OC-0347: Outcome and prognosticators in adult patients with medulloblastoma: a Rare Cancer Network study
Makaleler > Tam Makale · 2016
Yazarlar: B. Atalar, M. Ozsahin, J. Call, A. Napieralska, S. Kamer, V. Salvador, P. Erpolat, L. Negretti, Y.L. Ramstad, C. Onal, S. Akyurek, G. Ugurluer, B. Baumert, S. Servagi-Vernat, R.C. Miller, E. Ozyar, T. Sio
Radiotherapy and Oncology, Uluslararası, Wos, 2016, cilt 119, ss S159-S160
DOI: 10.1016/s0167-8140(16)31596-1
Özet
Purpose or Objective: The aim of this study was to investigate the patterns of failure after radiotherapy for pediatric intracranial ependymoma and their correlation to dose parameters.Material and Methods: Between 2000 and 2013, 206 patients with intracranial ependymoma were treated in the 13 french reference pediatric radiotherapy centers .The magnetic resonance imaging obtained at recurrence were registered with the original planning CT for topographic analysis of the patterns failure.Clinical target volume (CTV) and planning target volume (PTV) margins were extracted ; several dosimetric quality indices were derived from Dose Volume Histogram (DVH) to compare relapse with no-relapse patient.Results: With a median follow-up of 44.81 months (95% CI [36.80; 56.51]), 85 (41.3%) patients presented with recurrence.The topographic analysis of patterns of failure showed 50 (58.8%)patients with local recurrence in the radiation field (LF), 6 (4.1%) in the edge of field (EFG), 6 (7.1%) were loco-regional outside the field (LRF), 8 (9.4%) in spine (SF), 5 supratentorial (SUF) and 10 (11.8%) local and distant (LDF).The median prescription dose was respectively: 55.8 Gy [50.4; 60] in LF, 54 Gy [48.6; 59.4] in EF, 56.7 Gy [50.4; 60] in LRF, 54 Gy [50.4; 59.4] in LDF, 59.4 Gy [48.6-59.4] in SUF and 56.7Gy [54; 60] in SF.The median PTV margins was 0.5 mm [0.3; 1].The median Coverage index andThe Target Coverage index of the PTV were both lower in the relapse group as they were respectively 0.97 and 94.8% in the relapse group compared with 0.98 and 95.99% in the norelapse group.The median Homogeneity index was 0.097 in the relapse group versus 0.091 in the no-relapse group.The median volume of relapse was 1.29 cc [0.11; 27] in the LF group, with a median dose of 58.81 Gy [50.86; 61.38]. Conclusion:In patients with intracranial ependymoma, local failure in the tumor bed was the major pattern of failure.The preliminary results showed that all dosimetric indices on the PTV were worse in the relapse group.Improving the coverage of target volume may be an effective way to reduce the local failures.Thus a complementary correlation of relapse patterns with dose parameters to PTV and organs at risks and the irradiation techniques is under statistical analysis and final results will be presented at the meeting.