Results of Stereotactic Brachytherapy Used in the Initial Management of Patients With Glioblastoma

Abstract

Recent studies have shown a survival benefit for patients with recurrent glioblastomas treated with stereotactic brachytherapy. On the basis of these encouraging results, we began a prospective study in 1987 to evaluate the use of brachytherapy in patients with newly diagnosed glioblastoma. Patients were considered eligible for this study if they met the following criteria: Karnofsky performance status 70% or greater; tumor size not greater than 5 cm in any dimension; a radiographically well delineated, supratentorial lesion not involving the ependymal surfaces; and pathologically confirmed glioblastoma. We treated 35 such patients between 1987 and 1990 with stereotactic brachytherapy as part of their initial therapy. The treatment protocol involved surgery, partial brain external-beam radiotherapy (59.4 Gy in 33 fractions), and stereotactic brachytherapy with temporary high-activity iodine 125 sources giving an additional 50 Gy to the tumor bed. Chemotherapy was not used in the initial management of these 35 patients. To compare our results with those obtained in a matched control group, we identified 40 patients with glioblastoma treated with surgery and external radiotherapy, with or without chemotherapy, between 1977 and 1986 at our institution. These patients had clinical and radiographic characteristics that would have made them eligible for the brachytherapy protocol. Survival rates at 1 and 2 years after diagnosis were 87% and 57%, respectively, for patients receiving brachytherapy versus 40% and 12.5%, respectively, for the controls (P less than .001). We conclude that stereotactic brachytherapy improves the survival of patients with glioblastoma when it can be incorporated into the initial treatment approach. Unfortunately, only about one in four patients with glioblastoma are suitable candidates for brachytherapy at the time of initial presentation.

Role of adjuvant or salvage radiosurgery in the management of unresected residual or progressive glioblastoma multiforme in the pre–bevacizumab era

“…20,47 Across the world Gamma Knife (Elekta AB) stereotactic radiosurgery (SRS) has been used as an adjuvant therapy in more than 40,000 patients with glial neoplasms. Although prior retrospective studies have documented a modest survival advantage with the addition of SRS delivered using various technologies, 14,23,24,27,29,32,34,39 others have found no added benefit. 4,9,16,37,38 A single prospective randomized trial by the Radiation Therapy Oncology Group (RTOG 93-05) 42 found no improvement in overall survival (OS) when various forms of linear acceleratorand Gamma Knife-based SRS were given prior to conventional fractionated RT.…”

Design and application of oncolytic HSV vectors for glioblastoma therapy

“…Over the years, radiation treatment has been refined, going from whole brain radiation to more localized and higher dose radiation to the excised tumor bed and 2 cm surrounding it. The concept of direct implantation of radioactive seeds into the tumor bed has also been evaluated, but this has not shown significant therapeutic advantages [23]. Since prognosis in GBM patients is still grim, death usually precedes the onset of side effects: in fact, cognitive deficit secondary to radiation is rare within the first year after treatment and the majority of patients only experience transient malaise and general weakness [24].…”

Quality of life in patients with brain tumor: what's relevant in our quest for therapeutic efficacy

“…[5,10,32,34,39,45,59,65] This approach is usually combined with the assessment of conventional measures such as survival duration, time to relapse, and imaging-documented changes in tumor size. [12,13,18,28,35] The toxicity of therapy has also been assessed, for the most part, in categorical terms such as "major" or "minor" morbidity and mortality.…”

“…[34] As a result of these findings there is now increasing use of primary postoperative chemotherapy and deferred radiation therapy in children with medulloblastoma. [51] Multidimensional QOL considerations have also prompted deferred radiation therapy in the management of cerebral low-grade glioma.…”