Local control of metastatic lung tumors treated with SBRT of 48 Gy in four fractions: in comparison with primary lung cancer.
OBJECTIVE
The optimal dose of stereotactic body radiotherapy (SBRT) for metastatic lung tumors has not been clarified. Local control rates of metastatic lung tumors treated with SBRT of 48 Gy in four fractions, which is one of the common dose schedules for Stage I primary lung cancer in Japan, were examined.


METHODS
Between 2006 and 2008, 12 metastatic lung tumors (colorectal cancer, 7; others, 5) in 10 patients and 56 lesions of Stage I primary lung cancer (T1, 43; T2, 13) in 52 patients were treated with SBRT of 48 Gy in four fractions at the isocenter.


RESULTS
Two-year overall survival rates were 86% for patients with metastatic lung tumors and 96% for patients with Stage I primary lung cancer (P = 0.4773). One- and 2-year local control rates were 48% and 25% for metastatic lung tumors, and 91% and 88% for Stage I primary lung cancer, respectively (P < 0.0001).


CONCLUSIONS
The local control rates after SBRT of 48 Gy in four fractions were significantly worse in metastatic lung tumors compared with Stage I primary lung cancer. In SBRT, metastatic lung tumors should be clearly differentiated from primary lung cancer and should be given higher doses.
Hamamoto
Yasushi
Y
Department of Radiology, Shikoku Cancer Center, Matsuyama, Ehime, Japan. yhamamot@shikoku-cc.go.jp
Kataoka
Masaaki
M
Yamashita
Motohiro
M
Shinkai
Tetsu
T
Kubo
Yoshiro
Y
Sugawara
Yoshifumi
Y
Inoue
Takeshi
T
Sakai
Shinya
S
Aono
Shoji
S
Takahashi
Tadaaki
T
Semba
Takatoshi
T
Uwatsu
Kotaro
K
D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D009367:Neoplasm Staging; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016896:Treatment Outcome