The effect of patient-specific factors on radiation-induced regional lung injury.

Published

Journal Article

PURPOSE: To assess the impact of patient-specific factors on radiation (RT)-induced reductions in regional lung perfusion. METHODS: Fifty patients (32 lung carcinoma, 7 Hodgkin's disease, 9 breast carcinoma and 2 other thoracic tumors) had pre-RT and > or = 24-week post-RT single photon emission computed tomography (SPECT) perfusion images to assess the dose dependence of RT-induced reductions in regional lung perfusion. The SPECT data were analyzed using a normalized and non-normalized approach. Furthermore, two different mathematical methods were used to assess the impact of patient-specific factors on the dose-response curve (DRC). First, DRCs for different patient subgroups were generated and compared. Second, in a more formal statistical approach, individual DRCs for regional lung injury for each patient were fit to a linear-quadratic model (reduction = coefficient 1 x dose + coefficient 2 x dose2). Multiple patient-specific factors including tobacco history, pre-RT diffusion capacity to carbon monoxide (DLCO), transforming growth factor-beta (TGF-beta), chemotherapy exposure, disease type, and mean lung dose were explored in a multivariate analysis to assess their impact on the coefficients. RESULTS: None of the variables tested had a consistent impact on the radiation sensitivity of regional lung (i.e., the slope of the DRC). In the formal statistical analysis, there was a suggestion of a slight increase in radiation sensitivity in the dose range >40 Gy for nonsmokers (vs. smokers) and in those receiving chemotherapy (vs. no chemotherapy). However, this finding was very dependent on the specific statistical and normalization method used. CONCLUSION: Patient-specific factors do not have a dramatic effect on RT-induced reduction in regional lung perfusion. Additional studies are underway to better clarify this issue. We continue to postulate that patient-specific factors will impact on how the summation of regional injury translates into whole organ injury. Refinements in our methods to generate and compare SPECT scans are needed.

Full Text

Duke Authors

Cited Authors

  • Garipagaoglu, M; Munley, MT; Hollis, D; Poulson, JM; Bentel, GC; Sibley, G; Anscher, MS; Fan, M; Jaszczak, RJ; Coleman, RE; Marks, LB

Published Date

  • September 1, 1999

Published In

Volume / Issue

  • 45 / 2

Start / End Page

  • 331 - 338

PubMed ID

  • 10487553

Pubmed Central ID

  • 10487553

International Standard Serial Number (ISSN)

  • 0360-3016

Digital Object Identifier (DOI)

  • 10.1016/s0360-3016(99)00201-1

Language

  • eng

Conference Location

  • United States