A cost-minimising analysis of standard radiotherapy and two experimental therapies in glioblastoma

Fibrin glue mediated direct delivery of radiation sensitizers results in enhanced efficacy of radiation treatment

PURPOSE

Radiation therapy (RT) plays an important role in the treatment of glioblastoma multiforme (GBM). However, inherent intrinsic resistance of tumors to radiation, coupled with the need to consider the tolerance of normal tissues and the potential effects on neurocognitive function, impose constraints on the amount of RT that can be safely delivered. A strategy for augmenting the effectiveness of RT involves the utilization of radiation sensitizers (RS). Directly implanting RS-loaded fibrin glue (FG) into the tumor resection cavity would by-pass the blood brain barrier, potentially enhancing the impact of RT on tumor recurrence. This study investigated the ability of FG to incorporate and release, in non-degraded form, the radiation sensitizers 5-Fluorouracil (5FU) and Motexafin gadolinium (MGd).

METHODS

FG layers were created in a 24-well plate by combining thrombin, fibrinogen, and 5FU or MGd. Supernatants from these layers were collected at various intervals and added to F98 glioma spheroid cultures in 96-well plates. Radiation was applied either before or after RS application as single or fractionated dosages. Spheroid growth was monitored for 14 days.

RESULTS

Combined treatment of FG-released 5FU and RT significantly inhibited spheroid growth compared to RS or RT as a single treatment. As a free drug, MGd demonstrated its efficacy in reducing spheroid volume, but had diminished potency as a released RS. Fractionated radiation was more effective than single dose radiation.

CONCLUSION

Non-degraded RS was released from the FG for up to 72 h. FG-released 5FU greatly increased the efficacy of radiation therapy.

Economic implications of the modern treatment paradigm of glioblastoma: an analysis of global cost estimates and their utility for cost assessment

INTRODUCTION

Glioblastoma is the most common primary brain tumor in adults. Standard of care includes maximal surgical resection of the tumor followed by concurrent chemotherapy and radiation. The treatment of glioblastoma must account for an increased disease severity and treatment intensity compared to other cancers which place a significant cost burden on the patient and health system. Cost assessments of glioblastoma treatment have been sparse in comparison to other solid cancer subtypes. This study evaluates all currently available cost literature with an emphasis on the modern treatment paradigm to properly assess the economic implications of this disease.

METHODS

A critical review of 21 studies from 13 different countries measuring direct costs related to glioblastoma management was performed. Evaluated data included itemized costs, total costs of treatment regimens from diagnosis until death, the cost of second-line care after recurrence, and the incremental costs and cost-effectiveness of emerging therapies.

RESULTS

The average cost of a craniotomy was $10,042 across studies. Imaging for the duration of glioblastoma care had a mean cost of $2,788 ± 3,719. Studies examined different combinations of treatment modalities. Utilization of the modern treatment paradigm led to survival of 16.3 months across studies and had a mean cost of $62,602. Surgery for the recurrent disease had an average cost of $27,442 ± 18,992.

LIMITATIONS AND CONCLUSIONS

Direct cost estimates for glioblastoma varied substantially between institutions and countries and often failed to uniformly describe direct cost estimates associated with care for glioblastoma. The limitations of these studies make a true economic assessment of standards of care, costs of recurrence, and incremental costs associated with adjunctive therapy uncertain.

Young adults diagnosed with high grade gliomas: Patterns of care, outcomes, and impact on employment

There is limited information on the patterns of care and outcomes of high grade gliomas (HGGs) in young adults, in particular, the impact it has on a person's employment. We retrospectively identified young adult patients (age ≤ 40 years old) with newly diagnosed high grade gliomas treated between January 2013 and June 2018 across four major neuro-oncology centres in Australia. Patient demographics, tumour characteristics and treatment parameters were collected and outcomes determined. A total of 113 patients were identified with a median follow up of 27.0 months (range 1.0-70.2 months). The median age was 31 years, majority were male (65%) and employed (71.6%). IDH mutations were detected in 66 (62%) cases. The median progression-free survival (PFS) was 38.0 months (95% CI 23.3-52.7 months) and median overall survival (OS) was not reached. Patients with IDH wild type anaplastic astrocytoma and glioblastoma had a significantly shorter median PFS (19.3 months vs. NR, p = 0.001) and median OS (43.5 months vs NR, p = 0.007) than those with IDH mutated grade III anaplastic astrocytoma and oligodendroglioma. There was no significant difference in median OS or PFS between patients who underwent gross or subtotal tumour resection. Significantly, after diagnosis only 36 (32%) patients reported being employed. Young patients with IDH wild type astrocytomas and glioblastoma had better outcomes than reported historical controls. Most patients did not continue in employment post diagnosis.

Quality-adjusted life years in glioma patients: a systematic review on currently available data and the lack of evidence-based utilities

BACKGROUND

Cost-effectiveness studies gain importance in the context of rising health care expenses and treatment options. Especially in the neuro-oncological context, surgical therapy may increase overall survival, but restrain the patient by postoperative disability. Quality-adjusted life years, express treatment effects and are based on health utilities. In our study, we analyze the current evidence on health economic evaluations in glioma patients.

MATERIAL AND METHODS

We performed a systematic database search including Medline and Cochrane Library. Studies were critically appraised for statistical analyzes including glioma patients, health economic modeling and detailed health outcome. Study evidence was classified according to levels of evidence for therapeutic studies from the Centre for Evidence-Based Medicine (Oxford).

RESULTS

37 studies (1995-2018) were identified, 29 matched our inclusion criteria. Studies addressed surgical cost-efficiency and/or the standard treatment, postoperative chemotherapy (n = 6) and 5-ALA (n = 3). Only 16 studies used QALY as the outcome measure, most used overall survival or life years gained (LYG). Utilities were either based on one single study (Garside et al. in Health Technol Assess 11:iii-iv, ix-221) or derived from visual analogue scale (VAS). None assessed quality of life values for specific health statuses or utilities. Incremental cost-effectiveness ratios varied from 8325€ per QALY (5-ALA) to 518,342€ per LYG (tumor treating fields).

CONCLUSIONS

Only one study generated utility values to conduct cost-effectiveness analysis (CEA); most studies used indirect outcomes such as LYG or based their model on previously published data. Health economic evaluations lack specific utilities, further investigations are necessary to conduct reliable CEA in the neurosurgical context.

Photodynamic therapy mediated immune therapy of brain tumors

Photodynamic therapy of tumors requires the topical, systemic or oral administration of a photosensitizing compound, illumination of the tumor area by light of a specific wavelength and the presence of oxygen. Light activation of the photosensitizer transfers energy to molecular oxygen creating singlet oxygen, a highly reactive and toxic species that rapidly reacts with cellular components causing oxidative damage, ultimately leading to cell death. Tumor destruction caused by photodynamic therapy is not only a result of direct tumor cell toxicity via the generation of reactive oxygen species but there is also an immunological and vascular component involved. The immune response to photodynamic therapy has been demonstrated to significantly enhance its efficacy. Depending on a number of factors, including type of photosensitizer, light dose and dose rate, photodynamic therapy has been shown to induce cell death via apoptosis, necrosis, autophagy and in particular immunogenic cell death. It is the purpose of this review to focus mainly on the role photodynamic therapy could play in the generation of specific anti-tumor immunity and vaccines for the treatment of brain tumors.

Economics of Malignant Gliomas: A Critical Review

PURPOSE

Approximately 18,500 persons are diagnosed with malignant glioma in the United States annually. Few studies have investigated the comprehensive economic costs. We reviewed the literature to examine costs to patients with malignant glioma and their families, payers, and society.

METHODS

A total of 18 fully extracted studies were included. Data were collected on direct and indirect costs, and cost estimates were converted to US dollars using the conversion rate calculated from the study's publication date, and updated to 2011 values after adjustment for inflation. A standardized data abstraction form was used. Data were extracted by one reviewer and checked by another.

RESULTS

Before approval of effective chemotherapeutic agents for malignant gliomas, estimated total direct medical costs in the United States for surgery and radiation therapy per patient ranged from $50,600 to $92,700. The addition of temozolomide (TMZ) and bevacizumab to glioblastoma treatment regimens has resulted in increased overall costs for glioma care. Although health care costs are now less front-loaded, they have increased over the course of illness. Analysis using a willingness-to-pay threshold of $50,000 per quality-adjusted life-year suggests that the benefits of TMZ fall on the edge of acceptable therapies. Furthermore, indirect medical costs, such as productivity losses, are not trivial.

CONCLUSION

With increased chemotherapy use for malignant glioma, the paradigm for treatment and associated out-of-pocket and total medical costs continue to evolve. Larger out-of-pocket costs may influence the choice of chemotherapeutic agents, the economic implications of which should be evaluated prospectively.

Comparing the cost-effectiveness of two brain metastasis treatment modalities from a payer's perspective: stereotactic radiosurgery versus surgical resection

OBJECTIVES

This study aims to identify the cost-effectiveness of two brain metastatic treatment modalities, stereotactic radiosurgery (SRS) versus surgical resection (SR), from the perspective of Germany's Statutory Health Insurance (SHI) System.

METHODS

Retrospectively reviewing 373 patients with brain metastases (BMs) who underwent SR (n=113) and SRS (n=260). Propensity score matching was used to adjust for selection bias (n=98 each); means of survival time and survival curves were defined by the Kaplan-Meier estimator; and medical costs of follow-up treatment were calculated by the Direct (Lin) method. The bootstrap resampling technique was used to assess the impact of uncertainty.

RESULTS

Survival time means of SR and SRS were 13.0, 18.4 months, respectively (P=0.000). Medians of free brain tumor time were 10.4 months for SR and 13.8 months for SRS (P=0.003). Number of repeated SRS treatments significantly influenced the survival time of SRS (R(2)=0.249; P=0.006). SRS had a lower average cost per patient (€9964 - SD: 1047; Skewness: 7273) than SR (€11647 - SD: 1594; Skewness: 0.465), leading to an incremental cost effectiveness ratio of €-3740 per life year saved (LYS), meaning that using SRS costs €1683 less than SR per targeted patient, but increases LYS by 0.45 years.

CONCLUSION

SRS is more cost-effective than SR in the treatment of brain metastasis (BM) from the SHI perspective. When the clinical conditions allow it, early intervention with SRS in new BM cases and frequent SRS repetition in new BM recurrent cases should be advised.

Boron neutron capture therapy for newly diagnosed glioblastoma multiforme: an assessment of clinical potential

The purpose of this study was to assess the potential of boron neutron capture therapy (BNCT), with a 6-h infusion of the boron carrier l-boronophenylalanine as a fructose preparation (BPA-f), as first-line radiotherapy for newly diagnosed glioblastoma multiforme (GBM). Patient survival data from a Phase II study using BNCT were compared with retrospective data from the two arms of a Phase III study using conventional radiotherapy (RT) in the reference arm and using RT plus concomitant and adjuvant medication with temozolomide (TMZ) in the experimental arm, and were also compared with small subgroups of these patients for whom the methylation status of the MGMT (O(6)-methylguanine-DNA methyltransferase) DNA repair gene was known. Differences in the baseline characteristics, salvage therapy after recurrence and levels of severe adverse events were also considered. The results indicate that BNCT offers a treatment that is at least as effective as conventional RT alone. For patients with an unmethylated MGMT DNA repair gene, a possible clinical advantage of BNCT over RT/TMZ was suggested. BNCT is a single-day treatment, which is of convenience to patients, with mild side effects, which would offer an initial 6 weeks of good-quality life during the time when patients would otherwise be undergoing daily treatments with RT and TMZ. It is suggested that the use of BNCT with a 6-h infusion of BPA-f should be explored in a stratified randomised Phase II trial in which patients with the unmethylated MGMT DNA repair gene are offered BNCT in the experimental arm and RT plus TMZ in the reference arm.