Temozolomide and hypofractionated RT versus standard of care in the post-operative setting of GBM.
PD-0649
Abstract
Temozolomide and hypofractionated RT versus standard of care in the post-operative setting of GBM.
Authors: Milena Ferro1, Marica Ferro1, Gabriella Macchia1, Donato Pezzulla1, Savino Cilla2, Carmela Romano2, Silvia Cammelli3,4, Eleonora Cucci5, Daria Vallerossa3, Anna Benini3, Milly Buwenge3, Mariangela Boccardi1, Alessio Giuseppe Morganti3,4, Giovanni Piero Frezza6, Francesco Deodato1,7
1Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Radiation Oncology Unit, Campobasso, Italy; 2Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Medical Physics Unit, Campobasso, Italy; 3IRCCS Azienda Ospedaliero-Universitaria di Bologna, Radiation Oncology, Bologna, Italy; 4Alma Mater Studiorum Bologna University, Department of Experimental, Diagnostic, and Specialty Medicine - DIMES, Bologna, Italy; 5Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Radiology Unit, Campobasso, Italy; 6Bellaria Hospital, Radiation Oncology Unit, Bologna, Italy; 7Università Cattolica del Sacro Cuore, Istituto di Radiologia, Roma, Italy
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Purpose or Objective
Adjuvant radiation treatment with standard fractionation (SFRT) and short course hypofractionated radiotherapy (hRT) for elderly and/or poorly performing patients in combination with Temozolomide (TMZ) are the standard of care (SC) for patients with newly diagnosed glioblastoma (GBM). Long-course hRT represents a reliable option that has recently demonstrated excellent tolerance and encouraging outcomes in several phase-I studies, even in younger and fit patients. This retrospective multicenter analysis compares safety and effectiveness of SC versus long course hRT on real world large series of GBM patients regardless of age and performance status.
Material and Methods
The study included GBM patients who received SC or long course hRT in the postoperative setting between 2004 and 2021. SC treatment consisted in 60 Gy/30 fractions or 40 Gy/15 fractions according to age, performance status and physician choice. Long-course hRT was delivered into 25 daily fractions with total doses ranging from 60 to 82.5 Gy.
Results
A total of 265 patients were evaluated retrospectively. One hundred twenty-two patients received SC (96 SFRT and 26 short course hRT) and 143 received long course hRT. Seventy-four percent of SC patients were given TMZ, compared to 99% of those who were given long-term hRT. Patients who received SC were somewhat older than those who did not (median, 62 vs 60 years). The intensity modulated radiation treatment (IMRT) technique was used to treat all of the patients. Patients who received SC had a median overall survival of 18 months against 17 months (p=0.11) when compared to those who received long-course hRT. Patients treated with SC had a 2-year OS of 29.3%, whereas patients treated with long course hRT had a 2-year OS of 35.2%. Multivariate Cox regression, which took into account varying total dosages and age, revealed an association between age and overall survival (OS), with OS falling in patients older than 62 years (hazard ratio [HR], 1.82, p<0.001, IC 95%: 1.33-2.50).
Conclusion
Long-course hRT seems to have comparable survival rates as standard fractionation in a large real-world series of GBM patients, but with the benefit of a slight reduction in overall treatment time.