Bevacizumab in glioblastoma multiforme

Bevacizumab is a humanized IgG1 monoclonal antibody that selectively binds with high affinity to human VEGF and neutralizes VEGF' s biologic activity. Malignant gliomas are characterized by extensive microvascular proliferation and produce VEGF. Preclinical data indicate that angiogenesis is essential for the proliferation and survival of malignant glioma cells. Promising response rates, progression-free survival rates at 6 months and median overall survival in patients with recurrent glioblastoma multiforme (GBM) have been reported with bevacizumab, both in retrospective analyses and in prospective Phase II studies. In the pivotal randomized but noncomparative Phase II trial, a non-negligible percentage of patients survived beyond 1 and 2 years after the start of bevacizumab administration. However, randomized Phase III trial data on bevacizumab in recurrent GBM are lacking. Currently, bevacizumab is being studied in combination with temozolomide and radiation in previously untreated GBM patients in two large randomized Phase III trials.     

Multi-institutional phase II study of temozolomide administered twice daily in the treatment of recurrent high-grade gliomas

BACKGROUND: The prognosis for patients with recurrent high-grade gliomas is poor and treatment options are limited. Current chemotherapeutic regimens can improve clinical outcomes, but extend survival by only a few months. Temozolomide is a methylating agent that is typically administered once daily. Because preclinical studies suggested that a twice-daily dosing schedule might be more effective, the safety and efficacy of twice-daily dosing of temozolomide were studied in patients with recurrent gliomas at their first, second, or third recurrence. METHODS: This multi-institutional trial enrolled 120 patients with recurrent glioblastoma multiforme (GBM), anaplastic astrocytoma (AA), or anaplastic oligodendroglioma (AO). An initial oral dose of 200 mg/m(2) of temozolomide was followed by 9 consecutive doses of 90-mg/m(2) every 12 hours. Treatment cycles were repeated every 28 days. Doses were escalated to 100 mg/m(2) twice daily in the absence of unacceptable toxicity or were reduced if unacceptable toxicity occurred. RESULTS: For GBM, AA, and AO patients, respectively, the median progression-free survival (PFS) was 4.2 months, 5.8 months, and 7.7 months, whereas the median overall survival (OS) was 8.8 months, 14.6 months, and 18 months. The overall response rate (partial and complete) for the GBM, AA, and AO patients was 31%, 46%, and 46%, respectively. Grade 3/4 toxicities included neutropenia (1.1%), thrombocytopenia (3.6%), and anemia (0.3%) (graded according to the World Health Organization grading system). CONCLUSIONS: Twice-daily dosing may enhance the efficacy of temozolomide in the treatment of recurrent gliomas without increasing toxicity. This regimen compares favorably with other dosing schedules of temozolomide reported in the literature.     

Emerging clinical principles on the use of bevacizumab for the treatment of malignant gliomas

Despite advances in adjuvant therapy, the prognosis for most patients with high‐grade glioma (HGG) is poor, and almost all HGGs have a likelihood of disease recurrence. HGGs are highly vascularized tumors with elevated expression levels of vascular endothelial growth factor (VEGF), an important mediator of angiogenesis. A compelling biologic rationale, a pressing need for improved therapeutics and positive results from studies of bevacizumab in other tumor types, led to the evaluation of bevacizumab in the treatment of HGG. It was demonstrated previously that bevacizumab, which is a humanized monoclonal antibody that targets VEGF, improved outcomes when combined with chemotherapy (most commonly irinotecan) in patients with recurrent HGG; and, on the basis of an improved objective response rate in 2 prospective phase 2 studies, bevacizumab was granted accelerated approval by the US Food and Drug Administration as a single agent in patients with previously treated glioblastoma (GB). Bevacizumab‐containing therapy has been associated with manageable, class‐specific toxicity; however, severe treatment‐related adverse events are observed in a minority of patients. Preliminary data on bevacizumab‐based therapy in recurrent anaplastic gliomas, in the frontline treatment of GB, and in additional patient populations are also encouraging. With the goal of addressing unanswered questions regarding the optimal use of bevacizumab, the objective of the current review was to provide a summary of the clinical efficacy and safety data on bevacizumab in patients with HGG, the practical issues surrounding the administration of bevacizumab, and ongoing investigations of bevacizumab in additional brain tumor treatment settings. Cancer 2010. © 2010 American Cancer Society.     

Bevacizumab and irinotecan in recurrent malignant glioma,a single institution experience

Background

Treatment options of recurrent malignant gliomas are very limited and with a poor survival benefit. The results from phase II trials suggest that the combination of bevacizumab and irinotecan is beneficial.

Patients and methods.

The medical documentation of 19 adult patients with recurrent malignant gliomas was retrospectively reviewed. All patients received bevacizumab (10 mg/kg) and irinotecan (340 mg/m² or 125 mg/m²) every two weeks. Patient clinical characteristics, drug toxicities, response rate, progression free survival (PFS) and overall survival (OS) were evaluated.

Results

Between August 2008 and November 2011, 19 patients with recurrent malignant gliomas (median age 44.7, male 73.7%, WHO performance status 0–2) were treated with bevacizumab/irinotecan regimen. Thirteen patients had glioblastoma, 5 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. With exception of one patient, all patients had initially a standard therapy with primary resection followed by postoperative chemoradiotherapy. Radiological response was confirmed after 3 months in 9 patients (1 complete response, 8 partial responses), seven patients had stable disease and three patients have progressed. The median PFS was 6.8 months (95% confidence interval [CI]: 5.3–8.3) with six-month PFS rate 52.6%. The median OS was 7.7 months (95% CI: 6.6–8.7), while six-month and twelve-month survival rates were 68.4% and 31.6%, respectively. There were 16 cases of hematopoietic toxicity grade (G) 1–2. Non-hematopoietic toxicity was present in 14 cases, all G1-2, except for one patient with proteinuria G3. No grade 4 toxicities, no thromboembolic event and no intracranial hemorrhage were observed.

Conclusions

In recurrent malignant gliomas combination of bevacizumab and irinotecan might be an active regimen with acceptable toxicity.     

Phase II study of panobinostat in combination with bevacizumab for recurrent glioblastoma and anaplastic glioma

BackgroundPanobinostat is a histone deacetylase inhibitor with antineoplastic and antiangiogenic effects in glioma that may work synergistically with bevacizumab. We conducted a multicenter phase II trial of panobinostat combined with bevacizumab in patients with recurrent high-grade glioma (HGG).MethodsPatients with recurrent HGG were treated with oral panobinostat 30 mg 3 times per week, every other week, in combination with bevacizumab 10 mg/kg every other week. The primary endpoint was a 6-month progression-fee survival (PFS6) rate for participants with recurrent glioblastoma (GBM). Patients with recurrent anaplastic glioma (AG) were evaluated as an exploratory arm of the study.ResultsAt interim analysis, the GBM arm did not meet criteria for continued accrual, and the GBM arm was closed. A total of 24 patients with GBM were accrued prior to closure. The PFS6 rate was 30.4% (95%, CI 12.4%–50.7%), median PFS was 5 months (range, 3–9 months), and median overall survival (OS) was 9 months (range, 6–19 months). Accrual in the AG arm continued to completion, and a total of 15 patients were enrolled. The PFS6 rate was 46.7% (range, 21%–73%), median PFS was 7 months (range, 2–10 months), and median OS was 17 months (range, 5 months–27 months).ConclusionsThis phase II study of panobinostat and bevacizumab in participants with recurrent GBM did not meet criteria for continued accrual, and the GBM cohort of the study was closed. Although it was reasonably well tolerated, the addition of panobinostat to bevacizumab did not significantly improve PFS6 compared with historical controls of bevacizumab monotherapy in either cohort.     

The presence of necrosis and/or microvascular proliferation does not influence survival of patients with anaplastic oligodendroglial tumours: review of 98 patients

Accurate prognosis for patients with anaplastic oligodendroglial gliomas is increasingly difficult to make. Characterisation of these tumours remains challenging, increasing proportions of oligodendroglial diagnoses in gliomas are reported, and no WHO 2000 grade IV exists for them, so that highly anaplastic tumours can only be grouped with glioblastoma (GBM) or with grade III oligodendroglioma, which have differing clinical behaviour. Longer survival times reported for patients with glioblastoma containing an oligodendroglial element (GBMO) suggest that a grade IV for oligodendroglial tumours might exist.In patients with anaplastic gliomas containing an oligodendroglial element, we explored whether microvascular proliferation (MVP) and necrosis were associated with shorter survival, sufficient to create a grade IV. Biopsies for 98 patients with anaplastic oligodendroglioma, anaplastic oligoastrocytoma or tumours with an oligodendroglial and GBM element, discharged 1998–2004, were identified from databases at three allied neurosurgery units. Pathology reports were reviewed for the presence of MVP and necrosis. Anaplastic oligoastrocytoma and GBMO were combined to measure the effect of an astrocytic element on survival.For anaplastic oligodendroglioma patients, median survival time was 24 months, while for anaplastic oligoastrocytoma or GBMO patients, it was 9 months. Age 60 or over (P = 0.006) and astrocytic element (P = 0.01) were the only independent predictors of survival. Patients 60 and over with an astrocytic element had 4.6 times the risk of death of patients under 60 with anaplastic oligodendroglioma.A grade IV cannot be created using necrosis or MVP since neither feature predicted survival after adjustment for age and an astrocytic element. However age and an astrocytic element were strong predictors of poorer survival in patients with anaplastic oligodendroglial tumours.     

Large volume reirradiation as salvage therapy for glioblastoma after progression on bevacizumab

Outcomes after bevacizumab failure for recurrent glioblastoma (GBM) are poor. Our analysis of 16 phase II trials (n = 995) revealed a median overall survival (OS) of 3.8 months (±1.0 month SD) after bevacizumab failure with no discernible activity of salvage chemotherapy. Thus, the optimal treatment for disease progression after bevacizumab has yet to be elucidated. This study evaluated the efficacy of reirradiation for patients with GBM after progression on bevacizumab. An IRB approved retrospective (2/2008–5/2013) analysis was performed of 23 patients with recurrent GBM (after standard radiotherapy/temozolomide) treated with bevacizumab (10 mg/kg) every 2 weeks until progression (median age 53 years; median KPS 80; median progression free survival on bevacizumab 3.7 months). Within 7–14 days of progression on bevacizumab, patients initiated reirradiation to a dose of 54 Gy in 27 fractions using pulsed-reduced dose rate (PRDR) radiotherapy. The median planning target volume was 424 cm³. At the start of reirradiation, bevacizumab (10 mg/kg) was given every 4 weeks for two additional cycles. The median OS and 6 month OS after bevacizumab failure was 6.9 months and 65 %, respectively. Reirradiation was well tolerated with no symptomatic grade 3–4 toxicities. Favorable outcomes of reirradiation after bevacizumab failure in patients with recurrent GBM suggest its role as a treatment option for large volume recurrences not amenable to stereotactic radiosurgery. As PRDR is easily accomplished from a technological standpoint, we are in the process of expanding this approach to a multi-institutional cooperative group trial.     

Temozolomide for malignant primary spinal cord glioma: an experience of six cases and a literature review

Malignant primary spinal cord gliomas (PSCGs) are rare, and the optimal treatment for these lesions remains controversial. We report herein treatment outcomes of six malignant PSCGs managed with temozolomide (TMZ)-based multidisciplinary treatment. TMZ was administered concomitantly with fractionated radiotherapy for two newly diagnosed primary spinal cord glioblastoma multiforme (GBM), followed by adjuvant chemotherapy with TMZ. For one anaplastic astrocytoma (AA) and one anaplastic ependymoma (AEPN), TMZ was given as adjuvant therapy at first recurrence. One malignantly transformed ependymoma (EPN) and one malignantly transformed diffuse astrocytoma (DA) were treated with TMZ after radiotherapy at second recurrence. Two patients with newly diagnosed GBM died, 12 and 16 months, respectively, after being treated with TMZ, during and after radiation therapy. One patient with AA and one with malignantly transformed EPN showed good response to salvage therapy with TMZ and had stable disease 21 and 20 months, respectively, after TMZ treatment. One patient with recurrent AEPN and one with malignantly transformed DA died from uncontrolled progression of the lesions despite TMZ chemotherapy. Three patients developed grade 1 or 2 neutropenia, anemia, and infection. Nonhematologic toxicities occurred in all patients; however, they were below grade 3 in severity. TMZ treatment may have a positive effect on control of malignant PSCGs and survival for some patients. Specifically, treatment with TMZ during and after radiation therapy might provide survival benefit to patients with primary spinal cord GBM. A multicenter cooperative investigation for a large-scale study on malignant PSCGs may be required.     

Hypofractionated stereotactic radiotherapy in combination with bevacizumab or fotemustine for patients with progressive malignant gliomas

To evaluate the efficacy of hypofractionated stereotactic radiotherapy performed as reirradiation in combination with fotemustine or bevacizumab as salvage treatment in patients with recurrent malignant glioma. Between May 2006 and December 2013, 54 patients with recurrent malignant glioma received hypofractionated stereotactic radiotherapy (HSRT, 25 Gy in 5-Gy fractions) plus either fotemustine or bevacizumab at University of Rome Sapienza, Sant’Andrea Hospital. All patients had Karnofsky performance score (KPS) ≥ 60 and were previously treated with standard chemoradiotherapy. Forty-two patients had a GBM and 12 patients had an anaplastic astrocytoma (AA). The median overall survival (OS) time and 12-month OS rates after HSRT was 11 months and 30 % for patients treated with HSRT plus bevacizumab and 8.3 months and 5 % for those treated with HSRT plus fotemustine (p = 0.01). Median PFS times were 4 and 6 months for patients treated with HSRT plus fotemustine or bevacizumab, respectively (p = 0.01). KPS > 70 (p = 0.04), AA histology, and the treatment with bevacizumab were independent favourable prognostic factors for OS. In general, both treatments were well tolerated with relatively low treatment-related toxicity. HSRT combined with bevacizumab or fotemustine may represent a feasible treatment option for patients with progressive malignant gliomas, although most of the tumors recur in a few months. Efficacy of bevacizumab or alkylating agents in combination with different radiation schedules needs to be evaluated in prospective studies.     

Time course of imaging changes of GBM during extended bevacizumab treatment

Glioblastoma multiforme (GBM) are morphologically heterogeneous tumors, with varying amounts of necrosis, and edema. Previous studies have shown that treatments incorporating the VEGF antibody bevacizumab can reduce edema and tumor burden in GBM. Additionally it has been suggested that bevacizumab regimen treatment reduces the percent of tumoral necrosis. Therefore we sought to (1) determine the time course of change in necrosis, tumor, and edema volume in patients who respond to bevacizumab regimen treatment and (2) determine if GBM that progress following a response to bevacizumab regimen treatment are morphologically different from their appearance at prior tumor progression. Therefore, we retrospectively assessed tumor, necrosis, and edema volumes on MRI scans from 15 patients with recurrent GBM who responded to bevacizumab regimen treatment, and had extended (>7 month) follow-up. We found that the median time to best tumor response was 158 days (range, 16-261, SD = 63). The median best response was 72.1% reduction in tumor volume and 72.8% reduction in peritumoral edema. Most tumors (77.8%) showed resolution of necrotic areas. The relative reduction of edema and necrosis was sustained, even in patients (n = 7) who developed tumor progression. Thus the mean ratio of edema-to-tumor volume at progression on bevacizumab regimen treatment was 38.4% lower than that for the same tumors seen on progression scans following prior chemotherapy. The percentage of necrotic tumor also was diminished following progression on bevacizumab regimen treatment. These findings illustrate the time course of changes in edema and tumor volume with prolonged bevacizumab regimen treatment, and support the conclusion that the morphology of recurrent GBM following bevacizumab regimen therapy is distinct from that on other chemotherapy.     

Fractionated stereotactic radiotherapy using gamma unit after hyperbaric oxygenation on recurrent high-grade gliomas

Background To reduce this complication and to enhance the radiation effect to hypoxic cells of high-grade gliomas, the authors performed noninvasive fractionated stereotactic radiotherapy (FSRT) using a Gamma unit combined with hyperbaric oxygen (HBO) therapy for the treatment of recurrent disease. Patients and methods Twenty-five consecutive patients who had previously received radiotherapy with chemotherapy for recurrent high-grade gliomas, including 14 patients with anaplastic astrocytoma (AA) and 11 with glioblastoma multiforme (GBM), underwent Gamma FSRT immediately after HBO therapy (2.5 atmospheres absolute for 60 min). The Gamma FSRT was repeatedly performed using a relocatable head cast. Median tumor volume was 8.7 cc (range, 1.7–159.3 cc), and the median total radiation dose was 22 Gy (range, 18–27 Gy) to the tumor margin in 8 fractions. Results Actuarial median survival time after FSRT was 19 months for patients with AA and 11 months for patients with GBM, which was significantly different (P = 0.012, log-rank test). Two patients underwent subsequent second FSRT for regional or remote recurrence. Seven patients (28%) underwent subsequent craniotomies and resections at a mean of 8.4 months after FSRT treatment, and 4 of them had radiation effects without viable cells and remained alive for 50–78 months. Conclusion Gamma FSRT after HBO therapy appears to confer a survival benefit for patients with recurrent high-grade gliomas and warrants further investigation.     

Prognosis in patients with anaplastic oligoastrocytoma is associated with histologic grade

Background Anaplastic oligoastrocytomas (AOA) are relatively uncommon high-grade gliomas. While oligodendroglial elements are thought to be associated with better outcomes, the magnitude of the difference is not clear. Methods Between 1980 and 1999, Mayo Clinic and the NCCTG conducted 10 trials of radiation therapy and chemotherapy in adults with newly-diagnosed high-grade gliomas. All pathology slides were reviewed by one of the authors (BWS or CG). We grouped patients by cell type and grade, compared survival distributions by the log-rank statistic, and performed multiple variable analyses. Results Of 1368 patients, 68 (5%) had AOA, including 21 Grade 3 (OA3) and 47 grade 4 (OA4), 153 (11%) had anaplastic astrocytoma (AA), and 1147 (84%) had glioblastoma multiforme (GBM). Patients with OA3 survived significantly longer than those with OA4 (P = 0.0001) or AA (P = 0.0044). Patients with OA4 lived significantly longer than those with GBM (P = 0.0005). The same differences were noted for PFS. Prognostic factors for survival identified by multiple variable analysis were histology, age, ECOG performance score, and extent of surgical resection, but not treatment administered. Conclusions Patients with anaplastic oligoastrocytoma have distinct outcomes based upon grade (OA3 vs. OA4) and in comparison with pure astrocytoma (AA or GBM). Future trials which include more than one histologic entity need to report results by cell type and grade and account for the varying prognoses in interpreting treatment outcomes.     

Clinical outcomes following salvage Gamma Knife radiosurgery for recurrent glioblastoma

Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor with a survival prognosis of 14-16 mo for the highest functioning patients. Despite aggressive, multimodal upfront therapies, the majority of GBMs will recur in approximately six months. Salvage therapy options for recurrent GBM (rGBM) are an area of intense research. This study compares recent survival and quality of life outcomes following Gamma Knife radiosurgery (GKRS) salvage therapy. Following a PubMed search for studies using GKRS as salvage therapy for malignant gliomas, nine articles from 2005 to July 2013 were identified which evaluated rGBM treatment. In this review, we compare Overall survival following diagnosis, Overall survival following salvage treatment, Progression-free survival, Time to recurrence, Local tumor control, and adverse radiation effects. This report discusses results for rGBM patient populations alone, not for mixed populations with other tumor histology grades. All nine studies reported median overall survival rates (from diagnosis, range: 16.7-33.2 mo; from salvage, range: 9-17.9 mo). Three studies identified median progression-free survival (range: 4.6-14.9 mo). Two showed median time to recurrence of GBM. Two discussed local tumor control. Six studies reported adverse radiation effects (range: 0%-46% of patients). The greatest survival advantages were seen in patients who received GKRS salvage along with other treatments, like resection or bevacizumab, suggesting that appropriately tailored multimodal therapy should be considered with each rGBM patient. However, there needs to be a randomized clinical trial to test GKRS for rGBM before the possibility of selection bias can be dismissed.     

Bevacizumab salvage therapy following progression in high-grade glioma patients treated with VEGF receptor tyrosine kinase inhibitors

Agents targeting the vascular endothelial growth factor (VEGF) pathway are being used with increasing frequency in patients with recurrent high-grade glioma. The effect of more than one antiangiogenic therapy given in succession has not been established. We reviewed the efficacy of bevacizumab, a VEGF-A monoclonal antibody, in patients who progressed following prior therapy with VEGF receptor tyrosine kinase inhibitors (R-TKi). Seventy-three patients with recurrent high-grade gliomas received VEGF R-TKi (cediranib, sorafenib, pazopanib, or sunitinib) as part of phase I or II clinical trials. Twenty-four of these patients with glioblastoma progressed and received bevacizumab-containing regimens immediately after R-TKi. Those who stopped R-TKi therapy for reasons other than disease progression, or received a treatment that did not include bevacizumab, were excluded from the analysis. The efficacy of bevacizumab-containing regimens in these 24 patients was evaluated. During R-TKi therapy, 6 of 24 patients (25%) had a partial response (PR) to treatment. The 6-month progression-free survival (APF6) was 16.7% and median time-to-progression (TTP) was 14.3 weeks. Grade III/IV toxicities were seen in 13 of 24 patients (54%). Subsequently with bevacizumab salvage therapy, 5 of 24 patients (21%) had a PR, the APF6 was 12.5%, and the median TTP was 8 weeks. Five of 24 patients had grade III/IV toxicities (21%). The median overall survival (OS) from the start of R-TKi therapy was 9.2 months (range: 2.8–34.1+), whereas the median OS after bevacizumab was 5.2 months (range: 1.3–28.9+). Bevacizumab retains modest activity in high-grade glioma patients who progress on R-TKi. However, the APF6 of 12.5% in this cohort of patients indicates that durable tumor control is not achieved for most patients.     

贝伐单抗治疗高级别脑胶质瘤的研究进展

脑胶质瘤中3/4以上的患者为高级别脑胶质瘤,其恶性程度高,术后易复发,预后极差。虽然术后同步放化疗能使高级别脑胶质瘤患者生存获益,但其仅能延长有限的生存时间。近年来,肿瘤的分子靶向治疗逐渐成为研究热点。血管内皮生长因子在脑胶质瘤及其周围组织中高表达,调控着肿瘤的生长过程,是脑胶质瘤治疗的有效靶点。贝伐单抗能够特异性地阻止血管内皮生长因子与其受体结合,抑制肿瘤血管的形成;同时还能使肿瘤血管正常化,改善血管通透性,增加肿瘤组织有效药物浓度,从而达到其抗肿瘤的作用。本文就贝伐单抗的作用机制及近些年贝伐单抗单药与联合化疗或其他药物治疗高级别脑胶质瘤的研究进展进行综述。      

Treatment of malignant gliomas with surgery,intraarterial chemotherapy with ACNU and radiation therapy

Summary Forty-five patients with malignant gliomas were treated after aggressive surgical resection with alternating intravenous carmustine and cisplatin both during and after radiation therapy. Thirty-three patients were considered evaluable for responses, 17 had glioblastoma multiforme (GBM),14 had anaplastic astrocytoma (AA) and 2 had anaplastic oligodendroglioma (AO). The median age of the evaluable patients was 47 years. The median time to tumor progression was 34.5 weeks, and the median survival for the entire group was 76 weeks. Early progression occurred more frequently in patients with glioblastoma than in those with AA or AO. Seventeen patients (55%) were alive at 18 months (6 GBM, 9 AA, 2 AO). Toxicity was mainly hematologic, otic and tolerable. The results suggest that further trial is warranted to assess the efficacy of alternating carmustine and cisplatin in conjunction with radiation therapy postoperatively in patients with malignant gliomas.     

Discontinuing bevacizumab in patients with glioblastoma: an ethical analysis

Glioblastoma (GBM) is a highly lethal malignant brain tumor that expresses proangiogenic factors, including vascular endothelial growth factor (VEGF). Bevacizumab (Avastin®; Genentech, Inc., South San Francisco, CA), a monoclonal antibody against VEGF, is routinely used in the U.S. to treat GBM patients whose tumors have progressed following initial therapy. The Ethics Advisory Committee at the Dana-Farber Cancer Institute was asked to provide consultation on two cases involving patients with recurrent GBM who were receiving bevacizumab. Despite evidence of disease progression, family members advocated for the continued use of bevacizumab because of its mild toxicity profile and concern that discontinuation would impair quality of life. However, continuing bevacizumab in this setting posed physical and financial risks to the patients and raised ethical concerns about resource allocation and justice.We analyze the ethical questions regarding bevacizumab discontinuation in the setting of progressive GBM. We articulate the potential benefits and harms of continuing the drug and identify guiding principles for drug discontinuation that should be made transparent to patients and families. With the increasing availability of new, modestly toxic, expensive drugs for patients with advanced cancer, questions of when to stop these drugs will become increasingly relevant.     

Efficacy of fractionated stereotactic reirradiation in recurrent gliomas: long-term results in 172 patients treated in a single institution.

PURPOSE: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) performed as reirradiation in 172 patients with recurrent low- and high-grade gliomas. PATIENTS AND METHODS: Between 1990 and 2004, 172 patients with recurrent gliomas were treated with FSRT as reirradiation in a single institution. Seventy-one patients suffered from WHO grade 2 gliomas. WHO grade 3 gliomas were diagnosed in 42 patients, and 59 patients were diagnosed with glioblastoma multiforme (GBM). The median time between primary radiotherapy and reirradiation was 10 months for GBM, 32 months for WHO grade 3 tumors, and 48 months for grade 2 astrocytomas. FSRT was performed with a median dose of 36 Gy in a median fractionation of 5 x 2 Gy/wk. RESULTS: Median overall survival after primary diagnosis was 21 months for patients with GBM, 50 months for patients with WHO grade 3 gliomas, and 111 months for patients with WHO grade 2 gliomas. Histologic grading was the strongest predictor for overall survival, together with the extent of neurosurgical resection and age at primary diagnosis. Median survival after reirradiation was 8 months for patients with GBM, 16 months for patients with grade 3 tumors, and 22 months for patients with low-grade gliomas. Only time to progression and histology were significant in influencing survival after reirradiation. Progression-free survival after FSRT was 5 months for GBM, 8 months for WHO grade 3 tumors, and 12 months for low-grade gliomas. CONCLUSION: FSRT is well tolerated and may be effective in patients with recurrent gliomas. Prospective studies are warranted for further evaluation.