Phase I/II trial of definitive carbon ion radiotherapy for prostate cancer: evaluation of shortening of treatment period to 3 weeks.
BACKGROUND
The purpose of this study was to evaluate the feasibility of a new shortened 3-week treatment schedule of carbon ion radiotherapy (CIRT) for prostate cancer.


METHODS
Beginning in May 2010, patients with T1b-T3bN0M0, histologically proven prostate adenocarcinoma were enrolled in the phase II trial of CIRT. Patients received 51.6 GyE in 12 fractions over 3 weeks (protocol 1002). The primary end point was defined as the incidence of late adverse events that were evaluated based on the Common Terminology Criteria for Adverse Events version 4.0. Biochemical failure was determined using the Phoenix definition (nadir +2.0 ng ml(-1)).


RESULTS
Forty-six patients were enrolled, and all patients were included in the analysis. The number of low-, intermediate-, and high-risk patients was 12 (26%), 9 (20%), and 25 (54%), respectively. The median follow-up period of surviving patients was 32.3 months. Two patients had intercurrent death without recurrence, and the remaining 44 patients were alive at the time of this analysis. In the analysis of late toxicities, grade 1 (G1) rectal haemorrhage was observed in 3 (7%) patients. The incidence of G1 haematuria was observed in 6 (13%) patients, and G1 urinary frequency was observed in 17 (37%) patients. No ⩾G2 late toxicities were observed. In the analysis of acute toxicities, 2 (4%) patients showed G2 urinary frequency, and no other G2 acute toxicities were observed.


CONCLUSIONS
The new shortened CIRT schedule over 3 weeks was considered as feasible. The analysis of long-term outcome is warranted.
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
T
T
Nomiya
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
H
H
Tsuji
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
K
K
Maruyama
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
S
S
Toyama
Department of Urology, Toho University School of Medicine, Chiba, Japan.
H
H
Suzuki
Department of Urology, Tokyo Koseinenkin Hospital, Tokyo, Japan.
K
K
Akakura
Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan.
J
J
Shimazaki
Department of Radiation Oncology, Yamagata University School of Medicine, Yamagata, Japan.
K
K
Nemoto
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
T
T
Kamada
Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan.
H
H
Tsujii
D000230:Adenocarcinoma / Q000188:drug therapy / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D002244:Carbon / Q000009:adverse effects / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology / Q000209:etiology; D063193:Heavy Ion Radiotherapy / Q000009:adverse effects; D020450:Heavy Ions / Q000009:adverse effects; D006417:Hematuria / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000453:epidemiology / Q000209:etiology; D011880:Radiotherapy Planning, Computer-Assisted; D012007:Rectum / Q000528:radiation effects; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000528:radiation effects; D014555:Urination Disorders / Q000453:epidemiology / Q000209:etiology
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D002244:Carbon