Journal
RADIOTHERAPY AND ONCOLOGY
Volume 181, Issue -, Pages -Publisher
ELSEVIER IRELAND LTD
DOI: 10.1016/j.radonc.2022.11.024
Keywords
Glioblastoma; Radiotherapy; Clinical target volume; Recurrence patterns; Temozolomide; Target delineation
Ask authors/readers for more resources
The purpose of this study was to analyze recurrence patterns in glioblastoma (GBM) patients after standard chemoradiation using different target volume delineation strategies. 207 GBM patients who recurred after standard chemoradiation were evaluated. Recurrent lesions were classified as in-field, marginal, or distant, and a theoretical plan with a reduced margin was created for comparison.
Purpose: To analyze recurrence patterns in patients with glioblastoma (GBM) after standard chemoradi-ation according to different target volume delineation strategies.Methods and materials: Two hundred seven patients with GBM who recurred after standard chemoradi-ation were evaluated. According to ESTRO target volume delineation guideline, the CTV was generated by adding a 2-cm margin to the GTV, defined as the resection cavity plus residual tumor. Patterns of failure were analyzed using dose-volume histogram. Recurrent lesions were defined as in-field, marginal, or dis-tant if > 80 %, 20-80 %, or < 20 % of the intersecting volume was included in the 95 % isodose line. For each patient, a theoretical plan consisting of reduced 1-cm GTV-to-CTV margin was created to compare pat-terns of failure and radiation doses to normal brain.Results: Median overall survival and progression-free survival times were 15.3 months and 7.8 months, respectively, from the date of surgery. Recurrences were in-field in 180, marginal in 5, and distant in 22 patients. According to MGMT promoter methylation, distant recurrences occurred in 18.6 % of methy-lated and 6 % of unmethylated tumors (p = 0.0046). Following replanning with 1-cm reduced margin, dosimetric analysis showed similar patterns of failure. Recurrences were in-field, marginal, and distant in 177, 3, and 27 plans, respectively, although radiation doses to the healthy brain and hippocampi were significantly lower compared with standard target delineation (p = 0.0001).Conclusion: Current provide the rationale for evaluating GTV-to-CTV margin reduction in future clinical trials with the aim of limiting the cognitive sequelae of GBM irradiation while maintaining survival ben-efits of standard chemoradiation.(c) 2022 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 181 (2023) 109435
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available