Positron Emission Tomography and Whole-body Magnetic Resonance Imaging for Metastasis-directed Therapy in Hormone-sensitive Oligometastatic Prostate Cancer After Primary Radical Treatment: A Systematic Review

Abstract

Context: Next-generation imaging includes positron emission tomography (PET) imaging and whole-body magnetic resonance imaging (wbMRI) including diffusion-weighted imaging. Accurate quantification of oligometastatic disease using next-generation imaging is important to define the role and value of metastasisdirected therapy (MDT). Objective: To perform a review of next-generation imaging modalities in the detection of recurrent oligometastatic hormone-sensitive prostate cancer in men who received prior radical treatment for localized disease. Evidence acquisition: MEDLINE, Scopus, Cochrane Libraries, and Web of Science databases were systematically searched for studies reporting next-generation imaging and oncological outcomes. An expert panel of urologists, radiation oncologists, radiologists, and nuclear medicine physicians performed a nonsystematic review of strengths and limitations of currently available imaging options for detecting the presence and extent of recurrent oligometastatic disease. Evidence synthesis: From 370 articles identified, three clinical trials and 21 observational studies met the following inclusion criteria: metachronous oligometastatic recurrence after radical treatment for prostate cancer, MDT, and hormone-sensitive patients. Androgen deprivation therapy (ADT) was allowed before MDT. Next-generation imaging modalities included PET/computed tomography and/or PET/MRI with the following tracers: choline (n = 1), NaF (n = 1), and

Recent Advances in the Management of Hormone-Sensitive Oligometastatic Prostate Cancer

“…8 Moreover, a high level of interobserver agreement was demonstrated for 68 Ga-PSMA PET/ CT, both for nodal and bony lesions. 21,22 Admittedly, PSMA-based techniques may fail to detect clinical progression when PSMA is either absent or scarcely expressed. Although no definitive evidence of superiority of 68 Ga-PSMA PET/CT exists, in the 2017 APCCC, the panelists recommended the use of 68 Ga-PSMA PET/ CT to confirm the diagnosis of oligometastases after primary treatment.…”

“…28 Finally, in recent years, international guidelines have been published which provide indications for standardising acquisition, interpretation and reporting of WB-MRI. 29 A recent meta-analysis by Farolfi et al, 22 summarizing the strengths and limitations of such NGI modalities, identified PSMA-PET as the most promising modality, with lower inter-observer variability and higher degree of reproducibility. Nevertheless, this study also warns about pitfalls of this technique, such as the possible overestimation of lymph node detection sensitivity, encouraging randomized clinical trials investigating the role of NGI in combination with MDT in this setting.…”

“… 8 Moreover, a high level of interobserver agreement was demonstrated for 68 Ga-PSMA PET/CT, both for nodal and bony lesions. 21 , 22 …”

“…As a successful treatment relies on accurate imaging, the employment of NGI becomes mandatory in the era of high-precision medicine. 22 Comparisons of standard and modern imaging methods have always shown the superiority of the latter, 21 which are expected to replace conventional imaging in the course of a few years ( Table 1 ). At present, the available evidence on their improved detection capability over standard imaging is not mature enough to include them in guidelines, which still prioritize traditional techniques to evaluate PCa metastatic burden.…”

Role of PSMA PET-guided metastases-directed therapy in oligometastatic recurrent prostate cancer

“…Specifically, PSMA PET techniques allow visualisation of metastatic disease prior to metastatic deposits, reaching morphological criteria required for diagnosis on conventional imaging (21). Hence, recent trials have evaluated PSMA PETguided MDT in oligometastatic recurrent disease, typically with salvage surgery or radiotherapy, which potentially delays the need for systemic therapy (22)(23)(24). Therefore, we aim to comprehensively review PSMA PET-guided MDT in OMPC.…”