EMBR-17_Tejpal Gupta
EMBR-17 DE-INTENSIFICATION OF RADIOTHERAPY IN RIGOROUSLY DEFINED LOW-RISK WNT-SUBGROUP MEDULLOBLASTOMA IS ASSOCIATED WITH UNACCEPTABLY HIGH RISK OF NEURAXIAL FAILURE: RESULTS FROM THE PROSPECTIVE FOR-WNT STUDY
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Tejpal Gupta, Shizan Pervez, Archya Dasgupta, Abhishek Chatterjee, Rahul Krishnatry, Jayant GodaSastri, Maya Prasad, Girish Chinnaswamy, Sridhar Epari, Ayushi Sahay, Neelam Shirsat, Prakash Shetty, Aliasgar Moiyadi, Farnaz Shaikh, Nazia Bano, Rakesh Jalali;
Tata Memorial Centre, Mumbai, Maharashtra, India
BACKGROUND: Medulloblastoma is a heterogenous disease comprising four molecular subgroups (WNT, SHH, Group 3, and Group 4) with varying outcomes. Excellent long-term survival (>90%) has prompted de-intensification of therapy in WNT-subgroup medulloblastoma globally. FOR-WNT is one such prospective study (CTRI/2017/12/010767) testing the hypothesis that focal conformal radiotherapy (RT) (54Gy/30 fractions/6-weeks) with avoidance of upfront craniospinal irradiation (CSI) followed by standard adjuvant chemotherapy significantly reduces RT-related late toxicity without unduly compromising survival in low-risk WNT-subgroup medulloblastoma (residual tumor <1.5cm2 with no evidence of metastases in children aged between 3-16 years). METHODS: Patients with low-risk WNT-subgroup medulloblastoma were enrolled after written informed consent/assent. To ensure patient safety, stopping rules were devised according to group-sequential method. RESULTS: Between July 2017 till Feb 2019, seven children of WNT-pathway medulloblastoma were treated with focal conformal RT followed by 6-cycles of adjuvant chemotherapy (cisplatin, cyclophosphamide, and vincristine). One child succumbed to acute renal failure during chemotherapy, while the other 6 patients completed all 6-cycles as planned. Three children were detected with neuraxial failure (supratentorial brain and/or spine) without synchronous local recurrence in the treated tumor-bed on surveillance neuro-imaging between 1.5-2 years from index diagnosis following which the study was terminated prematurely. All 3 children with relapse were treated with salvage CSI (35Gy/21 fractions) with (conformal avoidance of previously treated tumor-bed) plus boost irradiation (10.8-18Gy/6-10 fractions) of metastatic deposits resulting in complete/near complete response and are alive with controlled disease. The other 3 children have not shown any evidence of relapse for over 2-years from index diagnosis and remain on active clinico-radiological surveillance. CONCLUSION: In rigorously defined low-risk WNT-subgroup medulloblastoma, avoidance of upfront CSI is associated with unacceptably high risk of neuraxial failure. A successor study (FOR-WNT 2) incorporating low-dose CSI (18Gy/10 fractions) with similar tumor-bed dose and adjuvant systemic chemotherapy is currently underway.
Contact Presenter
Tejpal Gupta, Shizan Pervez, Archya Dasgupta, Abhishek Chatterjee, Rahul Krishnatry, Jayant GodaSastri, Maya Prasad, Girish Chinnaswamy, Sridhar Epari, Ayushi Sahay, Neelam Shirsat, Prakash Shetty, Aliasgar Moiyadi, Farnaz Shaikh, Nazia Bano, Rakesh Jalali;
Tata Memorial Centre, Mumbai, Maharashtra, India
BACKGROUND: Medulloblastoma is a heterogenous disease comprising four molecular subgroups (WNT, SHH, Group 3, and Group 4) with varying outcomes. Excellent long-term survival (>90%) has prompted de-intensification of therapy in WNT-subgroup medulloblastoma globally. FOR-WNT is one such prospective study (CTRI/2017/12/010767) testing the hypothesis that focal conformal radiotherapy (RT) (54Gy/30 fractions/6-weeks) with avoidance of upfront craniospinal irradiation (CSI) followed by standard adjuvant chemotherapy significantly reduces RT-related late toxicity without unduly compromising survival in low-risk WNT-subgroup medulloblastoma (residual tumor <1.5cm2 with no evidence of metastases in children aged between 3-16 years). METHODS: Patients with low-risk WNT-subgroup medulloblastoma were enrolled after written informed consent/assent. To ensure patient safety, stopping rules were devised according to group-sequential method. RESULTS: Between July 2017 till Feb 2019, seven children of WNT-pathway medulloblastoma were treated with focal conformal RT followed by 6-cycles of adjuvant chemotherapy (cisplatin, cyclophosphamide, and vincristine). One child succumbed to acute renal failure during chemotherapy, while the other 6 patients completed all 6-cycles as planned. Three children were detected with neuraxial failure (supratentorial brain and/or spine) without synchronous local recurrence in the treated tumor-bed on surveillance neuro-imaging between 1.5-2 years from index diagnosis following which the study was terminated prematurely. All 3 children with relapse were treated with salvage CSI (35Gy/21 fractions) with (conformal avoidance of previously treated tumor-bed) plus boost irradiation (10.8-18Gy/6-10 fractions) of metastatic deposits resulting in complete/near complete response and are alive with controlled disease. The other 3 children have not shown any evidence of relapse for over 2-years from index diagnosis and remain on active clinico-radiological surveillance. CONCLUSION: In rigorously defined low-risk WNT-subgroup medulloblastoma, avoidance of upfront CSI is associated with unacceptably high risk of neuraxial failure. A successor study (FOR-WNT 2) incorporating low-dose CSI (18Gy/10 fractions) with similar tumor-bed dose and adjuvant systemic chemotherapy is currently underway.