NRG/RTOG 0837: Randomized, phase II, double-blind, placebo-controlled trial of chemoradiation with or without cediranib in newly diagnosed glioblastoma

Background

A randomized, phase II, placebo-controlled, and blinded clinical trial (NCT01062425) was conducted to determine the efficacy of cediranib, an oral pan-vascular endothelial growth factor receptor tyrosine kinase inhibitor, versus placebo in combination with radiation and temozolomide in newly diagnosed glioblastoma.

Methods

Patients with newly diagnosed glioblastoma were randomly assigned 2:1 to receive (1) cediranib (20 mg) in combination with radiation and temozolomide; (2) placebo in combination with radiation and temozolomide. The primary endpoint was 6-month progression-free survival (PFS) based on blinded, independent radiographic assessment of postcontrast T1-weighted and noncontrast T2-weighted MRI brain scans and was tested using a 1-sided Z test for 2 proportions. Adverse events (AEs) were evaluated per CTCAE version 4.

Results

One hundred and fifty-eight patients were randomized, out of which 9 were ineligible and 12 were not evaluable for the primary endpoint, leaving 137 eligible and evaluable. 6-month PFS was 46.6% in the cediranib arm versus 24.5% in the placebo arm (P = .005). There was no significant difference in overall survival between the 2 arms. There was more grade ≥ 3 AEs in the cediranib arm than in the placebo arm (P = .02).

Conclusions

This study met its primary endpoint of prolongation of 6-month PFS with cediranib in combination with radiation and temozolomide versus placebo in combination with radiation and temozolomide. There was no difference in overall survival between the 2 arms.

Germline polymorphisms in MGMT associated with temozolomide-related myelotoxicity risk in patients with glioblastoma treated on NRG Oncology/RTOG 0825

Background

We sought to identify clinical and genetic predictors of temozolomide-related myelotoxicity among patients receiving therapy for glioblastoma.

Methods

Patients (n = 591) receiving therapy on NRG Oncology/RTOG 0825 were included in the analysis. Cases were patients with severe myelotoxicity (grade 3 and higher leukopenia, neutropenia, and/or thrombocytopenia); controls were patients without such toxicity. A risk-prediction model was built and cross-validated by logistic regression using only clinical variables and extended using polymorphisms associated with myelotoxicity.

Results

23% of patients developed myelotoxicity (n = 134). This toxicity was first reported during the concurrent phase of therapy for 56 patients; 30 stopped treatment due to toxicity. Among those who continued therapy (n = 26), 11 experienced myelotoxicity again. The final multivariable clinical factor model included treatment arm, gender, and anticonvulsant status and had low prediction accuracy (area under the curve [AUC] = 0.672). The final extended risk prediction model including four polymorphisms in MGMT had better prediction (AUC = 0.827). Receiving combination chemotherapy (OR, 1.82; 95% CI, 1.02-3.27) and being female (OR, 4.45; 95% CI, 2.45-8.08) significantly increased myelotoxicity risk. For each additional minor allele in the polymorphisms, the risk increased by 64% (OR, 1.64; 95% CI, 1.43-1.89).

Conclusions

Myelotoxicity during concurrent chemoradiation with temozolomide is an uncommon but serious event, often leading to treatment cessation. Successful prediction of toxicity may lead to more cost-effective individualized monitoring of at-risk subjects. The addition of genetic factors greatly enhanced our ability to predict toxicity among a group of similarly treated glioblastoma patients.

Tumor treating fields and maintenance temozolomide for newly-diagnosed glioblastoma: a cost-effectiveness study

Purpose: The EF-14 trial demonstrated that adding tumor treating fields (TTFields) to maintenance temozolomide (TMZ) significantly extends progression-free survival (PFS) and overall survival (OS) for newly-diagnosed glioblastoma (GBM) patients. This study assessed the cost-effectiveness of TTFields and TMZ for newly-diagnosed GBM from the US healthcare system perspective. Methods and materials: Outcomes for newly-diagnosed GBM patients were estimated over a lifetime horizon using an area under the curve model with three states: stable disease, progressive disease, or death. The survival model integrated the 5-year EF-14 trial results with long-term GBM epidemiology data and US background mortality rates. Adverse event rates were derived from the EF-14 trial data. Utility values to determine quality-adjusted life-years, adverse event costs, and supportive care costs were obtained from published literature. A 3% discount rate was applied to future costs and outcomes. One-way and probabilistic sensitivity analyses were performed to assess result uncertainty due to parameter variability. Results: Treatment with TTFields and TMZ was estimated to result in a mean increase in survival of 1.25 life years (95% credible range [CR] = 0.89-1.67) and 0.96 quality-adjusted life years (QALYs) (95% CR = 0.67-1.30) compared to treatment with TMZ alone. The incremental total cost was $188,637 (95% CR = $145,324-$225,330). The incremental cost-effectiveness ratio (ICER) was $150,452 per life year gained and $197,336 per QALY gained. The model was most sensitive to changes in the cost of TTFields treatment. Conclusions: Adding TTFields to maintenance TMZ resulted in a substantial increase in the estimated mean lifetime survival and quality-adjusted survival for newly-diagnosed GBM patients. Treatment with TTFields can be considered cost-effective within the reported range of willingness-to-pay thresholds in the US.

Abstract LB-162: Treating elderly glioblastoma patients > 65 years with TTFields - a cost-effectiveness perspective

Objective: To compare the incremental cost effectiveness results of treating elderly Glioblastoma (GBM) patients age 65 years or older with tumor treating fields (TTFields) and maintenance Temozolomide (TMZ) versus maintenance TMZ alone with reported willingness to pay thresholds for cancer patients.

Background: Glioblastoma is the most aggressive form of primary brain cancer in adults. Around half of the patients in the real-world setting are diagnosed at the age of 65 and older. The EF-14 trial demonstrated significantly increased five-year overall survival results for all patients in the TTFields plus TMZ group, with the subgroup of patients age 65 and older showing the greatest survival benefit from TTFields plus TMZ treatment. We report on the cost-effectiveness of adding TTFields from a U.S. health system perspective and recent literature on willingness to pay for cancer patients.

Methods: We calculated the Incremental cost effectiveness ratio for patients above 65 years using TTFields as part of their first line treatment. Patient outcomes were simulated using a 3-state area under the curve model including alive with stable disease, progressed disease, and death. Survival was modeled over a lifetime horizon by integrating the 5-year survival results for elderly patients reported in the EF-14 trial with long-term GBM epidemiology data and U.S. background mortality rates. Data on patient utilities used to calculate quality-adjusted life years (QALYs) were based on a previous analysis of GBM-specific health-state preferences. Frequency of adverse events associated with TTFields and TMZ were derived from the EF-14 trial for the patients over 65 years. Costs for adverse events and supportive care cost estimates were used according to published literature. Future survival benefits and costs were discounted to present value at a rate of 3%. One-way and probabilistic sensitivity analyses were performed to assess result uncertainty due to parameter variability. A literature research with specific focus on willingness to pay threshold for elderly patients was conducted and the results of the ICER for using TTFields are discussed and compared to the literature.

Results: Willingness to pay thresholds is rarely reported separately for older patients. The recent literature reports a large scale of willingness to pay thresholds for cancer patient in general. For patients treated with TTFields and maintenance TMZ the resulting ICER was $109,500 per life year gained (LYG) and $142,400 per QALY gained. The probability of TTFields being cost-effective was 85% at a willingness-to-pay threshold of $200,000 per QALY.

Conclusions: TTFields therapy, evaluated at its full list price, demonstrated a high probability of cost-effectiveness at willingness-to-pay thresholds reported in economic literature for the United States. Treating newly diagnosed GBM patients over 65 years of age with TTFields and TMZ has the potential to increase mean lifetime survival and quality-adjusted survival substantially compared to treatment with TMZ alone. These results indicate that patients over age 65 may not only benefit from TTFields treatment more than other subgroups, but also that their treatment may be more cost-effective.

Citation Format: Gregory F. Guzauskas, Erqi L. Pollom, Volker W. Stieber. Treating elderly glioblastoma patients > 65 years with TTFields - a cost-effectiveness perspective [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-162.

A randomized phase II study of everolimus in combination with chemoradiation in newly diagnosed glioblastoma: results of NRG Oncology RTOG 0913

Background

This phase II study was designed to determine the efficacy of the mammalian target of rapamycin (mTOR) inhibitor everolimus administered daily with conventional radiation therapy and chemotherapy in patients with newly diagnosed glioblastoma.

Methods

Patients were randomized to radiation therapy with concurrent and adjuvant temozolomide with or without daily everolimus (10 mg). The primary endpoint was progression-free survival (PFS) and the secondary endpoints were overall survival (OS) and treatment-related toxicities.

Results

A total of 171 patients were randomized and deemed eligible for this study. Patients randomized to receive everolimus experienced a significant increase in both grade 4 toxicities, including lymphopenia and thrombocytopenia, and treatment-related deaths. There was no significant difference in PFS between patients randomized to everolimus compared with control (median PFS time: 8.2 vs 10.2 mo, respectively; P = 0.79). OS for patients randomized to receive everolimus was inferior to that for control patients (median survival time: 16.5 vs 21.2 mo, respectively; P = 0.008). A similar trend was observed in both O6-methylguanine-DNA-methyltransferase promoter hypermethylated and unmethylated tumors.

Conclusion

Combining everolimus with conventional chemoradiation leads to increased treatment-related toxicities and does not improve PFS in patients with newly diagnosed glioblastoma. Although the median survival time in patients receiving everolimus was comparable to contemporary studies, it was inferior to the control in this randomized study.

Randomized Phase II Study Comparing Prophylactic Cranial Irradiation Alone to Prophylactic Cranial Irradiation and Consolidative Extracranial Irradiation for Extensive-Disease Small Cell Lung Cancer (ED SCLC): NRG Oncology RTOG 0937

INTRODUCTION

NRG Oncology RTOG 0937 is a randomized phase II trial evaluating 1-year overall survival (OS) with prophylactic cranial irradiation (PCI) or PCI plus consolidative radiation therapy (PCI+cRT) to intrathoracic disease and extracranial metastases for extensive-disease SCLC.

METHODS

Patients with one to four extracranial metastases were eligible after a complete response or partial response to chemotherapy. Randomization was to PCI or PCI+cRT to the thorax and metastases. Original stratification included partial response versus complete response after chemotherapy and one versus two to four metastases; age younger than 65 years versus 65 years or older was added after an observed imbalance. PCI consisted of 25 Gy in 10 fractions. cRT consisted of 45 Gy in 15 fractions. To detect an improvement in OS from 30% to 45% with a 34% hazard reduction (hazard ratio = 0.66) under a 0.1 type 1 error (one sided) and 80% power, 154 patients were required.

RESULTS

A total of 97 patients were randomized between March 2010 and February 2015. Eleven patients were ineligible (nine in the PCI group and two in the PCI+cRT group), leaving 42 randomized to receive PCI and 44 to receive PCI+cRT. At planned interim analysis, the study crossed the futility boundary for OS and was closed before meeting the accrual target. Median follow-up was 9 months. The 1-year OS was not different between the groups: 60.1% (95% confidence interval [CI]: 41.2-74.7) for PCI and 50.8% (95% CI: 34.0-65.3) for PCI+cRT (p = 0.21). The 3- and 12-month rates of progression were 53.3% and 79.6% for PCI and 14.5% and 75% for PCI+cRT, respectively. Time to progression favored PCI+cRT (hazard ratio = 0.53, 95% CI: 0.32-0.87, p = 0.01). One patient in each arm had grade 4 therapy-related toxicity and one had grade 5 therapy-related pneumonitis with PCI+cRT.

CONCLUSIONS

OS exceeded predictions for both arms. cRT delayed progression but did not improve 1-year OS.

Effect of Radiosurgery Alone vs Radiosurgery With Whole Brain Radiation Therapy on Cognitive Function in Patients With 1 to 3 Brain Metastases: A Randomized Clinical Trial

IMPORTANCE

Whole brain radiotherapy (WBRT) significantly improves tumor control in the brain after stereotactic radiosurgery (SRS), yet because of its association with cognitive decline, its role in the treatment of patients with brain metastases remains controversial.

OBJECTIVE

To determine whether there is less cognitive deterioration at 3 months after SRS alone vs SRS plus WBRT.

DESIGN, SETTING, AND PARTICIPANTS

At 34 institutions in North America, patients with 1 to 3 brain metastases were randomized to receive SRS or SRS plus WBRT between February 2002 and December 2013.

INTERVENTIONS

The WBRT dose schedule was 30 Gy in 12 fractions; the SRS dose was 18 to 22 Gy in the SRS plus WBRT group and 20 to 24 Gy for SRS alone.

MAIN OUTCOMES AND MEASURES

The primary end point was cognitive deterioration (decline >1 SD from baseline on at least 1 cognitive test at 3 months) in participants who completed the baseline and 3-month assessments. Secondary end points included time to intracranial failure, quality of life, functional independence, long-term cognitive status, and overall survival.

RESULTS

There were 213 randomized participants (SRS alone, n = 111; SRS plus WBRT, n = 102) with a mean age of 60.6 years (SD, 10.5 years); 103 (48%) were women. There was less cognitive deterioration at 3 months after SRS alone (40/63 patients [63.5%]) than when combined with WBRT (44/48 patients [91.7%]; difference, -28.2%; 90% CI, -41.9% to -14.4%; P < .001). Quality of life was higher at 3 months with SRS alone, including overall quality of life (mean change from baseline, -0.1 vs -12.0 points; mean difference, 11.9; 95% CI, 4.8-19.0 points; P = .001). Time to intracranial failure was significantly shorter for SRS alone compared with SRS plus WBRT (hazard ratio, 3.6; 95% CI, 2.2-5.9; P < .001). There was no significant difference in functional independence at 3 months between the treatment groups (mean change from baseline, -1.5 points for SRS alone vs -4.2 points for SRS plus WBRT; mean difference, 2.7 points; 95% CI, -2.0 to 7.4 points; P = .26). Median overall survival was 10.4 months for SRS alone and 7.4 months for SRS plus WBRT (hazard ratio, 1.02; 95% CI, 0.75-1.38; P = .92). For long-term survivors, the incidence of cognitive deterioration was less after SRS alone at 3 months (5/11 [45.5%] vs 16/17 [94.1%]; difference, -48.7%; 95% CI, -87.6% to -9.7%; P = .007) and at 12 months (6/10 [60%] vs 17/18 [94.4%]; difference, -34.4%; 95% CI, -74.4% to 5.5%; P = .04).

CONCLUSIONS AND RELEVANCE

Among patients with 1 to 3 brain metastases, the use of SRS alone, compared with SRS combined with WBRT, resulted in less cognitive deterioration at 3 months. In the absence of a difference in overall survival, these findings suggest that for patients with 1 to 3 brain metastases amenable to radiosurgery, SRS alone may be a preferred strategy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00377156.

Reducing Set-up Uncertainty in the Elekta Stereotactic Body Frame Using Stealthstation Software

The Elekta Stereotactic Body Frame (SBF) is a device which allows extracranial targets to be localized and irradiated in a stereotactic coordinate system. Errors of positioning of the body relative to the frame are indirectly estimated by image fusion of multiple CT scans. A novel repositioning methodology, based on neurosurgical Stealth technology, is presented whereby accurate patient repositioning is directly confirmed before treatment delivery. Repositioning was performed on four extracranial stereotactic radiosurgery patients and a radiotherapy simulation phantom. The setup error was quantitatively measured by fiducial localization. A confirmatory CT scan was performed and the resulting image set registered to the initial scan to quantify shifts in the GTV isocenter. Alignment confirmation using Stealth took between 5 and 10 minutes. For the phantom studies, a reproducibly of 0.6 mm accuracy of phantom-to-SBF alignment was measured. The results on four actual patients showed setup errors of 1.5 mm or less. Using the Stealth Station process, rapid confirmation of alignment on the treatment table is possible.

NCCTG N0574 (Alliance): A phase III randomized trial of whole brain radiation therapy (WBRT) in addition to radiosurgery (SRS) in patients with 1 to 3 brain metastases

LBA4

Background: WBRT significantly improves tumor control in the brain after SRS, yet the role of adjuvant WBRT remains undefined due to concerns regarding neurocognitive risks. Methods: Patients with 1-3 brain metastases, each < 3 cm by contrast MRI, were randomized to SRS alone or SRS + WBRT and underwent cognitive testing before and after treatment. The primary endpoint was cognitive progression (CP) defined as decline > 1 SD from baseline in any of the 6 cognitive tests at 3 months. Time to CP was estimated using cumulative incidence adjusting for survival as a competing risk. Results: 213 patients were enrolled with 2 ineligible and 3 cancels prior to receiving treatment. Baseline characteristics were well-balanced between study arms. The median age was 60 and lung primary the most common (68%). CP at 3 months was more frequent after WBRT + SRS vs. SRS alone (88.0% vs. 61.9% respectively, p = 0.002). There was more deterioration in the WBRT + SRS arm in immediate recall (31% vs. 8%, p = 0.007), delayed recall (51% vs. 20%, p = 0.002), and verbal fluency (19% vs. 2%, p = 0.02). Intracranial tumor control at 6 and 12 months were 66.1% and 50.5% with SRS alone vs. 88.3% and 84.9% with SRS+WBRT (p < 0.001). Median OS was 10.7 for SRS alone vs. 7.5 months for SRS+WBRT respectively (HR = 1.02, p = 0.93). Conclusions: Decline in cognitive function, specifically immediate recall, memory and verbal fluency, was more frequent with the addition of WBRT to SRS. Adjuvant WBRT did not improve OS despite better brain control. Initial treatment with SRS and close monitoring is recommended to better preserve cognitive function in patients with newly diagnosed brain metastases that are amenable to SRS. Clinical trial information: NCT00377156.

Donepezil for Irradiated Brain Tumor Survivors: A Phase III Randomized Placebo-Controlled Clinical Trial

PURPOSE

Neurotoxic effects of brain irradiation include cognitive impairment in 50% to 90% of patients. Prior studies have suggested that donepezil, a neurotransmitter modulator, may improve cognitive function.

PATIENTS AND METHODS

A total of 198 adult brain tumor survivors ≥ 6 months after partial- or whole-brain irradiation were randomly assigned to receive a single daily dose (5 mg for 6 weeks, 10 mg for 18 weeks) of donepezil or placebo. A cognitive test battery assessing memory, attention, language, visuomotor, verbal fluency, and executive functions was administered before random assignment and at 12 and 24 weeks. A cognitive composite score (primary outcome) and individual cognitive domains were evaluated.

RESULTS

Of this mostly middle-age, married, non-Hispanic white sample, 66% had primary brain tumors, 27% had brain metastases, and 8% underwent prophylactic cranial irradiation. After 24 weeks of treatment, the composite scores did not differ significantly between groups (P = .48); however, significant differences favoring donepezil were observed for memory (recognition, P = .027; discrimination, P = .007) and motor speed and dexterity (P = .016). Significant interactions between pretreatment cognitive function and treatment were found for cognitive composite (P = .01), immediate recall (P = .05), delayed recall (P = .004), attention (P = .01), visuomotor skills (P = .02), and motor speed and dexterity (P < .001), with the benefits of donepezil greater for those who were more cognitively impaired before study treatment.

CONCLUSION

Treatment with donepezil did not significantly improve the overall composite score, but it did result in modest improvements in several cognitive functions, especially among patients with greater pretreatment impairments.

A randomized trial of bevacizumab for newly diagnosed glioblastoma

BACKGROUND

Concurrent treatment with temozolomide and radiotherapy followed by maintenance temozolomide is the standard of care for patients with newly diagnosed glioblastoma. Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor A, is currently approved for recurrent glioblastoma. Whether the addition of bevacizumab would improve survival among patients with newly diagnosed glioblastoma is not known.

METHODS

In this randomized, double-blind, placebo-controlled trial, we treated adults who had centrally confirmed glioblastoma with radiotherapy (60 Gy) and daily temozolomide. Treatment with bevacizumab or placebo began during week 4 of radiotherapy and was continued for up to 12 cycles of maintenance chemotherapy. At disease progression, the assigned treatment was revealed, and bevacizumab therapy could be initiated or continued. The trial was designed to detect a 25% reduction in the risk of death and a 30% reduction in the risk of progression or death, the two coprimary end points, with the addition of bevacizumab.

RESULTS

A total of 978 patients were registered, and 637 underwent randomization. There was no significant difference in the duration of overall survival between the bevacizumab group and the placebo group (median, 15.7 and 16.1 months, respectively; hazard ratio for death in the bevacizumab group, 1.13). Progression-free survival was longer in the bevacizumab group (10.7 months vs. 7.3 months; hazard ratio for progression or death, 0.79). There were modest increases in rates of hypertension, thromboembolic events, intestinal perforation, and neutropenia in the bevacizumab group. Over time, an increased symptom burden, a worse quality of life, and a decline in neurocognitive function were more frequent in the bevacizumab group.

CONCLUSIONS

First-line use of bevacizumab did not improve overall survival in patients with newly diagnosed glioblastoma. Progression-free survival was prolonged but did not reach the prespecified improvement target. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00884741.).

Quality of life (QOL) and cognitive status among irradiated brain tumor survivors treated with donepezil or placebo

2051

Background: Cognitive problems after cancer therapy can decrease QOL. This phase III randomized trial tested the effect of donepezil (5-10 mg daily for 24 weeks) on cognition and QOL in brain cancer patients. Methods: Between 2/2008-12/2011, 198 (99 placebo; 99 donepezil) adult primary and metastatic brain tumor survivors > 6 months post radiation (> 30 Gy) were recruited at 24 sites affiliated with the Wake Forest CCOP Research Base, 3 CTSU sites, and M.D. Anderson. Outcomes were assessed at baseline, 12 and 24 weeks. Regression analyses examined the association of demographics, fatigue (FACIT-Fatigue), and a cognitive performance composite score (CC) (comprised of the Controlled Oral Word Association Test, Hopkins Verbal Learning Test-Revised, Digit Span Test, Trail Making Test A&B, Rey-Osterreith Complex Figure-modified, Grooved Pegboard) on QOL, measured by the FACT-Brain (FACT-Br) total score. Results: Participants had a median age of 55, were predominantly female (54%) and non-Hispanic White (91%), with a median time from diagnosis of 38 months. Study completion was 74%. At 12 and 24 weeks, treatment had no significant effect on QOL, unadjusted and adjusted for race/ethnicity, age, sex, fatigue, baseline FACT-Br, and baseline CC. However, for those below the median on the baseline FACT-Br subscale (i.e., greater cognitive symptoms), donepezil was associated with higher (better) post-tx FACT-Br total scores (p =0.004), unadjusted for covariates. After adjustment for covariates, donepezil was borderline significantly associated with higher post-tx QOL (p=0.052). Improvement in QOL was associated with being female (p=0.017) and less baseline fatigue (p=0.005). For participants with baseline FACT-Br subscale scores above the median, only lower baseline FACT-Br total scores (p=0.015) were significantly related to greater improvements in FACT-Br. Donepezil treatment was not significant (p=0.48). Conclusions: The impact of donepezil on QOL was greater in survivors with more cognitive symptoms at baseline, although the results were borderline significant. Fatigue continued to be a major factor in lower QOL. Other interventions to better manage survivors’ symptoms are needed. Clinical trial information: NCT00369785.

Phase III randomized, double-blind, placebo-controlled trial of donepezil in irradiated brain tumor survivors

2006

Background: This RCT assessed the effect of 24 weeks of 5-10 mg per day of donepezil, an acetyl cholinesterase inhibitor, on cognitive functioning (primary endpoint) and fatigue, mood and QOL in long-term brain tumor survivors following partial or whole-brain irradiation. Cognitive results are reported herein. Methods: From 2/08-12/11,198 adult primary and metastatic brain tumor survivors > 6 months post radiation treatment (>30 Gray) recruited at 24 sites affiliated with the Wake Forest Community Clinical Oncology Program Research Base, 3 CTSU sites and M.D. Anderson Cancer Center were randomly assigned to receive donepezil (n=99) or placebo (n=99). Cognitive function was assessed at baseline, 12 and 24 weeks with Hopkins Verbal Learning Test-Revised, Rey-Osterreith Complex Figure, Trail Making Test, Digit Span, Controlled Oral Word Association, and Grooved Pegboard. A Cognitive Composite (CC) score was the primary outcome. Results: The sample was 91% White, 54% female, and median age was 55 yrs. 66% had primary tumors, 27% brain metastases and 8% PCI. Median time since diagnosis: 38 mos. 95% had 0-1 ECOG performance status scores. 74% completed the study. CC score improved significantly by 24 weeks in both arms (p < .01); however, there was not a statistically significant difference between groups (p = .57). Donepezil group performed better than placebo on HVLT Recognition (p = .03) and Discrimination (p = .01) and GP-Dominant Hand (p = 0.02). Significant interactions were found between treatment arm and baseline cognitive scores for: CC (p = .01), HVLT Immed. Recall (p = .03), HVLT %Savings (p < .01), Digit Span Forward (p = .01), ROCF Copy (p = .03), TMT-B (p = .05) and GP-Dominant (p < .01). In all cases, the benefit of donepezil, relative to placebo, was greater for those with worse baseline scores. Conclusions: Long-term brain tumor survivors treated with brain irradiation who have cognitive impairment can benefit from 5-10mg of donepezil for 24 weeks. Improvements in verbal memory, working memory, visuo- and psychomotor performance and executive functioning were observed in this group. (Study supported by NIH/NINR grant 5R01NR009675-04, NIH/NCI grant 2 U10 CA 81851-09-13 and Eisai, Inc.) Clinical trial information: NCT00369785.

Gamma Knife surgery targeting the resection cavity of brain metastasis that has progressed after whole-brain radiotherapy

OBJECT

Salvage treatment of large, symptomatic brain metastases after failure of whole-brain radiotherapy (WBRT) remains challenging. When these lesions require resection, there are few options to lower expected rates of local recurrence at the resection cavity margin. The authors describe their experience in using Gamma Knife surgery (GKS) to target the resection cavity in patients whose tumors had progressed after WBRT.

METHODS

The authors retrospectively identified 143 patients in whom GKS had been used to target a brain metastasis resection cavity between 2000 and 2005. Seventy-nine of these patients had undergone WBRT prior to resection and GKS. The median patient age was 53 years, and the median prescribed dose was 18 Gy (range 8-24 Gy), with resection cavities of relatively larger volume (> 15 cm3). The GKS dose was prescribed at the 40 to 95% isodose contour (mode 50%). Local recurrence within 1 cm of the treatment volume occurred in four (5.1%) of 79 cases. The median duration of time to local recurrence was 6.1 months (range 2-13 months). The median duration of time to occurrence of distant metastases following GKS of the resection cavity was 10.8 months (range 2-86 months). Carcinomatous meningitis developed in four (5.1%) of 79 cases. Symptomatic radionecrosis requiring surgical treatment occurred in three (3.8%) of 79 cases. The median duration of survival following GKS of the resection cavity was 69.6 weeks. The median 2- and 5-year survival rates were 20.2 and 6.3%, respectively.

CONCLUSIONS

When metastases progress after WBRT and require resection, GKS targeting the resection cavity is a viable strategy. In 75 (94.9%) of 79 cases, GKS of the resection cavity in patients in whom WBRT had failed appears to have achieved its goal of local disease control.

Multi-institutional phase I/II trial of stereotactic body radiation therapy for liver metastases

PURPOSE

To evaluate the efficacy and tolerability of high-dose stereotactic body radiation therapy (SBRT) for the treatment of patients with one to three hepatic metastases.

PATIENTS AND METHODS

Patients with one to three hepatic lesions and maximum individual tumor diameters less than 6 cm were enrolled and treated on a multi-institutional, phase I/II clinical trial in which they received SBRT delivered in three fractions. During phase I, the total dose was safely escalated from 36 Gy to 60 Gy. The phase II dose was 60 Gy. The primary end point was local control. Lesions with at least 6 months of radiographic follow-up were considered assessable for local control. Secondary end points were toxicity and survival.

RESULTS

Forty-seven patients with 63 lesions were treated with SBRT. Among them, 69% had received at least one prior systemic therapy regimen for metastatic disease (range, 0 to 5 regimens), and 45% had extrahepatic disease at study entry. Only one patient experienced grade 3 or higher toxicity (2%). Forty-nine discrete lesions were assessable for local control. Median follow-up for assessable lesions was 16 months (range, 6 to 54 months). The median maximal tumor diameter was 2.7 cm (range, 0.4 to 5.8 cm). Local progression occurred in only three lesions at a median of 7.5 months (range, 7 to 13 months) after SBRT. Actuarial in-field local control rates at one and two years after SBRT were 95% and 92%, respectively. Among lesions with maximal diameter of 3 cm or less, 2-year local control was 100%. Median survival was 20.5 months.

CONCLUSION

This multi-institutional, phase I/II trial demonstrates that high-dose liver SBRT is safe and effective for the treatment of patients with one to three hepatic metastases.

Radiation safety issues with positron-emission/computed tomography simulation for stereotactic body radiation therapy

Stereotactic body radiation therapy (SBRT) simulations using a Stereotactic Body Frame (SBF: Elekta, Stockholm, Sweden) were expanded to include 18F-deoxyglucosone positron-emission tomography (FDG PET) for treatment planning. Because of the length of time that staff members are in close proximity to the patient, concerns arose over the radiation safety issues associated with these simulations. The present study examines the radiation exposures of the staff performing SBRT simulations, and provides some guidance on limiting staff exposure during these simulations. Fifteen patients were simulated with PET/CT using the SBF. Patients were immobilized in the SBF before the FDG was administered. The patients were removed from the frame, injected with FDG, and allowed to uptake for approximately 45 minutes. After uptake, the patients were repositioned in the SBF. During the repositioning, exposure rates were recorded at the patient's surface, at the SBF surface, and at 15 cm, 30 cm, and 1 m from the SBF. Administered dose and the approximate time spent on patient repositioning were also recorded. The estimated dose to staff was compared with the dose to staff performing conventional diagnostic PET studies. The average length of time spent in close proximity (<50 cm) to the patient after injection was 11.7 minutes, or more than twice the length of time reported for diagnostic PET staff. That time yielded an estimated average dose to the staff of 26.5 microSv per simulation. The annual occupational exposure limit is 50 mSv. Based on dose per simulation, staff would have to perform nearly 1900 SBRT simulations annually to exceed the occupational limit. Therefore, at the current rate of 50-100 simulations annually, the addition of PET studies to SBRT simulations is safe for our staff. However, ALARA ("as low as reasonably achievable") principles still require some radiation safety considerations during SBRT simulations. The PET/CT-based SBRT simulations are safe and important for treatment planning that optimizes biologic dose distribution with highly accurate and reproducible target definition.

Advances in radiation therapy for brain tumors

Radiation therapy is used postoperatively as adjunctive therapy to decrease local failure; to delay tumor progression and prolong survival; as a curative treatment; as a therapy that halts further tumor growth; to alter function; and for palliation. Registration of MRI scan data sets with the treatment-planning CT scan is essential for accurate definition of the tumor and surrounding organs at risk. Integrating additional imaging studies that reflect the biologic characteristics of central nervous system tumors is an area of active research. Conformal treatment delivery is used to spare adjacent normal tissue from receiving unnecessary dose. In the dose range used when treating these tumors, the probability of causing serious late toxicity is relatively low and secondary malignancies are rare.

Optically guided linac radiosurgery with a Leksell head frame as an adjunct to Gamma Knife treatment

Because of geometrical limitations in the helmet of the Leksell Gamma Knife(Elekta Corp., Atlanta, GA, USA) certain regions within the cranium cannot be targeted for treatment. We describe a method by which lesions in these regions can be treated with the Varian-Zmed stereotactic radiosurgery system utilizing an infrared optical positioning system attached to a Leksell head frame. We have measured the accuracy of the optical tracking system using a phantom attached to a Leksell frame and have determined that the system can target a linear accelerator radiosurgery beam to an accuracy of within 1 millimeter.

Interim analysis of a prospective phase I/II trial of SBRT for liver metastases

Stereotactic Body Radiation Therapy (SBRT) is a potent means of systemic cytoreductive therapy for selected patients with metastatic cancer. We here report an interim analysis of a prospective Phase I/II study of SBRT for liver metastases. Eligible patients with liver metastases met these criteria: (1) maximum tumor diameter < 6 cm; (2) < or =3 discrete lesions; (3) treatment planning confirmed > or = 700 cm3 of normal liver receives < or =15 Gy. The gross tumor volume (GTV) was expanded 5-10 mm to yield the planning target volume, which received 60 Gy in 3 fractions of SBRT over 3-14 days in the Phase II component of the trial. As of July, 2006, 36 patients have been enrolled: 18 in Phase I, 18 in Phase II. The median age was 58 years (range 27-91); the M:F ratio was 20:16. The most common primary sites were lung (n = 10), colorectal (n = 9), and breast (n = 4). Among 21 pts with > or = 6 months post-SBRT follow-up (median 19 months, range 6-29), one instance of SBRT-related grade 3 toxicity occurred in subcutaneous tissue superficial to the liver. No grade IV toxicity occurred. For 28 discrete lesions treated (median GTV 14 cm3, range 1-98) the 18 month actuarial local control estimate is 93%. This interim analysis indicates that a very high rate of durable in-field tumor control can be safely achieved with SBRT to 1-3 liver lesions as administered in this protocol, to a prescription dose of 60 Gy in 3 fractions.

Does dose rate affect efficacy? The outcomes of 256 gamma knife surgery procedures for trigeminal neuralgia and other types of facial pain as they relate to the half-life of cobalt

OBJECT

Gamma Knife surgery (GKS) is a treatment option for patients with refractory typical trigeminal neuralgia (TN), TN with atypical features, and atypical types of facial pain. The Gamma Knife's 201 60Co sources decay with a half-life of 5.26 years. The authors examined whether the decrease in dose rate over 4.6 years between Co source replacements affected the control rates of facial pain in patients undergoing GKS.

METHODS

The authors collected complete follow-up data on 239 of 326 GKS procedures performed in patients with facial pain. Patients were classified by their type of pain. The isocenter of a 4-mm collimator helmet was targeted at the proximal trigeminal nerve root, and the dose (80-90 Gy) was prescribed at the 100% isodose line. Patients reported the amount of pain control following radiosurgery by answering a standardized questionnaire. Eighty percent of patients experienced greater than 50% pain relief, and 56% of patients experienced complete pain relief after GKS. Neither dose rate nor treatment time was significantly associated with either the control rate or degree of pain relief. A significant association between the type of facial pain and the pain control rate after GKS was observed (p < 0.001; Pearson chi-square test). In their statistical analysis, the authors accounted for changes in prescription dose over time to prevent the dose rate from being a confounding variable. There was no observable effect of the dose rate or of the treatment duration within the typical period to source replacement.

CONCLUSIONS

Patients with facial pain appear to receive consistent treatment with GKS at any time during the first half-life of the Co sources.

Results of a phase II trial of the GliaSite radiation therapy system for the treatment of newly diagnosed, resected single brain metastases

OBJECT

The aim of this study was to evaluate the effectiveness of brachytherapy using the GliaSite Radiation Therapy System in patients with a newly diagnosed resected single brain metastasis. The primary end point of the study was local tumor control. The secondary end points included patient survival, distant brain recurrence, quality of life, and treatment toxicity.

METHODS

The authors conducted a prospective multiinstitutional phase II study of GliaSite brachytherapy prescribed at a 60-Gy dose administered to a 1-cm depth after resection of a single brain metastasis. No whole-brain radiation therapy was given. Patients were assessed at 1 and 3 months after brachytherapy and every 3 months thereafter for up to 2 years. Seventy-one patients were enrolled at 13 centers. A GliaSite balloon catheter was implanted in 62 patients. Fifty-four patients received brachytherapy. The median patient age was 60 years. The most common tumor (54%) was non-small cell lung cancer. Fifty-seven percent of patients had brain metastasis only, whereas 43% had extracranial metastasis. The median final administered dose was 60 Gy. The magnetic resonance imaging--determined local control rate, based on several different methods, was 82 to 87%. Both the median patient survival time and the median duration of functional independence were 40 weeks. Among the 35 patients who died, the cause of death was neurological in 11%. Thirteen patients underwent reoperation for suspected tumor recurrence or radiation necrosis, and histological diagnoses included radiation necrosis without tumor (nine patients), radiation necrosis mixed with tumor (two patients), and tumor only (two patients). Extracranial metastasis, tumor size, and radiation necrosis were significant factors affecting patient survival.

CONCLUSIONS

In patients with a resected single brain metastasis, GliaSite brachytherapy leads to a local control rate, median patient survival time, and duration of functional independence similar to those achieved with resection plus whole-brain radiation therapy.

The role of radiosurgery in the management of malignant brain tumors

Stereotactic radiosurgery (SRS) provides the means for creating lesions in deep-seated areas of the brain inaccessible to invasive surgery, using single high doses of focused ionizing radiation, administered using stereotactic guidance. It is a surgical technique designed to produce a specific radiobiological effect within a sharply defined target region in a single treatment session. Its technical application requires a stereotactic coordinate system, highly accurate patient repositioning (usually fixed), and multiple convergent beams of photon radiation. SRS appears to provide no benefit in the upfront treatment of newly diagnosed malignant gliomas but may be used to effectively palliate small well-demarcated volumes of recurrent disease. For selected patients with brain metastases treated with whole-brain radiation therapy (WBRT), the addition of SRS improves median survival. In selected patients with brain metastases, it is also rational to withhold WBRT in favor of radiosurgery alone, with WBRT reserved for salvage without a decrease in median survival time.

Lessons learned from randomised clinical trials in adult low grade glioma

"Lesson" is a Middle English word that has been defined as "a passage from sacred writings read in a service of worship" as well as "something learned by study or experience". The term is quite appropriate in assessment of what has been learned from randomised trials in adult low-grade gliomas, since the treatment of these tumours has traditionally been guided as much by belief as by fact. Therefore, when assessing these trials we can apply the principles of hermeneutics. Thus, the first meaning of "lesson" given here can be described as literal, whereas the second may be seen as figurative. Since hermeneutics may also refer to an in-depth analysis of a particular text, the investigators will present their interpretation of data from randomised trials. The goal is to show that the lessons learned are not necessarily literal or dogmatic but can be much more allegorical in nature.

Glossopharyngeal neuralgia treated with gamma knife surgery: treatment outcome and failure analysis

✓ Glossopharyngeal neuralgia (GPN) is a rare condition in which patients present with intractable deep throat pain. Similar to trigeminal neuralgia (TN), treatment with microvascular decompression (MVD) has been successful in both. Because gamma knife surgery (GKS) has also been shown to be effective in treating TN, it seemed reasonable to apply it to GPN. The authors present the first report of GKS-treated GPN in a patient who presented with severe, poorly controlled GPN and who refused MVD.

Glossopharyngeal neuralgia treated with gamma knife surgery: treatment outcome and failure analysis

✓ Glossopharyngeal neuralgia (GPN) is a rare condition in which patients present with intractable deep throat pain. Similar to trigeminal neuralgia (TN), treatment with microvascular decompression (MVD) has been successful in both. Because gamma knife surgery (GKS) has also been shown to be effective in treating TN, it seemed reasonable to apply it to GPN. The authors present the first report of GKS-treated GPN in a patient who presented with severe, poorly controlled GPN and who refused MVD.

Meningioma: Current treatment options and future directions

Benign meningiomas can be observed if not symptomatic or growing. When treatment is indicated, the options are surgery, radiosurgery, fractionated radiation therapy, or a combination of these modalities. Except in certain cases, such as large tumors that require debulking for relief of symptoms, we do not recommend the routine use of combination therapy. Intracranial meningiomas have usually been treated with surgical resection with an expected durable local control of 80% to 90% when a gross total resection (GTR) is obtained. Patients who have inoperable disease, refuse surgery, undergo less than a GTR, or who have aggressive histology should instead be considered candidates for radiation therapy or radiosurgery. While benign meningiomas can be successfully treated definitively or postoperatively with either fractionated radiation therapy or single fraction radiosurgery, atypical or malignant lesions are best treated with fractionated radiation therapy with conventional dosimetric margins. The role of systemic therapy is not yet defined, but multiple agents are being investigated in early phase trials for patients with recurrent or progressive disease after standard therapy has failed.

Current controversies in the radiotherapeutic management of adult low-grade glioma

Over the last decade, the results of four prospective clinical trials of supratentorial low-grade glioma (LGG) in adults have been published. The data from the nearly 1,000 patients treated on these studies are summarized in this presentation, addressing the following three current controversies in the radiotherapeutic management of these patients: (1) optimum timing of radiation therapy (RT); (2) optimum RT dose; and (3) addition of chemotherapy to RT. The 5-year overall survival (OS) and progression-free survival (PFS) rates in these four studies ranged from 58% to 72% and from 37% to 55%, respectively. Significant prognostic factors included extent of surgical resection, histology, tumor size, and age. The European Organization for Research and Treatment of Cancer (EORTC) study 22845 randomized 311 adults to postoperative observation or RT. There was no difference in the 5-year OS rate between the two arms, but the irradiated patients had a significantly improved 5-year PFS rate. EORTC study 22844 randomized 379 adults to low- versus high-dose RT. Similarly, an intergroup study conducted by the North Central Cancer Treatment Group (NCCTG), Radiation Therapy Oncology Group (RTOG), and Eastern Cooperative Group (ECOG) randomized 211 adults to low- versus high-dose RT. There was no difference in the 5-year OS or PFS rates between the two dose groups in either study. A Southwest Oncology Group (SWOG) study randomized 60 adults with incompletely resected LGG to RT alone or RT plus lomustine (CCNU) chemotherapy. There was no difference in outcome between the two treatment arms. Further prospective clinical trials are needed to define the optimal management strategy for adults with supratentorial LGG. The schemata from recently completed and ongoing LGG studies will be presented.

The use of a Leksell-BRW adapter for linac radiosurgery as an adjunct to Gamma Knife treatment

We have investigated the use of an adapter that permits the use of a Leksell coordinate frame with a linear accelerator stereotactic radiosurgery system based on the Brown-Robert-Wells (BRW) design. This device is useful when lesions that are planned for treatment on a Leksell Gamma Knife system are found to be inaccessible to the Gamma Knife. We have found that with this device objects within a head phantom can be targeted by the linear accelerator within an accuracy of approximately 1 mm.

Oligodendroglioma

Oligodendroglial tumors have historically been a fatal disease, despite maximum medical and surgical treatment. However, in the past 10 years, effective adjuvant therapies have been developed that have been found to significantly prolong patient survival and, in some instances, provide a cure. Improvements in our understanding of the molecular biology of these tumors, refinements in surgical technique, and advances in chemotherapeutic treatment have combined to produce this improvement in survival with little additional toxicity to patients. At the time of diagnosis, patients should undergo maximum surgical resection or needle biopsy if maximum surgical resection is not possible. Patients with low-grade lesions may be followed, receiving radiation only at the time of progression. Patients with high-grade lesions should be irradiated up front. In addition, selected patients should receive chemotherapy. Clinical trials remain critical to advancing our understanding of these tumors and improving our ability to cure these patients.

Gentlemen (and ladies), choose your weapons: Gamma knife vs. linear accelerator radiosurgery

This article compares and contrasts Gamma Knife radiosurgery with linear accelerator-based radiosurgery; where appropriate, Cyberknife technology is discussed. Topics covered are: positioning of the head (invasive versus non-invasive positioning systems); collimator construction; beam properties; beam arrangements; treatment planning; and issues regarding manpower (including a discussion of patient repositioning during treatment), machine availability, and financial considerations.

Low-grade gliomas

Low-grade gliomas are uncommon primary brain tumors classified as histologic grades I or II in the World Health Organization (WHO) classification. The most common variants are pilocytic and low-grade astrocytomas, oligodendrogliomas, and mixed oligo-astrocytomas located in the cerebral hemispheres. Prognostic factors that predict progression-free and overall survival include young age, pilocytic histology, good Karnofsky performance status, gross total resection, lack of enhancement on imaging, and small preoperative tumor volumes. Edema and vasogenic effects are typically managed with corticosteroids. Dexamethasone is given at an initial dosage of 4 mg given four times daily. Anticonvulsants are given prophylactically after resection and for patients who present with seizures. The rationale for open craniotomy depends on the need for immediate palliation of symptoms by reduction of intracranial pressure or focal mass effect, and/or improved oncologic control. Gross total resection of tumor is generally defined as the absence of residual enhancement on contrast-enhanced postoperative MRI scan. Most retrospective studies suggest that patients who have undergone a gross total resection of tumor have improved survival. Depending upon the proximity of the tumor to eloquent brain, gross total resection may or may not be possible. In these cases a stereotactic biopsy is required to provide the histologic diagnosis. Adjuvant radiotherapy is recommended for patients with incompletely resected grade II tumors or for patients older than age 40 regardless of extent of resection. It may be considered for any pilocytic astrocytoma from which a biopsy has been performed. Phase III randomized prospective trials have shown statistically significantly improved progression-free survival at 5 years with the addition of radiotherapy, though overall survival does not appear different. Based on prospective randomized phase III trials, 50.4 Gy to 54 Gy of conventionally fractionated radiotherapy appears to be a safe and effective regimen with minimal neurotoxicity; 45 Gy may be adequate for biopsied pilocytic astrocytomas. Currently, RTOG trial 98-02 is investigating the efficacy of postradiation PCV chemotherapy (procarbazine, CCNU, and vincristine) in the treatment of newly diagnosed unfavorable low-grade gliomas. Other areas of investigation include Temozolomide chemotherapy and the association of 1p and 19q chromosomal deletions with prolonged survival in oligodendrogliomas and sensitivity to PCV chemotherapy. Radiosurgery and/or experimental chemotherapy may provide some measure of local control in the recurrent disease setting.