To characterize the effect of concurrent stereotactic radiosurgery-stereotactic radiation therapy (SRS-SRT) and immune checkpoint inhibitors on patient outcomes and safety in patients with brain ...metastases (BMs).
We retrospectively identified metastatic non-small cell lung cancer, melanoma, and renal cell carcinoma patients who had BMs treated with SRS-SRT from 2010 to 2016 without prior whole-brain radiation therapy. We included SRS-SRT patients who were treated with anti-cytotoxic T-lymphocyte-associated protein 4 (ipilimumab) and anti-programmed cell death protein 1 receptor (nivolumab, pembrolizumab). Patients who were given immune checkpoint inhibitors on active or unreported clinical trials were excluded, and concurrent immune checkpoint inhibition (ICI) was defined as ICI given within 2 weeks of SRS-SRT. Patients were managed with SRS-SRT, SRS-SRT with nonconcurrent ICI, or SRS-SRT with concurrent ICI. Progression-free survival and overall survival (OS) were estimated using Kaplan-Meier survival curves, and Cox proportional hazards models were used for multivariate analysis. Logistic regression was used to identify predictors of acute neurologic toxicity, immune-related adverse events, and new BMs.
A total of 260 patients were treated with SRS-SRT to 623 BMs. Of these patients, 181 were treated with SRS-SRT alone, whereas 79 received SRS-SRT and ICI, 35% of whom were treated with concurrent SRS-SRT and ICI. Concurrent ICI was not associated with increased rates of immune-related adverse events or acute neurologic toxicity and predicted for a decreased likelihood of the development of ≥3 new BMs after SRS-SRT (P=.045; odds ratio, 0.337). Median OS for patients treated with SRS-SRT, SRS-SRT with nonconcurrent ICI, and SRS-SRT with concurrent ICI was 12.9 months, 14.5 months, and 24.7 months, respectively. SRS-SRT with concurrent ICI was associated with improved OS compared with SRS-SRT alone (P=.002; hazard ratio HR, 2.69) and compared with nonconcurrent SRS-SRT and ICI (P=.006; HR, 2.40) on multivariate analysis. The OS benefit of concurrent SRS-SRT and ICI was significant in comparison with patients treated with SRS-SRT before ICI (P=.002; HR, 3.82) or after ICI (P=.021; HR, 2.64).
Delivering SRS-SRT with concurrent ICI may be associated with a decreased incidence of new BMs and favorable survival outcomes without increased rates of adverse events.
Current guidelines for esophageal cancer contouring are derived from traditional 2-dimensional fields based on bony landmarks, and they do not provide sufficient anatomic detail to ensure consistent ...contouring for more conformal radiation therapy techniques such as intensity modulated radiation therapy (IMRT). Therefore, we convened an expert panel with the specific aim to derive contouring guidelines and generate an atlas for the clinical target volume (CTV) in esophageal or gastroesophageal junction (GEJ) cancer.
Eight expert academically based gastrointestinal radiation oncologists participated. Three sample cases were chosen: a GEJ cancer, a distal esophageal cancer, and a mid-upper esophageal cancer. Uniform computed tomographic (CT) simulation datasets and accompanying diagnostic positron emission tomographic/CT images were distributed to each expert, and the expert was instructed to generate gross tumor volume (GTV) and CTV contours for each case. All contours were aggregated and subjected to quantitative analysis to assess the degree of concordance between experts and to generate draft consensus contours. The panel then refined these contours to generate the contouring atlas.
The κ statistics indicated substantial agreement between panelists for each of the 3 test cases. A consensus CTV atlas was generated for the 3 test cases, each representing common anatomic presentations of esophageal cancer. The panel agreed on guidelines and principles to facilitate the generalizability of the atlas to individual cases.
This expert panel successfully reached agreement on contouring guidelines for esophageal and GEJ IMRT and generated a reference CTV atlas. This atlas will serve as a reference for IMRT contours for clinical practice and prospective trial design. Subsequent patterns of failure analyses of clinical datasets using these guidelines may require modification in the future.
Several studies evaluating stereotactic radiosurgery (SRS) for patients with >4 brain metastases (BM) demonstrated similar outcomes after treatment of 1, 2 to 4, and 5 to 15 BM; others found ...clinically significant survival decrements in the latter group. In this review of 8 academic centers, we compared outcomes of patients undergoing initial SRS for 1, 2 to 4, and 5 to 15 BM.
A total of 2089 patients treated with initial SRS for BM were included. Overall survival (OS) was estimated using the Kaplan-Meier method and compared using the log-rank test. Patient and disease characteristics were evaluated for association with OS and cumulative incidence of distant brain failure (DBF) using stepwise multivariable Cox proportional hazards and competing risk regression modeling.
In this series, 989 (47%) patients had 1 metastasis, 882 (42%) had 2 to 4 metastases, and 212 (10%) had 5 to 15 metastases treated. Median OS for the 1, 2 to 4, and 5 to 15 BM groups was 14.6, 9.5, and 7.5 months, respectively (log-rank P < .01). Univariate and multivariable analyses revealed no difference in survival between 2 to 4 and 5 to 15 BM. DBF at 1 year was 30%, 41%, and 50%, respectively (Gray's P < .01). Two-year cumulative incidence of salvage SRS decreased with increasing number of BM (1: 21% vs 2-4: 19% vs 5-15: 13%; P < .01), but no difference in salvage whole brain radiation therapy was observed (1: 12% vs 2-4: 15% vs 5-15: 16%, P = .10). At the time of DBF, median brain metastasis velocity was 3.9, 6.1, and 11.7 new metastases per year in the 1, 2 to 4, and 5 to 15 BM groups, respectively (P < .01).
Patients treated with initial SRS for 5 to 15 BM experienced survival similar to that in patients with 2 to 4 BM. Lower rates of salvage SRS were observed in the 5 to 15 BM group, with no difference in rates of salvage whole brain radiation therapy.
To prospectively evaluate cognitive function and intracranial failure patterns after hippocampal-sparing prophylactic cranial irradiation (PCI) for limited-stage small cell lung cancer (SCLC).
Adults ...with limited-stage SCLC, achieving a complete response to chemoradiotherapy and no brain metastases, were eligible. Patients received PCI 25 Gy/10 fractions, with a mean hippocampal dose limited to <8 Gy and ≥90% of the brain receiving 90% of the prescription. A diverse battery of neuropsychological testing was performed at baseline and 6 and 12 months after PCI. Brain MRI scans were performed at baseline and 6, 12, 18, and 24 months. The primary endpoint was memory measured by the Hopkins Verbal Learning Test-Revised Delayed Recall at 6 months after PCI. The 25-Gy arm of Radiation Therapy Oncology Group protocol 0212 was used as a reference of potential efficacy. Development of intracranial metastases was recorded. Overall survival and progression-free survival were estimated using the Kaplan-Meier method.
Eight men and 12 women with a median age of 61 years enrolled. Two-year overall survival was 88% (95% confidence interval 68%-100%). There was no significant decline in performance between baseline and 6 or 12 months for any of the tests. The association between baseline intelligence quotient and change in performance on testing was not significant. Magnetic resonance imaging revealed asymptomatic brain metastases at a cumulative rate of 20%, with no concurrent extracranial progression. Two patients developed a metastasis in the under-dosed region. Neither involved the dentate gyrus, but 1 involved the avoidance region. Both patients concurrently developed additional metastasis in fully treated brain regions. There were 2 neurologic deaths.
This prospective study suggests a potential benefit of hippocampal sparing in limiting the neuropsychological sequelae of brain radiation, but with a risk of failures in the spared region. These data strongly support continued enrollment on ongoing cooperative group randomized trials. Clinical Trials registration number: NCT01797159.
Polifeprosan 20 with carmustine (GLIADEL
) polymer implant wafer is a biodegradable compound containing 3.85% carmustine (BCNU, bischloroethylnitrosourea) implanted in the brain at the time of ...planned tumor surgery, which then slowly degrades to release the BCNU chemotherapy directly into the brain thereby bypassing the blood-brain barrier. Carmustine implant wafers were demonstrated to improve survival in randomized placebo-controlled trials in patients undergoing a near total resection of newly diagnosed or recurrent malignant glioma. Based on these trials and other supporting data, carmustine wafer therapy was approved for use for newly diagnosed and recurrent malignant glioma in the United States and the European Union. Adverse events are uncommon, and as this therapy is placed at the time of surgery, it does not add to patient treatment burden. Nevertheless, this therapy appears to be underutilized. This article reviews the evidence for a favorable therapeutic ratio for the patient and the potential barriers. Consideration of these issues is important for optimal use of this therapeutic approach and may be important as this technology and other local therapies are further developed in the future.
Despite extraordinary advances that have been achieved in the last few decades, cancer continues to represent a leading cause of mortality worldwide. Lethal cancer types ultimately become refractory ...to standard of care approaches; thus, novel effective treatment options are desperately needed. Tumor Treating Fields (TTFields) are an innovative non-invasive regional anti-mitotic treatment modality with minimal systemic toxicity. TTFields are low intensity (1-3 V/cm), intermediate frequency (100-300 kHz) alternating electric fields delivered to cancer cells. In patients, TTFields are applied using FDA-approved transducer arrays, orthogonally positioned on the area surrounding the tumor region, with side effects mostly limited to the skin. The precise molecular mechanism of the anti-tumor effects of TTFields is not well-understood, but preclinical research on TTFields suggests it may act during two phases of mitosis: at metaphase, by disrupting the formation of the mitotic spindle, and at cytokinesis, by dielectrophoretic dislocation of intracellular organelles leading to cell death. This review describes the mechanism of action of TTFields and provides an overview of the most important
studies that investigate the disruptive effects of TTFields in different cancer cells, focusing mainly on anti-mitotic roles. Lastly, we summarize completed and ongoing TTFields clinical trials on a variety of solid tumors.
To prospectively evaluate hippocampal radiation dose volume effects and memory decline following cranial irradiation.
Effects of hippocampal radiation over a wide range of doses were investigated by ...combining data from three prospective studies. In one, adults with small cell lung cancer received hippocampal-avoidance prophylactic cranial irradiation. In the other two, adults with glioblastoma multiforme received neural progenitor cell sparing radiation or no sparing with extra dose delivered to subventricular zone. Memory was measured by the Hopkins Verbal Learning Test-Revised Delayed Recall (HVLT-R DR) at 6 months after radiation. Dose–volume histograms were generated and dose–response data were fitted to a nonlinear model.
Of 60 patients enrolled, 30 were analyzable based on HVLT-R DR testing completion status, baseline HVLT-R DR and intracranial metastasis/recurrence or prior hippocampal resection status. We observed a dose–response of radiation to the hippocampus with regard to decline in HVLT-R DR. D50% of the bilateral hippocampi of 22.1 Gy is associated with 20% risk of decline.
This prospective study demonstrates an association between hippocampal dose volume effects and memory decline measured by HVLT-R DR over a wide dose range. These data support a potential benefit of hippocampal sparing and encourage continued trial enrollment.
In patients with spinal instability, cord compression, or neurologic deficits, the standard of care is surgery followed by radiation therapy (RT). Recurrence rates after conventional RT remain high. ...The purpose of this study is to prospectively examine the efficacy of postoperative stereotactic body RT (SBRT) in patients who have undergone surgical intervention for spine metastases. We hypothesize that postoperative SBRT to the spine would be associated with higher local control than historical rates after conventional RT.
Thirty-five adult patients with a Karnofsky Performance Status score ≥40 and spine metastases from solid tumors with no prior overlapping RT and target volumes ≤3 consecutive vertebral levels were enrolled. Thirty-three patients were treated. Two patients underwent treatment to 2 target volumes for a total of 35 target volumes. All patients received SBRT 30 Gy in 5 fractions. Patients were followed with neurological examinations and computed tomography and/or magnetic resonance imaging every 3 months. Neurologic function was assessed at the same time points using the American Spinal Injury Association (ASIA) impairment score. Pain was rated according to the 10-point visual analogue scale and MD Anderson Cancer Center brief pain index. Toxicity was recorded according to National Cancer Institute Common Toxicity Criteria for Adverse Events Version 4. The primary objective was the rate of radiographic local recurrence at 12 months after completion of SBRT.
Patient characteristics were as follows: 34.3% had radioresistant primaries; 71.4% were ASIA E and the remainder ASIA D; and the median baseline Karnofsky Performance Status score was 70 (range, 50-100). Radiographic and symptomatic local control at 1 year were 90% (95% confidence interval, 76%-98%). The median time to recurrence in these 3 patients was 3.5 months (range, 3.4-5.8 months), all had radiosensitive tumors, and all recurrences were epidural. No patients experienced wound dehiscence, hardware failure, or spinal cord myelopathy. The median time to return to systemic therapy was 0.5 months (range, 0-9.4 months).
This prospective study of postoperative spine SBRT demonstrates excellent local control with low toxicity. These data suggest superior rates of local control compared with conventional RT; however, a formal comparative study is warranted.
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