Reassessment of declines in pulmonary function ≥1 year after stereotactic body radiotherapy.
BACKGROUND
Stereotactic body radiation therapy (SBRT) is standard care for patients with inoperable early-stage non-small cell lung cancer. However, clinicians may hesitate to use SBRT in patients with severe COPD because of potential negative effects on pulmonary function. We quantitatively analyzed long-term declines in pulmonary function after SBRT to ascertain lifelong tolerability to SBRT.


METHODS
Between 2005 and 2010 at Ofuna Chuo Hospital, 292 patients with lung tumors were treated with SBRT. Among them, patients who underwent pulmonary function tests (PFTs) both pretreatment and at ≥1 year after SBRT were evaluated in this retrospective analysis. The decline ratio in FEV(1) and FVC was assessed (ie, ΔFEV(1)/preFEV(1) and ΔFVC/preFVC). Predictors were identified using univariate and multivariate analyses.


RESULTS
The 141 eligible patients had follow-up PFTs at a median of 21.0 (range, 12.0-74.8) months after SBRT. Among groups with normal function, or mild to moderate or severe COPD, the median values for ΔFEV(1)/preFEV(1) were 7.9%, 7.9%, and 7.4%, respectively, and for ΔFVC/preFVC, 5.1%, 3.4%, and 0.5%, respectively. Low BMI was the only predictor for ΔFEV(1)/preFEV(1)> 10%. Low BMI, high lung volume receiving 20 Gy, and high pretreatment FVC were predictors for ΔFVC/preFVC > 10%.


CONCLUSIONS
Declines in FEV(1) and FVC were small, but statistically significant in patients with normal function or mild to moderate COPD, but nonsignificant in patients with severe COPD. These declines were primarily due to physiologic aging. SBRT had a limited effect on decline in long-term pulmonary function and may be an acceptable alternative to surgery for patients with comorbid lung cancer and COPD.
Department of Radiology, Ofuna Chuo Hospital, Kanagawa, Japan; Department of Radiology, Tokyo Metropolitan Hiroo General Hospital, Tokyo.
Atsuya
A
Takeda
Department of Respirology, Tokyo Metropolitan Hiroo General Hospital, Tokyo.
Tatsuji
T
Enomoto
Department of Radiology, Ofuna Chuo Hospital, Kanagawa, Japan.
Naoko
N
Sanuki
Department of Respirology, Ofuna Chuo Hospital, Kanagawa, Japan.
Hiroshi
H
Handa
Department of Radiology, Ofuna Chuo Hospital, Kanagawa, Japan.
Yousuke
Y
Aoki
Department of Radiology, Ofuna Chuo Hospital, Kanagawa, Japan.
Yohei
Y
Oku
Department of Radiation Oncology, Tokai University, Kanagawa, Japan. Electronic address: kunieda-mi@umin.ac.jp.
Etsuo
E
Kunieda
D000230:Adenocarcinoma / Q000150:complications / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000601:surgery*; D002294:Carcinoma, Squamous Cell / Q000150:complications / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000503:physiopathology / Q000528:radiation effects; D008175:Lung Neoplasms / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D016634:Radiosurgery / Q000009:adverse effects*; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012307:Risk Factors