Postoperative irradiation of glioblastomas. Results in a randomized series

Out-of-Field Dose Measurement by TLD Dosimetry and Estimation of Radiation-Induced Secondary Cancer Risk of Thyroid and Breast from Head Radiotherapy

Background

Radiation therapy, the most common form of cancer treatment, can result in late complications, such as secondary breast and thyroid cancers.

Objective

This study aimed to evaluate the risk of secondary cancers using two radiobiological models of Excess Absolute Risk (EAR) and Excess Relative Risk (ERR) in patients with brain cancer undergoing radiotherapy for improved survival rates of cancer patients.

Material and Methods

In this expository cross-sectional study, 45 patients under the age of 40 years underwent Whole Brain Radiotherapy (WBRT) using a compact accelerator in Shahid Ramezanzadeh Hospital, Yazd, Iran. Out-of-field organ dose measurement was performed using a Thermoluminescent Dosimeter (TLD) to determine the dose to thyroid and breast tissues. The risk of secondary cancers in these organs was calculated 3, 5, 10, 15, and 20 years after radiation therapy.

Results

The mean values of thyroid cancer risk in men and women were 0.418±0.509 and 0.274±0.306, respectively. ERR values of breast cancer in 3-, 5-, 10-, 15-, and 20-year women undergoing radiation therapy were 1.084±2.938, 0.594±1.407, 0.248±0.497, 0.138±0.248, and 0.091±0.148, respectively. EAR values of breast cancer in 3-, 5-, 10-, 15-, and 20-year women following radiation therapy were 0.064±0.060, 0.077±0.071, 0.119±0.100, 0.178±0.248, and 0.259±0.178, respectively.

Conclusion

After irradiation, the risk of secondary cancer is affected by factors, such as the patient's age and gender. The secondary thyroid cancer is higher than that of other organs, such as the breast, in the patients undergoing WBRT.

Leveraging the neurosurgical operating room for therapeutic development in NeuroOncology

Glioblastoma (GBM) remains a disease with a dismal prognosis. For all the hope and promise immunotherapies and molecular targeted therapies have shown for systemic malignancies, these treatments have failed to show any promise in GBM. In this context, the paradigm of investigation of therapeutics for this disease itself must be examined and modifications considered. The unique challenge of the presence of blood-brain and blood-tumor barriers (BBB/BTB) raises questions about both the true levels of systemic drug delivery to the affected tissues. Window-of-opportunity (WoO) trials in neuro-oncology allow for proof-of-concept at the start of a classic phase I-II-III clinical trial progression. For therapeutics that do not have the ability to cross the BBB/BTB, direct delivery into tumor and/or tumor-infiltrated brain in the setting of a surgical procedure can provide a novel route of therapeutic access. These approaches permit neurosurgeons to play a greater role in therapeutic development for brain tumors.

Nuclear medicine and radiotherapy in the clinical management of glioblastoma patients

Introduction

The aim of the narrative review was to analyse the applications of nuclear medicine (NM) techniques such as PET/CT with different tracers in combination with radiotherapy for the clinical management of glioblastoma patients.

Materials and methods

Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used.

Results

This paper contains a narrative report and a critical discussion of NM approaches in combination with radiotherapy in glioma patients.

Conclusions

NM can provide the Radiation Oncologist several aids that can be useful in the clinical management of glioblastoma patients. At the same, these results need to be validated in prospective and multicenter trials.

GammaTile® brachytherapy in the treatment of recurrent glioblastomas

Background

GammaTile® (GT) is a recent U.S. Food and Drug Administration (FDA) cleared brachytherapy platform. Here, we report clinical outcomes for recurrent glioblastoma patients after GT treatment following maximal safe resection.

Methods

We prospectively followed twenty-two consecutive Isocitrate Dehydrogenase (IDH) wild-type glioblastoma patients (6 O⁶-Methylguanine-DNA methyltransferase methylated (MGMTm); sixteen MGMT unmethylated (MGMTu)) who underwent maximal safe resection of recurrent tumor followed by GT placement.

Results

The cohort consisted of 14 second and eight third recurrences. In terms of procedural safety, there was one 30-day re-admission (4.5%) for an incisional cerebrospinal fluid leak, which resolved with lumbar drainage. No other wound complications were observed. Six patients (27.2%) declined in Karnofsky Performance Score (KPS) after surgery due to worsening existing deficits. One patient suffered a new-onset seizure postsurgery (4.5%). There was one (4.5%) 30-day mortality from intracranial hemorrhage secondary to heparinization for an ischemic limb. The mean follow-up was 733 days (range 279–1775) from the time of initial diagnosis. Six-month local control (LC₆) and twelve-month local control (LC₁₂) were 86 and 81%, respectively. Median progression-free survival (PFS) was comparable for MGMTu and MGMTm patients (~8.0 months). Median overall survival (OS) was 20.0 months for the MGMTu patients and 37.4 months for MGMTm patients. These outcomes compared favorably to data in the published literature and an independent glioblastoma cohort of comparable patients without GT treatment.

Conclusions

This clinical experience supports GT brachytherapy as a treatment option in a multi-modality treatment strategy for recurrent glioblastomas.

Chronic pathophysiological changes in the normal brain parenchyma caused by radiotherapy accelerate glioma progression

Radiation therapy is one of standard treatment for malignant glioma after surgery. The microenvironment after irradiation is considered not to be suitable for the survival of tumor cells (tumor bed effect). This study investigated whether the effect of changes in the microenvironment of parenchymal brain tissue caused by radiotherapy affect the recurrence and progression of glioma. 65-Gy irradiation had been applied to the right hemisphere of Fisher rats. After 3 months from irradiation, we extracted RNA and protein from the irradiated rat brain. To study effects of proteins extracted from the brains, we performed WST-8 assay and tube formation assay in vitro. Cytokine production were investigated for qPCR. Additionally, we transplanted glioma cell into the irradiated and sham animals and the median survival time of F98 transplanted rats was also examined in vivo. Immunohistochemical analyses and invasiveness of implanted tumor were evaluated. X-ray irradiation promoted the secretion of cytokines such as CXCL12, VEGF-A, TGF-β1 and TNFα from the irradiated brain. Proteins extracted from the irradiated brain promoted the proliferation and angiogenic activity of F98 glioma cells. Glioma cells implanted in the irradiated brains showed significantly high proliferation, angiogenesis and invasive ability, and the post-irradiation F98 tumor-implanted rats showed a shorter median survival time compared to the Sham-irradiation group. The current study suggests that the microenvironment around the brain tissue in the chronic phase after exposure to X-ray radiation becomes suitable for glioma cell growth and invasion.

Prospective prediction of clinical drug response in high-grade gliomas using an ex vivo 3D cell culture assay

Background

Clinical outcomes in high-grade glioma (HGG) have remained relatively unchanged over the last 3 decades with only modest increases in overall survival. Despite the validation of biomarkers to classify treatment response, most newly diagnosed (ND) patients receive the same treatment regimen. This study aimed to determine whether a prospective functional assay that provides a direct, live tumor cell-based drug response prediction specific for each patient could accurately predict clinical drug response prior to treatment.

Methods

A modified 3D cell culture assay was validated to establish baseline parameters including drug concentrations, timing, and reproducibility. Live tumor tissue from HGG patients were tested in the assay to establish response parameters. Clinical correlation was determined between prospective ex vivo response and clinical response in ND HGG patients enrolled in 3D-PREDICT (ClinicalTrials.gov Identifier: NCT03561207). Clinical case studies were examined for relapsed HGG patients enrolled on 3D-PREDICT, prospectively assayed for ex vivo drug response, and monitored for follow-up.

Results

Absent biomarker stratification, the test accurately predicted clinical response/nonresponse to temozolomide in 17/20 (85%, P = .007) ND patients within 7 days of their surgery, prior to treatment initiation. Test-predicted responders had a median overall survival post-surgery of 11.6 months compared to 5.9 months for test-predicted nonresponders (P = .0376). Case studies provided examples of the clinical utility of the assay predictions and their impact upon treatment decisions resulting in positive clinical outcomes.

Conclusion

This study both validates the developed assay analytically and clinically and provides case studies of its implementation in clinical practice.

Novel Radiation Approaches

The standard of care treatment for glioblastoma is surgical resection followed by radiotherapy to 60 Gy with concurrent and adjuvant temozolomide with or without tumor-treating fields. Advanced imaging techniques are under evaluation to better guide radiotherapy target volume delineation and allow for dose escalation. Particle therapy, in the form of protons, carbon ions, and boron neutron capture therapy, are being assessed as strategies to improve the radiotherapeutic ratio. Stereotactic, hypofractionated, pulsed-reduced dose-rate, and particle radiotherapy are re-irradiation techniques each uniquely suited for different clinical scenarios. Novel radiotherapy approaches, such as FLASH, represent promising advancements in radiotherapy for glioblastoma.

Incorporating genomic signatures into surgical and medical decision-making for elderly glioblastoma patients

Glioblastoma (GBM) is the most common type of malignant primary brain tumor in adults. It is a uniformly fatal disease (median overall survival 16 months) even with aggressive resection and an adjuvant temozolomide-based chemoradiation regimen. Age remains an independent risk factor for a poor prognosis. Several factors contribute to the dismal outcomes in the elderly population with GBM, including poor baseline health status, differences in underlying genomic alterations, and variability in the surgical and medical management of this subpopulation. The latter arises from a lack of adequate representation of elderly patients in clinical trials, resulting in limited data on the response of this subpopulation to standard treatment. Results from retrospective and some prospective studies have indicated that resection of only contrast-enhancing lesions and administration of hypofractionated radiotherapy in combination with temozolomide are effective strategies for optimizing survival while maintaining baseline quality of life in elderly GBM patients; however, survival remains dismal relative to that in a younger cohort. Here, the authors present historical context for the current strategies used for the multimodal management (surgical and medical) of elderly patients with GBM. Furthermore, they provide insights into elderly GBM patient-specific genomic signatures such as isocitrate dehydrogenase 1/2 (IDH1/2) wildtype status, telomerase reverse transcriptase promoter (TERTp) mutations, and somatic copy number alterations including CDK4/MDM2 coamplification, which are becoming better understood and could be utilized in a clinical trial design and patient stratification to guide the development of more effective adjuvant therapies specifically for elderly GBM patients.

External beam radiation dose escalation for high grade glioma

BACKGROUND

This is an updated version of the original Cochrane Review published in Issue 8, 2016. High grade glioma (HGG) is a rapidly growing brain tumour in the supporting cells of the nervous system, with several subtypes such as glioblastoma (grade IV astrocytoma), anaplastic (grade III) astrocytoma and anaplastic (grade III) oligodendroglioma. Studies have investigated the best strategy to give radiation to people with HGG. Conventional fractionated radiotherapy involves giving a daily radiation dose (called a fraction) of 180 cGy to 200 cGy. Hypofractionated radiotherapy uses higher daily doses, which reduces the overall number of fractions and treatment time. Hyperfractionated radiotherapy which uses a lower daily dose with a greater number of fractions and multiple fractions per day to deliver a total dose at least equivalent to external beam daily conventionally fractionated radiotherapy in the same time frame. The aim is to reduce the potential for late toxicity. Accelerated radiotherapy (dose escalation) refers to the delivery of multiple fractions per day using daily doses of radiation consistent with external beam daily conventionally fractionated radiotherapy doses. The aim is to reduce the overall treatment time; typically, two or three fractions per day may be delivered with a six to eight hour gap between fractions.

OBJECTIVES

To assess the effects of postoperative external beam radiation dose escalation in adults with HGG.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid and Embase Ovid to August 2019 for relevant randomised phase III trials.

SELECTION CRITERIA

We included adults with a pathological diagnosis of HGG randomised to the following external beam radiation regimens: daily conventionally fractionated radiotherapy versus no radiotherapy; hypofractionated radiotherapy versus daily conventionally fractionated radiotherapy; hyperfractionated radiotherapy versus daily conventionally fractionated radiotherapy or accelerated radiotherapy versus daily conventionally fractionated radiotherapy.

DATA COLLECTION AND ANALYSIS

The primary outcomes were overall survival and adverse effects. The secondary outcomes were progression free survival and quality of life. We used the standard methodological procedures expected by Cochrane. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Since the last version of this review, we identified no new relevant trials for inclusion. We included 11 randomised controlled trials (RCTs) with 2062 participants and 1537 in the relevant arms for this review. There was an overall survival benefit for people with HGG receiving postoperative radiotherapy compared to the participants receiving postoperative supportive care. For the four pooled RCTs (397 participants), the overall hazard ratio (HR) for survival was 2.01 favouring postoperative radiotherapy (95% confidence interval (CI) 1.58 to 2.55; P < 0.00001; moderate-certainty evidence). Although these trials may not have completely reported adverse effects, they did not note any significant toxicity attributable to radiation. Progression free survival and quality of life could not be pooled due to lack of data. Overall survival was similar between hypofractionated and conventional radiotherapy in five trials (943 participants), where the HR was 0.95 (95% CI 0.78 to 1.17; P = 0.63; very low-certainty evidence. The trials reported that hypofractionated and conventional radiotherapy were well tolerated with mild acute adverse effects. These trials only reported one participant in the hypofractionated arm developing symptomatic radiation necrosis that required surgery. Progression free survival and quality of life could not be pooled due to the lack of data. Overall survival was similar between hypofractionated and conventional radiotherapy in the subset of two trials (293 participants) which included participants aged 60 years and older with glioblastoma. For this category, the HR was 1.16 (95% CI 0.92 to 1.46; P = 0.21; high-certainty evidence). There were two trials which compared hyperfractionated radiotherapy versus conventional radiation and one trial which compared accelerated radiotherapy versus conventional radiation. However, the results could not be pooled. The conventionally fractionated radiotherapy regimens were 4500 cGy to 6000 cGy given in 180 cGy to 200 cGy daily fractions, over five to six weeks. All trials generally included participants with World Health Organization (WHO) performance status from 0 to 2 and Karnofsky performance status of 50 and higher. The risk of selection bias was generally low among these RCTs. The number of participants lost to follow-up for the outcome of overall survival was low. Attrition, performance, detection and reporting bias for the outcome of overall survival was low. There was unclear attrition, performance, detection and reporting bias relating to the outcomes of adverse effects, progression free survival and quality of life.

AUTHORS' CONCLUSIONS

Postoperative conventional daily radiotherapy probably improves survival for adults with good performance status and HGG compared to no postoperative radiotherapy. Hypofractionated radiotherapy has similar efficacy for survival compared to conventional radiotherapy, particularly for individuals aged 60 years and older with glioblastoma. There are insufficient data regarding hyperfractionation versus conventionally fractionated radiation (without chemotherapy) and for accelerated radiation versus conventionally fractionated radiation (without chemotherapy). There are HGG subsets who have poor prognosis even with treatment (e.g. glioblastoma histology, older age and poor performance status). These HGG individuals with poor prognosis have generally been excluded from randomised trials based on poor performance status. No randomised trial has compared comfort measures or best supportive care with an active intervention using radiotherapy or chemotherapy in these people with poor prognosis. Since the last version of this review, we found no new relevant studies. The search identified three new trials, but all were excluded as none had a conventionally fractionated radiotherapy arm.

CC12 Induces Apoptotic Cell Death and Cell Cycle Arrest in Human Glioblastoma Cell Lines and Mouse Xenograft Model

Among central nervous system tumors, glioblastoma (GBM) is the most common and the most malignant type. Even under current standard treatments, the overall survival rate is still low and the recurrence rate is high. Therefore, developing novel and effective therapy is urgently needed. CC12, a synthesized small molecule, was evaluated for the potential anti-GBM effects in two GBM cell lines, U87MG and U118MG. The observations of cell morphology, MTT assay, flow cytometry-based apoptosis after CC12 treatment, were conducted. Western blot was performed for the investigation of the apoptotic mechanism. Positron emission tomography scan analysis and bioluminescent imaging assay using a mouse xenograft model were performed for the effect of CC12 in vivo. After treated by 10 μM CC12 for 24 h, both U118MG and U87MG cells showed tumor cell death. MTT assay results showed that the survival rates decreased when the CC12 concentrations or the treatment periods increased. Ki-67 expression and flow cytometry results indicated that the proliferation was inhibited in GBM cells, and G1 phase arrest was shown. The results of 7-AAD, Br-dUTP, and JC-1 staining all showed the apoptosis of GBM cells after CC12 treatment. Increased γH2AX, caspase-3, and poly (ADP-ribose) polymerase (PARP) levels meant the DNA damage, and increased Bcl2 family proteins after CC12 treatment indicated the intrinsic apoptotic pathway was involved in CC12 induced apoptosis. Furthermore, CC12 can induce the decrease of tumor prognostic marker DcR3. In vivo experiment results showed the effect of CC12 on tumor size reduction of CC12. In addition, the ability to cross the brain-blood barrier of CC12 was also confirmed. CC12 may have anti-tumor ability through the regulation of cell cycle and apoptosis in vitro and in vivo.

Upfront Magnetic Resonance Imaging-Guided Stereotactic Laser-Ablation in Newly Diagnosed Glioblastoma: A Multicenter Review of Survival Outcomes Compared to a Matched Cohort of Biopsy-Only Patients

BACKGROUND

Laser ablation (LA) is used as an upfront treatment in patients with deep seated newly diagnosed Glioblastoma (nGBM).

OBJECTIVE

To evaluate the outcomes of LA in patients with nGBM and compare them with a matched biopsy-only cohort.

METHODS

Twenty-four nGBM patients underwent upfront LA at Cleveland clinic, Washington University in St. Louis, and Yale University (6/2011-12/2014) followed by chemo/radiotherapy. Also, 24 out of 171 nGBM patients with biopsy followed by chemo/radiotherapy were matched based on age (< 70 vs ≥ 70), gender, tumor location (deep vs lobar), and volume (<11 cc vs ≥11 cc). Progression-free survival (PFS), overall survival (OS), and disease-specific PFS and OS were outcome measures. Three prognostic groups were identified based on extent of tumor ablation by thermal-damage-threshold (TDT)-lines.

RESULTS

The median tumor volume in LA (n = 24) and biopsy only (n = 24) groups was 9.3 cm3 and 8.2 cm3 respectively. Overall, median estimate of OS and PFS in LA cohort was 14.4 and 4.3 mo compared to 15.8 mo and 5.9 mo for biopsy only cohort. On multivariate analysis, favorable TDT-line prognostic groups were associated with lower incidence of disease specific death (P = .03) and progression (P = .05) compared to other groups including biopsy only cohort. Only age (<70 yr, P = .02) and tumor volume (<11 cc, P = .03) were favorable prognostic factors for OS.

CONCLUSION

The maximum tumor coverage by LA followed by radiation/chemotherapy is an effective treatment modality in patients with nGBM, compared to biopsy only cohort. The TDT-line prognostic groups were independent predictor of disease specific death and progression after LA.

Synchrotron X-Ray Boost Delivered by Microbeam Radiation Therapy After Conventional X-Ray Therapy Fractionated in Time Improves F98 Glioma Control

PURPOSE

Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly collimated synchrotron beam into arrays of parallel microbeams depositing several hundred grays. It appears relevant to combine MRT with a conventional treatment course, preparing a treatment scheme for future patients in clinical trials. The efficiency of MRT delivered after several broad-beam (BB) fractions to palliate F98 brain tumors in rats in comparison with BB fractions alone was evaluated in this study.

METHODS AND MATERIALS

Rats bearing 10⁶ F98 cells implanted in the caudate nucleus were irradiated by 5 fractions in BB mode (3 × 6 Gy + 2 × 8 Gy BB) or by 2 boost fractions in MRT mode to a total of 5 fractions (3 × 6 Gy BB + MRT 2 × 8 Gy valley dose; peak dose 181 Gy [50/200 μm]). Tumor growth was evaluated in vivo by magnetic resonance imaging follow-up at T_-1, T₇, T₁₂, T₁₅, T₂₀, and T₂₅ days after radiation therapy and by histology and flow cytometry.

RESULTS

MRT-boosted tumors displayed lower cell density and cell proliferation compared with BB-irradiated tumors. The MRT boost completely stopped tumor growth during ∼4 weeks and led to a significant increase in median survival time, whereas tumors treated with BB alone recurred within a few days after the last radiation fraction.

CONCLUSIONS

The first evidence is presented that MRT, delivered as a boost of conventionally fractionated irradiation by orthovoltage broad x-ray beams, is feasible and more efficient than conventional radiation therapy alone.

Macrophage Exclusion after Radiation Therapy (MERT): A First in Human Phase I/II Trial using a CXCR4 Inhibitor in Glioblastoma

PURPOSE

Preclinical studies have demonstrated that postirradiation tumor revascularization is dependent on a stromal cell-derived factor-1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4)-driven process in which myeloid cells are recruited from bone marrow. Blocking this axis results in survival improvement in preclinical models of solid tumors, including glioblastoma (GBM). We conducted a phase I/II study to determine the safety and efficacy of Macrophage Exclusion after Radiation Therapy (MERT) using the reversible CXCR4 inhibitor plerixafor in patients with newly diagnosed glioblastoma.

PATIENTS AND METHODS

We enrolled nine patients in the phase I study and an additional 20 patients in phase II using a modified toxicity probability interval (mTPI) design. Plerixafor was continuously infused intravenously via a peripherally inserted central catheter (PICC) line for 4 consecutive weeks beginning at day 35 of conventional treatment with concurrent chemoradiation. Blood serum samples were obtained for pharmacokinetic analysis. Additional studies included relative cerebral blood volume (rCBV) analysis using MRI and histopathology analysis of recurrent tumors.

RESULTS

Plerixafor was well tolerated with no drug-attributable grade 3 toxicities observed. At the maximum dose of 400 μg/kg/day, biomarker analysis found suprathreshold plerixafor serum levels and an increase in plasma SDF-1 levels. Median overall survival was 21.3 months [95% confidence interval (CI), 15.9-NA] with a progression-free survival of 14.5 months (95% CI, 11.9-NA). MRI and histopathology support the mechanism of action to inhibit postirradiation tumor revascularization.

CONCLUSIONS

Infusion of the CXCR4 inhibitor plerixafor was well tolerated as an adjunct to standard chemoirradiation in patients with newly diagnosed GBM and improves local control of tumor recurrences.

11C-methionine-18F-FDG dual-PET-tracer-based target delineation of malignant glioma: evaluation of its geometrical and clinical features for planning radiation therapy

OBJECTIVE

It is important to correctly and precisely define the target volume for radiotherapy (RT) of malignant glioma. 11C-methionine (MET) positron emission tomography (PET) holds promise for detecting areas of glioma cell infiltration: the authors' previous research showed that the magnitude of disruption of MET and 18F-fluorodeoxyglucose (FDG) uptake correlation (decoupling score [DS]) precisely reflects glioma cell invasion. The purpose of the present study was to analyze volumetric and geometrical properties of RT target delineation based on DS and compare them with those based on MRI.

METHODS

Twenty-five patients with a diagnosis of malignant glioma were included in this study. Three target volumes were compared: 1) contrast-enhancing core lesions identified by contrast-enhanced T1-weighted images (T1Gd), 2) high-intensity lesions on T2-weighted images, and 3) lesions showing high DS (DS ≥ 3; hDS). The geometrical differences of these target volumes were assessed by calculating the probabilities of overlap and one encompassing the other. The correlation of geometrical features of RT planning and recurrence patterns was further analyzed.

RESULTS

The analysis revealed that T1Gd with a 2.0-cm margin was able to cover the entire high DS area only in 6 (24%) patients, which indicates that microscopic invasion of glioma cells often extended more than 2.0 cm beyond a Gd-enhanced core lesion. Insufficient coverage of high DS regions with RT target volumes was suggested to be a risk for out-of-field recurrence. Higher coverage of hDS by T1Gd with a 2-cm margin (i.e., higher values of "[T1Gd + 2 cm]/hDS") had a trend to positively impact overall and progression-free survival. Cox regression analysis demonstrated that low coverage of hDS by T1Gd with a 2-cm margin was predictive of disease recurrence outside the Gd-enhanced core lesion, indicative of out-of-field reoccurrence.

CONCLUSIONS

The findings of this study indicate that MRI is inadequate for target delineation for RT in malignant glioma treatment. Expanding the treated margins substantially beyond the MRI-based target volume may reduce the risk of undertreatment, but it may also result in unnecessary irradiation of uninvolved regions. As MET/FDG PET-DS seems to provide more accurate information for target delineation than MRI in malignant glioma treatment, this method should be further evaluated on a larger scale.

Recurrence patterns in patients with high-grade glioma following temozolomide-based chemoradiotherapy

There is currently no consensus regarding the optimal radiation volume for high-grade glioma (HGG). The brain volume irradiated is associated with the extent of radiation neurotoxicity. When reducing the treatment volume, the risk of geographic tumor miss should be considered. In such cases, the recurrence patterns and, particularly, the rate of marginal tumor recurrence, are important indices for determining the optimal radiation volume. In the present study, a smaller-target delineation protocol with limited margins was adopted. The postoperative enhancing tumor and resection cavity were defined as gross tumor volume (GTV); 1 and 2 cm were added to the GTV to create clinical target volume (CTV1 and CTV2), which received 60 and 54 Gy, respectively. At a median follow-up of 14 months, 54 HGG patients developed tumor recurrence. The median overall and progression-free survival were 14 and 10.5 months, respectively. A total of 34 patients developed central recurrence, 8 presented with in-field recurrence, 2 developed marginal recurrence, 2 had distant recurrence and 11 patients developed cerebrospinal fluid dissemination, 2 of whom developed central recurrence, with 1 patient simultaneously developing marginal recurrence. Local recurrence (central and in-field) was found to be the main recurrence pattern. As the rate of marginal recurrence was low (<5%), it appears that the smaller irradiated volume in the present study was appropriate. However, clinical trials investigating limited irradiation volume are required to validate our findings.

Anaplastic astrocytoma

Anaplastic astrocytoma (AA) is a diffusely infiltrating, malignant, astrocytic, primary brain tumor. AA is currently defined by histology although future classification schemes will include molecular alterations. AA can be separated into subgroups, which share similar molecular profiles, age at diagnosis and median survival, based on 1p/19q co-deletion status and IDH mutation status. AA with co-deletion of chromosomes 1p and 19q and IDH mutation have the best prognosis. AA with IDH mutation and no 1p/19q co-deletion have intermediate prognosis and AA with wild-type IDH have the worst prognosis and share many molecular alterations with glioblastoma. Treatment of noncodeleted AA based on preliminary results from the CATNON clinical trial consists of maximal safe resection followed by radiotherapy with post-radiotherapy temozolomide (TMZ) chemotherapy. The role of concurrent TMZ and whether IDH1 subgroups benefit from TMZ is currently being evaluated in the recently completed randomized, prospective Phase III clinical trial, CATNON.

The evolving roles and controversies of radiotherapy in the treatment of glioblastoma

Numerous randomised controlled trials have demonstrated the benefit of radiation therapy in patients with newly diagnosed glioblastoma and it has been the cornerstone of treatment for decades. The aims of this review are to (1) Briefly outline the historical studies which resulted in radiation being the current standard of care as used in the Stupp et al. trial (2) Discuss the evolving role of radiation therapy in the management of elderly patients (3) Review the current evidence and ongoing studies of radiation use in the recurrent/salvage setting and (4) Discuss the continuing controversies of volume delineation in the planning of radiation delivery.

Principles of radiation therapy

Although resection remains the mainstay in the treatment of gliomas, microscopically complete resection of most central nervous system tumors remains challenging, and is, in fact, rarely accomplished. Considering their invasive nature, gross total resections to clearly negative margins often do or would require removal or transection of functional brain, with likely serious neurologic deficits. Consequently, radiotherapy has emerged as an indispensable component of therapy. It is delivered primarily by external-beam radiotherapy or brachytherapy techniques. Herein, we present the biologic principles, techniques, and applications of radiotherapy in glioma treatment today.

Effect of Concomitant Radiochemotherapy on Invasion Potential of Glioblastoma

Glioblastoma (GBM) is the most common primary brain tumor in adults with inevitable recurrence after oncotherapy. The insufficient effect of "gold standard" temozolomide-based concomitant radiochemotherapy may be due to the inability to prevent tumor cell invasion. Peritumoral infiltration depends mainly on the interaction between extracellular matrix (ECM) components and cell membrane receptors. Changes in invasive behaviour after oncotherapy can be evaluated at the molecular level by determining the RNA expression and protein levels of the invasion-related ECM components. The expression of nineteen ECM molecules was determined at both RNA and protein levels in thirty-one GBM samples. Fifteen GBM samples originated from the first surgical procedure on patients before oncotherapy, and sixteen GBM samples were collected at the second surgery due to local recurrence after concomitant chemoirradiation. RNA expressions were measured with qRT-PCR, and protein levels were determined by quantitative analysis of Western blots. Only MMP-9 RNA transcript level was reduced (p < 0.05) whereas at protein level, eight molecules showed changes concordant with RNA expression with significant decrease in brevican only. The results suggest that concomitant radiochemotherapy does not have sufficient impact on the expression of invasion-related ECM components of glioblastoma, oncotherapy does not significantly affect its invasive behavior. To avoid the spread of tumors into the brain parenchyma, supplementation of antiproliferative treatment with anti-invasive agents may be worth consideration in oncotherapy for glioblastoma.

Delivery of local therapeutics to the brain: working toward advancing treatment for malignant gliomas

Malignant gliomas, including glioblastoma and anaplastic astrocytomas, are characterized by their propensity to invade surrounding brain parenchyma, making curative resection difficult. These tumors typically recur within two centimeters of the resection cavity even after gross total removal. As a result, there has been an emphasis on developing therapeutics aimed at achieving local disease control. In this review, we will summarize the current developments in the delivery of local therapeutics, namely direct injection, convection-enhanced delivery and implantation of drug-loaded polymers, as well as the application of these therapeutics in future methods including microchip drug delivery and local gene therapy.

Temozolomide and radiotherapy versus radiotherapy alone in high grade gliomas: a very long term comparative study and literature review

Temozolomide (TMZ) is the first line drug in the care of high grade gliomas. The combined treatment of TMZ plus radiotherapy is more effective in the care of brain gliomas then radiotherapy alone. Aim of this report is a survival comparison, on a long time (>10 years) span, of glioma patients treated with radiotherapy alone and with radiotherapy + TMZ.

MATERIALS AND METHODS

In this report we retrospectively reviewed the outcome of 128 consecutive pts with diagnosis of high grade gliomas referred to our institutions from April 1994 to November 2001. The first 64 pts were treated with RT alone and the other 64 with a combination of RT and adjuvant or concomitant TMZ.

RESULTS

Grade 3 (G3) haematological toxicity was recorded in 6 (9%) of 64 pts treated with RT and TMZ. No G4 haematological toxicity was observed. Age, histology, and administration of TMZ were statistically significant prognostic factors associated with 2 years overall survival (OS). PFS was for GBM 9 months, for AA 11.

CONCLUSIONS

The combination of RT and TMZ improves long term survival in glioma patients. Our results confirm the superiority of the combination on a long time basis.

A systematic review and meta-analysis of gene therapy in animal models of cerebral glioma: why did promise not translate to human therapy?

BACKGROUND

The development of therapeutics is often characterized by promising animal research that fails to translate into clinical efficacy; this holds for the development of gene therapy in glioma. We tested the hypothesis that this is because of limitations in the internal and external validity of studies reporting the use of gene therapy in experimental glioma.

METHOD

We systematically identified studies testing gene therapy in rodent glioma models by searching three online databases. The number of animals treated and median survival were extracted and studies graded using a quality checklist. We calculated median survival ratios and used random effects meta-analysis to estimate efficacy. We explored effects of study design and quality and searched for evidence of publication bias.

RESULTS

We identified 193 publications using gene therapy in experimental glioma, including 6,366 animals. Overall, gene therapy improved median survival by a factor of 1.60 (95% CI 1.53-1.67). Study quality was low and the type of gene therapy did not account for differences in outcome. Study design characteristics accounted for a significant proportion of between-study heterogeneity. We observed similar findings in a data subset limited to the most common gene therapy.

CONCLUSION

As the dysregulation of key molecular pathways is characteristic of gliomas, gene therapy remains a promising treatment for glioma. Nevertheless, we have identified areas for improvement in conduct and reporting of studies, and we provide a basis for sample size calculations. Further work should focus on genes of interest in paradigms recapitulating human disease. This might improve the translation of such therapies into the clinic.

Fetal radiation monitoring and dose minimization during intensity modulated radiation therapy for glioblastoma in pregnancy

We examined the fetal dose from irradiation of glioblastoma during pregnancy using intensity modulated radiation therapy (IMRT), and describe fetal dose minimization using mobile shielding devices. A case report is described of a pregnant woman with glioblastoma who was treated during the third trimester of gestation with 60 Gy of radiation delivered via a 6 MV photon IMRT plan. Fetal dose without shielding was estimated using an anthropomorphic phantom with ion chamber and diode measurements. Clinical fetal dose with shielding was determined with optically stimulated luminescent dosimeters and ion chamber. Clinical target volume (CTV) and planning target volume (PTV) coverage was 100 and 98 % receiving 95 % of the prescription dose, respectively. Normal tissue tolerances were kept below quantitative analysis of normal tissue effects in the clinic (QUANTEC) recommendations. Without shielding, anthropomorphic phantom measurements showed a cumulative fetal dose of 0.024 Gy. In vivo measurements with shielding in place demonstrated a cumulative fetal dose of 0.016 Gy. The fetal dose estimated without shielding was 0.04 % and with shielding was 0.026 % of the target dose. In vivo estimation of dose equivalent received by the fetus was 24.21 mSv. Using modern techniques, brain irradiation can be delivered to pregnant patients in the third trimester with very low measured doses to the fetus, without compromising target coverage or normal tissue dose constraints. Fetal dose can further be reduced with the use of shielding devices, in keeping with the principle of as low as reasonably achievable.

The role of laser interstitial thermal therapy in enhancing progression-free survival of difficult-to-access high-grade gliomas: a multicenter study

Surgical extent-of-resection has been shown to have an impact on high-grade glioma (HGG) outcomes; however, complete resection is rarely achievable in difficult-to-access (DTA) tumors. Controlled thermal damage to the tumor may have the same impact in DTA-HGGs. We report our multicenter results of laser interstitial thermal therapy (LITT) in DTA-HGGs. We retrospectively reviewed 34 consecutive DTA-HGG patients (24 glioblastoma, 10 anaplastic) who underwent LITT at Cleveland Clinic, Washington University, and Wake Forest University (May 2011-December 2012) using the NeuroBlate(®) System. The extent of thermal damage was determined using thermal damage threshold (TDT) lines: yellow TDT line (43 °C for 2 min) and blue TDT line (43°C for 10 min). Volumetric analysis was performed to determine the extent-of-coverage of tumor volume by TDT lines. Patient outcomes were evaluated statistically. LITT was delivered as upfront in 19 and delivered as salvage in 16 cases. After 7.2 months of follow-up, 71% of cases demonstrated progression and 34% died. The median overall survival (OS) for the cohort was not reached; however, the 1-year estimate of OS was 68 ± 9%. Median progression-free survival (PFS) was 5.1 months. Thirteen cases who met the following two criteria-(1) <0.05 cm(3) tumor volume not covered by the yellow TDT line and (2) <1.5 cm(3) additional tumor volume not covered by the blue TDT line-had better PFS than the other 21 cases (9.7 vs. 4.6 months; P = 0.02). LITT can be used effectively for treatment of DTA-HGGs. More complete coverage of tumor by TDT lines improves PFS which can be translated as the extent of resection concept for surgery.

Role of radiotherapy in the treatment of gliomas

Malignant gliomas are challenging tumors that are often treated with a multimodality approach. This article focuses on the role of radiotherapy in the management of these tumors. The role of radiotherapy in low-grade gliomas remains controversial and this review focuses on the importance of prognostic factors, recent randomized trials involving radiotherapy, and toxicity from radiotherapy. In terms of high-grade gliomas, radiotherapy has a more established role and this review will address methods that have been evaluated in order to improve radiotherapy outcome. Improvements in radiotherapy delivery, tumor imaging and biologic modifiers may ultimately lead to improved outcome in the treatment of these difficult tumors.

Whole brain radiation-induced cognitive impairment: pathophysiological mechanisms and therapeutic targets

Radiation therapy, the most commonly used for the treatment of brain tumors, has been shown to be of major significance in tu-mor control and survival rate of brain tumor patients. About 200,000 patients with brain tumor are treated with either partial large field or whole brain radiation every year in the United States. The use of radiation therapy for treatment of brain tumors, however, may lead to devastating functional deficits in brain several months to years after treatment. In particular, whole brain radiation therapy results in a significant reduction in learning and memory in brain tumor patients as long-term consequences of treatment. Although a number of in vitro and in vivo studies have demonstrated the pathogenesis of radiation-mediated brain injury, the cel-lular and molecular mechanisms by which radiation induces damage to normal tissue in brain remain largely unknown. Therefore, this review focuses on the pathophysiological mechanisms of whole brain radiation-induced cognitive impairment and the iden-tification of novel therapeutic targets. Specifically, we review the current knowledge about the effects of whole brain radiation on pro-oxidative and pro-inflammatory pathways, matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) system and extracellular matrix (ECM), and physiological angiogenesis in brain. These studies may provide a foundation for defin-ing a new cellular and molecular basis related to the etiology of cognitive impairment that occurs among patients in response to whole brain radiation therapy. It may also lead to new opportunities for therapeutic interventions for brain tumor patients who are undergoing whole brain radiation therapy.

Current status of local therapy in malignant gliomas--a clinical review of three selected approaches

Malignant gliomas are the most frequently occurring, devastating primary brain tumors, and are coupled with a poor survival rate. Despite the fact that complete neurosurgical resection of these tumors is impossible in consideration of their infiltrating nature, surgical resection followed by adjuvant therapeutics, including radiation therapy and chemotherapy, is still the current standard therapy. Systemic chemotherapy is restricted by the blood-brain barrier, while methods of local delivery, such as with drug-impregnated wafers, convection-enhanced drug delivery, or direct perilesional injections, present attractive ways to circumvent these barriers. These methods are promising ways for direct delivery of either standard chemotherapeutic or new anti-cancer agents. Several clinical trials showed controversial results relating to the influence of a local delivery of chemotherapy on the survival of patients with both recurrent and newly diagnosed malignant gliomas. Our article will review the development of the drug-impregnated release, as well as convection-enhanced delivery and the direct injection into brain tissue, which has been used predominantly in gene-therapy trials. Further, it will focus on the use of convection-enhanced delivery in the treatment of patients with malignant gliomas, placing special emphasis on potential shortcomings in past clinical trials. Although there is a strong need for new or additional therapeutic strategies in the treatment of malignant gliomas, and although local delivery of chemotherapy in those tumors might be a powerful tool, local therapy is used only sporadically nowadays. Thus, we have to learn from our mistakes in the past and we strongly encourage future developments in this field.

Epidermal growth factor receptor is related to poor survival in glioblastomas: single-institution experience

PURPOSE

There are conflicting results surrounding the prognostic significance of epidermal growth factor receptor (EGFR) status in glioblastoma (GBM) patients. Accordingly, we attempted to assess the influence of EGFR expression on the survival of GBM patients receiving postoperative radiotherapy.

MATERIALS AND METHODS

Thirty three GBM patients who had received surgery and postoperative radiotherapy at our institute, between March 1997 and February 2006, were included. The evaluation of EGFR expression with immunohistochemistry was available for 30 patients. Kaplan-Meier survival analysis and Cox regression were used for statistical analysis.

RESULTS

EGFR was expressed in 23 patients (76.7%), and not expressed in seven (23.3%). Survival in EGFR expressing GBM patients was significantly less than that in non-expressing patients (median survival: 12.5 versus 17.5 months, p=0.013). Patients who received more than 60 Gy showed improved survival over those who received up to 60 Gy (median survival: 17.0 versus 9.0 months, p=0.000). Negative EGFR expression and a higher radiation dose were significantly correlated with improved survival on multivariate analysis. Survival rates showed no differences according to age, sex, and surgical extent.

CONCLUSION

The expression of EGFR demonstrated a significantly deleterious effect on the survival of GBM patients. Therefore, approaches targeting EGFR should be considered in potential treatment methods for GBM patients, in addition to current management strategies.

Motexafin gadolinium: a promising radiation sensitizer in brain metastasis

INTRODUCTION

Motexafin gadolinium is a radiation sensitizer that is in the class of drugs known as texaphyrins. Though this drug is currently not FDA approved in the management of brain tumors, several prospective studies have been done showing promise with this agent, which this review highlights.

AREAS COVERED

This paper provides a clinical context by reviewing the background of radiosensitizers, followed by a review of the preclinical discovery of motexafin gadolinium and its clinical testing. We also highlight its most promising applications and comment on the reasons for the observed clinical outcomes.

EXPERT OPINION

Motexafin gadolinium is a novel radiosensitizer with clearly documented efficacy, particularly in patients with brain metastases. If this agent had been tested upfront in patients diagnosed with brain metastases from NSCLC who had not been delayed by the administration of systemic chemotherapy, it may have become part of the standard of care in this setting. Continued investigations using this agent are under way and remain promising.

Nimotuzumab prolongs survival in patients with malignant gliomas: A phase I/II clinical study of concomitant radiochemotherapy with or without nimotuzumab

The present study aimed to determine whether nimotuzumab enhances the effect of radiochemotherapy in malignant gliomas. Patients (n=41) with malignant gliomas were divided into 20 cases (treatment group) in which nimotuzumab plus radiochemotherapy were offered and 21 cases (control group) in which placebo and radiochemotherapy were administered to the patients. The response to treatment was evaluated according to the Response Evaluation Criteria in Solid Tumors, the Kaplan-Meier method was used to calculate the mean and median survival times and 1-year survival rate, and the log-rank test and the Chi-square test were used to analyze the difference in the survival and response rate between the treatment and control groups. The mean survival times of the treatment and control groups were 14.3 and 10.4 months and the median survival times of the treatment and control groups were 16.5 and 10.5 months, respectively. The 1-year survival rates of the treatment and control groups were 81.3 and 69.1%, respectively, with no significant difference (P>0.05). The objective response rates of the treatment and control groups were 70.0 and 52.4%, respectively, with no significant difference (P>0.05). In conclusion, there was a trend towards improved treatment efficacy of radiochemotherapy combined with nimotuzumab against malignant gliomas. This study demonstrated that the use of nimotuzumab combined with radiotherapy and concomitant temozolomide chemotherapy is effective for malignant gliomas.

The role of adjuvant radiation therapy in the management of high-grade gliomas

The purpose of this article is to update the neurosurgical community on the role of adjuvant radiation therapy in the management of patients with high-grade glioma. This information guides clinicians in the multidisciplinary management of these patients via a review of the literature describing current treatment paradigms as well as new avenues of investigation.

Combined modality approaches in the management of adult glioblastoma

Over the past two decades, management of newly diagnosed glioblastoma has undergone significant evolution. While surgery has long been a mainstay of management for this disease, and while radiotherapy has a proven survival role, initial efforts at radiotherapy dose escalation, use of radiosurgery, brachytherapy, and altered fractionation did not improve patient survival. Recently, multiple modality therapy integrating maximal safe resection, postoperative radiation, and new systemic therapies have resulted in improved patient outcomes compared with older regimens utilizing surgery and postoperative radiation alone. Numerous trials are currently underway investigating the combination of surgery, radiation, and systemic therapy with targeted agents to find ways to further improve outcomes for adults with glioblastoma.

Prognostic factors in glioblastoma multiforme patients receiving high-dose particle radiotherapy or conventional radiotherapy

The aim of this study was to evaluate the influence of prognostic factors related to patient selection on survival outcomes. Survival outcomes were retrospectively analysed in a consecutive series of 67 newly diagnosed glioblastoma multiforme (GBM) patients who had received either conventional fractionated photon radiotherapy (CRT) or high-dose particle radiotherapy (HDT). In the CRT protocol, a total dose of 60.0-61.2 Gy was administered. In the HDT protocol, an average dose of approximately 30 GyE in a single session and additional fractionated photon irradiation of total dose 30 Gy were administered to patients receiving boron neutron capture therapy; and a total dose of 96.6 GyE was administered to patients receiving proton therapy. Most of the patients had received chemotherapy with nimustine hydrochloride (ACNU) alone or with ACNU, procarbazine and vincristine. The median overall survival (OS) and progression-free survival times for all patients were 17.7 months [95% confidence interval (CI), 14.6-20.9 months] and 7.8 months (95% CI, 5.7-9.9 months), respectively. The 1- and 2-year survival rates were 67.2% and 33.7%, respectively. For patients treated with HDT, the median OS was 24.4 months (95% CI, 18.2-30.5 months), compared with 14.2 months (95% CI, 10.0-18.3 months) for those treated with CRT. The Cox proportional hazards model revealed radiation modality (HDT vs CRT) and European Organisation for Research and Treatment of Cancer recursive partitioning analysis class to be the significant prognostic factors. Age, sex, pre-operative performance status, treatment with or without advanced neuroimaging, extent of surgery and regimen of chemotherapy were not statistically significant factors in predicting prognosis. The median OS was 18.5 months (95% CI, 9.9-27.1 months) in patients of 65 years and older, compared with 16.8 months (95% CI, 13.6-20.1 months) in those 64 years and younger (p=0.871). The positive effect of HDT treatment is unlikely to reflect patient selection alone. Randomised trials with strictly controlled inclusion criteria to ensure the comparable selection of patients are required to demonstrate conclusively that prolonged survival can be attributed to high-dose particle radiotherapies.

A systematic overview of radiation therapy effects in brain tumours

A systematic review of radiation therapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation of the scientific literature are described separately (Acta Oncol 2003; 42: 357-365). This synthesis of the literature on radiation therapy for brain tumours is based on data from 9 randomized trials and 1 meta-analysis. Moreover, data from 2 prospective studies, 3 retrospective studies and 4 other articles were used. In total, 19 scientific articles are included, involving 4,266 patients. The results were compared with those of a similar overview from 1996 including 11,252 patients. The conclusions reached can be summarized as follows: The conclusion from SBU 129/2 that curative treatment is not available for patients with high-grade malignant glioma (grade III and IV) is still valid. The survival benefit from postoperative radiotherapy compared to supportive care only or chemotherapy is about 3-4 months, as demonstrated in earlier randomized studies. Quality of life is now currently estimated and considered to be of major importance when reporting the outcome of treatment for patients with brain tumours. There is no scientific evidence that radiotherapy using hyper- and hypofractionation leads to longer survival for patients with high-grade malignant glioma than conventional radiotherapy. There is large documentation, but only one randomized study. There is some documentation to support the view that patients with grade IV glioma and poor prognosis can be treated with hypofractionation and with an outcome similar to that after conventional fractionation. A shorter treatment time should be convenient for the patient. Documentation of the benefit of a radiotherapy boost with brachytherapy is limited and no conclusion can be drawn. There is no scientific evidence that radiotherapy prolongs life for patients with low-grade glioma. There are some data supporting that radiotherapy can be used to treat symptoms in patients with low-grade glioma. As no controlled studies have been reported, no firm conclusion can be drawn.

The potential of proton beam radiation therapy in intracranial and ocular tumours

A group of oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In intracranial benign and malignant tumours, it is estimated that between 130 and 180 patients each year are candidates for proton beam therapy. Of these, between 50 and 75 patients have malignant glioma, 30-40 meningeoma, 20-25 arteriovenous malformations, 20-25 skull base tumours and 10-15 pituitary adenoma. In addition, 15 patients with ocular melanoma are candidates.

Imaging after GliaSite brachytherapy: prognostic MRI indicators of disease control and recurrence

PURPOSE

In this study, we analyzed the magnetic resonance imaging (MRI) changes in patients after GliaSite treatment and characterized the prognostic MRI indicators in these patients.

METHODS AND MATERIALS

A total of 25 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System. Patients at the Johns Hopkins Hospital with recurrent glioblastoma multiforme underwent surgical resection followed by GliaSite balloon implantation. Available MRI scans for 20 patients were obtained throughout the post-GliaSite treatment course. These were reviewed and analyzed for prognostic significance.

RESULTS

After GliaSite treatment, all patients developed some degree of T(1)-weighted contrast and T(2)-weighted hyperintensity around the resection cavity. The development of enhancement on T(1)-weighted contrast-enhanced imaging and the size of these lesions, in the absence of increasing T(2)-weighted hyperintensity, before clinical progression was not associated with decreased survival. Patients with T(1)-weighted enhancement >1 cm had a median survival of 13.6 months and those with T(1)-weighted lesions <or=1 cm had a median survival of 8.5 months (p = .014). In contrast, the development of larger areas of T(2)-weighted hyperintensity surrounding the resection cavity was significantly associated with poorer survival (p = .027).

CONCLUSION

After GliaSite treatment, characteristic T(1)- and T(2)-weighted changes are seen on MRI. Greater T(1)-weighted changes in the absence of increasing edema appears not to indicate disease progression; however, greater T(2)-weighted changes were associated with decreased survival. These findings suggest that T(1)-weighted enhancement in the absence of concomitant edema after GliaSite treatment might represent pseudoprogression. Conversely, increasing T(2)-weighted hyperintensity might reflect infiltrative disease progression. These results provide a framework for the analysis of disease control in future prospective studies of GliaSite treatment.

Present trend in the primary treatment of aggressive malignant glioma: glioblastoma multiforme

The standard treatment for glioblastoma multiforme is surgery, radiation, and chemotherapy. Yet this aggressive therapy has only a modest effect on survival with most patients surviving less than 1 year after diagnosis. This poor prognosis has lead scientists to seek alternative molecular approaches for the treatment of glioblastoma multiforme. Among these, gene therapy, vaccine therapy, and immunotherapy are all approaches that are currently being investigated. While these molecular approaches may not herald an immediate change in the prognosis of these aggressive tumors, combining them with existing approaches may bring some progress in the standard of care. This paper reviews current treatments and several newer therapies in preclinical and early clinical studies.

Role of exclusive chemotherapy as first line treatment in oligodendroglioma

PURPOSE

The optimal therapy of oligodendrogliomas remains uncertain. Although chemosensitive, these tumors are not chemocurable. We investigated whether chemotherapy delays the need for radiation therapy (RT) without decreasing length and quality of survival.

METHODS AND MATERIALS

Among 89 patients treated for oligodendrogliomas at the Centre Léon Bérard of Lyon from 1982 to 1999, 59 patients fitted inclusion criteria, having had centrally reviewed pure oligodendroglioma requiring treatment. According to the WHO's classification 35 patients had Grade III and 24, Grade II oligodendrogliomas.

RESULTS

According to the intent to treat, patients were retrospectively classified in three groups as exclusive RT (Group 1), radio-chemotherapy (Group 2), or exclusive chemotherapy (Group 3). Median progression-free survival (PFS): was 47 months [95% confidence interval (CI) 39-56], and median overall survival (OS) was 109 months (95% CI 83-134). In univariate analysis, PFS was correlated with frontal location and WHO classification; OS was correlated with frontal location and Post-operative Karnosky performans status both appearing as independent prognostic factors for OS in multivariate analysis. There was no significant difference between the treatment groups with regard to PFS (P = 0.82) and OS (P = 0.64). In the group of patients treated with exclusive chemotherapy the 5-year PFS and OS rates were 44 and 71%, respectively.

CONCLUSION

Front-line exclusive chemotherapy results in prolonged OS in patients with confirmed pure oligodendroglioma. Whether this strategy improves quality of life remains debatable.

Patterns of practice and survival in a retrospective analysis of 1722 adult astrocytoma patients treated between 1985 and 2001 in 12 Italian radiation oncology centers

PURPOSE

To analyze the patterns of practice and survival in a series of 1722 adult astrocytoma patients treated in 12 Italian radiotherapy centers.

METHODS AND MATERIALS

A total of 1722 patients were treated with postoperative radiotherapy (90% World Health Organization [WHO] Grade 3-4, 62% male, 44% aged >60 years, 25% with severe neurologic deficits, 44% after gross total resection, 52% with high-dose radiotherapy, and 16% with chemotherapy). Variations in the clinical-therapeutic features in three subsequent periods (1985 through 2001) were evaluated, along with overall survival for the different subgroups.

RESULTS

The proportion of women, of older patients, of those with worse neurologic performance status (NPS), with WHO Grade 4, and with smaller tumors increased with time, as did the proportion of those treated with radical surgery, hypofractionated radiotherapy, and more sophisticated radiotherapy techniques, after staging procedures progressively became more accurate. The main prognostic factors for overall survival were age, sex, neurologic performance status, WHO grade, extent of surgery, and radiation dose.

CONCLUSIONS

Recently, broader selection criteria for radiotherapy were adopted, together with simpler techniques, smaller total doses, and larger fraction sizes for the worse prognostic categories. Younger, fit patients are treated more aggressively, more often in association with chemotherapy. Survival did not change over time. The accurate evaluation of neurologic status is therefore of utmost importance before the best treatment option for the individual patient is chosen.