TY - JOUR
T1 - Dummy run and conformity indices in the ongoing EORTC low-grade glioma trial 22033-26033
T2 - First evaluation of quality of radiotherapy planning
AU - Musat, Elena
AU - Roelofs, Erik
AU - Bar-Deroma, Raquel
AU - Fenton, Paul
AU - Gulyban, Akos
AU - Collette, Laurence
AU - Stupp, Roger
AU - Weber, Damien C.
AU - Davis, J. Bernard
AU - Aird, Edwin
AU - Baumert, Brigitta G.
PY - 2010/5
Y1 - 2010/5
N2 - Purpose: Early assessment of radiotherapy (RT) quality in the ongoing EORTC trial comparing primary temozolomide versus RT in low-grade gliomas. Materials and methods: RT plans provided for dummy cases were evaluated and compared against expert plans. We analysed: (1) tumour and organs-at-risk delineation, (2) geometric and dosimetric characteristics, (3) planning parameters, compliance with dose prescription and Dmax for OAR (4) indices: RTOG conformity index (CI), coverage factor (CF), tissue protection factor (PF); conformity number (CN = PF× CF); dose homogeneity in PTV (U). Results: Forty-one RT plans were evaluated. Only two (5%) centres were requested to repeat CTV-PTV delineations. Three (7%) plans had a significant under-dosage and dose homogeneity in one deviated > 10%. Dose distribution was good with mean values of 1.5, 1, 0.68, and 0.68 (ideal values = 1) for CI, CF, PF, and CN, respectively. CI and CN strongly correlated with PF and they correlated with PTV. Planning with more beams seems to increase PTVDmin, improving CF. U correlated with PTVDmax. Conclusion: Preliminary results of the dummy run procedure indicate that most centres conformed to protocol requirements. To quantify plan quality we recommend systematic calculation of U and either CI or CN, both of which measure the amount of irradiated normal brain tissue.
AB - Purpose: Early assessment of radiotherapy (RT) quality in the ongoing EORTC trial comparing primary temozolomide versus RT in low-grade gliomas. Materials and methods: RT plans provided for dummy cases were evaluated and compared against expert plans. We analysed: (1) tumour and organs-at-risk delineation, (2) geometric and dosimetric characteristics, (3) planning parameters, compliance with dose prescription and Dmax for OAR (4) indices: RTOG conformity index (CI), coverage factor (CF), tissue protection factor (PF); conformity number (CN = PF× CF); dose homogeneity in PTV (U). Results: Forty-one RT plans were evaluated. Only two (5%) centres were requested to repeat CTV-PTV delineations. Three (7%) plans had a significant under-dosage and dose homogeneity in one deviated > 10%. Dose distribution was good with mean values of 1.5, 1, 0.68, and 0.68 (ideal values = 1) for CI, CF, PF, and CN, respectively. CI and CN strongly correlated with PF and they correlated with PTV. Planning with more beams seems to increase PTVDmin, improving CF. U correlated with PTVDmax. Conclusion: Preliminary results of the dummy run procedure indicate that most centres conformed to protocol requirements. To quantify plan quality we recommend systematic calculation of U and either CI or CN, both of which measure the amount of irradiated normal brain tissue.
KW - Conformal radiotherapy
KW - Conformity indices
KW - Dummy run
KW - Homogeneity
KW - Low-grade gliomas
KW - Quality assurance
UR - http://www.scopus.com/inward/record.url?scp=77956621835&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2010.03.005
DO - 10.1016/j.radonc.2010.03.005
M3 - Article
C2 - 20378192
AN - SCOPUS:77956621835
SN - 0167-8140
VL - 95
SP - 218
EP - 224
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 2
ER -
