[Impact of dynamic IMRT and tomotherapy in pelvic cancers: a prospective dosimetric study with 51 patients]
S Servagi-Vernat1, P Giraud2, P Fenoglietto3
1Service de radiothérapie, hôpital universitaire Jean-Minjoz, 3, boulevard Alexandre-Fleming, 25030 Besançon, France; Informatics and radiation physics for medical and technical applications (Irma), LCPR, AC/CE, UMR 6249, CNRS, 4, place Tharradin, BP 71427, 25211 Montbéliard cedex, France; UMR 6249, université de Franche-Comté, 4, place Tharradin, BP 71427, 25211 Montbéliard, France.
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(®)) and 15 patients were treated for a localized anal cancer (nine with helical tomotherapy and six with Rapid'Arc(®)). 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(®) 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.
