Metastasis-directed Therapy (SBRT) Guided by PET-CT 18F-CHOLINE Versus PET-CT 68Ga-PSMA in Castration-sensitive Oligorecurrent Prostate Cancer: A Comparative Analysis of Effectiveness.

The present analysis aims to compare the impact of 18F-fluorocholine (18F-choline) and gallium-68 prostate-specific membrane antigen (68Ga-PSMA) positron emission tomography (PET)-computed tomography (CT)-guided metastases-directed therapies (MDTs) in patients with castration-sensitive oligorecurrent prostate cancer (PC).

Inclusion criteria were: (1) histologically proven prostate adenocarcinoma; (2) evidence of biochemical relapse after primary tumor treatment; (3) ≤ 3 hypermetabolic oligorecurrent lesions detected by 18F-choline or 68Ga-PSMA PET-CT; (4) PET-CT imaging performed in a single nuclear medicine department; (5) patients treated with upfront stereotactic body radiotherapy (SBRT) without hormone therapy; and (6) SBRT delivered with a dose per fraction ≥ 5 Gy. In the case of oligoprogression (≤ 3 lesions outside the previous RT field) after MTD, a further course of SBRT was proposed; otherwise, androgen deprivation therapy (ADT) was administered.

A total of 118 lesions in 88 patients were analyzed. Forty-four (50%) patients underwent 68Ga-PSMA PET-guided SBRT, and the remaining underwent choline PET-based SBRT. The median follow-up was 25 months (range, 5-87 months) for the entire cohort. Overall survival and local control were both 100%. Distant progression occurred in 48 (54.5%) patients, for a median distant progression-free survival of 22.8 months (range, 14.4-28.8 months). The median pre-SBRT prostate-specific antigen was 2.04 ng/mL in the choline PET cohort and 0.58 ng/mL in the PSMA-PET arm. Disease-free survival rates were 63.6% and 34%, respectively, in the 68Ga-PSMA and choline PET group (P = .06). The ADT administration rate was higher after choline-PET-guided SBRT (P = .00) owing to the higher incidence of polymetastatic disease after first-course SBRT compared with 68Ga-PSMA-based SBRT.

In the setting of oligorecurrent castration-sensitive PC, PSMA-PET-guided SBRT produced a higher rate of ADT-free patients when compared with the 18F-choline-PET cohort. Randomized trials are advocated.

Clinical genitourinary cancer. 2020 Aug 06 [Epub ahead of print]

Rosario Mazzola, Giulio Francolini, Luca Triggiani, Giuseppe Napoli, Francesco Cuccia, Luca Nicosia, Lorenzo Livi, Stefano Maria Magrini, Matteo Salgarello, Filippo Alongi

Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy., Radiation Oncology Unit, Azienda Ospedaliero Universitaria Careggi, University of Florence, Florence, Italy., Radiation Oncology Department, ASST Spedali Civili di Brescia, Brescia University, Brescia, Italy., Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy. Electronic address: ., Nuclear Medicine, IRCCS Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy., Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy; Radiation Oncology Unit, Azienda Ospedaliero Universitaria Careggi, University of Florence, Florence, Italy.

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