Outcomes and cost-effectiveness of gamma knife radiosurgery and whole brain radiotherapy for multiple metastatic brain tumors

Efficacy of Stereotactic Radiosurgery as Single or Combined Therapy for Brain Metastasis: A Systematic Review and Meta-Analysis

To determine the efficacy of stereotactic radiosurgery (SRS) in treating patients with brain metastases (BMs), a network meta-analysis (NMA) of randomized controlled trials (RCTs) and a direct comparison of cohort studies were performed. Relevant literature regarding the effectiveness of SRS alone and in combination with whole-brain radiotherapy (WBRT) and surgery was retrieved using systematic database searches up to April 2019. The patterns of overall survival (OS), one-year OS, progression-free survival (PFS), one-year local brain control (LBC), one-year distant brain control (DBC), neurological death (ND), and complication rate were analyzed. A total of 18 RCTs and 37 cohorts were included in the meta-analysis. Our data revealed that SRS carried a better OS than SRS+WBRT (p= 0.048) and WBRT (p= 0.041). Also, SRS+WBRT demonstrated a significantly improved PFS, LBC, and DBC compared to WBRT alone and SRS alone. Finally, SRS achieved the same LBC as high as surgery, but intracranial relapse occurred considerably more frequently in the absence of WBRT. However, there were not any significant differences in ND and toxicities between SRS and other groups. Therefore, SRS alone may be a better alternative since increased patient survival may outweigh the increased risk of brain tumor recurrence associated with it.

Demographic Analysis of Financial Hardships Faced by Brain Tumor Survivors

OBJECTIVE

Quantitative analysis of the financial hardship faced by patients with brain tumors is lacking. The present study sought to conduct a longitudinal analysis of responses to the National Health Interview Survey by patients diagnosed with brain tumors and characterize the impact of demographic factors on financial hardship indices.

METHODS

National Health Interview Survey respondents between 1997 and 2018 who reported previous diagnosis with cancer of the brain and who responded to 4 survey questions that assessed financial stress were included. Sociodemographic exposures included age, ethnicity/race, marriage status, insurance status, and degree of highest educational attainment.

RESULTS

Educational attainment, marital status, and insurance status were the most significant risk factors for temporary or indefinite delays to necessary medical care. Those with only a high-school diploma had 9.6 times higher odds (adjusted odds ratio, 9.68; 95% confidence interval, 2.96-31.70; P < 0.001) of reporting that, in the past 12 months, one of their family members had to limit their medical care in an effort to save money. Similarly, patients with brain tumors who were not married had 3.94 times greater odds (adjusted odds ratio, 3.94; 95% confidence interval, 1.49-10.44; P = 0.009) of avoiding necessary medical care because of an inability to afford it.

CONCLUSIONS

Given this variation in self-reported financial burden, demographics clearly have an impact on a patient's holistic experience after a brain cancer diagnosis. Therefore, by using the comparisons in this study, we hope that medical institutions and neurosurgical societies can more accurately predict which patients are most susceptible to significant financial stress and distribute resources accordingly.

The Role of Stereotactic Radiosurgery in the Management of Brain Metastases From a Health-Economic Perspective: A Systematic Review

BACKGROUND

Stereotactic radiosurgery (SRS) is an effective option in the management of brain metastases, offering improved overall survival to whole-brain radiation therapy (WBRT). However, given the need for active surveillance and the possibility of repeated interventions for local/distant brain recurrences, the balance between clinical benefit and economic impact must be evaluated.

OBJECTIVE

To conduct a systematic review of health-economic analyses of SRS for brain metastases, compared with other existing intervention options, to determine the cost-effectiveness of this treatment across different clinical scenarios.

METHODS

The MEDLINE, EMBASE, Cochrane, CRD, and EconLit databases were searched for health-economic analyses, according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using terms relevant to brain metastases and radiation-based therapies. Simple cost analysis studies were excluded. Quality analysis was based on BMJ Consolidated Health Economics Reporting Standards (CHEERS) checklist.

RESULTS

Eleven eligible studies were identified. For lesions with limited mass effect, SRS was more cost-effective than surgical resection (6 studies). In patients with Karnofsky performance scale (KPS) >70 and good predicted survival, SRS was cost-effective compared to WBRT (7 studies); WBRT became cost-effective with poor performance status or low anticipated life span. Following SRS, routine magnetic resonance imaging surveillance saved $1326/patient compared to symptomatic imaging due to reduced surgical salvage and hospital stay (1 study).

CONCLUSION

Based on our findings, SRS is cost-effective in the management of brain metastases, particularly in high-functioning patients with longer expected survival. However, before an optimal care pathway can be proposed, emerging factors such as tumor molecular subtype, diagnosis-specific graded prognostic assessment, neuroprognostic score, tailored surveillance imaging, and patient utilities need to be studied in greater detail.

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.

Unintended consequences of the potential phase-out of gamma irradiation

The radioisotope cobalt-60 (Co-60) is important for commercial, medical, and agricultural applications. Its widespread use has meant that Co-60 can be found in less secured facilities, leading to the fear that unauthorized persons could obtain and use it to produce a "dirty bomb". This potential security concern has led to government calls for phasing-out Co-60 and other radiation sources, despite ongoing safety and security regulations for handling, transport and use of radioactive sealed sources. This paper explores potential implications of phasing out radioisotopic technologies, including unintended safety and cost consequences for healthcare and food in the US and globally. The use of Co-60 for healthcare and agricultural applications is well-documented. Co-60 is used to sterilize single-use medical devices, tissue allografts, and a range of consumer products. Co-60 is used in Gamma Knife treatment of brain tumors in over 70,000 patients annually. Co-60 is also used to preserve food and kill insects and pathogens that cause food-borne illness. Co-60 is effective, reliable, and predictable. Limitations of alternative sterilization technologies include complex equipment, toxicities, incompatibilities with plastic, and physical hazards. Alternative ionizing radiation sources for wide-reaching applications, including e-beam and x-ray radiation, have advantages and drawbacks related to commercial scale capacity, penetrability, complexity and reliability. Identifying acceptable alternatives would require time, costs and lengthy regulatory review. FDA testing requirements and other hurdles would delay replacement of existing technologies and slow medical innovation, even delaying access to life-saving therapies.  A phase-out would raise manufacturing costs, and reduce supply-chain efficiencies, potentially increasing consumer prices, and reducing supply. These consequences are poorly understood and merit additional research. Given Co-60's importance across medical and non-medical fields, restrictions on Co-60 warrant careful consideration and evaluation before adoption.

Health State Utilities for Patients with Brain Metastases

PURPOSE

 Estimating the cost-effectiveness of whole-brain radiation therapy (WBRT) and stereotactic radiosurgery (SRS), including Gamma Knife radiosurgery (GKRS), requires the quantitative measurement of patients' health states after treatment. We sought to quantify individuals' preferences for the relevant health states after WBRT or GKRS for brain metastases on a 0 to 1 scale, where 1 is perfect health and 0 is death.

METHODS

 We prospectively measured utilities in patients with brain metastases evaluated at Yale for consideration of WBRT and/or GKRS, as well as oncology nurses who had cared for patients with brain metastases before and after WBRT or GKRS, using the Standard Gamble (SG) technique. Demographic information was also collected. Nonparametric tests were used to compare potential differences in utility values and for subgroups based on demographic characteristics.

RESULTS

 There were 24 patients and 31 nurses who completed the study between December 2013 and May 2015. Median utilities ranged from 0.85 for the status-post (S/P) GKRS state to 0.25 (for neurologic dying). The median utility of being S/P WBRT was 0.70 compared to 0.85 S/P GKRS (p < 0.001). The cognitive decline from WBRT was associated with a notably low utility score of 0.30. There were no statistically significant differences between patients' and nurses' median utility scores.

CONCLUSIONS

 These SG utilities provide unique insights into brain metastases-related health states from the patient and provider perspective. As perceived by individuals with direct knowledge of the health states in question, WBRT has a significantly lower utility compared to GKRS. Cognitive decline following WBRT is associated with significant perceived reduction in quality of life. Differences in the relative importance of overall survival and quality of life with treatment existed between patients with different stages of disease. These utilities can be used to calculate quality-adjusted life expectancy in cost-effectiveness evaluations of SRS and WBRT.

The biology of radiosurgery and its clinical applications for brain tumors

Stereotactic radiosurgery (SRS) was developed decades ago but only began to impact brain tumor care when it was coupled with high-resolution brain imaging techniques such as computed tomography and magnetic resonance imaging. The technique has played a key role in the management of virtually all forms of brain tumor. We reviewed the radiobiological principles of SRS on tissue and how they pertain to different brain tumor disorders. We reviewed the clinical outcomes on the most common indications. This review found that outcomes are well documented for safety and efficacy and show increasing long-term outcomes for benign tumors. Brain metastases SRS is common, and its clinical utility remains in evolution. The role of SRS in brain tumor care is established. Together with surgical resection, conventional radiotherapy, and medical therapies, patients have an expanding list of options for their care. Clinicians should be familiar with radiosurgical principles and expected outcomes that may pertain to different brain tumor scenarios.

Decision analysis of stereotactic radiation surgery versus stereotactic radiation surgery and whole-brain radiation therapy for 1 to 3 brain metastases

PURPOSE

Although whole-brain radiation therapy (WBRT) is effective for controlling intracranial disease, it is also associated with neurocognitive side effects. It is unclear whether a theoretically improved quality of life after stereotactic radiation surgery (SRS) alone relative to that after SRS with adjuvant WBRT would justify the omission of WBRT, given the higher risk of intracranial failure. This study compares SRS alone with SRS and WBRT, to evaluate the theoretical benefits of intracranial tumor control with adjuvant WBRT against its possible side effects, using quality-adjusted life expectancy (QALE) as a primary endpoint.

METHODS AND MATERIALS

A Markov decision analysis model was used to compare QALE in a cohort of patients with 1 to 3 brain metastases and Karnofsky performance status of at least 70. Patients were treated with SRS alone or with SRS immediately followed by WBRT. Patients treated with SRS alone underwent surveillance magnetic resonance imaging and received salvage WBRT if they developed intracranial relapse. All patients whose cancer relapsed after WBRT underwent simulation as dying of intracranial progression. Model parameters were estimated from published literature.

RESULTS

Treatment with SRS yielded 6.2 quality-adjusted life months (QALMs). The addition of initial WBRT reduced QALE by 1.2 QALMs. On one-way sensitivity analysis, the model was sensitive only to a single parameter, the utility associated with the state of no evidence of disease after SRS alone. At values greater than 0.51, SRS alone was preferred.

CONCLUSIONS

In general, SRS alone is suggested to have improved quality of life in patients with 1 to 3 brain metastases compared to SRS and immediate WBRT. Our results suggest that immediate treatment with WBRT after SRS can be reserved for patients who would have a poor performance status regardless of treatment. These findings are stable under a wide range of assumptions.

It Is Time to Reevaluate the Management of Patients With Brain Metastases

There are many elements to the science that drives the clinical care of patients with brain metastases. Although part of an understanding that continues to evolve, a number of key historical misconceptions remain that commonly drive physicians' and researchers' attitudes and approaches. By understanding how these relate to current practice, we can better comprehend our available science to provide both better research and care. These past misconceptions include: Misconception 1: Once a primary cancer spreads to the brain, the histology of that primary tumor does not have much impact on response to chemotherapy, sensitivity to radiation, risk of further brain relapse, development of additional metastatic lesions, or survival. All tumor primary histologies are the same once they spread to the brain. They are the same in terms of the number of tumors, radiosensitivity, chemoresponsiveness, risk of further brain relapse, and survival. Misconception 2: The number of brain metastases matters. This number matters in terms of subsequent brain relapse, survival, and cognitive dysfunction; the precise number of metastases can also be used as a limit in determining which patients might be eligible for a particular treatment option. Misconception 3: Cancer in the brain is always a diffuse problem due to the presence of micrometastases. Misconception 4: Whole-brain radiation therapy invariably causes disabling cognitive dysfunction if a patient lives long enough. Misconception 5: Most brain metastases are symptomatic. Thus, it is not worth screening patients for brain metastases, especially because the impact on survival is minimal. The conduct and findings of past clinical research have led to conceptions that affect clinical care yet appear limiting.

Stereotactic radiosurgery and stereotactic body radiation therapy cost-effectiveness results

Objective: To describe and synthesize the current stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) cost-effectiveness research to date across several common SRS and SBRT applications.

Methods: This review was limited to comparative economic evaluations of SRS, SBRT, and alternative treatments (e.g., other radiotherapy techniques or surgery). Based on PubMed searches using the terms, “stereotactic,” “SRS,” “stereotactic radiotherapy,” “stereotactic body radiotherapy,” “SBRT,” “stereotactic ablative radiotherapy,” “economic evaluation,” “quality adjusted life year (QALY),” “cost,” “cost-effectiveness,” “cost-utility,” and “cost analysis,” published studies of cost-effectiveness and health economics were obtained. Included were articles in peer-reviewed journals that presented a comparison of costs between treatment alternatives from January 1997 to November 2012. Papers were excluded if they did not present cost calculations, therapeutic cost comparisons, or health economic endpoints.

Results: Clinical outcomes and costs of SRS and SBRT were compared to other therapies for treatment of cancer in the brain, spine, lung, prostate, and pancreas. Treatment outcomes for SRS and SBRT are usually superior or comparable, and cost-effective, relative to alternative techniques.

Conclusion: Based on the review of current SRS and SBRT clinical and health economic literature, from a patient perspective, SRS and SBRT provide patients a clinically effective treatment option, while from the payer and provider perspective, SRS and SBRT demonstrate cost savings.

Gamma Knife, CyberKnife, TomoTherapy: gadgets or useful tools?

PURPOSE OF REVIEW

This review provides information and an update on stereotactic radiosurgery (SRS) equipment, with a focus on intracranial lesions and brain neoplasms.

RECENT FINDINGS

Gamma Knife radiosurgery represents the gold standard for intracranial radiosurgery, using a dedicated equipment, and has recently evolved with a newly designed technology, Leksell Gamma Knife Perfexion. Linear accelerator-based radiosurgery is more recent, and originally based on existing systems, either adapted or dedicated to radiosurgery. Equipment incorporating specific technologies, such as the robotic CyberKnife system, has been developed. Novel concepts in radiation therapy delivery techniques, such as intensity-modulated radiotherapy, were also developed; their integration with computed tomography imaging and helical delivery has led to the TomoTherapy system. Recent data on the management of intracranial tumors with radiosurgery illustrate the trend toward a larger use and acceptance of this therapeutic modality.

SUMMARY

SRS has become an important alternative treatment for a variety of lesions. Each radiosurgery system has its advantages and limitations. The 'perfect' and ubiquitous system does not exist. The choice of a radiosurgery system may vary with the strategy and needs of specific radiosurgery programs. No center can afford to acquire every technology, and strategic choices have to be made. Institutions with large neurosurgery and radiation oncology programs usually have more than one system, allowing optimization of the management of patients with a choice of open neurosurgery, radiosurgery, and radiotherapy. Given its minimally invasive nature and increasing clinical acceptance, SRS will continue to progress and offer new advances as a therapeutic tool in neurosurgery and radiotherapy.

Current standards in the management of cerebral metastases

The last 30 years have seen major changes in attitude toward patients with cerebral metastases. This paper aims to outline the major landmarks in this transition and the therapeutic strategies currently used. The controversies surrounding control of brain disease are discussed, and two emerging management trends are reviewed: tumor bed radiosurgery and salvage radiation.

Economic impact of stereotactic radiosurgery for malignant intracranial brain tumors

Brain metastases occur frequently in cancer patients and can lead to neurological complications that result in decreased quantity and quality of life. Treatment alternatives include whole-brain radiation therapy, neurosurgery and the newest modality, stereotactic radiosurgery (SRS). This article reviews economic evaluations of SRS in the metastatic setting compared with other treatment options. Studies were included if they were published in peer-reviewed journals, primarily focused on patients with malignant brain metastasis and included a cost analysis between interventions. Uncertainty surrounding the cost-effectiveness of SRS is due to a lack of efficacy information between treatment alternatives, methodological limitations and design differences between the available studies. When cost-effectiveness ratios are available, SRS appears to be a reasonable option in resource-limited settings, with incremental cost-effectiveness ratios just below the US$50,000 range. However, better-designed economic analysis in the setting of randomized clinical trials or observational studies needs to be conducted to fully understand the economic value of SRS.

Timing and risk factors for new brain metastasis formation in patients initially treated only with Gamma Knife surgery

Object

Stereotactic radiosurgery has been shown to afford a reasonable chance of local tumor control. However, new brain metastasis can arise following successful local tumor control from radiosurgery. This study evaluates the timing, number, and risk factors for development of subsequent new brain metastasis in a group of patients treated with stereotactic radiosurgery alone.

Methods

One hundred seventeen patients with histologically confirmed metastatic cancer underwent Gamma Knife surgery (GKS) to treat all brain metastases demonstrable on MR imaging. Patients were followed clinically and radiologically at approximately 3-month intervals for a median of 14.4 months (range 0.37–51.8 months). Follow-up MR images were evaluated for evidence of new brain metastasis formation. Statistical analyses were performed to determine the timing, number, and risk factors for development of new brain metastases.

Results

The median time to development of a new brain metastasis was 8.8 months. Patients with 3 or more metastases at the time of initial radiosurgery or those with cancer histologies other than non–small cell lung carcinoma were found to be at increased risk for early formation of new brain metastasis (p < 0.05). The mean number of new metastases per patient was 1.6 (range 0–11). Those with a higher Karnofsky Performance Scale score at the time of initial GKS were significantly more likely to develop a greater number of brain metastases by the last follow-up evaluation.

Conclusions

The timing and number of new brain metastases developing in patients treated with GKS alone is not inconsequential. Those with 3 or more metastases at the time of radiosurgery and those with cancer histology other than non–small cell lung carcinoma were at greater risk of early formation of new brain metastasis. Frequent follow-up evaluations, such as at 3-month intervals, appears appropriate in this patient population, particularly in high-risk patients. When detected early, salvage treatments including repeat radiosurgery can be used to treat new brain metastasis.

Radiation treatment strategies for acromegaly

The high morbidity and mortality associated with acromegaly can be addressed with multiple treatment modalities, including surgery, medicines, and radiation therapy. Radiation was initially delivered through conventional fractionated radiotherapy, which targets a wide area over many treatment sessions and has been shown to induce remission in 50%&#x2013;60% of patients with acromegaly. However, conventional fractionated radiotherapy takes several years to achieve remission in patients with acromegaly and carries a risk of hypopituitarism that may limit its use. Stereotactic radiosurgery, of which there are several forms, including Gamma Knife surgery, CyberKnife therapy, and proton beam therapy, offers slightly attenuated efficacy but achieves remission in less time and provides more precise targeting of the adenoma with better control of the dose of radiation received by adjacent structures such as the pituitary stalk, pituitary gland, optic chiasm, and cranial nerves in the cavernous sinus. Of the forms of stereotactic radiosurgery, Gamma Knife surgery is the most widely used and, because of its long-term follow-up in clinical studies, is the most likely to compete with medical therapy for first-line adjuvant use after resection. In this review, the authors outline the major modes of radiation therapies in clinical use today, and they critically assess the feasibility of these modalities for acromegaly treatment. Acromegaly is a multisystem disorder that demands highly specialized treatment protocols including neurosurgical and endocrinological intervention. As more efficient forms of pituitary radiation develop, acromegaly treatment options may continue to change with radiation therapies playing a more prominent role.