Clinical outcome of PSMA-guided radiotherapy for patients with oligorecurrent prostate cancer

Abstract

Purpose First-line treatment of patients with recurrent, metastatic prostate cancer involves hormone therapy with or without additional systemic therapies. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) allows the detection of oligometastatic disease that may be amenable to image-guided radiotherapy. The current study classifies the type and localization of metastases and the clinical outcome of PSMA-PET/CT-guided radiotherapy to selected metastases. Materials and methods Between 2011 and 2019, 86 patients with recurrent, oligometastatic prostate carcinoma were identified by PSMA-PET/CT and were treated with image-guided radiotherapy of their metastases. Sites of relapse were characterized, and the primary endpoint overall survival (OS), biochemical progression-free survival (bPFS), and androgen deprivation therapy (ADT)-free survival were tabulated. Results In total, 37% of the metastases were bone metastases, 48% were pelvic nodal metastases, and 15% were nodal metastases outside of the pelvis. After PSMA-guided radiotherapy, a biochemical response was detected in 83% of the cohort. A statistically significant decrease in the standard uptake value (SUV) was seen in irradiated metastases. After a median follow-up of 26 months, the 3-year OS and bPFS were 84% and 55%, respectively. The median time of ADT-free survival was 13.5 months. A better clinical outcome was observed for patients receiving concomitant ADT or more than 24 fractions of radiation. Conclusion PSMA-guided radiotherapy is a promising therapeutic approach with excellent infield control for men with oligorecurrent prostate carcinoma. However, prospective, randomized trials are necessary to determine if this approach confers a survival advantage.

Comparison of Hormone-Sensitive Oligorecurrent Prostate Cancer Patients Based on Routine Use of Choline and/or PSMA PET/CT to Guide Metastasis-Directed Therapy

“…Koerber et al retrospectively included 86 patients with oligometastatic relapse (≤5 lesions detected by PSMA PET/CT) and treated them with RT ± ADT. They showed higher BR-FS rates at 2 and 3 years (85.1% and 55.1%, respectively) than those in our study [ 46 ]. However, their study included a greater proportion of patients receiving concomitant ADT, which may explain this difference.…”

18F-DCFPyL (PSMA) PET in the Management of Men with Biochemical Failure after Primary Therapy: Initial Clinical Experience of an Academic Cancer Center

“…Prior studies have shown a change in intended or actual management in between a third to two-thirds of patients [11][12][13][14]. Multiple further studies assessed the impact of PET on patient outcome [15][16][17][18][19][20][21][22]. A prior prospective study documented a PSA response of >50% in nearly 3 of 4 patients (63 of 86; 73.3%), much like the results from our registry, and the 3-year biochemical free survival was 55% [15].…”

Moving the goalposts while scoring―the dilemma posed by new PET technologies

“…PSMA-guided treatment of single-lesion or oligometastatic relapse is being increasingly applied and may achieve favorable outcomes [109][110][111][112]. In this context, improved accuracy in detecting such lesions may result in superior progression-free survival after targeted treatment.…”