Clinical outcomes of single-fraction stereotactic radiation therapy of lung tumors.
BACKGROUND
The objective of the current study was to investigate the effects and the morbidities of single-fraction stereotactic radiation therapy (SRT) for lung tumors.


METHODS
A Microtron device was modified to deliver stereotactic irradiation under respiratory gating. Between August 1998 and December 2004, 59 malignant lung tumors (11 primary tumors, 48 metastases) that measured < 40 mm in greatest dimension were treated by single-fraction SRT. Nine tumors received a minimal dose of < 30 grays (Gy), and 50 tumors received a minimal dose of > or = 30 Gy. The macroscopic target volume ranged from 1 cc to 19 cc (mean, 5 cc).


RESULTS
The 1-year and 2-year local progression-free rates (LPFRs) were 93% and 78%, respectively. The overall survival rate was 76.5% at 1 year and 41% at 2 years. Local regrowth of the irradiated tumor was a direct cause of death in two patients. Only the minimal radiation dose to the reference target volume tended to have an influence on the LPFR (P = 0.068). The 2-year LPFRs for patients who received irradiation doses of > or = 30 Gy and < 30 Gy were 83% and 52%, respectively. With regard to morbidities, Grade 3 respiratory symptoms (according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring scheme) were noted in one patient.


CONCLUSIONS
The results from the current study suggested that single-fraction SRT was tolerable and was capable of attaining excellent local control in patients who had malignant lung tumors that measured < 4 cm in greatest dimension.
Department of Radiation Therapy and Oncology, International Medical Center of Japan, Toyama 1-21-1, Shinjuku-ku, 162-8655 Tokyo, Japan.
Ryusuke
R
Hara
Jun
J
Itami
Tatsuya
T
Kondo
Takashi
T
Aruga
Takashi
T
Uno
Nakashi
N
Sasano
Kayoko
K
Ohnishi
Makoto
M
Kiyozuka
Masashi
M
Fuse
Masashi
M
Ito
Kuniji
K
Naoi
Yuzuru
Y
Kohno
D000230:Adenocarcinoma / Q000532:radiotherapy / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000532:radiotherapy / Q000556:secondary; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy / Q000556:secondary; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009367:Neoplasm Staging; D013238:Stereotaxic Techniques; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome