A Randomized Phase II Trial of Prostate Boost Irradiation With Stereotactic Body Radiotherapy (SBRT) or Conventional Fractionation (CF) External Beam Radiotherapy (EBRT) in Locally Advanced Prostate Cancer: The PBS Trial (NCT03380806)

• Published in: Clinical genitourinary cancer Vol. 18; no. 4; pp. e410 - e415
• Main Authors: Isfahanian, Naghmeh, Lukka, Himanshu, Dayes, Ian, Quan, Kimmen, Schnarr, Kara Lynne, Douvi, Georgia, Goldberg, Mira, Wright, Jim, Swaminath, Anand, Chow, Tom, Diamond, Kevin, Cutz, Jean Claude, Kavsak, Peter, Thabane, Lehana, Tsakiridis, Theodoros
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2020
• Subjects: Androgen deprivation therapy; High risk prostate cancer; Quality of life; Radiotherapy toxicity; Radiotherapy toxicity; Androgen deprivation therapy; High risk prostate cancer; Quality of life
• ISSN: 1558-7673; 1938-0682
• DOI: 10.1016/j.clgc.2019.12.020

Standard therapy for high-risk (HR) prostate cancer (PrCa) involves androgen deprivation therapy (ADT) and pelvic conventional fractionation (CF) external beam radiotherapy (EBRT) followed by boost CF-EBRT treatment to prostate for a total of 78 to 80 Gy in 39 to 40 fractions. This is a long and inconvenient treatment for patients. Brachytherapy boost treatment studies indicate that escalation of biological dose of radiotherapy (RT) can improve outcomes in HR-PrCa. However, brachytherapy is an invasive treatment associated with increased toxicity and requires specialized resources. Stereotactic body radiotherapy (SBRT) is a promising, non-invasive alternative to brachytherapy. However, its impact on patient quality of life (QoL) and RT-associated toxicity has not been investigated in a randomized setting. In this study, we investigate SBRT as a boost treatment, following pelvic CF-EBRT, in patients with HR-PrCa treated with ADT. One hundred patients with locally advanced PrCa will be randomized to receive daily CF-EBRT of 45 to 46 Gy in 23 to 25 fractions followed by either daily CF-EBRT of 32 to 33 Gy in 15 to 16 fractions (control arm) or SBRT boost treatment of 19.5 to 21 Gy in 3 fractions (1 fraction per week) (experimental arm). The primary objective of the PBS trial is early bowel and urinary QoL (expanded prostate index composite [EPIC], up to 6 months after RT). This phase II randomized study (PBS) provides an appropriate setting to investigate effectively the impact of SBRT boost on QoL and toxicity in patients with HR-PrCa, before this modality can be compared against the current standard of care in larger phase III protocols.