A Review of the Role of Re-Irradiation in Recurrent High-Grade Glioma (HGG)

Abstract

Despite the use of more effective multimodal treatments in high-grade glioma (HGG), the outcome of patients affected by this disease is still dismal and recurrence is a very common event. Many therapeutic approaches, alone or combined (surgery, drugs, targeted agents, immunotherapy, radiotherapy, supportive therapy), are available in the clinical armamentarium so far. The attitude of physicians is increasingly interventionist, but recurrent HGG still remains a very difficult scenario to be treated. Radiotherapy with different re-irradiation techniques is increasingly proposed as a therapeutic option with interesting results, even though the resulting duration of response is usually quite short. Most lesions re-recur locally, with inadequate identification and targeting of viable tumor being the most important cause of failure. Prognosis is affected by many patient-, tumor-, and treatment-associated prognostic factors. Radiotherapy is delivered with many advanced modalities: 3D-CRT, intensity-modulated radiation therapy, stereotactic fractionated radiotherapy, radiosurgery, and brachitherapy with or without chemotherapy administration. In order to evaluate the feasibility and efficacy of re-irradiation in this setting, we reviewed the PubMed and MEDLINE databases restricting the search to original reports published from January 1990 to June 2011. The search resulted in a total of 155 reports: 78 of them covering 2,688 patients treated with different irradiation modalities overall fulfilled the entry criteria. Radiation therapy demonstrated to be an acceptable option in recurrent HGG with good response rates and acceptable toxicity.

Validation of an established prognostic score after re-irradiation of recurrent glioma

“…The largest series have irradiated with a total dose of 36 Gy in 2 Gy single fractions [4]. Often, it is discussed whether the dose is sufficient, and extensive literature research confirms that further dose escalation might be possible [5]. Smaller series have increased the dose, and some facilities use hypofractionation RT concepts.…”

3D Conformal Re-Irradiation with Temozolamide for Recurrent Glioblastoma: A Prospective Cohort Study

“…Salvage treatment of recurrent Glioblastoma is one of the most challenging tasks in neuro-oncology [18]. Re-irradiation has been widely accepted as useful therapeutic option in treatment of recurrent Glioblastoma [19] [20]. Stereotactic Re-irradiation volume 0.691 ≤100 cm 3 10 (4 -13) >100 cm 3 10 (5 -13) [22].…”

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

“…The standard of care for patients with recurrent GBM or grade III glioma has not yet been clearly defined, and many approaches are available for salvage strategies, including surgery, reirradiation, or systemic agents. 10 - 18 …”

“…For the treatment of HGG recurrence by radiotherapy, many approaches have been studied, including brachytherapy, single-fraction radiosurgery, hypofractionated stereotactic radiotherapy (HFSRT), or conventional fractionated radiotherapy 10 - 18 ; however, none of these treatments demonstrated significant improvement in a phase III study.…”