Permanent iodine 125 brachytherapy in patients with progressive or recurrent glioblastoma multiforme

Brachytherapy is an effective and safe salvage option for re-irradiation in recurrent glioblastoma (rGBM): A systematic review

PURPOSE

To evaluate the clinical efficacy and toxicity of brachytherapy as a salvage therapy for patients with recurrent glioblastoma (rGBM).

METHODS AND MATERIALS

We searched the PubMed, Embase, and Cochrane libraries from its inception to June 2023, for eligible studies in which patients underwent brachytherapy for rGBM. Outcomes of interest were mOS, mPFS, OS, PFS, and adverse events (AEs). For individual clinical survival outcomes and common AEs, weighted-mean descriptive statistics were calculated as a summary measure using study sample size as the weight. The calculation formula is as follows: weighted-mean = Σwx/Σw (w is the sample size and x is the outcome).

RESULTS

This review included 29 studies with a total of 1202 rGBM patients, including 22 retrospective and 7 prospective studies. The results showed that from the time of brachytherapy, the mOS and mPFS were 6.8 to 24.4 months and 3.7 to 11.7 months. The OS of 6 months, 1 year, 18 months, 2 years, and 3 years after brachytherapy were 58.3 % to 85.2 % (weighted-mean 76.2 %), 26 % to 66 % (weighted-mean 41.9 %), 20 % to 37 % (weighted-mean 27.6 %), 11 % to 23 % (weighted-mean 14.8 %), and 8 % to 15 % (weighted-mean 12.1 %), respectively. The PFS of 6 months and 1 year after brachytherapy were 26.7 % to 86 % (weighted-mean 53.4 %) and 14 % to 81 % (weighted-mean 24.1 %). Most patients with rGBM will experience treatment failure again during the follow-up period, mainly local (10.7 % to 79.4 %) or marginal(3.6 % to 22.2 %) recurrence, followed by distant failure (6.7 % to 57.7 %). Although therapeutic AEs had not been uniformly reported, the overall toxicity rate was considered to be low. The common AEs reported included progressive neurologic deterioration, seizures, CSF leak, brain necrosis, hemorrhage, and infection/meningitis, with a weighted-mean incidence of 1.9 %, 2.4 %, 4.1 %, 5.4 %, 2.1 %, and 3.8 %, respectively.

CONCLUSIONS

The evidence summarized above, albeit mostly level III, suggests that brachytherapy has acceptable safety and good post-treatment clinical efficacy for selected patients with rGBM. Well-designed, high-quality, large-sample randomized controlled and prospective studies are needed to further validate these findings.

Effect of neoadjuvant iodine-125 brachytherapy upon resection of glioma

Background

A more extensive surgical resection of glioma contributes to improved overall survival (OS) and progression-free survival (PFS). However, some patients miss the chance of surgical resection when the tumor involves critical structures.

Purpose

The present study aimed to assess the feasibility of neoadjuvant ¹²⁵I brachytherapy followed by total gross resection for initially inoperable glioma.

Methods

Six patients diagnosed with inoperable glioma due to invasion of eloquent areas, bihemispheric diffusion, or large tumor volume received ¹²⁵I brachytherapy. Surgical resection was performed when the tumor shrank, allowing a safe resection, assessed by the neurosurgeons. Patients were followed up after surgery.

Results

Shrinkage of the tumor after adjuvant ¹²⁵I brachytherapy enabled a total gross resection of all six patients. Four patients were still alive at the last follow-up, with the longest survival time of more than 50 months, two of which returned to everyday life with a KPS of 100. Another two patients had neurological injuries with KPSs of 80 and 50, respectively. One patient with grade II glioma died 34 months, and another with grade IV glioma died 40 months after the combined therapy.

Conclusions

In the present study, the results demonstrated that ¹²⁵I brachytherapy enabled a complete resection of patients with initially unresectable gliomas. ¹²⁵I brachytherapy may offer a proper neoadjuvant therapy method for glioma.

A Retrospective Study on Using a Novel Single Needle Cone Puncture Approach for the Iodine-125 Seed Brachytherapy in Treating Patients With Thoracic Malignancy

Background

Patients with progressive thoracic malignancy characterized by large irregular tumors with necrosis and life-threatening symptoms lack effective treatments. We set out to develop a single needle cone puncture method for the Iodine-125 seed (SNCP-¹²⁵I) brachytherapy, and aim to report the initial results.

Methods

294 patients with advanced thoracic malignancy were treated with local SNCP-¹²⁵I brachytherapy between March 2009 and July 2020, followed by thorough evaluation of clinical outcome, overall survival (OS), progression-free survival (PFS) and procedure-related complications after treatment.

Results

The overall response rate (ORR) among the treated patients was 81.0% (238/294). Life-threatening symptoms due to tumor oppression, hemoptysis and large irregular tumor with necrosis were successfully alleviated after the SNCP-¹²⁵I treatment with a remission rate at 91% to 94%. The median OS and PFS were 13.6 months and 5.8 months, respectively. Procedure-related side effects including pneumothorax (32/294), blood-stained sputum (8/294), subcutaneous emphysema (10/294), puncture site bleeding (16/294) and chest pain (6/294) were observed. Patients who were able to follow with chemotherapy or immunotherapy experienced extended OS and PFS, as compared with patients who opted to receive hospice care (16.5 months Vs. 11.2 months). Further pathological and immunological analysis showed that SNCP-¹²⁵I induced tumor lymphocytes infiltration and long-term tumor necrosis.

Conclusion

SNCP-¹²⁵I brachytherapy effectively eliminates life-threatening symptoms due to local tumor oppression, hemoptysis and large irregular and necrotic tumors in patients with unresectable chest malignancy and significantly induces local tumor regression. SNCP-¹²⁵I brachytherapy combines with chemotherapy significantly prolong OS and PFS compare with SNCP-¹²⁵I brachytherapy alone.

Clinical importance of ADC in the prediction of 125I in the treatment for gliomas

Objectives: To determine whether the minimum apparent diffusion coefficient (minADC) value can stratify survival in patients with glioma before ¹²⁵I brachytherapy.

Methods: The study was approved by the Institutional Review Board, and the requirement for informed consent was waived. Twenty-three patients (16 male, 7 female; median age, 48 years) with high-grade glioma (HGG) (n=9) or recurrence after multimodal treatment (n=14) were included in this study. minADC values were obtained before ¹²⁵I implantation. Overall survival (OS) and progression-free survival (PFS) were analyzed with Cox proportional hazards regression models and the Kaplan-Meier method with the log-rank test.

Results: For ¹²⁵I-treated patients, the hazard ratio for OS in patients with ADC≥1.0*10^^-3 mm²·sec^-1 (high minADC) versus ADC<1.0*10^^-3 mm²·sec^-1 (low minADC) was 0.220 (95% confidence interval: 0.066, 0.735). The median OS was 12 months for patients with high minADC values and 6.0 months for those with low minADC values, and the differences were significant (p=0.032). The median PFS was 12 months for patients with high minADC values and 4 months for those with low minADC values. Significant differences were found in the long-rank test (p=0.013). The multivariate analysis results showed that minADC pre-¹²⁵I implantation was an independent predictor of OS and PFS in patients receiving ¹²⁵I brachytherapy.

Conclusions: Pre-¹²⁵I implantation ADC analysis can stratify prognosis in ¹²⁵I-treated patients with glioma, which may aid in choosing a suitable therapy for glioma patients.

Perioperative Management of Patients with Glioblastoma

The clinical presentation of glioblastomas is varied, and definitive diagnosis requires pathologic examination and study of the tissue. Management of glioblastomas includes surgery and adjuvant chemotherapy and radiotherapy, with surgery playing an important role in the prognosis of these patients. Awake craniotomy plays a crucial role in tumors in or adjacent to eloquent areas, allowing surgeons to maximize resection, while minimizing iatrogenic deficits. However, the prognosis remains dismal. This article presents the perioperative management of patients with glioblastoma including tools and surgical adjuncts to maximize extent of resection and minimize poor outcomes.

Permanent iodine-125 brachytherapy for patients with progressive or recurrent high-grade gliomas

Background

The prognosis of patients with progressive or recurrent high-grade gliomas (HGGs) after surgery remains poor. Iodine-125 brachytherapy is emerging as a salvage method for the treatment of gliomas. This study aimed to investigate whether permanent iodine-125 brachytherapy could be used as an effective therapeutic method even without radiotherapy and/or chemotherapy for progressive or recurrent HGG after gross total resection.

Methods

Between March 2004 and August 2016, 58 patients with progressive or recurrent HGG after gross total resection were included in this study. Twenty-nine patients underwent radiotherapy and/or chemotherapy and then permanent iodine-125 brachytherapy (SRCI group). Twenty-nine patients underwent permanent iodine-125 brachytherapy alone (SI group). Follow-up was carried out at 1, 3, and 6 months and then at 1, 2, 3, and 5 years after iodine-125 implantation. The median overall survival (OS) and progression-free survival (PFS), procedure-related complications and clinical outcomes were evaluated.

Results

No procedure-related fatal events happened. The temporary morbidity rate was 11.9%. The median OS and PFS for patients in the SI group were 22 and 8 months compared with 21 and 7 months in the SRCI group. No significant differences were found. Age and Karnofsky Performance Status (KPS) were independent prognostic factors for OS. Age, KPS and histology were independent prognostic factors for PFS.

Conclusions

Permanent iodine-125 brachytherapy could be used as an effective therapeutic method even without radiotherapy and/or chemotherapy for progressive or recurrent HGG after gross total resection.

Intraoperative brachytherapy for resected brain metastases

Brain metastases are the most common intracranial malignancies in adults. Surgical resection is the preferred treatment approach when a pathological diagnosis is required, for symptomatic patients who are refractory to steroids, and to decompress lesions causing mass effect. Radiotherapy is administered to improve local control rates after surgical resection. After a brief review of the literature describing the treatment of brain metastases using whole-brain radiotherapy, postoperative stereotactic radiosurgery, preoperative radiosurgery, and brachytherapy, we compare patient-related, technical, practical, and radiobiological considerations of each technique. Finally, we focus our discussion on intraoperative brachytherapy, with an emphasis on the technical aspects, benefits, efficacy, and outcomes of studies utilizing permanent Cs-131 implants.

Resection and permanent intracranial brachytherapy using modular, biocompatible cesium-131 implants: results in 20 recurrent, previously irradiated meningiomas

OBJECTIVE

Effective treatments for recurrent, previously irradiated intracranial meningiomas are limited, and resection alone is not usually curative. Thus, the authors studied the combination of maximum safe resection and adjuvant radiation using permanent intracranial brachytherapy (R+BT) in patients with recurrent, previously irradiated aggressive meningiomas.

METHODS

Patients with recurrent, previously irradiated meningiomas were treated between June 2013 and October 2016 in a prospective single-arm trial of R+BT. Cesium-131 (Cs-131) radiation sources were embedded in modular collagen carriers positioned in the operative bed on completion of resection. The Cox proportional hazards model with this treatment as a predictive term was used to model its effect on time to local tumor progression.

RESULTS

Nineteen patients (median age 64.5 years, range 50-78 years) with 20 recurrent, previously irradiated tumors were treated. The WHO grade at R+BT was I in 4 (20%), II in 14 (70%), and III in 2 (10%) cases. The median number of prior same-site radiation courses and same-site surgeries were 1 (range 1-3) and 2 (range 1-4), respectively; the median preoperative tumor volume was 11.3 cm3 (range 0.9-92.0 cm3). The median radiation dose from BT was 63 Gy (range 54-80 Gy). At a median radiographic follow-up of 15.4 months (range 0.03-47.5 months), local failure (within 1.5 cm of the implant bed) occurred in 2 cases (10%). The median treatment-site time to progression after R+BT has not been reached; that after the most recent prior therapy was 18.3 months (range 3.9-321.9 months; HR 0.17, p = 0.02, log-rank test). The median overall survival after R+BT was 26 months, with 9 patient deaths (47% of patients). Treatment was well tolerated; 2 patients required surgery for complications, and 2 experienced radiation necrosis, which was managed medically.

CONCLUSIONS

R+BT utilizing Cs-131 sources in modular carriers represents a potentially safe and effective treatment option for recurrent, previously irradiated aggressive meningiomas.

Re-irradiation for recurrent glioblastoma (GBM): a systematic review and meta-analysis

PURPOSE

To determine the efficacy and toxicity of re-irradiation for patients with recurrent GBM.

MATERIALS AND METHODS

We searched various biomedical databases from 1998 to 2018, for eligible studies where patients were treated with re-irradiation for recurrent GBM. Outcomes of interest were 6 and 12-month overall survival (OS-6, OS-12), 6 and 12-month progression free survival (PFS-6, PFS-12) and serious (Grade 3 +) adverse events (AE). We used the random effects model to pool outcomes across studies and compared pre-defined subgroups using interaction test. Methodological quality of each study was assessed using the Newcastle-Ottawa scoring system.

RESULTS

We found 50 eligible non-comparative studies including 2095 patients. Of these, 42% were of good or fair quality. The pooled results were as follows: OS-6 rate 73% (95% confidence interval (CI) 69-77%), OS-12 rate 36% (95% CI 32-40%), PFS-6 rate 43% (95% CI 35-50%), PFS-12 rate 17% (95% CI 13-20%), and Grade 3 + AE rate 7% (95% CI 4-10%). Subgroup analysis showed that prospective studies reported higher toxicity rates, and studies which utilized brachytherapy to have a longer OS-12. Within the external beam radiotherapy group, there was no dose-response [above or below 36 Gy in 2 Gy equivalent doses (EQD2)]. However, a short fractionation regimen (≤ 5 fractions) seemed to provide superior PFS-6.

CONCLUSION

The available evidence, albeit mostly level III, suggests that re-irradiation provides encouraging disease control and survival rates. Toxicity was not uniformly reported, but seemed to be low from the included studies. Randomized controlled trials (RCT) are needed to establish the optimal management strategy for recurrent GBM.

Adjuvant stereotactic fractionated radiotherapy to the resection cavity in recurrent glioblastoma - the GlioCave study (NOA 17 - ARO 2016/3 - DKTK ROG trial)

Background

Glioblastoma relapses in the vast majority of cases within 1 year. Maximum safe resection of the recurrent glioblastoma can be offered in some cases. Re-irradiation has been established for the treatment of recurrent glioblastoma, too. In both cases, adjuvant treatment, mostly using temozolomide, can improve PFS and OS after these interventions. However, combining gross tumor resection and adjuvant re-radiotherapy to the resection cavity has not been tested so far.

Methods/Design

In the multicenter two-armed randomized Phase II GlioCave Study, fractionated stereotactic radiotherapy to the resection cavity, after gross tumor resection of recurrent glioblastoma, will be compared to observation. Depending on the size of the target volume, a total dose of 46 Gy in 2 Gy per fraction or a total dose if 36 Gy in 3 Gy per fraction will be applied. Progression free survival will be the primary endpoint of the study.

Discussion

Adjuvant treatment after gross tumor resection of recurrent glioblastoma is currently deemed to be limited to chemotherapy. However, re-irradiation has proven safety and tolerability in the treatment of macroscopic disease. Performing re-irradiation as an adjuvant measure after gross tumor resection has not been tested so far. The GlioCave Study will investigate the efficacy and the safety profile of this approach.

Trial registration

The trial was prospectively registered at clinicaltrials.gov (NCT02715297, registration date February 29th, 2016). The protocol presented hereby refers to the version 1.2 of the protocol (January 11^th, 2017).

Injectable Hydrogels for Localized Chemotherapy and Radiotherapy in Brain Tumors

Overall survival of patients with newly diagnosed glioblastoma (GBM) remains dismal at 16 months with state-of-the-art treatment that includes surgical resection, radiation, and chemotherapy. GBM tumors are highly heterogeneous, and mechanisms for overcoming tumor resistance have not yet fully been elucidated. An injectable chitosan hydrogel capable of releasing chemotherapy (temozolomide [TMZ]) while retaining radioactive isotopes agents (iodine, [¹³¹I]) was used as a vehicle for localized radiation and chemotherapy, within the surgical cavity. Release from hydrogels loaded with TMZ or ¹³¹I was characterized in vitro and in vivo and their efficacy on tumor progression and survival on GBM tumors was also measured. The in vitro release of ¹³¹I was negligible over 42 days, whereas the TMZ was completely released over the first 48 h. ¹³¹I was completely retained in the tumor bed with negligible distribution in other tissues and that when delivered locally, the chemotherapy accumulated in the tumor at 10-fold higher concentrations than when delivered systemically. We found that the tumors were significantly decreased, and survival was improved in both treatment groups compared to the control group. Novel injectable chemo-radio-hydrogel implants may potentially improve the local control and overall outcome of aggressive, poor prognosis brain tumors.

Iodine-125 seed migration within brain parenchyma after brachytherapy for brain metastasis: case report

This case report documents the migration of 3 iodine-125 (125I) seeds from the tumor resection cavity into brain parenchyma over a 7-year period. A 66-year-old woman had a history of metastatic ovarian carcinoma, nickel allergy, and reaction to a titanium hip implant that required reoperation for hardware removal. In this unique case of parenchymal migration, the seed paths seemed to follow white matter tracts, traveling between 18.5 and 35.5 mm from the initial implant site. The patient's initial neurological decline, which was thought to be related to radiation necrosis, appeared to stabilize with medical therapy. She subsequently developed progressive right hemispheric edema that resulted in neurological deterioration and death. Considering her previous reactions to nickel and titanium, the authors now speculate that her later clinical course reflected an allergic reaction to the titanium casing of the 125I seeds. Containing a trace amount of nickel, 125I seeds can elicit a delayed hypersensitivity reaction in patients with a history of nickel dermatitis. Preoperative patch testing is recommended in these patients, and 125I seed implantation should be avoided in those who test positive.

Re-irradiation alternatives for recurrent high-grade glioma

Despite advances in the fields of surgery, chemotherapy and radiotherapy, the prognosis for high-grade glioma (HGG) remains unsatisfactory. The majority of HGG patients experience disease recurrence. To date, no standard treatments have been established for recurrent HGG. Repeat surgery and chemotherapy demonstrate moderate efficacy. As recurrent lesions are usually located within the previously irradiated field, a second course of irradiation was once considered controversial, as it was considered to exhibit unsatisfactory efficacy and radiation-related toxicities. However, an increasing number of studies have indicated that re-irradiation may present an efficacious treatment for recurrent HGG. Re-irradiation may be delivered via conventionally fractionated stereotactic radiotherapy, hypofractionated stereotactic radiation therapy, stereotactic radiosurgery and brachytherapy techniques. In the present review, the current literature regarding re-irradiation treatment for recurrent HGG is summarized with regard to survival outcome and side effects.

The role of brachytherapy in the treatment of glioblastoma multiforme

Brachytherapy (BT) for glioblastoma multiforme (GBM) involves the use of radioactive isotopes to deliver ionizing radiation directly into the tumor bed. Its application as a means to prolong survival in GBM patients over the past few decades has come with variable success. The objective of this review is to describe the utility of BT in GBM, and to report the outcomes and adverse events associated with its use in different multimodal treatment approaches. A search of the literature was conducted using the PubMed database. The most recent search was performed in September 2015. Thirty-two series involving 1571 patients were included in our review. The longest median overall survival (MOS) following BT for newly diagnosed GBM reached 28.5 months. Overall, 1-, 2-, and 3-year survival rates were 46-89 %, 20-57 %, and 14-27 %. For recurrent GBM, the longest reported MOS after BT was 15.9 months. One-, 2- and 3-year survival rates for recurrent GBM were 10-66 %, 3-23 %, and 9-15 %. Adverse events were reported in 27 % of patients. Reoperation for radiation necrosis occurred in 4 and 27 % of patients following low- and high-dose rate BT, respectively. BT is a feasible option for extending survival in carefully selected GBM patients. As patient outcomes and overall survival improve with more aggressive radiotherapy, so does the risk of radiation-related complications. The most effective use of BT is likely as a part of multimodal treatment with other novel therapies.

Clinical trials in neurosurgical oncology

Brain tumors such as diffuse infiltrating gliomas continue to represent a major clinical challenge. Overall survival for patients diagnosed with glioblastoma, the most common primary brain tumor, remains less than 2 years despite intensive multimodal therapy with surgery, radiation, and chemotherapy. However, advances have been made in standard therapies and novel treatments that are showing great potential. These advances reflect careful study performed in the context of clinical trials. Neurosurgeons have played and will continue to play key parts in these studies. In this manuscript, we review clinical trials in neuro-oncology from a neurosurgical point of view and discuss potential roles for neurosurgeons in advancing glioma therapy in the future.

Treatment of adults with recurrent malignant glioma

Virtually all malignant gliomas recur. Treatment options at recurrence have relied upon surgical intervention, radiation therapy or cytotoxic chemotherapy. Unfortunately, none are associated with significant improvements in survival. Advances in treatment options at recurrence have been dependent upon the combination of surgical resection, focal radiation and chemotherapy. Despite aggressive interventions, few patients have meaningful improvements. Current research focuses on novel targeted molecular therapy that will hopeful be able to take advantage of advances in our understanding of the biology of glial neoplasms.

Efficacy and limitations of stereotactic radiosurgery in the treatment of glioblastoma

Treatment of recurrent glioblastoma is still challenging. Stereotactic radiosurgery has been accepted as a treatment option for recurrent glioblastoma after standard chemotherapy and irradiation. However, the efficacy of stereotactic radiosurgery at recurrence has been limited, mainly due to the highly infiltrative nature of the tumor which makes the lesion difficult to define as the target. To enhance the efficacy of stereotactic radiosurgery, several methods of targeting based on neuroimaging technology such as positron emission tomography and magnetic resonance imaging have been adopted to irradiate as many of the viable tumor cells as possible and showed some enhanced efficacy. In a trial of intensified treatment by extending the irradiation field, improvement of local control did not result in longer survival. Radiation-induced adverse event is another problem after stereotactic radiosurgery for recurrent glioblastoma because almost all patients underwent irradiation as a part of the initial treatment. To overcome the side effects associated with re-irradiation, use of bevacizumab, a humanized monoclonal antibody to vascular endothelial growth factor, has shown some efficacy. Advances in irradiation technology, neuroimaging, and adjuvant treatment are needed to enhance the efficacy of stereotactic radiosurgery for recurrent glioblastoma and reduce the morbidity associated with irradiation.

Immediate post-operative brachytherapy prior to irradiation and temozolomide for newly diagnosed glioblastoma

To determine whether immediate post-operative brachytherapy can be safely applied to newly diagnosed glioblastomas to retard tumor progression prior to initiation of external beam radiation therapy (EBRT) and temozolomide. Between 1996 and 2011, eleven patients underwent implantation of GliaSite (n = 9) or MammoSite (n = 2) at the time of surgical resection. Brachytherapy was carried out on post-operative day 2-3, with 45-60 Gy delivered to a 1 cm margin. All patients underwent subsequent standard radiation/temozolomide treatment 4-5 weeks post-irradiation. There were no wound related complications. Toxicity was observed in two patients (2/11 or 18 %), including one post-operative seizure and one case of cerebral edema that resolved after a course of steroid treatment. Immediate post-operative and pre-irradiation/temozolomide magnetic resonance imaging assessment was available for 9 of the 11 patients. Two of these nine patients (22 %) developed new regions of contrast enhancement prior to irradiation/temozolomide. This compares favorably to historical data where 53 % of patient suffer such tumor progression. While there was a trend toward improved 6 month progression free survival in the brachytherapy/temozolomide/radiation treated patients, the overall survival of these patients were comparable to historical controls. This case series demonstrates the safety of immediate post-operative brachytherapy when applied prior to EBRT and temozolomide in the treatment of newly diagnosed glioblastomas.

Current trends in glioblastoma multiforme treatment: radiation therapy and immune checkpoint inhibitors

Glioblastoma multiforme (GBM) is the most common primary brain cancer. Even with aggressive combination therapy, the median life expectancy for patients with GBM remains approximately 14 months. In order to improve the outcomes of patients with GBM, the development of newer treatments is critical. The concept of using the immune system as a therapeutic option has been suggested for several decades; by harnessing the body's adaptive immune mechanisms, immunotherapy could provide a durable and targeted treatment against cancer. However, many cancers, including GBM, have developed mechanisms that protect tumor cells from being recognized and eliminated by the immune system. For new immunotherapeutic regimens to be successful, overcoming immunosuppression via immune checkpoint signaling should be taken into consideration.

Multidisciplinary care of patients with brain tumors

Patients with brain tumors are some of the most complex patients in the medical system, necessitating treatment teams of multiple subspecialists for optimal care. This article examines the roles of these subspecialists, with the goal of summarizing standard-of-care practices, recent therapeutic advances, and ongoing clinical investigations within each subspecialty.

Population-based survival data for brain tumors in Korea

Primary brain tumors are relatively uncommon but particularly lethal cancers. Although survival is useful for monitoring the effects of early cancer detection and treatment, there are few population-based estimates of survival for subjects with brain tumors, especially in Asian countries. Using the Korea National Cancer Incidence Database, 4,721 newly diagnosed cases of histologically confirmed malignant primary brain tumors from 1999 to 2004 were analyzed for observed survival. For trend analyses of glioblastomas, we included 2,751 glioblastoma cases diagnosed between 1999 and 2007. We compared survival by age group and histological type by use of the Kaplan-Meier method. For all ages and all brain tumor types in Korea, five-year survival was 37.5 %. For each histological type of brain tumor survival of pediatric and younger adult populations was much better than that of older adults. Five-year survival for glioblastoma, astrocytoma, anaplastic astrocytoma, and oligodendroglioma was 8.9, 51.6, 25.2, and 73.5 %, respectively. Two-year survival for glioblastoma increased from 18.6 % for cases diagnosed in 1999-2001 to 21.3 % for cases diagnosed in 2002-2004 and to 24.7 % for cases diagnosed in 2005-2007. These results may help clinicians and patients to assess long-term prognoses for brain tumors, and the data presented here could serve as master control data set for single-arm clinical trials, especially in Asian populations.

Radiation therapy for the treatment of recurrent glioblastoma: an overview

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.

Iodine-125 brachytherapy for brain tumours--a review

Iodine-125 brachytherapy has been applied to brain tumours since 1979. Even though the physical and biological characteristics make these implants particularly attractive for minimal invasive treatment, the place for stereotactic brachytherapy is still poorly defined.An extensive review of the literature has been performed, especially concerning indications, results and complications. Iodine-125 seeds have been implanted in astrocytomas I-III, glioblastomas, metastases and several other tumour entities. Outcome data given in the literature are summarized. Complications are rare in carefully selected patients.All in all, for highly selected patients with newly diagnosed or recurrent primary or metastatic tumours, this method provides encouraging survival rates with relatively low complication rates and a good quality of life.

Extended field stereotactic radiosurgery for recurrent glioblastoma

BACKGROUND

Stereotactic radiosurgery (SRS) is among the few therapeutic options for glioblastoma that recurs after standard radiation and chemotherapy, but its efficacy has been limited.

METHODS

Since November 2007, the authors have modified the clinical target volume by adding a 0.5- to 1-cm margin to the gadolinium-enhanced area (extended field SRS), in contrast to conventional SRS using no margin to set the clinical target volume. A total of 35 recurred glioblastoma lesions in 9 patients were treated with conventional SRS between December 1990 and January 2007, and 14 lesions in 9 patients were treated with extended field SRS.

RESULTS

The median follow-up periods were 7 months (range, 3-29 months) and 8 months (range, 6-27 months), respectively. The local control rate was 47% for conventional SRS and 93% for extended field SRS (P = .0035), and the numbers of radiation necrosis observed in SRS-treated lesions were 2 and 4, respectively. The median overall survival from the diagnosis was 24 months (range, 14-57 months) for conventional SRS and 21 months (range, 15-51 months) for extended field SRS (statistically not significant). Seven patients treated with conventional SRS died during follow-up, 6 from progression of the SRS-treated tumor, whereas 7 patients treated with extended field SRS died during follow-up, 6 from remote intracerebral dissemination.

CONCLUSIONS

Extended field SRS was superior to conventional SRS in the local control of small recurrent lesions of glioblastoma, although a further device to suppress remote dissemination may be necessary to increase survival.

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

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.

Improved survival time trends for glioblastoma using the SEER 17 population-based registries

The EORTC/NCIC 22981/26981 study demonstrated an improvement in median overall survival (OS) from 12.1 to 14.6 months in patients with glioblastoma (GBM) who received temozolomide with post-operative radiotherapy (RT). The current study was performed to determine if those results translated into a survival benefit in a population-based cohort. Patients diagnosed between 2000 and 2006 with a GBM who underwent surgery and post-operative RT were selected from the Surveillance, Epidemiology and End Results database. Patients were grouped into time periods: 2000-2001, 2002-2003, 2004 and 2005-2006 (which represented those treated after the EORTC/NCIC trial presentation in 2004). Relative survival (RS) was estimated by the Kaplan-Meier method, and Cox multivariable regression modeling was used to estimate proportional hazard ratios (HR). Over time, there was improvement in the median and 2-year RS of 12 months and 15% for 2000-2001, 13 months and 19% for 2002-2003, 14 months and 24% for 2004, and 15 months and 26% for 2005-2006 (P < 0.0001 compared to 2000-2001 and 2002-2003; P = 0.07 compared to 2004). The estimated adjusted HR showed that patients diagnosed in 2005-2006 had significantly improved survival when compared to patients diagnosed in 2000-2001 (HR = 0.648, 95% CI 0.604-0.696). The median and 2 year RS of 15 months and 26% in 2005-2006 was similar to the median and 2 year OS of 14.6 months and 26% seen in the EORTC/NCIC phase III study. These results are encouraging and suggest that the current treatment of glioblastoma nationwide is now associated with an improved survival compared to previous time cohorts.

Efficacy and safety of intratumoral thermotherapy using magnetic iron-oxide nanoparticles combined with external beam radiotherapy on patients with recurrent glioblastoma multiforme

Therapy options at the time of recurrence of glioblastoma multiforme are often limited. We investigated whether treatment with a new intratumoral thermotherapy procedure using magnetic nanoparticles improves survival outcome. In a single-arm study in two centers, 66 patients (59 with recurrent glioblastoma) received neuronavigationally controlled intratumoral instillation of an aqueous dispersion of iron-oxide (magnetite) nanoparticles and subsequent heating of the particles in an alternating magnetic field. Treatment was combined with fractionated stereotactic radiotherapy. A median dose of 30 Gy using a fractionation of 5 × 2 Gy/week was applied. The primary study endpoint was overall survival following diagnosis of first tumor recurrence (OS-2), while the secondary endpoint was overall survival after primary tumor diagnosis (OS-1). Survival times were calculated using the Kaplan–Meier method. Analyses were by intention to treat. The median overall survival from diagnosis of the first tumor recurrence among the 59 patients with recurrent glioblastoma was 13.4 months (95% CI: 10.6–16.2 months). Median OS-1 was 23.2 months while the median time interval between primary diagnosis and first tumor recurrence was 8.0 months. Only tumor volume at study entry was significantly correlated with ensuing survival (P < 0.01). No other variables predicting longer survival could be determined. The side effects of the new therapeutic approach were moderate, and no serious complications were observed. Thermotherapy using magnetic nanoparticles in conjunction with a reduced radiation dose is safe and effective and leads to longer OS-2 compared to conventional therapies in the treatment of recurrent glioblastoma.

Controversies concerning the application of brachytherapy in central nervous system tumors

INTRODUCTION

Brachytherapy (BRT) is defined as a therapy technique where a radioactive source is placed a short distance from or within the tumor being treated. Much expectation has been placed on its efficacy to improve the outcome for patients with central nervous system (CNS) tumors due to the initial promising results from single institution retrospective studies. However, these optimistic findings have been highly debated since the selection criteria itself is preferable to other therapeutic modalities. The fact that BRT demonstrated no significant survival advantage in two prospective studies, together with the emerging role of stereotactic convergence therapy as a promising alternative, has further decreased the enthusiasm for BRT. Despite all the negative aspects, BRT continues to be conducted for the management of CNS tumors including gliomas, meningiomas and brain metastases.

MATERIAL AND METHODS

As many controversies have been aroused concerning the experience and future application of BRT, this article reviews the existing heterogeneities in terms of implants choice, optimal dose rate, targeting volume, timing of BRT, patients selection, substantial efficacy, BRT in comparison with stereotactic convergence therapy techniques and BRT in combination with other treatment modalities (data were identified by Pubmed searches).

RESULTS AND CONCLUSION

Though it is inconvincible to argue for the routine use of BRT, BRT may provide a choice for patients with large recurrent or inoperable deep-seated tumors, especially with the Glia-site technique. Radiotherapies including BRT may hold more promise if biologic mechanisms of radiation could be better understand and biologic modifications could be added in clinical trials.

Role of stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of recurrent glioblastoma multiforme

Glioblastoma multiforme (GBM) is a devastating malignant brain tumor characterized by resistance to available therapeutic approaches and relentless malignant progression that includes widespread intracranial invasion, destruction of normal brain tissue, progressive disability, and death. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (fSRT) are increasingly used in patients with recurrent GBM to complement traditional treatments such as resection, conventional external beam radiotherapy, and chemotherapy. Both SRS and fSRT are powerful noninvasive therapeutic modalities well suited to treat focal neoplastic lesions through the delivery of precise, highdose radiation. Although no randomized clinical trials have been performed, a variety of retrospective studies have been focused on the use of SRS and fSRT for recurrent GBMs. In addition, state-of-the-art neuroimaging techniques, such as MR spectroscopic imaging, diffusion tensor tractography, and nuclear medicine imaging, have enhanced treatment planning methods leading to potentially improved clinical outcomes. In this paper the authors reviewed the current applications and efficacy of SRS and fSRT in the treatment of GBM, highlighting the value of these therapies for recurrent focal disease.

A pilot study: 131I-antitenascin monoclonal antibody 81c6 to deliver a 44-Gy resection cavity boost

The purpose of this study was to determine the feasibility and assess the efficacy and toxicity, among newly diagnosed malignant glioma patients, of administering (131)I-labeled murine antitenascin monoclonal antibody 81C6 ((131)I-81C6) into a surgically created resection cavity (SCRC) to achieve a patient-specific, 44-Gy boost to the 2-cm SCRC margin. A radioactivity dose of (131)I-81C6 calculated to achieve a 44-Gy boost to the SCRC was administered, followed by conventional external beam radiotherapy (XRT) and chemotherapy. Twenty-one patients were enrolled in the study: 16 with glioblastoma multiforme (GBM) and 5 with anaplastic astrocytoma. Twenty patients received the targeted 44-Gy boost (+/-10%) to the SCRC. Attributable toxicity was mild and limited to reversible grade 3 neutropenia or thrombocytopenia (n = 3; 14%), CNS wound infections (n = 3; 14%), and headache (n = 2; 10%). With a median follow-up of 151 weeks, median overall survival times for all patients and those with GBM are 96.6 and 90.6 weeks, respectively; 87% of GBM patients are alive at 1 year. It is feasible to consistently achieve a 44-Gy boost dose to the SCRC margin with patient-specific dosing of (131)I-81C6. Our study regimen ((131)I-81C6 + XRT + temozolomide) was well tolerated and had encouraging survival. To determine if selection of good-prognosis patients affects outcome associated with this approach, the U.S. Food and Drug Administration has approved a trial randomizing newly diagnosed GBM patients to either our study regimen or standard XRT plus temozolomide.

Experimental iodine-125 seed irradiation of intracerebral brain tumors in nude mice

BACKGROUND

High-dose radiotherapy is standard treatment for patients with brain cancer. However, in preclinical research external beam radiotherapy is limited to heterotopic murine models- high-dose radiotherapy to the murine head is fatal due to radiation toxicity. Therefore, we developed a stereotactic brachytherapy mouse model for high-dose focal irradiation of experimental intracerebral (orthotopic) brain tumors.

METHODS

Twenty-one nude mice received a hollow guide-screw implanted in the skull. After three weeks, 5 x 105 U251-NG2 human glioblastoma cells were injected. Five days later, a 2 mCi iodine-125 brachytherapy seed was inserted through the guide-screw in 11 randomly selected mice; 10 mice received a sham seed. Mice were euthanized when severe neurological or physical symptoms occurred. The cumulative irradiation dose 5 mm below the active iodine-125 seeds was 23.0 Gy after 13 weeks (BEDtumor = 30.6 Gy).

RESULTS

In the sham group, 9/10 animals (90%) showed signs of lethal tumor progression within 6 weeks. In the experimental group, 2/11 mice (18%) died of tumor progression within 13 weeks. Acute side effects in terms of weight loss or neurological symptoms were not observed in the irradiated animals.

CONCLUSION

The intracerebral implantation of an iodine-125 brachytherapy seed through a stereotactic guide-screw in the skull of mice with implanted brain tumors resulted in a significantly prolonged survival, caused by high-dose irradiation of the brain tumor that is biologically comparable to high-dose fractionated radiotherapy- without fatal irradiation toxicity. This is an excellent mouse model for testing orthotopic brain tumor therapies in combination with radiation therapy.

Radiotherapeutic alternatives for previously irradiated recurrent gliomas

Re-irradiation for recurrent gliomas has been discussed controversially in the past. This was mainly due to only marginal palliation while being associated with a high risk for side effects using conventional radiotherapy.

With modern high-precision radiotherapy re-irradiation has become a more wide-spread, effective and well-tolerated treatment option. Besides external beam radiotherapy, a number of invasive and/or intraoperative radiation techniques have been evaluated in patients with recurrent gliomas.

The present article is a review on the available methods in radiation oncology and summarizes results with respect to outcome and side effects in comparison to clinical results after neurosurgical resection or different chemotherapeutic approaches.

Phase I trial of gross total resection, permanent iodine-125 brachytherapy, and hyperfractionated radiotherapy for newly diagnosed glioblastoma multiforme

PURPOSE

To evaluate the feasibility of gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy for patients with newly diagnosed glioblastoma.

METHODS AND MATERIALS

From April 1999 to May 2002, 21 patients with glioblastoma multiforme were enrolled on a Phase I protocol investigating planned gross total resection and immediate placement of permanent I-125 seeds, followed by postoperative hyperfractionated radiotherapy to a dose of 60 Gy at 100 cGy b.i.d., 5 days per week. Median age and Karnofsky performance status were 50 years (range, 32-65 years) and 90 (range, 70-100), respectively. Toxicity was assessed according to Radiation Therapy Oncology Group criteria.

RESULTS

Eighteen patients completed treatment according to protocol. The median preoperative tumor volume on magnetic resonance imaging was 18.6 cm(3) (range, 4.4-41.2 cm(3)). The median brachytherapy dose measured 5 mm radially outward from the resection cavity was 400 Gy (range, 200-600 Gy). Ten patients underwent 12 reoperations, with 11 of 12 reoperations demonstrating necrosis without evidence of tumor. Because of high toxicity, the study was terminated early. Median progression-free survival and overall survival were 57 and 114 weeks, respectively, but not significantly improved compared with historical patients treated at University of California, San Francisco, with gross total resection and radiotherapy without brachytherapy.

CONCLUSIONS

Treatment with gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy as performed in this study results in high toxicity and reoperation rates, without demonstrated improvement in survival.

Fibrin glue system for adjuvant brachytherapy of brain tumors with 188Re and 186Re-labeled microspheres

Brain tumors such as glioblastoma reappear in their original location in almost 50% of cases. To prevent this recurrence, we developed a radiopharmaceutical system that consists of a gel applied immediately after surgical resection of a brain tumor to deliver local radiation booster doses. The gel, which strongly adheres to tissue in the treatment area, consists of fibrin glue containing the beta-emitters rhenium-188 and rhenium-186 in microsphere-bound form. Such microspheres can be prepared by short (2 h or less) neutron activation even in low neutron flux reactors, yielding a mixture of the two beta-emitters rhenium-188 (E(max)=2.1 MeV, half life=17 h) and rhenium-186 (E(max)=1.1 MeV, half life=90.6h). The dosimetry of this rhenium-188/rhenium-186 fibrin glue system was determined using gafchromic film measurements. The treatment efficacy of the radioactive fibrin glue was measured in a 9L-glioblastoma rat model. All animals receiving the non-radioactive fibrin glue died within 17+/-3 days, whereas 60% of the treated animals survived 36 days, the final length of the experiment. Control animals that were treated with the same amount of radioactive fibrin glue, but had not received a previous tumor cell injection, showed no toxic effects over one year. The beta-radiation emitting rhenium-188/rhenium-186-based gel thus provides an effective method of delivering high doses of local radiation to tumor tissue, particularly to wet areas where high adhesive strength and long-term radiation (with or without drug) delivery are needed.

New trends in the medical management of glioblastoma multiforme: the role of temozolomide chemotherapy

Standard care for newly diagnosed glioblastoma multiforme (GBM) previously consisted of resection to the greatest extent feasible, followed by radiotherapy. The role of chemotherapy was controversial and its efficacy was marginal at best. Five years ago temozolomide (TMZ) was approved specifically for the treatment of recurrent malignant glioma. The role of TMZ chemotherapy administered alone or as an adjuvant therapy for newly diagnosed GBM has been evaluated in a large randomized trial whose results suggested a significant prolongation of survival following treatment. Findings of correlative molecular studies have indicated that methylguanine methyltransferase promoter methylation may be used as a predictive factor in selecting patients most likely to benefit from such treatment. In this short review the authors summarize the current role of TMZ chemotherapy in the management of GBM, with an emphasis on approved indications and practical aspects.

Diagnosis and treatment of recurrent high-grade astrocytoma

High-grade gliomas represent a significant source of cancer-related death, and usually recur despite treatment. In this analysis of current brain tumor medicine, we review diagnosis, standard treatment, and emerging therapies for recurrent astrocytomas. Difficulties in interpreting radiographic evidence, especially with regard to differentiating between tumor and necrosis, present a formidable challenge. The most accurate diagnoses come from tissue confirmation of recurrent tumor, but a combination of imaging techniques, such as magnetic resonance spectroscopy imaging, may also be relevant for diagnosis. Repeat resection can prolong life, but repeat irradiation of the brain poses serious risks and results in necrosis of healthy brain tissue; therefore, reirradiation is usually not offered to patients with recurrent tumors. We describe the use of conventional radiotherapy, intensity-modulated radiotherapy, brachytherapy, radiosurgery, and photodynamic therapy for recurrent high-grade glioma. The use of chemotherapy is limited by drug distribution and toxicity, but the development of new drug-delivery techniques such as convection-enhanced delivery, which delivers therapeutic molecules at an effective concentration directly to the brain, may provide a way to reduce systemic exposure to cytotoxic agents. We also discuss targeted therapies designed to inhibit aberrant cell-signaling pathways, as well as new experimental therapies such as immunotherapy. The treatment of this devastating disease has so far been met with limited success, but emerging knowledge of neuroscience and the development of novel therapeutic agents will likely give patients new options and require the neuro-oncology community to redefine clinical trial design and strategy continually.

Current treatment approaches to surgery for brain metastases

The role for surgical treatment of brain metastases continues to evolve. Data have demonstrated survival and quality-of-life benefits for surgical treatment of appropriate lesions in selected patients. With improvements in surgical technique, along with therapeutic improvements in the management of systemic cancers, more patients are now eligible for surgical resection. Selection of patients for surgical treatment depends on performance status, size, location, and number of brain lesions, as well as the status of systemic disease. Although surgery has traditionally been performed for patients with a single brain metastasis, an increasing number of patients with multiple brain metastases may also be treated surgically. Surgical techniques, such as image guidance, intraoperative ultrasound, functional neuronavigation, cortical mapping, and awake craniotomies, have expanded the scope of lesions that can be removed safely to optimize outcomes. Seizures, peritumoral edema, and venous thromboembolic disease all contribute significantly to surgical morbidity and mortality and thus require aggressive treatment around the time of the surgical procedure to improve the quality of life and maximize survival time.

Salvage radioimmunotherapy with murine iodine-131-labeled antitenascin monoclonal antibody 81C6 for patients with recurrent primary and metastatic malignant brain tumors: phase II study results

PURPOSE

To assess the efficacy and toxicity of intraresection cavity iodine-131-labeled murine antitenascin monoclonal antibody 81C6 (131I-m81C6) among recurrent malignant brain tumor patients.

PATIENTS AND METHODS

In this phase II trial, 100 mCi of 131I-m81C6 was injected directly into the surgically created resection cavity (SCRC) of 43 patients with recurrent malignant glioma (glioblastoma multiforme [GBM], n = 33; anaplastic astrocytoma [AA], n = 6; anaplastic oligodendroglioma [AO], n = 2; gliosarcoma [GS], n = 1; and metastatic adenocarcinoma, n = 1) followed by chemotherapy.

RESULTS

With a median follow-up of 172 weeks, 63% and 59% of patients with GBM/GS and AA/AO tumors were alive at 1 year. Median overall survival for patients with GBM/GS and AA/AO tumors was 64 and 99 weeks, respectively. Ten patients (23%) developed acute hematologic toxicity. Five patients (12%) developed acute reversible neurotoxicity. One patient (2%) developed irreversible neurotoxicity. No patients required reoperation for radionecrosis.

CONCLUSION

In this single-institution phase II study, administration of 100 mCi of 131I-m81C6 to recurrent malignant glioma patients followed by chemotherapy is associated with a median survival that is greater than that of historical controls treated with surgery plus iodine-125 brachytherapy. Furthermore, toxicity was acceptable. Administration of a fixed millicurie dose resulted in a wide range of absorbed radiation doses to the SCRC. We are now conducting a phase II trial, approved by the US Food and Drug Administration, using patient-specific 131I-m81C6 dosing, to deliver 44 Gy to the SCRC followed by standardized chemotherapy. A phase III multicenter trial with patient-specific dosing is planned.