Efficacy of salvage stereotactic radiotherapy for recurrent glioma: impact of tumor morphology and method of target delineation on local control

Abstract

In this study, we assessed the efficacy of salvage stereotactic radiotherapy (SRT) for recurrent glioma. From August 2008 to December 2012, 30 patients with recurrent glioma underwent salvage SRT. The initial histological diagnoses were World Health Organization (WHO) grades II, III, and IV in 6, 9, and 15 patients, respectively. Morphologically, the type of recurrence was classified as diffuse or other. Two methods of clinical target delineation were used: A, a contrast-enhancing tumor; or B, a contrast-enhancing tumor with a 3–10-mm margin and/or surrounding fluid attenuation inversion recovery (FLAIR) high-intensity areas. The prescribed dose was 22.5–35 Gy delivered in five fractions at an isocenter using a dynamic conformal arc technique. The overall survival (OS) and local control probability (LCP) after SRT were calculated using the Kaplan–Meier method. A univariate analysis was used to test the effect of clinical variables on OS/LCP. The median follow-up period was 272 days after SRT. The OS and LCP were 83% and 56% at 6 months after SRT, respectively. Morphologically, the tumor type correlated significantly with both OS and LCP (P = 0.006 and <0.001, respectively). The method of target delineation also had a significant influence on LCP (P = 0.016). Grade 3 radiation necrosis was observed in two patients according to Common Terminology Criteria for Adverse Events, version 3. Salvage SRT was safe and effective for recurrent glioma, especially non-diffuse recurrences. Improved local control might be obtained by adding a margin to contrast-enhancing tumors or including increased FLAIR high-intensity areas.

Re-irradiation of recurrent glioblastoma using helical TomoTherapy with simultaneous integrated boost: preliminary considerations of treatment efficacy

“…A further millimetric margin is usually added to the CTV to create a planning target volume (PTV). As reported by some authors 11,15,51 , we also included the area of peritumoral edema, defined on the Flair sequences with a 2-mm margin expansion, in the PTV Flair, whereas the PTV-boost was defined as the visible tumor on enhanced T1-MRI with a 1-mm margin expansion.…”

Acute and chronic hemorrhage from radiation‑induced cavernous malformation associated with late‑delayed radiation necrosis in long surviving glioma patients: A case report

“…Stereotactic radiotherapy could be an option for the treatment of unresectable gliomas, even as an initial treatment (5)(6)(7)19). However, cases 1 and 2 received obvious overdose of radiation by an additional stereotactic radiotherapy and presented with repeated hemorrhages, medically uncontrollable symptomatic epilepsy, and cerebral edema.…”

“…Radiation therapy is a less invasive treatment for brain and neck diseases, such as head and neck cancers and arteriovenous malformations (1)(2)(3)(4). Although some studies reported the efficacy of stereotactic radiation therapy for either newly diagnosed glioma or recurrent glioma, especially for lesions that are unamenable to resection, such as lesions of eloquent areas of the brain, strong recommendation of stereotactic radiation therapy for glioma has not yet been established (5)(6)(7). Necrosis, cavernous malformation, and radiation-induced tumor formation are major side effects observed in the latter stages of radiation therapy; these side effects sometimes distress the patients (8)(9)(10).…”

Hypofractionated Stereotactic Radiotherapy as a Salvage Therapy for Recurrent High-Grade Gliomas: Single-Center Experience

“…In 1997, Glass et al 20 tested this combined approach of stereotactic radiotherapy and chemotherapy with cisplatin. Since then, several studies that combined HFSRT with various drugs (paclitaxel, TMZ, topotecan, gefitinib, sunitinib, fotemustine, panobinostat, or bevacizumab) 20 , 23 , 27 , 28 , 30 , 33 , 35 - 38 , 40 , 41 , 43 - 46 have been conducted. According to these studies, combined modality management appears to be feasible and well tolerated, and the results are encouraging especially with bevacizumab.…”