http://www.ncbi.nlm.nih.gov/pubmed/22420964

Int J Radiat Oncol Biol Phys. 2012 Mar 13. [Epub ahead of print]

Changes in Pulmonary Function after Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-CellLung Cancer.

Lopez Guerra JL, Gomez DR, Zhuang Y, Levy LB, Eapen G, Liu H, Mohan R, Komaki R, Cox JD, Liao Z.

Source

Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Radiation Oncology, Hospitales Universitarios Virgen del Rocio, Seville, Spain; Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.

Abstract

PURPOSE:

To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-celllung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics.

PATIENTS AND METHODS:

We analyzed 250 patients who had received ≥60 Gy radio(chemo)therapy for primary NSCLC in 1998-2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient's preradiation value at the following time intervals: 0-4 (T1), 5-8 (T2), and 9-12 (T3) months.

RESULTS:

Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC.

CONCLUSIONS:

Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy or intensity-modulated radiotherapy, may decrease the pulmonary impairment through greater lung sparing.