Background: Intensification of systemic therapy for high-risk neuroblastoma (HRNB) has resulted in improved local control and overall survival leaving potential for de-escalation of primary site radiotherapy. The utility of primary site de-escalation should be evaluated in the context of potential for successful local-regional salvage. We evaluated salvage strategies and outcomes in HRNB patients with local-regional recurrence as a component of first failure. Methods: Twenty of 89 patients with HRNB experienced local-regional recurrence as a component of first relapse after chemotherapy, radiotherapy, surgery, and stem cell transplant from 1997–2013. We reviewed salvage therapy strategies and disease control, and report on the impact of local therapy as salvage for local-regional relapse. Results: Six of 20 patients with local-regional failure (LRF) were alive after a median follow-up of 13 years (range, 0.9–25.2 years). Median overall survival (OS) was 4.6 years (95% CI, 0.6 – not reached) vs. 0.6 years (95% CI, 0.05–2.6) after LRF with and without distant failure (DF) respectively (p=0.03). Overall survival in patients receiving salvage radiotherapy was comparable to those receiving initial adjuvant but no salvage radiotherapy. Time to first failure and death was significantly impacted by the intensity of frontline systemic therapy (p=0.03). Salvage radiotherapy reduced the hazard for subsequent LRF (HR 0.3, 95% CI 0.1–0.9, p=0.04) but not OS (p=0.07). Conclusions: Our study highlights the potential of local control strategies at first failure in patients with LRF when primary site radiotherapy was initially omitted, and delineates potential selection factors which may further improve the therapeutic ratio.

all patient and tumor factors, adults were associated with less chance of receiving RT (pZ0.002) but not surgery (pZ0.084). The median and 5 year OS of adults continued to be significantly worse than those of pediatrics (p < 0.0001) which could be partially secondary to a lower chance of having RT in adults. Conclusion: Adult patients with PMS had inferior survival as compared to pediatric patients even following propensity matching of all patient and tumor factors. Adults had less odds of receiving RT which could be partially responsible for the poor outcomes. Further studies on adults adopting pediatric treatment regimens are warranted. TX Purpose/Objective(s): Radiation plays a pivotal role in the treatment of pediatric brain tumors. For such patients, proton radiation (PRT) has been utilized in an attempt to prevent neurocognitive deficits by sparing normal tissues. Recent studies suggest that minimizing dose to the hippocampus or subventricular zone (SVZ), may lessen the negative impact of radiation on neurocognition. We evaluated the relationship between change in neurocognitive scores over time and PRT dose to the hippocampus and SVZ. Materials/Methods: Pediatric brain tumor patients treated with partial brain PRT underwent serial neurocognitive testing. IQ, working memory (WMI), and processing speed scores (PSI) were examined. Hippocampal and SVZ were delineated, and dosimetric data compiled. In general linear mixed models controlling for tumor volume, associations were examined between IQ, WMI, and PSI score trajectories and: 1) median hippocampal and SVZ doses, and 2) percentage of hippocampus and SVZ receiving 50 (V50), 30 (V30) and 10 (V10) CGE. Results: Data were available for 15 of a total 44 planned patients (9 males, 6 females) receiving PRT between 2007 and 2015. The median age at PRT was 9 years (range 1.5 to 13 y). Patients were 4.8 years post-PRT at last testing on average (range 1.2-9.0 y). Eleven patients had supratentorial tumors (3 craniopharyngiomas, 1 ependymoma, 1 germinoma, 2 low grade gliomas, 1 desmoplastic ganglion cell tumor, 1 optic pathway, 1 ganglioblastoma, 1 DNET) and 4 patients had infratentorial tumors (1 ependymoma, 1 medulloblastoma, 1 desmoplastic ganglion, 1 tectal glioma). The median prescription dose was 50.4 Gy (RBE) (range 45 e 50.4) with median tumor volume of 7.7cm 3 (range 2.1 e 67.6cm 3 ). Significant decline in PSI scores over time-from-PRTwas observed (pZ0.03), while IQ and WMI scores were stable. There were no significant associations between change in scores over time and any clinical variables (age at RT, gross tumor volume (GTV), gender, and tumor location). Also, there were no significant associations between change in scores over time and any dosimetric variables in the models adjusting for tumor volume. There was a trend between PSI decline and GTV (p Z 0.057), and right hippocampal V50 (p Z 0.08). A trend was also seen between change in WMI scores and left SVZ V10 (p Z 0.07). Conclusion: Preliminary findings suggest processing speed is most vulnerable t...

Z 6), or 3D (n Z 20) photon therapy for oligometastatic cervical cancer. Patients presented either with synchronous oligometastatic disease to mediastinum (n Z 1) or supraclavicular (SCV) lymph nodes (n Z 8) with intact pelvic primary, or with recurrent disease to mediastinum (n Z 10), SCV (n Z 15), lung (n Z 6), or bone (n Z 1). Patients with recurrent disease were diagnosed at a median 21 months following initial diagnosis of primary disease (range: 2-177 months). Overall survival (OS) and progression-free survival (PFS) were evaluated via Kaplan-Meier method. Results: Median follow-up time was 31.5 months (range: 1-104 months). Thirty-two patients presented with squamous cell carcinoma, 7 with adenocarcinoma, 1 with neuroendocrine, and 1 with papillary serous histology. The median age at diagnosis of patients in the cohort was 45 years (range: 24-77 years). Seven of 41 patients received induction chemotherapy prior to radiation (17.1%). Median overall survival (OS) from end of radiation treatment was 42 months (95% CI: 21-63 months), with an OS rate at 2-years of 72.2%. Median progression-free survival (PFS) was 13 months (95% CI: 4.2-21.8 months). Of the 41 patients treated, a total of 9 experienced disease progression (22%), with a median time-to-progression of 13 months (range: 4-42 months). Relapses occurred in the mediastinum (n Z 5), lungs (n Z 2), pelvis (n Z 1), or brain (n Z 1). All mediastinal recurrences occurred following treatment of SCV nodal basins. There were no local or in-field recurrences. There were no statistically significant associations with age (50 vs. <50 years), race (white vs. non), histology (SCC vs. non-squamous), induction chemotherapy, oligometastatic presentation (synchronous vs. recurrent), radiation technique (IMRT/stereotactic vs. 3D), radiation dose (50 vs. <50 Gy), or metastatic site (distant vs. mediastinal vs. SCV) in regard to either OS or PFS; however, a trend towards increased mortality was noted for patients presenting with pulmonary or osseous metastasis (HR 2.908, P Z .062). Conclusion: Treatment with definitive radiation therapy to sites of oligometastatic cervical cancer can result in durable survival and excellent local control. Randomized trials are needed to determine if higher rates of survival can be attributed to treatment effect or patients selection.

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