Timing and characteristics of radiation pneumonitis after stereotactic body radiotherapy for peripherally located stage I lung cancer.
BACKGROUND
This study was conducted to determine the timing and characteristics of radiation pneumonitis (RP) associated with stereotactic body radiotherapy (SBRT) for stage I lung cancer.


METHODS
Two hundred thirty-one patients treated with SBRT using 52 Gy in 4 fractions were identified. Control rate, RP incidence rate, and predictive factors and timing of RP were evaluated retrospectively.


RESULTS
The 3-year overall survival and local control rates were 80.7 and 92.0 %, respectively. The grade ≥2 RP rate was 13.0 %; no grade 4-5 RP occurred. The most statistically significant predictive factor of grade ≥2 RP was V10. The median intervals to first graphical appearance were 4.2 and 2.5 months for grade 1 and grade 2-3 RP, respectively. Median intervals to maximum radiological density change were 6.0 and 4.6 months for grade 1 and grade 2-3 RP, respectively. A significantly different interval to first graphical appearance between grade 1 and grade 2-3 RP was observed; no significantly different interval to maximum radiological density change was noted.


CONCLUSIONS
The first graphical appearance of grade ≥2 RP was earlier than that of grade 1 RP, although the timing of maximum radiological density change was not significantly different.
Department of Radiation Oncology, Niigata Cancer Center Hospital, 2-15-3 Kawagishi-cho, Niigata, 951-8566, Japan, ayae-kanemoto@umin.ac.jp.
Ayae
A
Kanemoto
Yasuo
Y
Matsumoto
Tadashi
T
Sugita
D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D017564:Radiation Pneumonitis / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies