Carbon ion radiotherapy for unresectable sacral chordomas.
OBJECTIVE
The purpose is to evaluate the efficacy and toxicity of carbon ion radiotherapy for unresectable sacral chordomas.


METHODS
We performed a retrospective analysis of 30 patients with unresectable sacral chordomas treated with carbon ion radiotherapy at the Heavy Ion Medical Accelerator in Chiba, Japan. Twenty-three patients presented with no prior treatment, and the remaining 7 patients had locally recurrent disease following previous surgical resection. The median clinical target volume was 546 cm(3). The applied carbon ion dose ranged from 52.8 to 73.6 GyE (gray equivalent, median 70.4) in 16 fixed fractions over 4 weeks.


RESULTS
At median follow-up of 30 months (range, 9 to 87 months), 26 patients were still alive and 24 patients remained continuously disease-free. Overall and cause-specific survival rates at 5 years were 52 and 94%, respectively. The overall local control rate at 5 years was 96%. Two patients experienced severe skin/soft tissue complications requiring skin grafts. No other treatment-related surgical interventions, including colostomy or urinary diversion, were carried out. All patients have remained ambulatory and able to stay at home after carbon ion radiotherapy.


CONCLUSIONS
Carbon ion radiotherapy is effective and safe in the management of patients with unresectable sacral chordomas and offers a promising alternative to surgery.
Imai
Reiko
R
Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba.
Kamada
Tadashi
T
Tsuji
Hiroshi
H
Yanagi
Takeshi
T
Baba
Masayuki
M
Miyamoto
Tadaaki
T
Kato
Shingo
S
Kandatsu
Susumu
S
Mizoe
Jun-etsu
JE
Tsujii
Hirohiko
H
Tatezaki
Shin-ichiro
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes / Q000627:therapeutic use*; D002817:Chordoma / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012189:Retrospective Studies; D012447:Sacrum; D013125:Spinal Neoplasms / Q000532:radiotherapy*; D015996:Survival Rate; D016896:Treatment Outcome
D002250:Carbon Radioisotopes