title: Preserving functional lung using perfusion imaging and intensity-modulated radiation therapy for advanced-stage non-small cell lung cancer.
abstract: OBJECTIVE
  To assess quantitatively the impact of incorporating functional lung imaging into intensity-modulated radiation therapy planning for locally advanced non-small cell lung cancer (NSCLC).
  
  
  METHODS
  Sixteen patients with advanced-stage NSCLC who underwent radiotherapy were included in this study. Before radiotherapy, each patient underwent lung perfusion imaging with single-photon-emission computed tomography and X-ray computed tomography (SPECT-CT). The SPECT-CT was registered with simulation CT and was used to segment the 50- and 90-percentile hyperperfusion lung (F50 lung and F90 lung). Two IMRT plans were designed and compared in each patient: an anatomic plan using simulation CT alone and a functional plan using SPECT-CT in addition to the simulation CT. Dosimetric parameters of the two types of plans were compared in terms of tumor coverage and avoidance of normal tissues.
  
  
  RESULTS
  In incorporating perfusion information in IMRT planning, the median reductions in the mean doses to the F50 and F90 lung in the functional plan were 2.2 and 4.2 Gy, respectively, compared with those in the anatomic plans. The median reductions in the percentage of volume irradiated with >5 Gy, >10 Gy, and >20 Gy in the functional plans were 7.1%, 6.0%, and 5.1%, respectively, for F50 lung, and 11.7%, 12.0%, and 6.8%, respectively, for F90 lung. A greater degree of sparing of the functional lung was achieved for patients with large perfusion defects compared with those with relatively uniform perfusion distribution.
  
  
  CONCLUSIONS
  Function-guided IMRT planning appears to be effective in preserving functional lung in locally advanced-stage NSCLC patients.
authors: Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
authors: Yoshiyuki
authors: Y
authors: Shioyama
authors: Si Young
authors: SY
authors: Jang
authors: H Helen
authors: HH
authors: Liu
authors: Thomas
authors: T
authors: Guerrero
authors: Xuanmin
authors: X
authors: Wang
authors: Isis W
authors: IW
authors: Gayed
authors: William D
authors: WD
authors: Erwin
authors: Zhongxing
authors: Z
authors: Liao
authors: Joe Y
authors: JY
authors: Chang
authors: Melenda
authors: M
authors: Jeter
authors: Brian P
authors: BP
authors: Yaremko
authors: Yerko O
authors: YO
authors: Borghero
authors: James D
authors: JD
authors: Cox
authors: Ritsuko
authors: R
authors: Komaki
authors: Radhe
authors: R
authors: Mohan
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000532:radiotherapy*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D050397:Radiotherapy, Intensity-Modulated; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed