Carbon ion radiation therapy for prostate cancer: results of a prospective phase II study.
OBJECTIVE
To determine the efficacy and feasibility of carbon ion radiotherapy (C-ion RT) for prostate cancer.


METHODS
Between April 2000 and November 2003, 175 patients received C-ion RT using a recommended dose fractionation (66.0 GyE/20 fractions) established from prior studies. C-ion RT alone was performed for 33 patients constituting a low-risk group (Stage < or =T2a and PSA <20 ng/ml and Gleason score < or =6); the remaining 142 high-risk patients received an additional androgen deprivation therapy (ADT).


RESULTS
The 4-year overall survival and bNED rates were 91% and 87%, respectively. Local control was achieved in all but one patient. The 4-year bNED rates were 87% in the low-risk group and 88% in the high-risk group. In very advanced diseases (Stage > or= T3a or PSA > or= 20 ng/ml or Gleason score > or =8), there was significant difference in the bNED rate according to period of ADT administration (ADT > or =24 months: 93%, ADT <24 months: 73%, p<0.01). Grade 2 late toxicities developed in 4 patients (2%) for the rectum and 9 patients (5%) for the genitourinary system but no Grade 3 or higher toxicity was observed.


CONCLUSIONS
The effectiveness of C-ion RT for prostate cancer has been well confirmed. Based on these results, new study of a C-ion RT modified for the administration strategy of ADT according to the patient risk has been started by dividing patients into 3 groups, high-risk, intermediate-risk, and low-risk.
Ishikawa
Hitoshi
H
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage-ku, Chiba-city, Japan.
Tsuji
Hiroshi
H
Kamada
Tadashi
T
Yanagi
Takeshi
T
Mizoe
Jun-Etsu
JE
Kanai
Tatsuaki
T
Morita
Shinroku
S
Wakatsuki
Masaru
M
Shimazaki
Jun
J
Tsujii
Hirohiko
H
D000230:Adenocarcinoma / Q000401:mortality / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000008:administration & dosage; D002250:Carbon Radioisotopes / Q000627:therapeutic use*; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D011788:Quality of Life; D011832:Radiation Injuries / Q000209:etiology; D018709:Statistics, Nonparametric; D016019:Survival Analysis
D000726:Androgen Antagonists; D002250:Carbon Radioisotopes