Preserving functional lung using perfusion imaging and intensity-modulated radiation therapy for advanced-stage non-small cell lung cancer.
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.
Shioyama
Yoshiyuki
Y
Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
Jang
Si Young
SY
Liu
H Helen
HH
Guerrero
Thomas
T
Wang
Xuanmin
X
Gayed
Isis W
IW
Erwin
William D
WD
Liao
Zhongxing
Z
Chang
Joe Y
JY
Jeter
Melenda
M
Yaremko
Brian P
BP
Borghero
Yerko O
YO
Cox
James D
JD
Komaki
Ritsuko
R
Mohan
Radhe
R
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