TY - JOUR
T1 - Dosimetric Evaluation of Heterogeneity Corrections for RTOG 0236
T2 - Stereotactic Body Radiotherapy of Inoperable Stage I-II Non-Small-Cell Lung Cancer
AU - Xiao, Ying
AU - Papiez, Lech
AU - Paulus, Rebecca
AU - Timmerman, Robert
AU - Straube, William L.
AU - Bosch, Walter R.
AU - Michalski, Jeff
AU - Galvin, James M.
N1 - Funding Information:
Supported by National Cancer Institute Grants U24 CA 81647, U10 CA21661, and U10 CA32115.
PY - 2009/3/15
Y1 - 2009/3/15
N2 - Purpose: Using a retrospective analysis of treatment plans submitted from multiple institutions accruing patients to the Radiation Therapy Oncology Group (RTOG) 0236 non-small-cell stereotactic body radiotherapy protocol, the present study determined the dose prescription and critical structure constraints for future stereotactic body radiotherapy lung protocols that mandate density-corrected dose calculations. Method and Materials: A subset of 20 patients from four institutions participating in the RTOG 0236 protocol and using superposition/convolution algorithms were compared. The RTOG 0236 protocol required a prescription dose of 60 Gy delivered in three fractions to cover 95% of the planning target volume. Additional requirements were specified for target dose heterogeneity and the dose to normal tissue/structures. The protocol required each site to plan the patient's treatment using unit density, and another plan with the same monitor units and applying density corrections was also submitted. These plans were compared to determine the dose differences. Two-sided, paired Student's t tests were used to evaluate these differences. Results: With heterogeneity corrections applied, the planning target volume receiving ≥60 Gy decreased, on average, 10.1% (standard error, 2.7%) from 95% (p = .001). The maximal dose to any point ≥2 cm away from the planning target volume increased from 35.2 Gy (standard error, 1.7) to 38.5 Gy (standard error, 2.2). Conclusion: Statistically significant dose differences were found with the heterogeneity corrections. The information provided in the present study is being used to design future heterogeneity-corrected RTOG stereotactic body radiotherapy lung protocols to match the true dose delivered for RTOG 0236.
AB - Purpose: Using a retrospective analysis of treatment plans submitted from multiple institutions accruing patients to the Radiation Therapy Oncology Group (RTOG) 0236 non-small-cell stereotactic body radiotherapy protocol, the present study determined the dose prescription and critical structure constraints for future stereotactic body radiotherapy lung protocols that mandate density-corrected dose calculations. Method and Materials: A subset of 20 patients from four institutions participating in the RTOG 0236 protocol and using superposition/convolution algorithms were compared. The RTOG 0236 protocol required a prescription dose of 60 Gy delivered in three fractions to cover 95% of the planning target volume. Additional requirements were specified for target dose heterogeneity and the dose to normal tissue/structures. The protocol required each site to plan the patient's treatment using unit density, and another plan with the same monitor units and applying density corrections was also submitted. These plans were compared to determine the dose differences. Two-sided, paired Student's t tests were used to evaluate these differences. Results: With heterogeneity corrections applied, the planning target volume receiving ≥60 Gy decreased, on average, 10.1% (standard error, 2.7%) from 95% (p = .001). The maximal dose to any point ≥2 cm away from the planning target volume increased from 35.2 Gy (standard error, 1.7) to 38.5 Gy (standard error, 2.2). Conclusion: Statistically significant dose differences were found with the heterogeneity corrections. The information provided in the present study is being used to design future heterogeneity-corrected RTOG stereotactic body radiotherapy lung protocols to match the true dose delivered for RTOG 0236.
KW - Non-small-cell lung cancer
KW - RTOG
KW - Radiation Therapy Oncology Group
KW - Radiotherapy
KW - Stereotactic body
UR - http://www.scopus.com/inward/record.url?scp=61349168409&partnerID=8YFLogxK
U2 - 10.1016/j.ijrobp.2008.11.019
DO - 10.1016/j.ijrobp.2008.11.019
M3 - Article
C2 - 19251095
AN - SCOPUS:61349168409
SN - 0360-3016
VL - 73
SP - 1235
EP - 1242
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 4
ER -