Dose-escalated pelvic radiotherapy for prostate cancer in definitive or postoperative setting.

Given the absence of standardized planning approach for clinically node-positive (cN1) prostate cancer (PCa), we collected data about the use of prophylactic pelvic irradiation and nodal boost. The aim of the present series is to retrospectively assess clinical outcomes after this approach to compare different multimodal treatment strategies in this scenario.

Data from clinical records of patients affected by cN1 PCa and treated in six different Italian institutes with prophylactic pelvic irradiation and boost on pathologic pelvic lymph nodes detected with CT, MRI or choline PET/CT were retrospectively reviewed and collected. Clinical outcomes in terms of overall survival (OS) and biochemical relapse-free survival (b-RFS) were explored. The correlation between outcomes and baseline features (International Society of Urological Pathology-ISUP pattern, total dose to positive pelvic nodes ≤ / > 60 Gy, sequential or simultaneous integrated boost (SIB) administration and definitive vs postoperative treatment) was explored.

ISUP pattern < 2 was a significant predictor of improved b-RFS (HR = 0.3, 95% CI 0.1220-0.7647, P = 0.0113), while total dose < 60 Gy to positive pelvic nodes was associated with worse b-RFS (HR = 3.59, 95% CI 1.3245-9.741, P = 0.01). Conversely, treatment setting (postoperative vs definitive) and treatment delivery technique (SIB vs sequential boost) were not associated with significant differences in terms of b-RFS (HR = 0.85, 95% CI 0.338-2.169, P = 0.743, and HR = 2.39, 95% CI 0.93-6.111, P = 0.067, respectively).

Results from the current analysis are in keeping with data from literature showing that pelvic irradiation and boost on positive nodes are effective approaches. Upfront surgical approach was not associated with better clinical outcomes.

La Radiologia medica. 2021 Nov 30 [Epub ahead of print]

Giulio Francolini, Giulia Stocchi, Beatrice Detti, Vanessa Di Cataldo, Alessio Bruni, Luca Triggiani, Andrea Emanuele Guerini, Rosario Mazzola, Francesco Cuccia, Matteo Mariotti, Viola Salvestrini, Pietro Garlatti, Simona Borghesi, Gianluca Ingrosso, Rita Bellavita, Cynthia Aristei, Isacco Desideri, Lorenzo Livi

Radiation Oncology Unit, University of Florence, Viale Morgagni 85, 50134, Florence, Italy. ., Department of Biomedical, Experimental, and Clinical Sciences "Mario Serio", University of Florence, Florence, Italy., Radiation Oncology Unit, University of Florence, Viale Morgagni 85, 50134, Florence, Italy., CyberKnife Center, Istituto Fiorentino di Cura ed Assistenza, Florence, Italy., Radiotherapy Unit, University Hospital of Modena, Modena, Italy., Department of Radiation Oncology, Brescia University, Brescia, Italy., Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy., Radiation Oncology Unit of Arezzo-Valdarno, Azienda USL Toscana Sud Est, Arezzo, Italy., Radiation Oncology Section, Department of Surgical and Biomedical Science, University of Perugia and Perugia General Hospital, Perugia, Italy.

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