Treatment of high numbers of brain metastases with Gamma Knife radiosurgery: a review

Synergistic Effects of Radiotherapy With JNK Inhibitor-Incorporated Nanoparticle in an Intracranial Lewis Lung Carcinoma Mouse Models

BACKGROUND

Radiosurgery has been recognized as a reasonable treatment for metastatic brain tumors. Increasing the radiosensitivity and synergistic effects are possible ways to improve the therapeutic efficacy of specific regions of tumors. c-Jun-N-terminal kinase (JNK) signaling regulates H2AX phosphorylation to repair radiation-induced DNA breakage. We previously showed that blocking JNK signaling influenced radiosensitivity in vitro and in an in vivo mouse tumor model. Drugs can be incorporated into nanoparticles to produce a slow-release effect. This study assessed JNK radiosensitivity following the slow release of the JNK inhibitor SP600125 from a poly (DL-lactide-co-glycolide) (LGEsese) block copolymer in a brain tumor model.

MATERIALS AND METHODS

A LGEsese block copolymer was synthesized to fabricate SP600125-incorporated nanoparticles by nanoprecipitation and dialysis methods. The chemical structure of the LGEsese block copolymer was confirmed by 1H nuclear magnetic resonance (NMR) spectroscopy. The physicochemical and morphological properties were observed by transmission electron microscopy (TEM) imaging and measured with particle size analyzer. The blood-brain barrier (BBB) permeability to the JNK inhibitor was estimated by BBBflammaTM 440-dye-labeled SP600125. The effects of the JNK inhibitor were investigated using SP600125-incorporated nanoparticles and by optical bioluminescence, magnetic resonance imaging (MRI), and a survival assay in a mouse brain tumor model for Lewis lung cancer (LLC)-Fluc cells. DNA damage was estimated by histone γ H2AX expression and apoptosis was assessed by the immunohistochemical examination of cleaved caspase 3.

RESULTS

The SP600125-incorporated nanoparticles of the LGEsese block copolymer were spherical and released SP600125 continuously for 24h. The use of BBBflammaTM 440-dye-labeled SP600125 demonstrated the ability of SP600125 to cross the BBB. The blockade of JNK signaling with SP600125-incorporated nanoparticles significantly delayed mouse brain tumor growth and prolonged mouse survival after radiotherapy. γ H2AX, which mediates DNA repair protein, was reduced and the apoptotic protein cleaved-caspase 3 was increased by the combination of radiation and SP600125-incorporated nanoparticles.

Comparison of survival outcomes after CyberKnife® radiotherapy in Taiwan using preapproved insurance-based reimbursement versus out-of-pocket expenditure

BACKGROUND

With technological advances, radiotherapy has progressed from simple irradiation to robotic arm-based stereotactic radiosurgery systems (SRS, in this case, CyberKnife®). This equipment is high-priced and might be cost-effective or not. The National Health Insurance (NHI) in Taiwan has a premedical claims review process for approving CyberKnife® treatment; however, patients might have to pay for the procedure themselves if the NHI rejects the practice. Under the high treatment cost and such an insurance system, a sketch of patients treated by these high-cost machines and whether the prereview of insurance for reimbursement is reasonable without hindering the patient's right to undergo treatment should be investigated. In this study, the patients of CyberKnife® radiotherapy in our institute were investigated as an example for this purpose.

METHODS

Patients who underwent CyberKnife® radiotherapy in our department were investigated retrospectively. Their demographic characteristics, disease patterns, and treatment sites were analyzed. Survivals were compared according to clinical features, and treatment expenses were reimbursed after prereview or out-of-pocket.

RESULTS

From October 19, 2014, to January 30, 2018, there were 331 patients included in this study, 205 (55.3%) of whom underwent CyberKnife® radiotherapy at their own expense, while 166 (44.7%) had their expenses approved for reimbursement after prereview by NHI. Most patients were treated for metastatic tumors (37.5%), and the brain was the most frequent treatment site (46.1%). The 1-year overall survival was 67.1%, and the 2-year overall survival was 56.3% after CyberKinfe® radiotherapy. The best survival rate (96.8% at 1 year) was for patients with brain tumors. In patient's characteristics, A better Eastern Cooperative Oncology Group (ECOG) performance status, treatment for primary tumors, and outpatient treatment were independent factors for superior survival after CyberKnife® radiotherapy. The survivals for patients whose treatment expenses were approved for reimbursement after prereview by NHI were also better than out-of-pocket.

CONCLUSIONS

Besides the patients' characteristics, the treatment expense could be approved or rejected for reimbursement by the NHI prereview was an independent factor for survival in CyberKnife® radiotherapy. Prereview to reimburse expensive treatment is not an unreasonable requirement.

Improving efficiency in the radiation management of multiple brain metastases using a knowledge-based planning solution for single-isocentre volumetric modulated arc therapy (VMAT) technique

INTRODUCTION

This study aimed to develop a single-isocentre volumetric modulated arc therapy (si-VMAT) technique for multiple brain metastases using knowledge-based planning software, comparing it with a multiple-isocentre stereotactic radiosurgery (mi-SRS) planning approach.

METHODS

Twenty-six si-VMAT plans were created and uploaded into RapidPlanTM (RP) to create a si-VMAT model. Ten patients, with 2 to 6 metastases (mets), were planned with a si-VMAT technique utilising RP, and a mi-SRS technique on Brainlab iPlan. Paddick Conformity Index (PCI) was used to compare conformity. The volumes of the brain receiving 15Gy, 12Gy, 10Gy, 7.5Gy and 3Gy were also compared. Retrospective treatment times from the last eight patients treated were averaged for pre-imaging and beam on time to calculate treatment times for both techniques.

RESULTS

There was a significant difference in the PCI scores for the mi-SRS plans (M = 0.667, SD = 0.114) and si-VMAT plans (M = 0.728, SD = 0.088), with PCI values suggesting better prescription dose conformity with the si-VMAT technique (P = 0.014). Percentage of total brain volume receiving low-dose wash at four of the five different dose levels was significantly less (P < 0.05) with mi-SRS. Average time to treat a single met with current mi-SRS technique is 25.7 min, with each additional met requiring this same amount of time. The average time to treat 2-3 mets using si-VMAT would be 25.3 min and 4+ metastases 33.5 min.

CONCLUSION

A knowledge-based si-VMAT approach was efficient in planning and treating multi metastases while achieving clinically acceptable dosimetry with respect to dose conformity and low-dose fall off.

Executive summary from American Radium Society's appropriate use criteria on neurocognition after stereotactic radiosurgery for multiple brain metastases

BACKGROUND

The American Radium Society (ARS) Appropriate Use Criteria brain malignancies panel systematically reviewed (PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses]) published literature on neurocognitive outcomes after stereotactic radiosurgery (SRS) for patients with multiple brain metastases (BM) to generate consensus guidelines.

METHODS

The panel developed 4 key questions (KQs) to guide systematic review. From 11 614 original articles, 12 were selected. The panel developed model cases addressing KQs and potentially controversial scenarios not addressed in the systematic review (which might inform future ARS projects). Based upon quality of evidence, the panel confidentially voted on treatment options using a 9-point scale of appropriateness.

RESULTS

The panel agreed that SRS alone is usually appropriate for those with good performance status and 2-10 asymptomatic BM, and usually not appropriate for >20 BM. For 11-15 and 16-20 BM there was (between 2 case variants) agreement that SRS alone may be appropriate or disagreement on the appropriateness of SRS alone. There was no scenario (among 6 case variants) in which conventional whole-brain radiotherapy (WBRT) was considered usually appropriate by most panelists. There were several areas of disagreement, including: hippocampal sparing WBRT for 2-4 asymptomatic BM; WBRT for resected BM amenable to SRS; fractionated versus single-fraction SRS for resected BM, larger targets, and/or brainstem metastases; optimal treatment (WBRT, hippocampal sparing WBRT, SRS alone to all or select lesions) for patients with progressive extracranial disease, poor performance status, and no systemic options.

CONCLUSIONS

For patients with 2-10 BM, SRS alone is an appropriate treatment option for well-selected patients with good performance status. Future study is needed for those scenarios in which there was disagreement among panelists.

Pathologically confirmed brain metastases from primary uterine cervical tumors: two cases and a literature review

Background

Pathologically confirmed brain metastasis from primary cervical cancer is extremely rare. Herein, we report two cases of intracranial metastasis from cervical cancer that were histopathologically confirmed after surgical excision. In addition, we conducted a literature review to characterize the clinical manifestation, pathogenesis, and treatment of these patients.

Case summary

Among the 1800 patients with primary cervical cancer who received therapy at our center from 2010 to 2018, two patients (0.1%) had definite histopathological evidence of brain metastasis. A 46-year-old female who had a history of poorly differentiated stage IIB cervical cancer with neuroendocrine differentiation presented with a solitary mass in the right occipital lobe 26 months after the initial diagnosis. She underwent surgery and chemotherapy but died of disease progression 9 months later. Another 55-year-old female diagnosed with poorly differentiated stage IVB cervical squamous cancer presented with a solitary mass in the right frontal lobe 16 months after simple hysterectomy. Twelve months later, multiple lesions were observed in the bilateral frontal-parietal lobe. The lesions were treated by surgery and stereotactic radiosurgery. The patient died of multiple organ failure 14 months later.

Conclusion

The pathogenesis and best management of brain metastasis from cervical cancer are not clear. Highly invasive subtypes or advanced cancer stages may be the key clinicopathological factors of brain metastasis. Surgical treatment is warranted in patients with a good health status and without metastasis to other sites.

Tumor control and survival in patients with ten or more brain metastases treated with stereotactic radiosurgery: a retrospective analysis

INTRODUCTION

To assess tumor control and survival in patients treated with stereotactic radiosurgery (SRS) for 10 or more metastatic brain tumors.

METHODS

Patients were retrospectively identified. Clinical records were reviewed for follow-up data, and post-treatment MRI studies were used to assess tumor control. For tumor control studies, patients were separated based on synchronous or metachronous treatment, and control was assessed at 3-month intervals. The Kaplan-Meier method was employed to create survival curves, and regression analyses were employed to study the effects of several variables.

RESULTS

Fifty-five patients were treated for an average of 17 total metastases. Forty patients received synchronous treatment, while 15 received metachronous treatment. Univariate analysis revealed an association between larger brain volumes irradiated with 12 Gy and decreased overall survival (p = 0.0406); however, significance was lost on multivariate analysis. Among patients who received synchronous treatment, the median percentage of tumors controlled was 100%, 91%, and 82% at 3, 6, and 9 months, respectively. Among patients who received metachronous treatment, the median percentage of tumors controlled after each SRS encounter was 100% at all three time points.

CONCLUSIONS

SRS can be used to treat patients with 10 or more total brain metastases with an expectation of tumor control and overall survival that is equivalent to that reported for patients with four or fewer tumors. Development of new metastases leading to repeat SRS is not associated with worsened tumor control or survival. Survival may be adversely affected in patients having a higher volume of normal brain irradiated.

Survival Patterns of 5750 Stereotactic Radiosurgery-Treated Patients with Brain Metastasis as a Function of the Number of Lesions

BACKGROUND

The number of brain metastases (BMs) plays an important role in the decision between stereotactic radiosurgery (SRS) and whole-brain radiation therapy.

METHODS

We analyzed the survival of 5750 SRS-treated patients with BM as a function of BM number. Survival analyses were performed with Kaplan-Meier analysis as well as univariate and multivariate Cox proportional hazards models.

RESULTS

Patients with BMs were first categorized as those with 1, 2-4, and 5-10 BMs based on the scheme proposed by Yamamoto et al. (Lancet Oncology 2014). Median overall survival for patients with 1 BM was superior to those with 2-4 BMs (7.1 months vs. 6.4 months, P = 0.009), and survival of patients with 2-4 BMs did not differ from those with 5-10 BMs (6.4 months vs. 6.3 months, P = 0.170). The median survival of patients with >10 BMs was lower than those with 2-10 BMs (6.3 months vs. 5.5 months, P = 0.025). In a multivariate model that accounted for age, Karnofsky Performance Score, systemic disease status, tumor histology, and cumulative intracranial tumor volume, we observed a ∼10% increase in hazard of death when comparing patients with 1 versus 2-10 BMs (P < 0.001) or 10 versus >10 BMs (P < 0.001). When BM number was modeled as a continuous variable rather than using the classification by Yamamoto et al., we observed a step-wise 4% increase in the hazard of death for every increment of 6-7 BM (P < 0.001).

CONCLUSIONS

The contribution of BM number to overall survival is modest and should be considered as one of the many variables considered in the decision between SRS and whole-brain radiation therapy.