Prostate cancer: nuclear medicine imaging in the biochemical recurrence and in oligometastatic disease.

INTRODUCTION: The aim of this article was to offer a comprehensive non-systematic review of the literature about the use of Nuclear Medicine imaging exams for the evaluation of prostate cancer (PCa) in the recurrent setting, with a particular regard to positron emission tomography/computed tomography (PET/CT) imaging. EVIDENCE ACQUISITION: A comprehensive nonsystematic literature review was performed in March 2024. Literature search was updated until March 2024. The most relevant studies have been summarized, giving priority to registered clinical trials and multicenter collaborations. EVIDENCE SYNTHESIS: Restaging BCR with advanced Nuclear Medicine Imaging, such as prostate-specific membrane antigen-PET/CT could lead to stage migration and pave the way for additional management strategies, such as stereotactic ablative radiotherapy in patients with low-burden or oligometastatic disease, potentially delaying the need of systemic therapies. While OS benefits of targeting PET/CT positive disease are still lacking, data on progression- and metastasis-free-survival are emerging. Improvements in quality-of-life assessments are already evident. CONCLUSIONS: PCa is one of the most common malignancy in men. In the last 10 years PCa imaging has become significantly more accurate and is now essential for the definition of the extent of the disease in different phases of its natural history. This opened the road to novel management strategies, especially in the recurrent setting, in which the oligometastatic state is now being explored in several trials regarding the prognostic significance of metastasis directed therapies aimed at personalizing the treatment for every single patient.

Prostate-Specific Membrane Antigen-Targeted Therapy in Prostate Cancer: History, Combination Therapies, Trials, and Future Perspective.

In the last decades, the development of PET/CT radiopharmaceuticals, targeting the Prostate-Specific Membrane Antigen (PSMA), changed the management of prostate cancer (PCa) patients thanks to its higher diagnostic accuracy in comparison with conventional imaging both in staging and in recurrence. Alongside molecular imaging, PSMA was studied as a therapeutic agent targeted with various isotopes. In 2021, results from the VISION trial led to the Food and Drug Administration (FDA) approval of [177Lu]Lu-PSMA-617 as a novel therapy for metastatic castration-resistant prostate cancer (mCRPC) and set the basis for a radical change in the future perspectives of PCa treatment and the history of Nuclear Medicine. Despite these promising results, primary resistance in patients treated with single-agent [177Lu]Lu-PSMA-617 remains a real issue. Emerging trials are investigating the use of [177Lu]Lu-PSMA-617 in combination with other PCa therapies in order to cover the multiple oncologic resistance pathways and to overcome tumor heterogeneity. In this review, our aim is to retrace the history of PSMA-targeted therapy from the first preclinical studies to its future applications in PCa.

First Live-Experience Session with PET/CT Specimen Imager: A Pilot Analysis in Prostate Cancer and Neuroendocrine Tumor.

OBJECTIVE: to evaluate the feasibility of the intra-operative application of a specimen PET/CT imager in a clinical setting. MATERIALS AND METHODS: this is a pilot analysis performed in three patients who received an intra-operative administration of 68Ga-PSMA-11 (n = 2) and 68Ga-DOTA-TOC (n = 1), respectively. Patients were administrated with PET radiopharmaceuticals to perform radio-guided surgery with a beta-probe detector during radical prostatectomy for prostate cancer (PCa) and salvage lymphadenectomy for recurrent neuroendocrine tumor (NET) of the ileum, respectively. All procedures have been performed within two ongoing clinical trials in our Institute (NCT05596851 and NCT05448157). Pathologic assessment with immunohistochemistry (PSMA-staining and SSA immunoreactivity) was considered as standard of truth. Specimen images were compared with baseline PET/CT images and histopathological analysis. RESULTS: Patients received 1 MBq/Kg of 68Ga-PSMA-11 (PCa) or 1.2 MBq/Kg of 68Ga-DOTA-TOC (NET) prior to surgery. Specimens were collected, positioned in the dedicated specimen container, and scanned to obtain high-resolution PET/CT images. In all cases, a perfect match was observed between the findings detected by the specimen imager and histopathology. Overall, the PET spatial resolution was sensibly higher for the specimen images compared to the baseline whole-body PET/CT images. Furthermore, the use of the PET/CT specimen imager did not significantly interfere with any procedures, and the overall length of the surgery was not affected using the PET/CT specimen imager. Finally, the radiation exposure of the operating theater staff was lower than 40 µSv per procedure (range 26-40 µSv). CONCLUSIONS: the image acquisition of specimens obtained by patients who received intra-surgery injections of 68Ga-PSMA-11 and 68Ga-DOTA-TOC was feasible and reliable also in a live-experience session and has been easily adapted to surgery daily practice. The high sensitivity, together with the evaluation of intra-lesion tumor heterogeneity, were the most relevant results since the data derived from specimen PET/CT imaging matched perfectly with the histopathological analysis.

[18F]FDG PET/CT: Lung Nodule Evaluation in Patients Affected by Renal Cell Carcinoma.

Renal Cell Carcinoma (RCC) is generally characterized by low-FDG avidity, and [18F]FDG-PET/CT is not recommended to stage the primary tumor. However, its role to assess metastases is still unclear. The aim of this study was to evaluate the diagnostic accuracy of [18F]FDG-PET/CT in correctly identifying RCC lung metastases using histology as the standard of truth. The records of 350 patients affected by RCC were retrospectively analyzed. The inclusion criteria were: (a) biopsy- or histologically proven RCC; (b) Computed Tomography (CT) evidence of at least one lung nodule; (c) [18F]FDG-PET/CT performed prior to lung surgery; (d) lung surgery with histological analysis of surgical specimens; (e) complete follow-up available. A per-lesion analysis was performed, and diagnostic accuracy was reported as sensitivity and specificity, using histology as the standard of truth. [18F]FDG-PET/CT semiquantitative parameters (Standardized Uptake Value [SUVmax], Metabolic Tumor Volume [MTV] and Total Lesion Glycolysis [TLG]) were collected for each lesion. Sixty-seven patients with a total of 107 lesions were included: lung metastases from RCC were detected in 57 cases (53.3%), while 50 lesions (46.7%) were related to other lung malignancies. Applying a cut-off of SUVmax ≥ 2, the sensitivity and the specificity of [18F]FDG-PET/CT in detecting RCC lung metastases were 33.3% (95% CI: 21.4-47.1%) and 26% (95%CI: 14.6-40.3%), respectively. Although the analysis demonstrated a suboptimal diagnostic accuracy of [18F]FDG-PET/CT in discriminating between lung metastases from RCC and other malignancies, a semiquantitative analysis that also includes volumetric parameters (MTV and TLG) could support the correct interpretation of [18F]FDG-PET/CT images.

Metastatic Sites' Location and Impact on Patient Management After the Introduction of Prostate-specific Membrane Antigen Positron Emission Tomography in Newly Diagnosed and Biochemically Recurrent Prostate Cancer: A Critical Review.

CONTEXT: The introduction of prostate-specific membrane antigen positron emission tomography (PSMA-PET) had a substantial impact on the management of prostate cancer (PCa) patients with a stage migration phenomenon and consequent treatment changes. OBJECTIVE: To summarise the role of PSMA-PET to define the burden of disease through an accurate location of metastatic site(s) in PCa patients, describing the most common locations at PSMA-PET in the primary staging and recurrence setting, and to assess the clinical impact in the decision-making process. EVIDENCE ACQUISITION: A comprehensive nonsystematic literature review was performed in April 2022. Literature search was updated until March 2022. The most relevant studies have been summarised, giving priority to registered clinical trials and multicentre collaborations. EVIDENCE SYNTHESIS: PSMA-PET showed higher diagnostic accuracy than conventional imaging both in newly diagnosed PCa and in recurrent disease. This greater accuracy led to a migration of a higher proportion of patients identified with metastatic disease. Bone metastases were reported as the most frequent site of metastatic spread in staging (up to 17%) and restaging (up to 18%). In staging, considering the suboptimal sensitivity in lymph node metastasis detection prior to radical surgery, PSMA-PET should be performed in patients with high risk or unfavourable intermediate risk only, and it is not recommended to routinely avoid pelvic lymph node dissection in case of a negative scan. In case of prostate-specific antigen relapse, PSMA-PET had higher diagnostic accuracy than other diagnostic procedures in the early detection of the sites of recurrence, thus influencing the therapy decision-making process. CONCLUSIONS: PSMA-PET detects a higher number of lesions than conventional imaging or other PET radiotracers, especially metastatic lesions unseen with other modalities. The high diagnostic accuracy of PSMA-PET leads to a significant patient upstage and thus an impact in clinical management, even if the overall impact on cancer mortality is still to be assessed. PATIENT SUMMARY: Prostate-specific membrane antigen positron emission tomography (PSMA-PET) identifies metastatic lesions with higher accuracy than conventional imaging, both in primary prostate cancer and during disease recurrence. Skeletal metastasis and extrapelvic lymph nodes are the most common sites of metastatic spread. The high accuracy of PSMA-PET in the detection of metastatic disease led to a significant impact on patient management, even if the overall impact on cancer mortality is still to be assessed.

Ten-year follow-up of cardiac resynchronization therapy patients with non-ischemic dilated cardiomyopathy assessed by radionuclide angiography: a single-center cohort study.

PURPOSE: Relatively few data are available on long-term survival and incidence of ventricular arrhythmias in cardiac resynchronization therapy (CRT) patients. We investigated long-term outcomes of CRT patients with non-ischemic dilated cardiomyopathy stratified as responders or non-responders according to radionuclide angiography. METHODS: Fifty patients with non-ischemic dilated cardiomyopathy undergoing CRT were assessed by equilibrium Tc99 radionuclide angiography with bicycle exercise at baseline and after 3 months. Intra- and interventricular dyssynchrony were derived by Fourier phase analysis. Patient clinical outcome was assessed after 10 years. RESULTS: At 3 months, 50% of patients were identified as CRT responders according to an increase in LV ejection fraction ≥ 5%. During a follow-up of 109 ± 48 months, 30% of patients died and 6% underwent heart transplantation. Age and history of paroxysmal atrial fibrillation were found to be predictors of all-cause mortality. CRT responders showed lower risk of death from cardiac causes than non-responders. At follow-up, 38% of patients presented at least one episode of sustained ventricular tachycardia, with a similar percentage between responders and non-responders. CONCLUSION: At long-term follow-up, non-ischemic CRT recipients identified as responders by radionuclide angiography were found to be at lower risk of worsening heart failure death than non-responders. Long-term risk for sustained ventricular arrhythmia was similar between CRT responders and non-responders.