Quality of Life Outcome in Patients with Localized Prostate Cancer after Hypofractionatied Carbon-Ion Radiation Therapy

Abstract

Carbon ion radiotherapy (C-ion RT) has excellent dose conformity and greater biological effectiveness than X-ray and proton beam. Moreover hypofractionatied schedule is better than conventional fractionated schedule to treat prostate cancer (PC) from the view point of biological aspect. The excellent outcome of C-ion RT for the patients with localized PC was already published. In our country, national health insurance has started to cover C-ion RT for localized PC since April 2018. Our hypothesis is that quality of life (QOL) outcome is maintained after hypofractionatied C-ion RT. The purpose of this study is to assess QOL outcome of the patients with localized PC received hypofractionatied C-ion RT. QOL outcome of 213 patients with localized PC received C-ion RT from August 2013 to July 2014 were analyzed. The prescribed dose of the C-ion RT was 51.6 Gy (RBE) in 12 fractions in 3 weeks. The median age at the time of the C-ion RT was 68 (range 46-88). The number of the patients of low, intermediate and high risk according to D’Amico criteria were 28 (13.1%), 82 (38.5%) and 103 (48.4%), respectively. Out of the 213 patients, 186 patients (87.3%) received hormonal therapy (HT). Two QOL assessment questionnaires of International Prostate Symptom Score (IPSS) and Expanded Prostate Cancer Index Composite (EPIC) were used at 6 points; before the C-ion RT, the last day of the C-ion RT, and 6, 12, 24 and 36 months after the C-ion RT. Among a subgroup of the 23 low risk patients not received any HT, the EPIC sexual domain was assessed in addition. The median follow-up time was 38.3 months (range 0.7-52.1). At the time of this analysis, 9 patients recurred and no patient experienced grade 3 and worse adverse event. The EPIC scores were available for 97.7%, 90.6%, 86.9%, 85.0%, 80.8% and 75.1% at the 6 points as above, respectively. The average IPSS and EPIC scores of the analyzed 213 patients are noted in the table. The IPSS score and the EPIC urinary score worsened temporarily during the C-ion RT and recovered to the baseline level. The EPIC bowel, sexual and hormonal scores did not change. The EPIC sexual scores of the subgroup of the 23 low risk patients not received any HT are also noted in the table, the score slightly worsened temporarily during the C-ion RT and recovered to the baseline level.Abstract SU_35_2341; Table 1The average scores of IPSS and EPICBefore the C-ion RTThe last day of the C-ion RT6 months12 months24 months36 monthsIPSS7.912.26.76.75.32.6EPICUrinary91.584.691.691.792.493.6Bowel93.892.394.194.592.794.2Sexual33.332.835.136.037.538.8(subgroup*Twenty-three low-risk patients not received any HT.)43.741.346.945.447.644.2Hormonal83.384.385.788.791.093.0∗ Twenty-three low-risk patients not received any HT. Open table in a new tab It is suggested that the QOL outcome of the patients with localized PC is well maintained after the hypofractionatied C-ion RT. Further studies are required to asses QOL outcome more precisely especially sexual function because most patients in this analysis received HT.