The role of lung perfusion imaging in predicting the direction of radiation-induced changes in pulmonary function tests

Cancer. 2000 May 1;88(9):2135-41.


Background: The aim of this study was to determine whether preradiation (pre-RT) single photon emission computed tomography (SPECT) lung perfusion scans can be used to predict RT-induced changes in pulmonary function tests (PFTs).

Methods: Ninety-four patients irradiated for thoracic tumors had pre-RT SPECT lung perfusion scans. The presence of SPECT hypoperfusion distal to a central mediastinal tumor was qualitatively assessed visually without knowledge of PFT changes. Patients were grouped based on whether the diffusion capacity (DLCO) ever increased post-RT. Comparisons of patient groups were performed using 1-tailed Fisher exact tests. Patient follow-up was 6-56 months (mean, 30 months). To assess SPECT hypoperfusion objectively, the average dose to the computed tomography (CT)-defined lung was compared with the weighted-average dose (based on relative perfusion) to the SPECT-defined lung. The ratio between the CT- and SPECT-defined mean lung dose provided a quantitative assessment of hypoperfusion. The mean ratio for patients with central tumor and adjacent hypoperfusion was compared with that of the others (Wilcoxon rank-sum one-sided test).

Results: In patients with central tumors, 41% (9 of 22) with adjacent hypoperfusion had improvements in DLCO following radiation, versus 18% (3 of 17) of those without hypoperfusion (P = 0.11). In patients with lung carcinoma, the corresponding ratios were 40% (8 of 20) and 10% (1 of 10), respectively (P = 0.10). The mean ratio of CT dose to SPECT dose was 1.35 for patients with central tumors and adjacent hypoperfusion versus 1.16 for others (P = 0.017).

Conclusions: The presence of SPECT hypoperfusion adjacent to a central mediastinal mass may identify patients likely to have improved PFTs following RT. Thus, SPECT imaging may be useful in models for predicting radiation-induced changes in PFTs.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma / physiopathology
  • Carcinoma / radiotherapy
  • Female
  • Follow-Up Studies
  • Forecasting
  • Humans
  • Lung / diagnostic imaging*
  • Lung / physiopathology
  • Lung / radiation effects
  • Lung Neoplasms / physiopathology
  • Lung Neoplasms / radiotherapy
  • Lung Volume Measurements
  • Male
  • Mediastinal Neoplasms / physiopathology
  • Mediastinal Neoplasms / radiotherapy
  • Middle Aged
  • Prospective Studies
  • Pulmonary Diffusing Capacity / radiation effects
  • Radiation Dosage
  • Radiopharmaceuticals
  • Respiratory Function Tests*
  • Spirometry
  • Statistics as Topic
  • Technetium Tc 99m Aggregated Albumin
  • Thoracic Neoplasms / physiopathology
  • Thoracic Neoplasms / radiotherapy*
  • Tomography, Emission-Computed, Single-Photon* / methods
  • Tomography, X-Ray Computed


  • Radiopharmaceuticals
  • Technetium Tc 99m Aggregated Albumin