PQA 04 - PQA 04 Palliative Care and Central Nervous System Poster Q&A
2610 - Dose Escalation with Simultaneously Integrated Boost Followed by Cyberknife Boost(SIB-CK) with BEVULTRA-100 in Newly Diagnosed Glioblastoma Multiformae (GBM): A Real World Data Analysis
Healthcare Global Enterprises Ltd. Bangalore, Karnataka
P. S. Sridhar1, P. Anuradha2, D. Priyasha2, M. Gupta2, R. Satish3, G. Swaroop4, K. Kallur2, K. A. R. Avinash2, R. S. Bilimagga2, and S. Patil2; 1HCG, Bangalore, Karnataka, India., Bangalore, India, 2Health Care Global Enterprises Ltd, Bangalore, India, 3Sakra World Hospital, Bangalore, India, 4Sakra World Health Hospital, Bangalore, India
Purpose/Objective(s): GBM is an aggressive tumor of the brain with a dismal prognosis. Despite decades of research the median-survival ranges from 14-8 months. Maximal safe resection followed by Chemoradiotherapy and adjuvant Temozolomide is the standard of care. Various prognostic factors have been identified and attempted to be targeted in attempt to achieve improved survival. Genomic-guided Dose escalated Radiotherapy has been attempted in various trials but have not shown any significant benefit. Bevacizumab has been used in recurrent disease with some benefit. However, its use and benefit in newly diagnosed GBM is under explored. Here we study the benefit of DE-RT by SIB & CK boost in newly diagnosed GBM and explore the feasibility of Low Dose Bevacizumab(BEVULTRA-100) in specific subgroups of patients. Materials/
Methods: We prospectively studied 102 patients(M:F= 69:33) of newly diagnosed GBM post surgery from July 2009 to May 2023, with a median age of 53 years(Range 10-79yrs) treated with DOPA PET CT and MRI-based radiotherapy planning with SIB to dose of 54Gy/25# to GTV PET, 50Gy/25# to GTV MR and 45Gy/25# to CTV (1cm expansion from MR volume) in 5 weeks in phase1 followed by DOPA PETCT based planning SBRT CK Boost to residual GTV PET/MR to a dose 12-20Gy (median 16Gy) in 2# to achieve a Total BED of 94.4 Gy with alpha/beta of 10, with concurrent Temozolomide 120 mg daily for 45 days followed by adjuvant monthly Temozolomide 300mg daily from D1 to D5 for a minimum of 12 cycles. BEVULTRA-100 was given on D6. Response Assessment was done with DOPA PET and MRI every 3 months for 1 year, every 6 months for 2 year and annually/ as and when required and the imaging parameters were assessed. Of these patients, 43 patients were given BEVULTRA-100 to decrease the edema and necrosis, wherein 18 patients were started symptomatically and prophylactically for 25 patients to account for anticipated edema and radiation necrosis. Results: Median Survival (in Months) OS- 1yr OS-2yr OS-3yr SIB-CK (Overall) 26 79% 50% 38% SIB-CK with BEV 32 95.1% 59.7% 48.3% SIB-CK + symptomatic BEV 32 94.4% 59.5% 45.4% In Bevacizumab group there is significant improvement in the Overall Survival(HR-0.48, p=0.012). Conclusion: In this unique dose escalation study, there is a significant improvement in OS with the addition of SIB CK Boost(c >> SIB CKboost alone). Addition of BEVULTRA100 in the dose escalated group of patients had tremendous improvement in local control and survival.
