Impact of dynamic IMRT and tomotherapy in pelvic cancers: A prospective dosimetric study with 51 patients

Purpose. - To compare the dosimetric results of different techniques of dynamic intensity modulated radiation therapy (IMRT) in patients treated for a pelvic cancer with nodal irradiation. Patients and methods. - Data of 51 patients included prospectively in the Artpelvis study were analyzed. Thirty-six patients were treated for a high-risk prostate cancer (13 with helical tomotherapy, and 23 with Rapid'Arc (R)) and 15 patients were treated for a localized anal cancer (nine with helical tomotherapy and six with Rapid'Arc (R)). Plan quality was assessed according to several different dosimetric indexes of coverage of planning target volume and sparing of organs at risk. Results. - Although some dosimetric differences were statistically significant, helical tomotherapy and Rapid'Arc provided very similar and highly conformal plans. Regarding organs at risk, Rapid'Arc (R) provided better pelvic bone sparing with a lower non-tumoral integral dose Conclusion. - In pelvis cancer with nodal irradiation, Rapid'Arc and helical tomotherapy provided very similar plans. The clinical evaluation of Artpelvis study will verify this equivalence hypothesis. (C) 2014 Societe francaise de radiotherapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.