BackgroundMany studies have demonstrated in the last years that once medulloblastoma has recurred, the probability of regaining tumor control is poor despite salvage therapy. Although re-irradiation has an emerging role in other relapsed brain tumors, there is a lack of strong data on re-irradiation for medulloblastoma. MethodsThis is a retrospective cohort study of patients aged 18 years or under, treated at least by a second course of external beam for recurrence medulloblastoma at Garrahan Hospital between 2009 and 2020. Twenty-four patients met eligibility criteria for inclusion. All patients received upfront radiotherapy as part of the curative-intent rst radiotherapy, either craniospinal irradiation (CSI) followed by posterior fossa boost in 20 patients or focal posterior fossa radiation in 4 infants. The second course of radiation consisted of CSI in 15 and focal in 9. The 3-year post rst failure OS (50% vs. 0%; p = 0.0010) was signi cantly better for children who received re-CSI compared to children who received focal re-irradiation. Similarly, the 3-year post-re-RT PFS (31% vs. 0%; p = 0.0005) and OS (25% vs. 0%; p = 0.0003) was signi cantly improved for patients who received re-CSI compared to patients who received focal re-irradiation. No symptomatic intratumoral haemorrhagic events or symptomatic radionecrosis were observed. Survivors fell within mild to moderate intellectual disability range, with a median IQ at last assessment of 58 (range 43-69). ConclusionRe-irradiation with CSI is a safe and effective treatment for children with relapsed medulloblastoma; improves disease control and survival compared with focal re-irradiation. However this approach carries a high neurocognitive cost.All radiation treatments were given at Garrahan Hospital, Buenos Aires, Argentina. Photon external beam therapy was used for all patients. All but four patients received CSI as part of the rst radiation course (RT1), followed by a boost to the entire posterior fossa. Standard risk (SR) patients received CSI 23.4Gy followed by posterior fossa boost 30.6Gy and high-risk (HR) patients received CSI 36Gy followed by posterior fossa boost 19.8Gy. Except for one, all of them received maintenance platinum based chemotherapy; SR as per ACNS0331 (N=2) and COG 9961 (regimen A=3, regimen B= 6); HR as per ACNS0332 (Regimen A=4, Regimen B=4). Four patients received upfront posterior fossa radiotherapy (54 Gy) due to the young age at diagnosis as per standard of care treatment administered between 2002 and 2020 at Hospital Garrahan, based on a modi ed POG-9934 strategy (15). Upon recurrence, most patients with brain solitary lesions were offered surgery followed by metronomic chemotherapy and a second course of irradiation (RT2), while those with multifocal disease received chemotherapy followed by radiotherapy. CSI was administered using standard beam's eye-view treatment planning techniques. Boost treatment and focal radiotherapy was administered using 3D-conformal radiation therapy methods. Hypofractionated stereotactic radiother...

Background: Intracranial germ cell tumor (iGCT) represents a rare and heterogeneous group, with variable incidence and diverse treatment strategies. Although multiagent chemotherapy with reduced radiotherapy strategy has been applied by several cooperative groups in North America and Western Europe, there is a paucity of data to understand if this combined regimen issuitable in low-middle income countries (LMIC). Methods: We evaluate the outcome in a cohort of iGCT treated by SIOP-CNS-GCT-96 strategy at Hospital J.P Garrahan in Argentinaover the last 20 years. Radiation field and dose included focal radiotherapy (FRT) before 2009 or focal radiotherapy plus whole ventricular radiotherapy (WVRT) after 2009 for localized germinoma and FRT or FRT plus WVRT or CSI for non germinomatous germ cell tumors (NGGCT) Results: Sixty iGCT were identified; 39 germinoma and 21 NGGCT. Median follow-up was 6.57 years (range 0.13-20.5). Five-year PFS and OS were 83.5% (95% CI [165.53-223.2]) and 88.7% (95% CI [169.84-223.2]) for the germinoma group, while for the NGGCT group were 75% (95% CI [133.27-219.96]) and 64.2% (95% CI [107.38-201.81]) respectively. The localized germinoma group showed poor results between 2000-2009 with 5-year PFS and OS of 69% and 75% respectively, and an excellent outcome between 2010-2019 with a 5-years PFS and OS of 92.8% and 100%. A univariable analysis identified this difference in survival as related to the field of radiotherapy, specifically whole ventricular radiotherapy. FRT increased the risk of recurrence in localized germinoma, involving not only 4 ventricular relapses; but spinal cord and disseminated disease as well. There were no relapses of localized NGGCT after FRT and FRT plus WVRT. Conclusion: Herein we demonstrate that intensive chemotherapy followed by FRT plus WVRT for germinoma is a feasible and effective strategy, warranting further study in the developing world.

Background Many studies have demonstrated in the last years that once medulloblastoma has recurred, the probability of regaining tumor control is poor despite salvage therapy. Although re-irradiation has an emerging role in other relapsed brain tumors, there is a lack of strong data on re-irradiation for medulloblastoma. Methods This is a retrospective cohort study of patients aged 18 years or under, treated at least by a second course of external beam for recurrence medulloblastoma at Garrahan Hospital between 2009 and 2020. Twenty-four patients met eligibility criteria for inclusion. All patients received upfront radiotherapy as part of the curative-intent first radiotherapy, either craniospinal irradiation (CSI) followed by posterior fossa boost in 20 patients or focal posterior fossa radiation in 4 infants. The second course of radiation consisted of CSI in 15 and focal in 9. The 3-year post first failure OS (50% vs. 0%; p = 0.0010) was significantly better for children who received re-CSI compared to children who received focal re-irradiation. Similarly, the 3-year post-re-RT PFS (31% vs. 0%; p = 0.0005) and OS (25% vs. 0%; p = 0.0003) was significantly improved for patients who received re-CSI compared to patients who received focal re-irradiation. No symptomatic intratumoral haemorrhagic events or symptomatic radionecrosis were observed. Survivors fell within mild to moderate intellectual disability range, with a median IQ at last assessment of 58 (range 43–69). Conclusion Re-irradiation with CSI is a safe and effective treatment for children with relapsed medulloblastoma; improves disease control and survival compared with focal re-irradiation. However this approach carries a high neurocognitive cost.

BACKGROUND/OBJECTIVES Central nervous system (CNS) germ cell tumors (GCTs) represent 3% of primary paediatric brain tumours in occident. They can be divided into major groups including germinomas and nongerminomatous GCTs (NGGCTs). The aim is to describe demographic characteristics, Event Free Survival (EFS) and Overall Survival (OS) in patients with GCTs treated at Oncology Unit of Garrahan Hospital (HG). DESIGN/METHODS Retrospective analysis of patients with GCTs admitted between September 1st,2000 to September 1st,2019. Variables analysed: age, localization, treatment, relapse and death. Patients were treated per SIOP-CNSGCTs protocol. For statically analysis SPSS (IBM), for EFS/OS Kaplan-Meyer, Long-rank for significance. RESULTS Fifty-seven patients were included, comprising 38 Germinomas and 19 NGGCTS. Median age was 146 months (range 11–228). Primary site in localized Germinomas were pineal (16p), suprasellar (7p) and bifocal (7p). Five-year EFS and OS of 100% and 88.5%, respectively. Four patients presented metastatic disease, with an EFS and OS of 60.9% and 66.6%. Tumor site in localized NGGCT were pineal(8p) and suprasellar(5p). Five-year EFS was 81.8% and OS was 80.2%. No patients presented metastatic disease. All patients with high-risk tumor markers at diagnosis relapsed. No significative differences were found in OS neither EFS between groups (Germinomas OS5y 90% vs NGGCTs 74.6%p=0.19[CI95%0.0786–1.689]), (Germinomas EFS5y 78.9% vs NGGCTs5y 81.8%p=0.85[CI95%0.3046–4.230). Global OS and EFS5y was 83% and 72.9%. CONCLUSION OS of our cohort is lower than what has been shown in current literature. This result may be related to the lack of resources and lower social economic status in our population.

Background: Intracranial germ cell tumor (iGCT) represents a rare and heterogeneous group, with variable incidence and diverse treatment strategies. Although multiagent chemotherapy with reduced radiotherapy strategy has been applied by several cooperative groups in North America and Western Europe, there is a paucity of data to understand if this combined regimen issuitable in low-middle income countries (LMIC).Methods: We evaluate the outcome in a cohort of iGCT treated by SIOP-CNS-GCT-96 strategy at Hospital J.P Garrahan in Argentinaover the last 20 years. Radiation field and dose included focal radiotherapy (FRT) before 2009 or focal radiotherapy plus whole ventricular radiotherapy (WVRT) after 2009 for localized germinoma and FRT or FRT plus WVRT or CSI for non germinomatous germ cell tumors (NGGCT)Results: Sixty iGCT were identified; 39 germinoma and 21 NGGCT. Median follow-up was 6.57 years (range 0.13-20.5). Five-year PFS and OS were 83.5% (95% CI [165.53 - 223.2]) and 88.7% (95% CI [169.84 - 223.2]) for the germinoma group, while for the NGGCT group were 75% (95% CI [133.27 – 219.96]) and 64.2% (95% CI [107.38 – 201.81]) respectively. The localized germinoma group showed poor results between 2000-2009 with 5-year PFS and OS of 69% and 75% respectively, and an excellent outcome between 2010-2019 with a 5-years PFS and OS of 92.8% and 100%. A univariable analysis identified this difference in survival as related to the field of radiotherapy, specifically whole ventricular radiotherapy. FRT increased the risk of recurrence in localized germinoma, involving not only ventricular relapses; but spinal cord and disseminated disease as well. There were no relapses of localized NGGCT after FRT and FRT plus WVRT.Conclusion: Herein we demonstrate that intensive chemotherapy followed by FRT plus WVRT for germinoma is a feasible and effective strategy, warranting further study in the developing world.