Background and purpose (extract from abstract): The purpose of the study is to confirm the efficacy and feasibility of moderately hypofractionated proton beam therapy (PBT) at a total dose of 63 Gy relative biological effectiveness (RBE) in 21 fractions for prostate cancer.
Materials and methods (extract): For each patient, two fiducial markers (Gold Anchor; Naslund Medical AB, Huddinge, Sweden, or VISICOIL; RadioMed, Bartlett, TN, USA) were implanted in the prostate before CT simulation for the use of image-guided PBT.
Daily treatment was performed using a passive scattering method with daily matching of the intraprostatic fiducial markers using kilovoltage orthogonal X-ray images...
Discussion (extract): …the lower toxicity observed in the current cohort is hypothesized to result from the use of image-guided RT (IGRT) with fiducial markers using a shrunken field technique, which significantly contributed to this more favorable toxicity rate.
Conclusion (extract): We demonstrated low incidence of late adverse GU and GI events alongside excellent disease control, validating the safety of this fractionation schedule.