Dose escalation study of carbon ion radiotherapy for locally advanced carcinoma of the uterine cervix.
OBJECTIVE
To evaluate the toxicity and efficacy of carbon ion radiotherapy (CIRT) for locally advanced cervical cancer by two phase I/II clinical trials.


METHODS
Between June 1995 and January 2000, 44 patients were treated with CIRT. Thirty patients had Stage IIIB disease, and 14 patients had Stage IVA disease. Median tumor size was 6.5 cm (range, 4.2-11.0 cm). The treatment consisted of 16 fractions of whole pelvic irradiation and 8 fractions of local boost. In the first study, the total dose ranged from 52.8 to 72.0 gray equivalents (GyE) (2.2-3.0 GyE per fraction). In the second study, the whole pelvic dose was fixed at 44.8 GyE, and an additional 24.0 or 28.0 GyE was given to the cervical tumor (total dose, 68.8 or 72.8 GyE).


RESULTS
No patient developed severe acute toxicity. In contrast, 8 patients developed major late gastrointestinal complications. The doses resulting in major complications were > or =60 GyE. All patients with major complications were surgically salvaged. The 5-year local control rate for patients in the first and second studies was 45% and 79%, respectively. When treated with > or =62.4 GyE, the local control was favorable even for the patients with stage IVA disease (69%) or for those with tumors > or =6.0 cm (64%).


CONCLUSIONS
In CIRT for advanced cervical cancer, the dose to the intestines should be limited to <60 GyE to avoid major complications. Although the number of patients in this study was small, the results support continued investigation to confirm therapeutic efficacy.
Kato
Shingo
S
Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan. s.kato@nirs.go.jp
Ohno
Tatsuya
T
Tsujii
Hirohiko
H
Nakano
Takashi
T
Mizoe
Jun-Etsu
JE
Kamada
Tadashi
T
Miyamoto
Tadaaki
T
Tsuji
Hiroshi
H
Kato
Hirotoshi
H
Yamada
Shigeru
S
Kandatsu
Susumu
S
Yoshikawa
Kyosan
K
Ezawa
Hidefumi
H
Suzuki
Michiya
M
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D018196:Carcinoma, Adenosquamous / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D041981:Gastrointestinal Tract / Q000528:radiation effects; D006801:Humans; D008875:Middle Aged; D011832:Radiation Injuries / Q000150:complications; D011859:Radiography; D011879:Radiotherapy Dosage; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*
D002250:Carbon Radioisotopes