Automated volumetric modulated Arc therapy treatment planning for stage III lung cancer: how does it compare with intensity-modulated radio therapy?
OBJECTIVE
To compare the quality of volumetric modulated arc therapy (VMAT) or intensity-modulated radiation therapy (IMRT) plans generated by an automated inverse planning system with that of dosimetrist-generated IMRT treatment plans for patients with stage III lung cancer.


METHODS
Two groups of 8 patients with stage III lung cancer were randomly selected. For group 1, the dosimetrists spent their best effort in designing IMRT plans to compete with the automated inverse planning system (mdaccAutoPlan); for group 2, the dosimetrists were not in competition and spent their regular effort. Five experienced radiation oncologists independently blind-reviewed and ranked the three plans for each patient: a rank of 1 was the best and 3 was the worst. Dosimetric measures were also performed to quantitatively evaluate the three types of plans.


RESULTS
Blind rankings from different oncologists were generally consistent. For group 1, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.6, 2.13, and 2.18, respectively. The auto-VMAT plans in group 1 had 10% higher planning tumor volume (PTV) conformality and 24% lower esophagus V70 (the volume receiving 70 Gy or more) than the manual IMRT plans; they also resulted in more than 20% higher complication-free tumor control probability (P+) than either type of IMRT plans. The auto- and manual IMRT plans in this group yielded generally comparable dosimetric measures. For group 2, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.55, 1.75, and 2.75, respectively. Compared to the manual IMRT plans in this group, the auto-VMAT plans and auto-IMRT plans showed, respectively, 17% and 14% higher PTV dose conformality, 8% and 17% lower mean lung dose, 17% and 26% lower mean heart dose, and 36% and 23% higher P+.


CONCLUSIONS
mdaccAutoPlan is capable of generating high-quality VMAT and IMRT treatment plans for stage III lung cancer. Manual IMRT plans could achieve quality similar to auto-IMRT plans if best effort was spent.
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Enzhuo M
EM
Quan
Joe Y
JY
Chang
Zhongxing
Z
Liao
Tingyi
T
Xia
Zhiyong
Z
Yuan
Hui
H
Liu
Xiaoqiang
X
Li
Cody A
CA
Wages
Radhe
R
Mohan
Xiaodong
X
Zhang
D004947:Esophagus / Q000000981:diagnostic imaging; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D058958:Organs at Risk / Q000000981:diagnostic imaging; D018787:Radiation Oncology; D011859:Radiography; D011874:Radiometry; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods / Q000592:standards*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods / Q000592:standards*; D012015:Reference Standards; D013116:Spinal Cord / Q000000981:diagnostic imaging; D047368:Tumor Burden