This study by the Hyogo group in Japan analyzed 30 patients who had initially undergone surgery but isolated local recurrence occurred. PBT was administered with dose of 67.5 (GyE) in 19 to 25 fractions. Four patients (13.3%) experienced acute grade ≥ 3 gastrointestinal toxicities.

After a median follow-up period of 17.6 months, this study reported the median overall, progression-free, and local progression-free survival rates were 26.1, 12.3, and 41.2 months. This study concluded that PBT after surgery was well tolerated and produced good locoregional control and should be considered for eligible patients.