Radiation Therapy for the Treatment of Recurrent Glioblastoma: An Overview

Abstract

Despite the therapeutic advances in neuro-oncology, most patients with glioblastoma ultimately experience local progression/relapse. Re-irradiation has been poorly viewed in the past, mainly due to the overestimated risk of side effects using conventional radiotherapy. To date, thanks to the improvement of several delivery techniques, together with improved imaging capabilities, re-irradiation is a viable salvage treatment option to manage such clinical scenario. A literature overview on the feasibility and efficacy of the different irradiation modalities for recurrent glioblastoma along with considerations on areas of improvement are provided.

Multicenter, Phase 1, Dose Escalation Study of Hypofractionated Stereotactic Radiation Therapy With Bevacizumab for Recurrent Glioblastoma and Anaplastic Astrocytoma

“…1,2 However, tumor progression or recurrence remains the norm, and salvage therapy options are limited, typically achieving median overall survival (OS) of 6–9 months. 3–5 With the main pattern of failure remaining local recurrence, 6 improved survival requires optimized local control.…”

Re-Irradiation with Stereotactic Radiosurgery/Radiotherapy for Recurrent High-Grade Gliomas: Improved Survival in the Modern Era

“…In particular, SRS, fSRT, and brachytherapy are logical adjuncts based on their ability to deliver high doses of radiation to a focal target. However, brachytherapy has been associated with increased risk of infections and risk of hemorrhage due to its invasive nature, while traditional EBRT techniques expose the brain to radiation-related toxicity and necrosis [5, 13, 14]. …”

Intracavitary moderator balloon combined with252Cf brachytherapy and boron neutron capture therapy, improving dosimetry in brain tumour and infiltrations

“…Nevertheless, recurrence is observed in most cases. 2,4 Brachytherapy is often prescribed following external beam radiation, especially in cases of recurrence. However, recent studies have investigated the use of brachytherapy as an initial treatment at the time of diagnosis.…”

“…The average patient's survival is usually less than 2 years; thus, treatment is considered palliative owing to the frequent local recurrence. 4 Boron neutron capture therapy (BNCT) is an experimental radiotherapy for patients with glioblastoma. In this case, a borate compound infusion that concentrates on the tumour is applied, and later, the entire brain is exposed to an epithermal neutron beam.…”

“…During the irradiation period, the balloon is filled with 125 I radioactive solution, emitting photons with an average energy of 28 keV. 4,42 The device is inserted into the patient during the surgical procedure for tumour resection so that the space originally occupied by the tumour is filled by the balloon. 33,42 Early investigations 42,43 showed that the mean survival of patients treated with such a technique was 4.6-14 months and 13.7 months, respectively.…”