Radiation Necrosis in Intracranial Lesions

Cost-effectiveness analysis of bevacizumab for cerebral radiation necrosis treatment based on real-world utility value in China

BACKGROUND

Bevacizumab shows superior efficacy in cerebral radiation necrosis (CRN) therapy, but its economic burden remains heavy due to the high drug price. This study aims to evaluate the cost-effectiveness of bevacizumab for CRN treatment from the Chinese payers' perspective.

METHODS

A decision tree model was developed to compare the costs and health outcomes of bevacizumab and corticosteroids for CRN therapy. Efficacy and safety data were derived from the NCT01621880 trial, which compared the effectiveness and safety of bevacizumab monotherapy with corticosteroids for CRN in nasopharyngeal cancer patients, and demonstrated that bevacizumab invoked a significantly higher response than corticosteroids (65.5% vs. 31.5%, P < 0.001) with no significant differences in adverse events between two groups. The utility value of the "non-recurrence" status was derived from real-world data. Costs and other utility values were collected from an authoritative Chinese network database and published literature. The primary outcomes were total costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). The uncertainty of the model was evaluated via one-way and probabilistic sensitivity analyses.

RESULTS

Bevacizumab treatment added 0.12 (0.48 vs. 0.36) QALYs compared to corticosteroid therapy, along with incremental costs of $ 2010 ($ 4260 vs. $ 2160). The resultant ICER was $ 16,866/QALY, which was lower than the willingness-to-pay threshold of $ 38,223/QALY in China. The price of bevacizumab, body weight, and the utility value of recurrence status were the key influential parameters for ICER. Probabilistic sensitivity analysis revealed that the probability of bevacizumab being cost-effectiveness was 84.9%.

CONCLUSION

Compared with corticosteroids, bevacizumab is an economical option for CRN treatment in China.

Comparable survival in rats with intracranial glioblastoma irradiated with single-fraction conventional radiotherapy or FLASH radiotherapy

Background

Radiotherapy increases survival in patients with glioblastoma. However, the prescribed dose is limited by unwanted side effects on normal tissue. Previous experimental studies have shown that FLASH radiotherapy (FLASH-RT) can reduce these side effects. Still, it is important to establish an equal anti-tumor efficacy comparing FLASH-RT to conventional radiotherapy (CONV-RT).

Methods

Fully immunocompetent Fischer 344 rats with the GFP-positive NS1 intracranial glioblastoma model were irradiated with CONV-RT or FLASH-RT in one fraction of 20 Gy, 25 Gy or 30 Gy. Animals were monitored for survival and acute dermal side effects. The brains were harvested upon euthanasia and tumors were examined post mortem.

Results

Survival was significantly increased in animals irradiated with CONV-RT and FLASH-RT at 20 Gy and 25 Gy compared to control animals. The longest survival was reached in animals irradiated with FLASH-RT and CONV-RT at 25 Gy. Irradiation at 30 Gy did not lead to increased survival, despite smaller tumors. Tumor size correlated inversely with irradiation dose, both in animals treated with CONV-RT and FLASH-RT. Acute dermal side effects were mild, but only a small proportion of the animals were alive for evaluation of those side effects.

Conclusion

The dose response was similar for CONV-RT and FLASH-RT in the present model. Tumor size upon the time of euthanasia correlated inversely with the irradiation dose.

GammaTile: Comprehensive Review of a Novel Radioactive Intraoperative Seed-Loading Device for the Treatment of Brain Tumors

GammaTile is a Food and Drug Administration (FDA)-licensed device consisting of four cesium-131 (Cs-131) radiation-emitting seeds in the collagen tile about the postage stamp size. The tiles are utilized to line the brain cavity immediately after tumor resection. GammaTile therapy is a surgically targeted radiation therapy (STaRT) that helps provide instant, dose-intense treatment after the completion of resection. The objective of this study is to explore the safety and efficacy of GammaTile surgically targeted radiation therapy for brain tumors. This study also reviews the differences between GammaTile surgically targeted radiation therapy (STaRT) and other traditional treatment options for brain tumors. The electronic database searches utilized in this study include PubMed, Google Scholar, and ScienceDirect. A total of 4,150 articles were identified based on the search strategy. Out of these articles, 900 articles were retrieved. A total of 650 articles were excluded for various reasons, thus retrieving 250 citations. We applied the exclusion and inclusion criteria to these retrieved articles by screening their full text and excluding 180 articles. Therefore, 70 citations were retrieved and included in this comprehensive literature review, as outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram. Based on the findings of this study, GammaTile surgically targeted radiation therapy (STaRT) is safe and effective for treating brain tumors. Similarly, the findings have also shown that the efficacy of GammaTile therapy can be enhanced by combining it with other standard-of-care treatment options/external beam radiation therapy (EBRT). Also, the results show that patients diagnosed with recurrent glioblastoma (GBM) exhibit poor median overall survival because of the possibility of the tumor returning. Therefore, combining STaRT with other standard-of-care treatment options/EBRT can improve the patient's overall survival (OS). GammaTile therapy enhances access to care, guarantees 100% compliance, and eliminates patients' need to travel regularly to hospitals for radiation treatments. Its implementation requires collaboration from various specialties, such as radiation oncology, medical physics, and neurosurgery.

The Value of FET PET/CT in Recurrent Glioma with a Different IDH Mutation Status: The Relationship between Imaging and Molecular Biomarkers

The evaluation of treatment response remains a challenge in glioma cases because the neuro oncological therapy can lead to the development of treatment-related changes (TRC) that mimic true progression (TP). Positron emission tomography (PET) using O-(2-[¹⁸F] fluoroethyl-)-L-tyrosine (¹⁸F-FET) has been shown to be a useful tool for detecting TRC and TP. We assessed the diagnostic performance of different ¹⁸F-FET PET segmentation approaches and different imaging biomarkers for differentiation between late TRC and TP in glioma patients. Isocitrate dehydrogenase (IDH) status was evaluated as a predictor of disease outcome. In our study, the proportion of TRC in IDH wild type (IDHwt) and IDH mutant (IDHm) subgroups was without significant difference. We found that the diagnostic value of static and dynamic biomarkers of ¹⁸F-FET PET for discrimination between TRC and TP depends on the IDH mutation status of the tumor. Dynamic ¹⁸F-FET PET acquisition proved helpful in the IDH wild type (IDHwt) subgroup, as opposed to the IDH mutant (IDHm) subgroup, providing an early indication to discontinue dynamic imaging in the IDHm subgroup.

Stereotactic Laser Ablation (SLA) followed by consolidation stereotactic radiosurgery (cSRS) as treatment for brain metastasis that recurred locally after initial radiosurgery (BMRS): a multi-institutional experience

INTRODUCTION

The optimal treatment paradigm for brain metastasis that recurs locally after initial radiosurgery remains an area of active investigation. Here, we report outcomes for patients with BMRS treated with stereotactic laser ablation (SLA, also known as laser interstitial thermal therapy, LITT) followed by consolidation radiosurgery.

METHODS

Clinical outcomes of 20 patients with 21 histologically confirmed BMRS treated with SLA followed by consolidation SRS and > 6 months follow-up were collected retrospectively across three participating institutions.

RESULTS

Consolidation SRS (5 Gy × 5 or 6 Gy × 5) was carried out 16-73 days (median of 26 days) post-SLA in patients with BMRS. There were no new neurological deficits after SLA/cSRS. While 3/21 (14.3%) patients suffered temporary Karnofsky Performance Score (KPS) decline after SLA, no KPS decline was observed after cSRS. There were no 30-day mortalities or wound complications. Two patients required re-admission within 30 days of cSRS (severe headache that resolved with steroid therapy (n = 1) and new onset seizure (n = 1)). With a median follow-up of 228 days (range: 178-1367 days), the local control rate at 6 and 12 months (LC₆, LC₁₂) was 100%. All showed diminished FLAIR volume surrounding the SLA/cSRS treated BMRS at the six-month follow-up; none of the patients required steroid for symptoms attributable to these BMRS. These results compare favorably to the available literature for repeat SRS or SLA-only treatment of BMRS.

CONCLUSIONS

This multi-institutional experience supports further investigations of SLA/cSRS as a treatment strategy for BMRS.