities. On a patient-based analysis, MIBI scan and ⁶⁸Ga-Trivehexin PET/CT identified parathyroid lesions in 10 and 11 patients, respectively. However, ⁶⁸Ga-Trivehexin PET/CT detected 7 additional parathyroid lesions that were negative on the MIBI scan. Consequently, 17 lesions were identified and confirmed as hyperfunctioning parathyroid tissue through imaging, PTH-WO, or a combination of both modalities. In lesion-based evaluation, ⁶⁸Ga-Trivehexin identified 16 lesions compared to 10 by MIBI scan, resulting in a detection rate of 94.1% and 58.8%, respectively. Notably, in three patients who underwent [¹⁸F]fluorocholine PET/CT, no lesions were detected; yet ⁶⁸Ga-Trivehexin PET/CT successfully identified parathyroid lesions in two of these patients. Conclusion: Our study provides the first evidence that ⁶⁸Ga-Trivehexin PET/CT can effectively identify hyperfunctioning parathyroid tissue with a high detection rate warranting further investigations to comprehensively explore its potential in PHPT management.

The aim of this narrative review is to evaluate the current status of ¹⁷⁷Lu-PSMA (prostate specific membrane antigen) therapy for metastatic castration-resistant prostate cancer (mCRPC) in the light of the current literature. We also addressed patient preparation, therapy administration and side effect profiles. ¹⁷⁷Lu-PSMA therapy efficacy was assessed by using prospective trials, meta-analyses and major retrospective trials. Predictors of efficacy were also mentioned. Although there are some different approaches regarding the use of ¹⁷⁷Lu-PSMA therapy in different countries, this type of therapy is generally safe, with a low toxicity profile. From the oncological point of view, a PSA (prostate specific antigen) decline of ≥50% was seen in 10.6–69% of patients with mCRPC; whereas progression-free survival (PFS) was reported to be 3–13.7 months in different studies. Consequently, ¹⁷⁷Lu-PSMA therapy is a promising treatment in patients with mCRPC, with good clinical efficacy, even in heavily pretreated patients with multiple lines of systemic therapy. Currently, there are ongoing clinical trials in the United States, including a phase III multicenter FDA registration trial.

Purpose: This study aimed to evaluate the personalized dosimetric approach by calculating the cumulative renal absorbed dose (cRD) and assessing its impact on renal functions in patients diagnosed with metastatic castration-resistant prostate cancer who underwent four or more cycles of [¹⁷⁷Lu] Lu-PSMA − 617 therapy. Methods: The study included 110 patients who received ≥ 4 cycles of [¹⁷⁷Lu] Lu-PSMA − 617 therapy. Whole-body static and abdominal SPECT-CT imaging was performed at 4, 24, and 96 h post-administration. Kidney function was assessed using dynamic renal scintigraphy and biochemical tests conducted prior to treatment. Estimated glomerular filtration rate (eGFR) levels were calculated using the CKD-EPI formula before each treatment cycle and at the 6th week post-treatment. Results: Pearson correlation analysis reveal no significant relationship between cRD and CKD-EPI values (p >.05). No significant differences were observed between pre-treatment CKD-EPI levels and those measured after the 4th, 5th, 6th, 7th, and 8th cycles (p >.05). Among patients reaching a cRD of 23 Gy, a statistically significant difference was observed between pre- and post-treatment CKD-EPI values (p <.05). Of the 13 patients exceeding cRD of 28 Gy, five maintained CKD-EPI levels above 90 mL/min/1.73 m² post-treatment. Conclusion: Despite treatment-related declines in eGFR levels, our findings indicate that a personalized dosimetric approach may enable extended cycles of [¹⁷⁷Lu] Lu-PSMA-617 therapy with manageable nephrotoxicity. Considering the significant inter-patient variability, establishing universal absorbed dose-response relationships remains challenging. Prospective multicenter studies are crucial to refining toxicity thresholds and advancing tailored treatment strategies to optimize safety and efficacy.