Defining Optimal Target Volumes of Conformal Radiation Therapy for Diffuse Intrinsic Pontine Glioma
| Autor: | Christopher L. Tinkle, Suzanne J. Baker, Zoltan Patay, Yuanyuan Han, Yimei Li, Thomas E. Merchant, Laura D. Hover, Xiaoyu Li, Kristen Campbell, Jason Chiang, Jason K. Molitoris, Jared Becksfort, Alberto Broniscer, Brittany Simone, John T. Lucas |
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| Rok vydání: | 2019 |
| Předmět: |
Male
Cancer Research medicine.medical_specialty medicine.medical_treatment Article 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Medicine Brain Stem Neoplasms Humans Radiology Nuclear Medicine and imaging Cumulative incidence Child Survival analysis Retrospective Studies Radiation medicine.diagnostic_test business.industry Hazard ratio Diffuse Intrinsic Pontine Glioma Retrospective cohort study Magnetic resonance imaging Survival Analysis Confidence interval Radiation therapy Oncology 030220 oncology & carcinogenesis Child Preschool Cohort Disease Progression Female Radiology Radiotherapy Conformal business Tomography X-Ray Computed |
| Zdroj: | Int J Radiat Oncol Biol Phys |
| ISSN: | 1879-355X |
| Popis: | Purpose Optimal radiation therapy (RT) target margins for diffuse intrinsic pontine glioma (DIPG) are unknown. We sought to define disease progression patterns in a contemporary cohort treated with conformal RT using different clinical target volume (CTV) margins. Methods and Materials We reviewed 105 patients with newly diagnosed DIPG treated with conformal conventionally fractionated RT at our institution from 2006 to 2014. CTV margins were classified as standard (1 cm) for 60 patients and extended (2-3 cm) for 45 patients. Survival and cumulative incidence of progression in treatment groups were compared by log-rank and Gray’s tests, respectively. Cox proportional hazard models identified predictors of survival. Results For 97 patients evaluated with magnetic resonance imaging at progression, the cumulative incidences of isolated local, isolated distant, and synchronous disease progression at 1 year were 62.6%, 12.3%, and 7.2%, respectively, and did not differ significantly according to the CTV margin. Central dosimetric progression (Vprogression95% ≥95%) was observed in 80 of 81 evaluable patients. Median progression-free survival and overall survival (OS) were 7.6 months (95% confidence interval, 6.9-8.2) and 11.3 months (95% confidence interval, 10.0-12.8), respectively, and did not differ significantly according to margin status. DIPG survival prediction risk group (standard vs high, P = .02; intermediate vs high, P = .009) and development of distant metastasis (P = .003) were independent predictors of OS. For the 41 patients (39%) with a pathologic diagnosis, H3.3 K27M mutation was associated with shorter OS (hazard ratio [HR], 0.41; P =.02), whereas H3.1 K27M and ACVR1 mutations were associated with longer OS (HR, 3.56; P =.004 and HR, 2.58; P =.04, respectively). Conclusions All patients who experienced local failure showed progression within the high-dose volume, and there was no apparent survival or tumor-control benefit to extending the CTV margins beyond 1 cm. Given the increasing use of reirradiation, standardizing the CTV margin to 1 cm may improve retreatment tolerance. |
| Databáze: | OpenAIRE |
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