Hypofractionated stereotactic radiotherapy (HypoFXSRT) for stage I non-small cell lung cancer: updated results of 257 patients in a Japanese multi-institutional study.
BACKGROUND
Hypofractionated stereotactic radiotherapy (HypoFXSRT) has recently been used for the treatment of small lung tumors. We retrospectively analyzed the treatment outcome of HypoFXSRT for stage I non-small cell lung cancer (NSCLC) treated in a Japanese multi-institutional study.


METHODS
This is a retrospective study to review 257 patients with stage I NSCLC (median age, 74 years: 164 T1N0M0, 93 T2N0M0) were treated with HypoFXSRT alone at 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. A total dose of 18 to 75 Gy at the isocenter was administered in one to 22 fractions. The median calculated biological effective dose (BED) was 111 Gy (range, 57-180 Gy) based on alpha/beta = 10.


RESULTS
During follow-up (median, 38 months), pulmonary complications of above grade 2 arose in 14 patients (5.4%). Local progression occurred in 36 patients (14.0%), and the local recurrence rate was 8.4% for a BED of 100 Gy or more compared with 42.9% for less than 100 Gy (p < 0.001). The 5-year overall survival rate of medically operable patients was 70.8% among those treated with a BED of 100 Gy or more compared with 30.2% among those treated with less than 100 Gy (p < 0.05).


CONCLUSIONS
Although this is a retrospective study, HypoFXSRT with a BED of less than 180 Gy was almost safe for stage I NSCLC, and the local control and overall survival rates in 5 years with a BED of 100 Gy or more were superior to the reported results for conventional radiotherapy. For all treatment methods and schedules, the local control and survival rates were better with a BED of 100 Gy or more compared with less than 100 Gy. HypoFXSRT is feasible for curative treatment of patients with stage I NSCLC.
Onishi
Hiroshi
H
Department of Radiology, School of Medicine, Yamanashi University, Shimokato, Chuo-city, Yamanashi, Japan. honishi@yamanashi.ac.jp
Shirato
Hiroki
H
Nagata
Yasushi
Y
Hiraoka
Masahiro
M
Fujino
Masaharu
M
Gomi
Kotaro
K
Niibe
Yuzuru
Y
Karasawa
Katsuyuki
K
Hayakawa
Kazushige
K
Takai
Yoshihiro
Y
Kimura
Tomoki
T
Takeda
Atsuya
A
Ouchi
Atsushi
A
Hareyama
Masato
M
Kokubo
Masaki
M
Hara
Ryusuke
R
Itami
Jun
J
Yamada
Kazunari
K
Araki
Tsutomu
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D015996:Survival Rate