Stereotactic Radiosurgery for Multiple Brain Metastases From Renal-Cell Carcinoma

Management of Brain Metastases in Metastatic Renal Cell Carcinoma

The development of brain metastases is a poor prognostic indicator in renal cell carcinoma. Regular imaging and clinical examinations are necessary to monitor the brain before or during systemic therapy. Central nervous system-targeted radiation therapy, including stereotactic radiosurgery, whole-brain radiation therapy, and surgical resection, is a standard treatment option. Clinical trials are currently investigating the role of targeted therapy and immune checkpoint inhibitor combinations in treating brain metastases and decreasing intracranial disease progression.

A Neurosurgical Perspective on Brain Metastases from Renal Cell Carcinoma: Multi-Institutional, Retrospective Analysis

BACKGROUND

While acknowledging the generally poor prognostic features of brain metastases from renal cell carcinoma (BM RCC), it is important to be aware of the fact that neurosurgery still plays a vital role in managing this disease, even though we have entered an era of targeted therapies. Notwithstanding their initial high effectiveness, these agents often fail, as tumors develop resistance or relapse.

METHODS

The authors of this study aimed to evaluate patients presenting with BM RCC and their outcomes after being treated in the Neurosurgical Department of Clinical Emergency Hospital "Bagdasar-Arseni", and the Neurosurgical Department of the National Institute of Neurology and Neurovascular Diseases, Bucharest, Romania. The study is based on a thorough appraisal of the patient's demographic and clinicopathological data and is focused on the strategic role of neurosurgery in BM RCC.

RESULTS

A total of 24 patients were identified with BM RCC, of whom 91.6% had clear-cell RCC (ccRCC) and 37.5% had a prior nephrectomy. Only 29.1% of patients harbored extracranial metastases, while 83.3% had a single BM RCC. A total of 29.1% of patients were given systemic therapy. Neurosurgical resection of the BM was performed in 23 out of 24 patients. Survival rates were prolonged in patients who underwent nephrectomy, in patients who received systemic therapy, and in patients with a single BM RCC. Furthermore, higher levels of hemoglobin were associated in our study with a higher number of BMs.

CONCLUSION

Neurosurgery is still a cornerstone in the treatment of symptomatic BM RCC. Among the numerous advantages of neurosurgical intervention, the most important is represented by the quick reversal of neurological manifestations, which in most cases can be life-saving.

Survival in Metastatic Renal Cell Carcinoma Treated With Immunotherapy and Stereotactic Radiation Therapy or Immunotherapy Alone: A National Cancer Database Analysis

Purpose

Immunotherapy (IO) has significantly improved outcomes in metastatic renal cell carcinoma (mRCC). Preclinical evidence suggests that responses to IO may be potentiated via immunomodulatory effects of stereotactic radiation therapy (SRT). We hypothesized that clinical outcomes from the National Cancer Database (NCDB) would demonstrate improved overall survival (OS) in patients with mRCC receiving IO + SRT versus IO alone.

Methods and Materials

Patients with mRCC receiving first-line IO ± SRT were identified from the NCDB. Conventional radiation therapy was allowed in the IO alone cohort. The primary endpoint was OS stratified by the receipt of SRT (IO + SRT vs IO alone). Secondary endpoints included OS stratified by the presence of brain metastases (BM) and timing of SRT (before or after IO). Survival was estimated using Kaplan-Meier methodology and compared via the log-rank test.

Results

Of 644 eligible patients, 63 (9.8%) received IO + SRT, and 581 (90.2%) received IO alone. Median follow-up time was 17.7 months (range, 2-24 months). Sites treated with SRT included the brain (71.4%), lung/chest (7.9%), bones (7.9%), spine (6.3%), and other (6.3%). OS was 74.4% versus 65.0% at 1 year and 71.0% versus 59.4% at 2 years for the IO + SRT and IO alone groups, respectively, although this difference did not reach statistical significance (log-rank P = .1077). In patients with BM, however, 1-year OS (73.0% vs 54.7%) and 2-year OS (70.8% vs 51.4%) was significantly higher in those receiving IO + SRT versus IO alone, respectively (pairwise P = .0261). Timing of SRT (before or after IO) did not influence OS (log-rank P = .3185).

Conclusions

Patients with BM secondary to mRCC had prolonged OS with the addition of SRT to IO. Factors such as International mRCC Database Consortium risk stratification, oligometastatic tumor burden, SRT dose/fractionation, and utilization of doublet therapy should be considered in future analyses to better identify patients who may benefit from combined IO + SRT. Further prospective studies are warranted.

An Italian multicenter retrospective real-life analysis of patients with brain metastases from renal cell carcinoma: the BMRCC study

BACKGROUND

The treatment of patients with brain-spread renal cell carcinoma (RCC) is an unmet clinical need, although more recent therapeutic strategies have significantly improved RCC patients' life expectancy. Our multicenter, retrospective, observational study investigated a real-world cohort of patients with brain metastases (BM) from RCC (BMRCC).

PATIENTS AND METHODS

A total of 226 patients with histological diagnosis of RCC and radiological evidence of BM from 22 Italian institutions were enrolled. Univariate and multivariate models were performed to investigate the impact of clinicopathological features and multimodal treatments on both overall survival (OS) from the BM diagnosis and intracranial progression-free survival (iPFS).

RESULTS

The median OS from the BM diagnosis was 18.8 months (interquartile range: 6.2-43 months). Multivariate analysis confirmed the following as positive independent prognostic factors: a Karnofsky Performance Status >70% [hazard ratio (HR) = 0.49, 95% confidence interval (CI) 0.26-0.92, P = 0.0026] and a single BM (HR = 0.51, 95% CI 0.31-0.86, P = 0. 0310); in contrast, the following were confirmed as worse prognosis factors: progressive extracranial disease (HR = 1.66, 95% CI 1.003-2.74, P = 0.00181) and only one line of systemic therapy after the BM occurrence (HR = 2.98, 95% CI 1.62-5.49, P = 0.029). Subgroup analyses showed no difference in iPFS according to the type of the first systemic treatment [immunotherapy (IT) or targeted therapy (TT)] carried out after the BM diagnosis (HR = 1.033, 95% CI 0.565-1.889, P = 0.16), and revealed that external radiation therapy (eRT) significantly prolonged iPFS when combined with IT (10.7 months, 95% CI 4.9-48 months, P = 0.0321) and not when combined with TT (9.01 months, 95% CI 2.7-21.2 months, P = 0.59).

CONCLUSIONS

Our results suggest a potential additive effect in terms of iPFS for eRT combined with IT and encourage a more intensive multimodal therapeutic strategy in a multidisciplinary context to improve the survival of BMRCC patients.

Evaluating the impact of early identification of asymptomatic brain metastases in metastatic renal cell carcinoma

BACKGROUND

Brain metastases (BM) in metastatic renal cell carcinoma (mRCC) have been reported to be present in up to 25% of patients diagnosed with mRCC. There is limited published literature evaluating the role of routine intra-cranial imaging for the screening of asymptomatic BM in mRCC.

AIMS

To evaluate the potential utility of routine intra-cranial imaging, a retrospective cohort study was conducted to characterize the outcomes of mRCC patients who presented with asymptomatic BM, as compared to symptomatic BM.

METHODS AND RESULTS

The Canadian Kidney Cancer Information System (CKCis) database was used to identify mRCC patients diagnosed with BM. This cohort was divided into two groups based on the presence or absence of BM symptoms. Details regarding patient demographics, disease characteristics, systemic treatments, BM characteristics and survival outcomes were extracted. Statistical analysis was through chi-square tests, analysis of variance, and Kaplan-Meier method to characterize survival outcomes. A p-value of <0.05 was considered statistically significant for all analyses. A total of 267 mRCC patients with BM were identified of which 106 (40%) presented with asymptomatic disease. The majority of patients presented with multiple (i.e., >1) BM (75%) with no significant differences noted in number of BM or BM-directed therapy received in symptomatic, as compared to asymptomatic BM patients. Median [95% confidence interval (CI)] overall survival (OS) from mRCC diagnosis was 42 months (95% CI: 32-62) for patients with asymptomatic BM, and 39 months (95% CI: 29-48) with symptomatic BM (p = 0.10). OS from time of BM diagnosis was 28 months (95% CI: 18-42) for the asymptomatic BM group, as compared to 13 months (95% CI: 10-21) in the symptomatic BM group (p = 0.04).

CONCLUSIONS

Given a substantial proportion of patients may present with asymptomatic BM, limiting intra-cranial imaging to patients with symptomatic BM, may be associated with a missed opportunity for timely diagnosis and treatment. The utility of routine intra-cranial imaging in patients with renal cell carcinoma, warrants further prospective evaluation.

The Emerging Role of Radiation Therapy in Renal Cell Carcinoma

Simple Summary

Stereotactic ablative radiation therapy (SAbR) is a safe and effective local therapy for renal cell cancer (RCC) with emerging and evolving indications. In this review we provide an overview of the evidence to support SAbR for RCC in a variety of clinical settings.

Abstract

Advancements in radiation delivery technology have made it feasible to treat tumors with ablative radiation doses via stereotactic ablative radiation therapy (SAbR) at locations that were previously not possible. Renal cell cancer (RCC) was initially thought to be radioresistant, even considered toxic, in the era of conventional protracted course radiation. However, SAbR has been demonstrated to be safe and effective in providing local control to both primary and metastatic RCC by using ablative radiation doses. SAbR can be integrated with other local and systemic therapies to provide optimal management of RCC patients. We will discuss the rationale and available evidence for the integration and sequencing of SAbR with local and systemic therapies for RCC.

An interdisciplinary consensus on the management of brain metastases in patients with renal cell carcinoma

Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients. CA Cancer J Clin. 2022;72:454-489.

The Role of Stereotactic Ablative Body Radiotherapy in Renal Cell Carcinoma

CONTEXT

Stereotactic ablative body radiotherapy (SABR) is an emerging treatment modality for primary and metastatic renal cell carcinoma (RCC).

OBJECTIVE

To review and summarise the evidence on the use of SABR in RCC in a narrative review.

EVIDENCE ACQUISITION

We performed an online search of the PubMed database from January 2000 through December 2021. Studies of SABR/stereotactic radiosurgery (SRS) targeting primary, extracranial, or intracranial metastatic RCC were included.

EVIDENCE SYNTHESIS

Two meta-analyses (including 54 studies), and 13 prospective and 20 retrospective studies were included in this review. In aggregate, SABR for 589 primary RCCs in 575 patients resulted in a local control rate of above 90% with grade 3-4 toxicity of 0-9%. Similarly, the local control rate ranged between 90% and 97% with SRS in 1225 patients with intracranial metastatic RCC. SABR was able to delay systemic therapy for at least 1 yr in 70-90% of oligometastatic RCC patients with grade 3-4 toxicity of <10%. As per the early data, the combination of SABR with systemic therapy for metastatic RCC, such as targeted therapy or immunotherapy, appears safe, feasible, and tolerable.

CONCLUSIONS

We outlined data supporting SABR in the key clinical scenarios of primary and metastatic, including oligometastatic, RCC in lieu of systemic therapy, in combination with systemic therapy, and palliation of brain and spinal metastases.

PATIENT SUMMARY

Stereotactic ablative body radiotherapy (SABR) is a relatively new treatment option in kidney cancer. Here, we review the published literature on the experience of using SABR in kidney cancer. The accumulated evidence demonstrates that SABR can be used safely and effectively to treat selected cases of primary or secondary kidney cancer.

Reshaping Treatment Paradigms for Advanced Renal Cell Cancer Patients and Improving Patient Management : Optimal Management for Renal Cell Cancer Patients

OPINION STATEMENT

The treatment of renal cell carcinoma (RCC) is one of the great success stories in the field of oncology, which was revolutionized with the development of therapies aimed at disrupting crucial pathways. Tumor biology of RCC has provided insight into the disease through elucidation of the role of vascular endothelial growth-factor (VEGF) and the mammalian target of rapamycin (mTOR). Targeted agents against VEGF and mTOR, as well as agents targeting relevant immunomodulatory pathways, have shown clinical benefit for advanced disease. The targeted agents are highly effective in achieving a response and survival, particularly in high-risk patients. These include the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) axitinib and cabozantinib, and programmed cell death 1 protein (PD-1) immune checkpoint inhibitors (ICI) nivolumab and pembrolizumab. There is a wealth of evidence investigating different therapeutic options and combinations for first-line treatment of advanced RCC including the CheckMate 214 study, KEYNOTE-426, JAVELIN Renal 101, and CheckMate 9ER. Dual ICI and combination agents targeting the programmed cell death protein 1/programmed cell death protein ligand 1 (PD1/PDL1) and VEGF, began to demonstrate superiority over previously accepted standards in advanced clear-cell RCC. Data from a number of clinical studies are available to help physicians with evidence-based decisions for the sequence of second-line and future treatments for patients with progressive RCC. In this review, we focus on essentials for clinicians treating patients with clear-cell RCC.

Cerebral metastases

Brain metastases are common and deadly. Over the last 25 years GKNS has been established as an invaluable treatment. It may be used as a primary treatment or after either surgery or WBRT. Patients are assessed using one of a number of available scales. GKNS may be repeated for new metastases and for unresponsive tumors. Prescription doses are usually between 18 and 20Gy. The use of advanced MR techniques to highlight sensitive structures like the hippocampi have extended the efficacy of the treatment. More recently GKNS has been used with different target therapies with improved results. More recently frameless treatments have become more popular in this group of very sick patients. GKNS controls tumors in between 80% and over 95% of cases and may even be used for brainstem tumors.

Risk-group Classification by Recursive Partitioning Analysis of Patients Affected by Oligometastatic Renal Cancer Treated with Stereotactic Radiotherapy

AIMS

Due to the absence of consensus on metastases-directed treatment in kidney cancer, we conducted an analysis of patients treated with stereotactic radiotherapy (SRT) on cranial or extracranial metastases to classify them in survival class risk according to pre-treatment characteristics.

MATERIALS AND METHODS

We included oligometastatic kidney cancer patients treated with SRT on up to five metastases. Concomitant systemic treatment was allowed. End points included overall survival and the binary classification tree approach with recursive partitioning analysis was applied to stratify patients into overall survival risk groups.

RESULTS

In total, 129 patients were treated on 242 metastases. The brain was the most common site (34.71%), followed by lung (25.62%). With a median follow-up of 19.4 months, 1- and 3-year overall survival were 82.62 and 55.11%. The recursive partitioning analysis identified four prognostic classes. Class 1 included patients aged ≤ 65 years treated on extracranial metastases, with 3-year overall survival of 82.66%. Class 2 included patients aged > 65 years, without history of metastatic bone disease, treated on extracranial metastases, with a 3-year overall survival of 67.91%. Patients aged > 65 years and a history of bone disease, treated on extracranial metastases, were classified as class 3, with a 3-year overall survival of 37.50%. Class 4 included patients treated on brain metastases, with a 3-year overall survival of 9.70%.

CONCLUSION

We produced a stratification model that can predict survival of oligometastatic kidney cancer patients treated with metastases-directed SRT. Site of disease, patient's age and presence of bone disease can help clinicians in the decision-making process.

Prolonged Survival Using First-Line Pazopanib in a Filipino Male with Renal Cell Carcinoma and Brain Metastasis: A Case Report

Renal cell carcinoma is one of the leading causes of cancer worldwide. Brain metastasis is a poor prognostic factor among patients with this disease. The advancements in understanding of the molecular framework behind malignancy and brain metastasis led to more sophisticated treatment regimens which include targeted drugs and immunotherapy. While the role of tyrosine kinase inhibitors in metastatic renal cell carcinoma has been proven in the literature, its specific role among patients with brain metastasis has not yet been fully elucidated. We report a case of a Filipino male with renal cell carcinoma and brain metastasis who underwent stereotactic radiosurgery of his right frontal lesion followed by pazopanib taken initially at 800 mg/day and then decreased to 600 mg/day. A significant increase in creatinine level led to the discontinuation of the medication after >3 years. He had a remarkable progression-free survival of 38 months. This is the first documented case of such significant response to pazopanib in a patient with renal cell carcinoma and brain metastasis. In the Philippine setting where options for cancer treatment are limited by the prohibitive cost of medications, this case can support the use of pazopanib as a potent agent for treating patients with this condition.

Stereotactic Ablative Radiation (SAbR) for Oligometastatic RCC

A significant proportion of metastatic renal cell carcinoma (mRCC) patients present with oligometastatic disease. Retrospective and limited prospective data suggests that a subgroup of patients with oligometastatic mRCC benefits from aggressive local therapy. With the emerging data of high local control efficacy with low toxicity of stereotactic ablative radiation (SAbR) for both CNS and extra-cranial mRCC, SAbR may play a critical role in the multi-modality management of mRCC patients with oligometastatic disease. In addition to local control benefit, the benefit of SAbR in this patient population can range from longitudinal disease control, maintaining quality of life, deferring systemic therapy, immune-modulation and even improving survival. A review of the retrospective data suggests that SAbR benefits oligometastatic mRCC patients with metachronous metastases, and perhaps those with indolent biology. Large prospective trials are indicated to successfully integrate SAbR of oligometastatic mRCC with the available systemic therapies to harness the optimal benefit of SAbR for this patient population.

Validation of the updated renal graded prognostic assessment (GPA) for patients with renal cancer brain metastases treated with gamma knife radiosurgery

INTRODUCTION

Prognosis of patients with brain metastasis (BM) from renal cell carcinoma (RCC) is relevant for treatment decisions and can be estimated with the Renal Graded Prognostic Assessment (GPA). The aim of this study is to validate the updated version of this instrument in a cohort treated with Gamma Knife radiosurgery (GKRS) without prior local intracerebral therapy.

METHODS

Between 2007 and 2018, 106 RCC patients with BM were treated with GKRS. They were categorized according to the updated Renal GPA. Overall survival (OS), distant intracranial failure and local failure were estimated using the Kaplan-Meier method and risk factors were identified with Cox proportional hazard regressions.

RESULTS

Median OS was 8.6 months. Median OS for GPA categories 0.0-1.0 (15%), 1.5-2.0 (12%), 2.5-3.0 (35%) and 3.5-4.0 (29%) was 2.9, 5.5, 8.1 and 20.4 months, respectively. Karnofsky performance status < 90, serum hemoglobin ≤ 12.5 g/dL, age > 65 years and time from primary diagnosis to brain metastasis < 1 year were significantly related with shorter survival, while presence of extracranial disease, the volume and total number of BM had no significant impact on OS. A total count of > 4 BM was the only predictive factor for distant intracranial failure, while none of the investigated factors predicted local failure.

CONCLUSIONS

This study confirms the updated Renal GPA in an independent cohort as a valuable instrument to estimate survival in patients with BM from RCC treated with GKRS.

Radiotherapy and Renal Cell Carcinoma: A Continuing Saga

Renal cell carcinoma (RCC) is one of the most aggressive malignancies of the genito-urinary tract, having a poor prognosis especially in patients with metastasis. Surgical resection remains the gold standard for localized renal cancer disease, with radiotherapy (RT) receiving much skepticism during the last decades. However, many studies have evaluated the role of RT, and although renal cancer is traditionally considered radio-resistant, technological advances in the RT field with regards to modern linear accelerators, as well as advanced RT techniques have resulted in breakthrough therapeutic outcomes. Additionally, the combination of RT with immune checkpoint inhibitors and targeted agents may maximize the clinical benefit. This review article focuses on the role of RT in the therapeutic management of renal cell carcinoma.

Consensus statements on the management of metastatic renal cell carcinoma from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology 2019

BACKGROUND

To establish a set of consensus statements for the management of metastatic renal cell carcinoma, a total of 12 urologists and clinical oncologists from two professional associations in Hong Kong formed an expert consensus panel.

METHODS

Through a series of meetings and using the modified Delphi method, the panelists presented recent evidence, discussed clinical experiences, and drafted consensus statements on several areas of focus regarding the management of metastatic renal cell carcinoma. Each statement was eventually voted upon by every panelist based on the practicability of recommendation.

RESULTS

A total of 46 consensus statements were ultimately accepted and established by panel voting.

CONCLUSIONS

Derived from recent evidence and expert insights, these consensus statements were aimed at providing practical guidance to optimize metastatic renal cell carcinoma management and promote a higher standard of clinical care.

Phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost for metastatic cancer

BACKGROUND

Advanced radiotherapeutic treatment techniques limit the cognitive morbidity associated with whole-brain radiotherapy (WBRT) for brain metastasis through avoidance of hippocampal structures. However, achieving durable intracranial control remains challenging.

METHODS

We conducted a single-institution single-arm phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost (HSIB-WBRT) to metastatic deposits in adult patients with brain metastasis. Radiation therapy consisted of intensity-modulated radiation therapy delivering 20 Gy in 10 fractions over 2-2.5 weeks to the whole brain with a simultaneous integrated boost of 40 Gy in 10 fractions to metastatic lesions. Hippocampal regions were limited to 16 Gy. Cognitive performance and cancer outcomes were evaluated.

RESULTS

A total of 50 patients, median age 60 years (interquartile range, 54-65), were enrolled. Median progression-free survival was 2.9 months (95% CI: 1.5-4.0) and overall survival was 9 months. As expected, poor survival and end-of-life considerations resulted in a high exclusion rate from cognitive testing. Nevertheless, mean decline in Hopkins Verbal Learning Test-Revised delayed recall (HVLT-R DR) at 3 months after HSIB-WBRT was only 10.6% (95% CI: -36.5‒15.3%). Cumulative incidence of local and intracranial failure with death as a competing risk was 8.8% (95% CI: 2.7‒19.6%) and 21.3% (95% CI: 10.7‒34.2%) at 1 year, respectively. Three grade 3 toxicities consisting of nausea, vomiting, and necrosis or headache were observed in 3 patients. Scores on the Multidimensional Fatigue Inventory 20 remained stable for evaluable patients at 3 months.

CONCLUSIONS

HVLT-R DR after HSIB-WBRT was significantly improved compared with historical outcomes in patients treated with traditional WBRT, while achieving intracranial control similar to patients treated with WBRT plus stereotactic radiosurgery (SRS). This technique can be considered in select patients with multiple brain metastases who cannot otherwise receive SRS.

A general algorithm for distributed treatments of multiple brain metastases

PURPOSE

Stereotactic radiosurgery (SRS) has become a primary treatment for multiple brain metastases (BM) but may require distribution of BMs over several sessions to make delivery time and radiation toxicity manageable. Contrasting to equal fraction dose in conventional fractionation, distributed SRS delivers full dose to a subset of BMs in each session while avoiding adjacent BMs in the same session to reduce toxicity from overlapping radiation. However, current clinical treatment planning for distributed SRS relies on manual BM assignment, which can be tedious and error prone. This work describes a novel approach to automate the distribution of BM in the Gamma Knife (GK) clinical workflow.

METHODS

We represent each BM as an electrostatic field of the same polarity that exerts repulsive forces on other BMs in the same session. This representation naturally leads to separation of close BMs into different sessions to lower the potential energy. Indeed, the BM distribution problem can be formulated as minimization of the total potential energy from all treatment sessions subject to delivery time constraints in mixed-integer quadratic programming (MIQP). We retrospectively studied eight clinical GK cases of multiple BM and compared the automated MIQP solution with clinically used BM distribution to demonstrate the efficacy of the proposed approach.

RESULTS

With the problem size equal to the number of BMs times the number of sessions, this MIQP can be solved in a minute on a personal workstation. The MIQP solution effectively separated BMs for a given number of treatment sessions and evened out the delivery time distribution among sessions. Compared to the clinically used manual BM distributions in paired t-test for a similar range of delivery time variation, the automated BM distributions had lower energy objectives (range of decrease: [11% 89%]; median: 25%; P = . 073 ), more uniformly distributed treatment volumes (range of decrease for the normalized standard deviation of volume distribution: [0.02 0.95]; median: 0.16; P = . 013 ), more scattered BMs in each treatment session (range of increase for the mean minimum BM distance: [0 14] mm; median: 6 mm; P = . 008 ), and lower overall V 12 (range of decrease: [0.0 1.6] cc; median: 0.2 cc; P = . 052 ). Moreover, without distribution, that is, with all BMs treated in the same session, V 12 was substantially larger compared to both manual and automated BM distributions; the increase ranged from 0.1 to 16.6 cc with a median of 1.3 cc.

CONCLUSIONS

The proposed approach models the clinical practice and provides an efficient solution for optimal selection of BM subsets for distributed SRS. Further evaluations are underway to establish this approach as a tool for improving clinical workflow and to facilitate systematic study on the benefits of distributed SRS treatments.

Metastatic renal cell carcinoma to the brain: optimizing patient selection for gamma knife radiosurgery

INTRODUCTION

The effects of single-fraction gamma knife radiosurgery (sf-GKRS) on patients with renal cell carcinoma (RCC) brain metastases (BM) in the era of targeted agents (TA) and immune checkpoint inhibitors (ICI) are insufficiently studied.

METHODS AND MATERIALS

Clear cell metastatic RCC patients treated with sf-GKRS due to BM in 2005-2014 at three European centres were retrospectively analysed (n = 43). Median follow-up was 56 months. Ninety-five percent had prior nephrectomy, 53% synchronous metastasis and 86% extracranial disease at first sf-GKRS. Karnofsky performance status (KPS) ranged from 60 to 100%. Outcome measures were overall survival (OS), local control (LC) and adverse radiation effects (ARE).

RESULTS

One hundred and ninety-four targets were irradiated. The median number of targets at first sf-GKRS was two. The median prescription dose was 22.0 Gy. Thirty-seven percent had repeated sf-GKRS. Eighty-eight percent received TA. LC rates at 12 and 18 months were 97% and 90%. Median OS from the first sf-GKRS was 15.7 months. Low serum albumin (HR for death 5.3), corticosteroid use pre-sf-GKRS (HR for death 5.8) and KPS < 80 (HR for death 9.1) were independently associated with worse OS. No further prognostic information was gleaned from MSKCC risk group, synchronous metastasis, age, number of BM or extracranial metastases. Other prognostic scores for BM radiosurgery, including DS-GPA, renal-GPA, LLV-SIR and CITV-SIR, again, did not add further prognostic value. ARE were seldom symptomatic and were associated with tumour volume, 10-Gy volume and pre-treatment perifocal oedema. ARE were less common among patients treated with TA within 1 month of sf-GKRS.

CONCLUSIONS

We identified albumin, corticosteroid use and KPS as independent prognostic factors for sf-GKRS of clear cell RCC BM. Studies focusing on the prognostic significance of albumin in sf-GKRS are rare. Further studies with a larger number of patients are warranted to confirm the above analytical outcome. Also, in keeping with previous studies, our data showed optimal rates of local tumour control and limited toxicity post radiosurgery, rendering GKRS the tool of choice in the management of RCC BM.

The promising role of radiotherapy in the treatment of advanced or metastatic renal cell carcinoma: a narrative review

Traditionally, renal cell carcinoma (RCC) has been regarded to be “radioresistant”. Conventional fractionated radiation (CFRT) has played a limited role in RCC as a palliative treatment to relieve pain and bleeding. Succeed to the rapid development of precise radiotherapy techniques, realizing safe delivery of high-dose radiotherapy, an increasing amount of convincing data suggests that the delivery of high-dose-per-fraction radiation through stereotactic radiosurgery (SRS) or stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy (SABR) can help to overcome resistance to radiotherapy. Herein, we summarized and analyzed the data from randomized controlled trials, retrospective and prospective studies, and meta-analyses relating to the treatment of advanced and metastatic RCC (mRCC) with CFRT, SBRT, or SBRT combined with systemic therapy. CFRT has a limited effect on local control (LC) of advanced RCC and mRCC, but it is a major palliative treatment which could obviously relieve pain caused by cancer. SBRT and SRS have the significant advantage of being able to precisely deliver a high dose of radiation to the target tissues. SBRT could cause a higher LC for advanced and metastatic RCC and could be used as an alternative to surgery for patients with oligometastatic RCC. The combination of SBRT with systemic therapy, such as targeted therapy or immunotherapy, is safe and tolerable. Concurrent immunotherapy and SBRT is a promising treatment strategy for patients with advanced or metastatic RCC. However, research on radiotherapy combined with systemic therapy is still limited and further studies to explore this treatment for RCC are urgently needed.

Current Approaches to the Treatment of Advanced or Metastatic Renal Cell Carcinoma

The optimal management approach to advanced or metastatic renal cell cancer of the clear cell type continues to rapidly evolve. Risk stratification of patients into favorable-, intermediate-, and poor-risk categories is now routinely performed. In selected individuals with low-volume indolent disease, active surveillance may be an appropriate option. Cytoreductive nephrectomy and/or surgical metastasectomy may be also be considered for selected patients after evaluation by a multidisciplinary tumor board. Systemic frontline therapy options now include immune checkpoint inhibitor-based combination (IBC) therapies such as pembrolizumab/axitinib, nivolumab/ipilimumab, and avelumab/axitinib. With unusual exceptions, monotherapy with vascular growth factor receptor tyrosine kinase inhibitors or mTOR inhibitors are no longer appropriate options in the frontline setting. Despite the established efficacy of frontline IBC, most patients will ultimately require additional lines of therapy, and oncologists must think carefully when switching to another therapy, particularly in situations of drug intolerance or apparent disease progression. Systemic therapy options after IBC are generally tyrosine kinase inhibitor-based, and ongoing clinical trials will help optimize the treatment algorithm further. Despite many recent drug approvals for renal cell cancer (RCC), there remains a pressing must identify new therapeutic targets. Finally, other systemic therapy or supportive care approaches must be considered for special patient populations such as those with poor performance status, end-organ dysfunction, brain metastases, or who have undergone metastasectomy.