Survival in Patients With Spinal Metastatic Disease Treated Nonoperatively With Radiotherapy: Are the SORG-ML Algorithms Relevant?

SUMMARY OF BACKGROUND DATA

The SORG-ML algorithms for survival in spinal metastatic disease were developed in patients who underwent surgery and were externally validated for patients managed operatively.

OBJECTIVE

To externally validate the SORG-ML algorithms for survival in spinal metastatic disease in patients managed nonoperatively with radiation.

STUDY DESIGN

Retrospective cohort.

METHODS

The performance of the SORG-ML algorithms was assessed by discrimination [receiver operating curves and area under the receiver operating curve (AUC)], calibration (calibration plots), decision curve analysis, and overall performance (Brier score). The primary outcomes were 90-day and 1-year mortality.

RESULTS

Overall, 2074 adult patients underwent radiation for spinal metastatic disease and 29% (n=521) and 59% (n=917) had 90-day and 1-year mortality, respectively. On complete case analysis (n=415), the AUC was 0.76 (95% CI: 0.71-0.80) and 0.78 (95% CI: 0.73-0.83) for 90-day and 1-year mortality with fair calibration and positive net benefit confirmed by the decision curve analysis. With multiple imputation (n=2074), the AUC was 0.85 (95% CI: 0.83-0.87) and 0.87 (95% CI: 0.85-0.89) for 90-day and 1-year mortality with fair calibration and positive net benefit confirmed by the decision curve analysis.

CONCLUSION

The SORG-ML algorithms for survival in spinal metastatic disease generalize well to patients managed nonoperatively with radiation.

Hippocampal Avoidance Whole Brain Radiotherapy with Reduced Whole Brain Dose in Patients with Non-Small Cell Lung Cancer Brain Metastases

PURPOSE/OBJECTIVE(S)

Hippocampal avoidance whole brain radiation (HA-WBRT) results in improved neurocognitive function (NCF) compared to standard WBRT, but > 50% of patients still experience NCF failure. We examined whether gentler fractionation of HA-WBRT with lower biologically effective dose (BED), typically delivering 30 Gy over 15 versus 10 fractions, may allow for better hippocampal sparing without impacting intracranial disease control in patients with non-small cell lung cancer (NSCLC).

MATERIALS/METHODS

We conducted a retrospective study of patients with NSCLC receiving HA-WBRT between 2014-2022. Endpoints were distant brain failure free survival (DBFFS), local brain failure free survival (LBFFS), left and right hippocampal mean BED2 and BED21%. Kaplan-Meier survival analysis and Welch's t-test were performed. NCF outcomes were graded with CTCAEv5. The IRB approved this study.

RESULTS

Sixty-nine consecutive patients treated with HA-WBRT were included, with median follow up of 51.2 weeks. Median age was 63 years and 29% had a targetable mutation. Thirty-six patients received standard HA-WBRT with median dose of 30 Gy (range 30-35 Gy) in 10 fractions (range 10-14). Thirty-three patients received reduced BED HA-WBRT, with median dose of 30 Gy (range 23-30) in 15 fractions (range 9-15) to the radiographically uninvolved brain. All patients in the reduced BED (RD) group had a simultaneous integrated boost (SIB) to gross disease (median 37.5 Gy (range 36-37.5 Gy)), while 18/36 in the standard dose (SD) group had an SIB (median 35 Gy (range 34-39 Gy)). There were no significant differences between SD and RD cohorts in age, systemic therapy use before WBRT or targetable mutations. There was no significant difference in median DBFFS of the SD [23.1 weeks (IQR 11.3-49.3)] and RD groups [40 weeks, (IQR 20.9-109.1)] (p = 0.27). There was also no difference in LBFFS of the SD (median 26.4 weeks, IQR 11.3-76.2) and RD groups (median 40 weeks, IQR (21-71.4) (p = 0.84). For the left and right hippocampi, both mean BED2 and D1% were significantly lower in the RD group (Table 1). Median cognitive disturbance was Grade (G) 0 (range 0-3) in both groups, with 4 G>2 events in the SD cohort vs. 3 in the RD cohort.

CONCLUSION

In this single-institution cohort, HA-WBRT using a gentler fractionation with SIB was associated with improved hippocampal sparing without compromising intracranial control in patients with NSCLC. We suggest that further optimization of HA-WBRT dose and schedule may improve both intracranial control and NCF outcomes. This study is limited by its retrospective nature and potential selection bias. A phase II prospective study to test these concepts is ongoing.

Adjuvant Radiotherapy in Atypical Meningioma: Are the Risks Worth the Benefit?

PURPOSE/OBJECTIVE(S)

Adjuvant radiotherapy (RT) improves progression-free survival (PFS) in atypical meningiomas. Herein, we assess whether the treatment-related acute and long-term toxicity of upfront RT in atypical meningioma patients versus surveillance merits the PFS benefit.

MATERIALS/METHODS

In our prior single institution retrospective study of 230 patients with resected intracranial atypical meningiomas between 2000-2015, adjuvant RT was associated with a significantly lower risk of progression/recurrence compared to surveillance (HR = 0.21 [95% CI 0.11-0.41]; p<0.01), with 36% of surveillance patients eventually requiring salvage RT. In the current study, the acute (≤6 months) and long term (>6 months) RT-related toxicities from the same patient cohort for those who received adjuvant RT (n = 51) were evaluated and compared to those who received salvage RT (n = 64) in the surveillance group. Additionally, overall treatment-related toxicity at time of last follow up was obtained for comparison between the adjuvant RT (n = 51) vs surveillance (n = 179) group. All toxicities were graded per CTCAE v5.0. Kaplan-Meier analysis was used to calculate the cumulative incidence of toxicities; Pearson's chi-squared and log-rank test were used for comparison.

RESULTS

Adjuvant RT as compared to salvage RT was generally associated with greater RT-related toxicities both in the acute (90% vs 69%, p = 0.006) and long term (57% vs 33%, p = 0.010). While there was no significant difference in grade 3-4 acute toxicities, long term grade 3-4 toxicities (including headache, seizure, vision loss, neuromotor deficit, and neurocognitive deficit) were present in 14% of adjuvant vs 3% of salvage RT group (p = 0.035). Radionecrosis occurred in 18% of adjuvant RT vs 8% of salvage RT group (p = 0.11). Between adjuvant RT vs surveillance groups, any-treatment related toxicity at last follow up was greater with adjuvant RT (31% vs 15%; p = 0.006), with trend towards greater grade 3-4 toxicities (including headache, vision loss, neuromotor deficit, neurocognitive deficit, and cerebral edema) as well (8% vs 3%; p = 0.101). Cumulative incidence of treatment-related neuromotor deficit (any grade) was significantly greater in the adjuvant RT vs surveillance group with 14% vs 2% at 10 years (p = 0.004). There was no difference in rate of cerebrovascular accident between adjuvant RT (6%) vs surveillance (4%) groups (p = 0.83).

CONCLUSION

Adjuvant RT for patients with atypical meningioma was associated with greater acute and long-term treatment toxicities. Potential RT-related toxicity and impact on quality-of-life should thus be carefully weighed against the tumor control benefit of RT in deciding the optimal use and timing of RT.

NRG Oncology/RTOG1205: A Randomized Phase II Trial of Concurrent Bevacizumab and Reirradiation Versus Bevacizumab Alone as Treatment for Recurrent Glioblastoma

PURPOSE

To assess whether reirradiation (re-RT) and concurrent bevacizumab (BEV) improve overall survival (OS) and/or progression-free survival (PFS), compared with BEV alone in recurrent glioblastoma (GBM). The primary objective was OS, and secondary objectives included PFS, response rate, and treatment adverse events (AEs) including delayed CNS toxicities.

METHODS

NRG Oncology/RTOG1205 is a prospective, phase II, randomized trial of re-RT and BEV versus BEV alone. Stratification factors included age, resection, and Karnofsky performance status (KPS). Patients with recurrent GBM with imaging evidence of tumor progression ≥ 6 months from completion of prior chemo-RT were eligible. Patients were randomly assigned 1:1 to re-RT, 35 Gy in 10 fractions, with concurrent BEV IV 10 mg/kg once in every 2 weeks or BEV alone until progression.

RESULTS

From December 2012 to April 2016, 182 patients were randomly assigned, of whom 170 were eligible. Patient characteristics were well balanced between arms. The median follow-up for censored patients was 12.8 months. There was no improvement in OS for BEV + RT, hazard ratio, 0.98; 80% CI, 0.79 to 1.23; P = .46; the median survival time was 10.1 versus 9.7 months for BEV + RT versus BEV alone. The median PFS for BEV + RT was 7.1 versus 3.8 months for BEV, hazard ratio, 0.73; 95% CI, 0.53 to 1.0; P = .05. The 6-month PFS rate improved from 29.1% (95% CI, 19.1 to 39.1) for BEV to 54.3% (95% CI, 43.5 to 65.1) for BEV + RT, P = .001. Treatment was well tolerated. There were a 5% rate of acute grade 3+ treatment-related AEs and no delayed high-grade AEs. Most patients died of recurrent GBM.

CONCLUSION

To our knowledge, NRG Oncology/RTOG1205 is the first prospective, randomized multi-institutional study to evaluate the safety and efficacy of re-RT in recurrent GBM using modern RT techniques. Overall, re-RT was shown to be safe and well tolerated. BEV + RT demonstrated a clinically meaningful improvement in PFS, specifically the 6-month PFS rate but no difference in OS.

Long-term outcomes and late toxicity of adult medulloblastoma treated with combined modality therapy: A contemporary single-institution experience

BACKGROUND

Medulloblastoma (MB) is a rare central nervous system malignancy of adults, with limited contemporary studies to define treatment guidelines and expected late toxicity.

METHODS

A single-center, retrospective study was conducted of patients age ≥18 years from 1997-2019 with MB and who were treated with postoperative radiotherapy. Late toxicity was defined as a minimum of 18 months from diagnosis. Overall survival (OS) and progression-free survival (PFS) were characterized using Kaplan-Meier and Cox regression analyses.

RESULTS

Fifty-nine patients met criteria, with median age of 25 years (range 18-62 y) and median follow-up of 6.5 years (range 0.7-23.1 y). At diagnosis, 68% were standard-risk, 88% Chang M0, and 22% with anaplastic histology. Gross total resection was achieved in 75%; median craniospinal irradiation dose was 30.6 Gy (relative biological effectiveness [RBE]), median total dose was 54.0 Gy (RBE), 80% received proton radiotherapy; 81% received chemotherapy. 5 year PFS and OS were 86.5% and 95.8%, respectively; 10 year PFS and OS were 83.9% and 90.7%, respectively. Anaplastic histology was associated with worse PFS (P = .04). Among eight recurrences, 25% presented after 5 years. Most common grade ≥2 late toxicities were anxiety/depressive symptoms (30%), motor dysfunction (25%), and ototoxicity (22%). Higher posterior fossa radiation dose was associated with increased risk of late toxicity, including worse cognitive dysfunction (P = .05).

CONCLUSIONS

Adults with MB have favorable survival outcomes, but late failures and toxicity are not uncommon. Better understanding of prognostic factors, possibly from molecular subtyping, may help to define more personalized treatments for patients with high risk of recurrence and long-term treatment sequelae.

Advanced imaging to assess longitudinal vascular changes in brain metastases treated with checkpoint inhibition

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Background: Immune checkpoint inhibitors (ICI) have recently been shown to be effective for brain metastases (BM) in melanoma and lung cancer. Several studies demonstrate that 20-50% of BM patients respond to ICI. The reasons behind this wide variability in treatment response is not clear. Therefore, using physiologic imaging, we seek to identify the longitudinal biological changes exerted on BM as a result of ICI administration. Methods: Given the importance of aberrant tumor vasculature in cancer proliferation, we have focused on assessing changes in vascular physiology. We analyzed standard post-contrast and dynamic susceptibility contrast (DSC) MRI to identify characteristic vascular signatures as part of an ongoing Phase 2 study of pembrolizumab for patients with untreated or progressive, previously treated BM from any histology. Tumor volume measurements were calculated by summating all enhancing voxels. As per modified RECIST and RANO criteria for immunotherapy, volumetric increase of > 40% was defined as progressive disease (PD), a decrease of > 60% as partial response (PR), and stable disease (SD) as between -60% and +40%. Results: 35 patients, out of the total cohort of 60, have undergone DSC-MRI analysis. Histologies include 15 with breast cancer, 6 with non-small cell lung cancer, 4 with melanoma, and 10 with other cancers. At baseline, the total number of BM was 1-50+ per patient. Based on summing the entire enhancing intracranial disease burden, best volumetric responses for the 35 evaluable patients include 4 PR, 12 SD, and 19 PD. Thus far, we found that ICI-resistant BM had a 50% increase in cerebral blood flow (CBF), 105% increase in cerebral blood volume (CBV), a 15% increase in mean transit time (MTT), and an 80% increase in vessel caliber at 6 weeks post-treatment. On the other hand, ICI-responsive BM had no change in CBF, a 33% increase in CBV, a 10% decrease in MTT, and no change in vessel caliber. Ongoing analysis to uncover additional vascular changes (e.g. tumor oxygenation, vessel size index) within BM to ICI are pending. Conclusions: Our data provides evidence that effective ICI for BM is associated with unique intra-tumoral vascular physiology. With final analysis, we will uncover other facets of vascular physiology that correlate with ICI response, and may reveal mechanisms of response/resistance within tumors to ICI.

Genetic profile of naïve untreated primary cutaneous melanomas with a negative sentinel lymph node

Sentinel lymph node (SLN) biopsy is typically offered to patients with primary cutaneous melanomas (PCMs) of ≥ 1 mm depth, but not all SLNs are positive using this cutoff. To ascertain whether positivity is genetically regulated, genetic analysis was performed using an augmented enrichment-based next-generation DNA and RNA sequencing assay in SLN-negative (Group 1, n = 8, mean depth 1.3 mm) and SLN-positive PCMs (controls, Group 2, n = 4, mean depth 1.4 mm). In Group 1, the mean number of mutations was 21 (range 3-48) with the most frequent mutations occurring in NF1 (75%) followed by TP53 (63%), CDKN2A and BRAF (38%), and NRAS (25%), while in Group 2, the ean number of mutations was 9.5 (range 5-18) with mutations in NRAS and BRAF being the most frequent (50%) followed by those in ATM, CDKN2A, CDKN2B, and NOTCH1 (25%). Increased frequency of NF1-inactivating mutations in Group 1 provides provocative early data that the presence of NF1 mutations might confer a less aggressive phenotype.

Advanced imaging to assess longitudinal vascular changes in brain metastases treated with immune checkpoint inhibition

2529

Background: Immune checkpoint inhibitors (ICI) have recently been shown to be effective for brain metastases (BM) for melanoma and lung cancer. This breakthrough has prompted interest in evaluating ICI in BM of other histologies. However, accurately assessing intracranial response in patients undergoing ICI is a challenge, as current measures cannot distinguish pseudoprogression from true tumor progression. To shed light on potential biomarkers of response, we prospectively use perfusion MRI to identify characteristic vascular signatures in a BM-specific trial of ICI. Methods: As part of an ongoing phase II study of pembrolizumab for patients with untreated or progressive, previously treated BM from any histology, patients underwent advanced MRI that includes tumor volume measurements and perfusion imaging with dynamic susceptibility contrast MRI. To calculate volumetric radiographic response, all enhancing voxels were summated. A volumetric increase of >40% was categorized as progressive disease (PD), a decrease of >60% as partial response (PR), and stable disease (SD) as between -60% and +40%. Results: 53 patients have been enrolled, of whom 44 have received at least baseline advanced MR imaging. Histologies include 21 with breast cancer, 5 with non-small cell lung cancer, 4 with melanoma, and 13 with other cancers. At baseline, the total number of BM was 1-50+ per patient. Based on summing the entire enhancing intracranial disease burden, best volumetric responses for the 33 evaluable patients include 4 PR, 10 SD, and 19 PD. On preliminary analysis, there was a correlation between increased tumor cerebral blood volume/flow with tumor progression. Correlation of additional vascular physiologic parameters (e.g. vessel caliber, tissue oxygenation) and volumetric response to patient outcome and standardized response criteria (iRANO) are ongoing. Conclusions: Pembrolizumab likely has anti-tumor efficacy in BM. Our data provides potential evidence that effective ICI is associated with a decrease in perfusion. Ongoing analyses to uncover additional vascular changes – specifically longitudinal metrics reflecting vascular structure and function - within BM to ICI are pending. These findings have potential to illustrate mechanisms of efficacy for ICI and biomarkers of response in this patient population.

Development of Machine Learning Algorithms for Prediction of 30-Day Mortality After Surgery for Spinal Metastasis

BACKGROUND

Preoperative prognostication of short-term postoperative mortality in patients with spinal metastatic disease can improve shared decision making around end-of-life care.

OBJECTIVE

To (1) develop machine learning algorithms for prediction of short-term mortality and (2) deploy these models in an open access web application.

METHODS

The American College of Surgeons, National Surgical Quality Improvement Program was used to identify patients that underwent operative intervention for metastatic disease. Four machine learning algorithms were developed, and the algorithm with the best performance across discrimination, calibration, and overall performance was integrated into an open access web application.

RESULTS

The 30-d mortality for the 1790 patients undergoing surgery for spinal metastatic disease was 8.49%. Preoperative factors used for prognostication were albumin, functional status, white blood cell count, hematocrit, alkaline phosphatase, spinal location (cervical, thoracic, lumbosacral), and severity of comorbid systemic disease (American Society of Anesthesiologist Class). In this population, machine learning algorithms developed to predict 30-d mortality performed well on discrimination (c-statistic), calibration (assessed by calibration slope and intercept), Brier score, and decision analysis. An open access web application was developed for the best performing model and this web application can be found here: https://sorg-apps.shinyapps.io/spinemets/.

CONCLUSION

Machine learning algorithms are promising for prediction of postoperative outcomes in spinal oncology and these algorithms can be integrated into clinically useful decision tools. As the volume of data in oncology continues to grow, creation of learning systems and deployment of these systems as accessible tools may significantly enhance prognostication and management.

ACTR-32. NRG ONCOLOGY RTOG 1205: RANDOMIZED PHASE II TRIAL OF CONCURRENT BEVACIZUMAB AND RE-IRRADIATION VS. BEVACIZUMAB ALONE AS TREATMENT FOR RECURRENT GLIOBLASTOMA

This study sought to determine whether re-irradiation (ReRT) and concurrent bevacizumab (BEV) improves overall survival (OS) compared to BEV alone in recurrent glioblastoma (GBM). Patients (pts) were randomized 1:1 to ReRT (35 Gy/10 fractions) plus BEV (IV 10 mg/kg q2 wks) vs. BEV alone. With 160 pts, there was 80% power to detect a 31% reduction in death hazard for BEV+RT at a one-sided significance level of 0.10 using a log rank test. OS and PFS were estimated by Kaplan-Meier and HRs estimated by exact binomial distribution. Objective response was assessed using MacDonald and RANO criteria. From 11/2012 to 4/2016, 182 pts were randomized, with 170 eligible, analyzable pts. 11 pts did not receive protocol treatment. Patient characteristics (age, KPS, re-resection rates) were balanced between arms. Median f/u for censored pts was 12.8 months (mos; min-max, 0.03–52.8). BEV+ReRT did not improve OS vs BEV alone, with median OS of 10.1 vs 9.7 mos, (HR=0.98, 95% CI=0.70–1.38, p=0.46). Median PFS for BEV+RT and BEV was 7.1 vs. 3.8 mos, respectively (HR=0.73, 95% CI=0.53–1.0, p=0.051). BEV+ReRT improved 6-mo PFS rate (PFS6): 54 vs. 29%, (HR=0.42, 95% CI=0.34–0.5, p=0.001). Overall, treatment was well tolerated: 5% acute and 0% delayed grade 3+ treatment-related AE. Most patients died from recurrent GBM. CONCLUSION: RTOG 1205 is the first, prospective, randomized multi-institutional study to evaluate the safety and efficacy of ReRT in recurrent GBM using modern RT techniques. Overall, ReRT was shown to be safe and well tolerated. BEV+ReRT did not demonstrate a benefit in OS but an improved PFS6, and clinically meaningful PFS improvement. Molecular correlates of response analyses are ongoing. Funded by U10CA180868, U10CA180822 from the National Cancer Institute.

Radiation and chemotherapy for high-risk lower grade gliomas: Choosing between temozolomide and PCV

Purpose

The majority of patients with high‐risk lower grade gliomas (LGG) are treated with single‐agent temozolomide (TMZ) and radiotherapy despite three randomized trials showing a striking overall survival benefit with adjuvant procarbazine, lomustine, and vincristine (PCV) chemotherapy and radiotherapy. This article aims to evaluate the evidence and rationale for the widespread use of TMZ instead of PCV for high‐risk LGG.

Methods and Materials

We conducted a literature search utilizing PubMed for articles investigating the combination of radiotherapy and chemotherapy for high‐risk LGG and analyzed the results of these studies.

Results

For patients with IDH mutant 1p/19q codeleted LGG tumors, there is limited evidence to support the use of TMZ. In medically fit patients with codeleted disease, existing data demonstrate a large survival benefit for PCV as compared to adjuvant radiation therapy alone. For patients with non‐1p/19q codeleted LGG, early data from the CATNON study supports inclusion of adjuvant TMZ for 12 months. Subset analyses of the RTOG 9402 and EORTC 26951 do not demonstrate a survival benefit for adjuvant PCV for non‐1p/19q codeleted gliomas, however secondary analyses of RTOG 9802 and RTOG 9402 demonstrated survival benefit in any IDH mutant lower grade gliomas, regardless of 1p/19q codeletion status.

Conclusions

At present, we conclude that current evidence does not support the widespread use of TMZ over PCV for all patients with high‐risk LGG, and we instead recommend tailoring chemotherapy recommendation based on IDH status, favoring adjuvant PCV for patients with any IDH mutant tumors, both those that harbor 1p/19q codeletion and those non‐1p/19q codeleted. Given the critical role radiation plays in the treatment of LGG, radiation oncologists should be actively involved in discussions regarding chemotherapy choice in order to optimize treatment for their patients.

Volumetric and actuarial analysis of brain necrosis in proton therapy using a novel mixture cure model

BACKGROUND AND PURPOSE

High-dose fractionated radiotherapy is often necessary to achieve long-term tumor control in several types of tumors involving or within close proximity to the brain. There is limited data to guide on optimal constraints to the adjacent nontarget brain. This investigation explored the significance of the three-dimensional (3D) dose distribution of passive scattering proton therapy to the brain with other clinicopathological factors on the development of symptomatic radiation necrosis.

MATERIALS AND METHODS

All patients with head and neck, skull base, or intracranial tumors who underwent proton therapy (minimum prescription dose of 59.4 Gy(RBE)) with collateral moderate to high dose radiation exposure to the nontarget brain were retrospectively reviewed. A mixture cure model with respect to necrosis-free survival was used to derive estimates for the normal tissue complication probability (NTCP) model while adjusting for potential confounding factors.

RESULTS

Of 179 identified patients, 83 patients had intracranial tumors and 96 patients had primary extracranial tumors. The optimal dose measure obtained to describe the occurrence of radiation necrosis was the equivalent uniform dose (EUD) with parameter a = 9. The best-fit parameters of logistic NTCP models revealed D₅₀ = 57.7 Gy for intracranial tumors, D₅₀ = 39.5 Gy for extracranial tumors, and γ₅₀ = 2.5 for both tumor locations. Multivariable analysis revealed EUD and primary tumor location to be the strongest predictors of brain radiation necrosis.

CONCLUSION

In the current clinical volumetric data analyses with multivariable modelling, EUD was identified as an independent and strong predictor for brain radiation necrosis from proton therapy.

The impact of a dedicated multidisciplinary tumor board on care for patients with brain metastases

e13585

Background: Brain metastases are the most common tumors to affect the central nervous system. Treatment options have recently evolved with the use of targeted therapies, immunotherapy, and increased clinical trials availability. We describe our institutional experience with a novel, weekly tumor board dedicated to brain metastases and its impact on treatment decisions and survival. Methods: We conducted a single institution cohort study at a large academic hospital with a dedicated center for CNS metastases. Attendance at tumor board included representatives from neuro-oncology, medical oncology, radiation oncology, neurosurgery, and neuroradiology. We prospectively gathered data on patient demographics, clinical history, and tumor board recommendations. Patients were followed to assess treatment course and survival. The Kaplan Meier method was used to calculate time to progression. Results: A total of 49 patients were presented over 2 months, with 4 patients presented twice. The median age at presentation was 63 yrs with a median ECOG of 1. The primary malignancy was 35% melanoma, 49% lung, 22% breast, the remainder other. Most patients had advanced, heavily pretreated disease: 69% had Stage IV disease at time of tumor board presentation with a median of 2 prior lines of systemic therapy, 73% had multiple brain metastases, 39% had prior surgical resection of brain metastases, and 57% had prior CNS radiation. The tumor board recommended a change in management in 26/53 case presentations: 5 surgery, 8 radiation, 9 medical therapy, 3 clinical trial, and 1 surveillance. Recommendations were followed in all except 4 cases due to patient preference and loss to follow-up. When active therapy was recommended, the median time to start was 7 days. Only 3 patients have died at a median follow-up of 62 days. 9 patients have progressed, with a median time to progression of 57 days. Conclusions: A multidisciplinary brain metastasis tumor board provides unique opportunities in the management of complex brain metastasis patients in an era of rapidly evolving therapeutic options. Additional follow-up is needed to assess long-term outcomes, and comparison to non-tumor board presented patients will be necessary.

Predicting 90-Day and 1-Year Mortality in Spinal Metastatic Disease: Development and Internal Validation

BACKGROUND

Increasing prevalence of metastatic disease has been accompanied by increasing rates of surgical intervention. Current tools have poor to fair predictive performance for intermediate (90-d) and long-term (1-yr) mortality.

OBJECTIVE

To develop predictive algorithms for spinal metastatic disease at these time points and to provide patient-specific explanations of the predictions generated by these algorithms.

METHODS

Retrospective review was conducted at 2 large academic medical centers to identify patients undergoing initial operative management for spinal metastatic disease between January 2000 and December 2016. Five models (penalized logistic regression, random forest, stochastic gradient boosting, neural network, and support vector machine) were developed to predict 90-d and 1-yr mortality.

RESULTS

Overall, 732 patients were identified with 90-d and 1-yr mortality rates of 181 (25.1%) and 385 (54.3%), respectively. The stochastic gradient boosting algorithm had the best performance for 90-d mortality and 1-yr mortality. On global variable importance assessment, albumin, primary tumor histology, and performance status were the 3 most important predictors of 90-d mortality. The final models were incorporated into an open access web application able to provide predictions as well as patient-specific explanations of the results generated by the algorithms. The application can be found at https://sorg-apps.shinyapps.io/spinemetssurvival/

CONCLUSION

Preoperative estimation of 90-d and 1-yr mortality was achieved with assessment of more flexible modeling techniques such as machine learning. Integration of these models into applications and patient-centered explanations of predictions represent opportunities for incorporation into healthcare systems as decision tools in the future.

Patterns of Failure Among Patients With Low-grade Glioma Treated With Proton Radiation Therapy

PURPOSE

Proton treatment may be a useful radiation therapy modality for long-term surviving patients with glioma to reduce normal tissue toxicities. Photon studies demonstrate that most low-grade glioma (LGG) failures occur within the radiation field, supporting the use of more conformal treatment plans, yet it is unclear whether this can be translated to proton radiation therapy (PRT). Our objective is to examine our institutional experience to determine patterns of failure in patients with LGG with respect to the volume irradiated with PRT.

METHODS AND MATERIALS

Patients with World Health Organization 2007 grade I to II or isocitrate dehydrogenase 1-positive mutation grade III LGG treated with PRT between 2005 and 2015 were retrospectively reviewed. Patients with documented local recurrences on magnetic resonance imaging after receipt of PRT underwent a comparison with the initial treatment plan dosimetry to evaluate patterns of failure. A total of 141 patients were included in the final cohort.

RESULTS

The median follow-up time was 46.7 months (range, 2.8-144 months), and 5-year overall survival was 84%. The median PRT dose delivered was 54 Gy (relative biological effectiveness) (range, 45-60 Gy). There were 42 failures after PRT (30%). The median time to progression after treatment was 32.7 months (range, 4.8-93.6 months). Thirty-one patients (74%) failed in-field (defined as within the 95% isodose volume), 5 patients (12%) failed out-of-field, and 5 patients (12%) had marginal failures (defined as within the 50%-95% isodose volume). The 5-year freedom from progression after PRT was 60.1% (95% confidence interval, 48.7-70.0). The 5-year cumulative incidence of overall survival was 33% among those with recurrence after PRT and 96% among those without recurrence after PRT (P < .001).

CONCLUSIONS

Of the patients with LGG who had documented failures after PRT, most recurred within the radiation field with few marginal failures, indicating that even with PRT, which often can have steeper dose gradients, coverage is adequate. Survival was poor for patients whose tumors recurred.

Enrichment of HER2 Amplification in Brain Metastases from Primary Gastrointestinal Malignancies

BACKGROUND

In nongastric gastrointestinal (GI) cancers, HER2-positive (HER2+) disease is not common. In breast cancer, HER2 status is associated with increased risk of brain metastases and response to HER2-targeted therapy. The purpose of this project was to compare HER2 status in GI cancer brain metastases versus matched prior sites of disease in order to determine if HER2+ disease is more common intracranially.

MATERIALS AND METHODS

We identified 28 patients with GI cancer who had craniotomy for brain metastases between 1999 and 2017 with intracranial metastatic tissue available at Massachusetts General Hospital. Twenty-four patients also had tissue from a prior site of disease. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for HER2 were performed on all samples. A tumor was defined as HER2+ if it had 3+ staining by IHC or amplification by FISH.

RESULTS

A prior site of disease (including intracranial metastases) was HER2+ for 13% of evaluable patients: 3 of 11 patients with colorectal cancer and no patients with esophageal or pancreatic cancer. The most recent brain metastases were HER2+ for 32% of patients: 2 of 3 esophageal squamous cell carcinomas, 3 of 10 esophageal adenocarcinomas (ACs), 3 of 14 colorectal ACs, and 1 of 1 pancreatic AC. Only 37.5% of patients with HER2+ brain metastasis had concordant HER2+ prior tissue (κ = 0.38, p = .017).

CONCLUSION

In this cohort of patients with GI cancer with brain metastases, HER2+ status was more common intracranially compared with prior sites of disease. These findings suggest that testing HER2 in patients with GI cancer with brain metastases may lead to additional therapeutic options, regardless of HER2 status in previously examined tissue.

IMPLICATIONS FOR PRACTICE

HER2 amplification is a well-known driver of oncogenesis in breast cancer, with associated increased risk of brain metastases and response to HER2-directed therapy. In nongastric gastrointestinal (GI) cancers, HER2 amplification is not common and consequently is infrequently tested. The current study shows that brain metastases in patients with GI primary malignancies have a relatively high likelihood of being HER2 positive despite HER2 amplification or overexpression being less commonly found in matched tissue from prior sites of disease. This suggests that regardless of prior molecular testing, patients with GI cancer with brain metastases who have tissue available are likely to benefit from HER2 assessment to identify potential novel therapeutic options.

Spinal Growth Patterns After Craniospinal Irradiation in Children With Medulloblastoma

PURPOSE

This study aimed to evaluate the impact on spine growth in children with medulloblastoma using either photon or electron craniospinal irradiation (CSI).

METHODS AND MATERIALS

This was a single institution retrospective review of children who were treated with CSI for medulloblastoma. Spine growth was measured on magnetic resonance imaging scans at defined locations on the basis of a published predictive model of spine growth after CSI. Differences between spine growth in the anterior, middle, and posterior aspect of the designated vertebral segments were also assessed. Differences between the groups treated with photons or electrons were assessed with student's t test.

RESULTS

A total of 19 patients (10 patients treated with electrons and 9 with photons) with a median follow-up time of 45.5 months (confidence interval, 34.9-55.1 months) were evaluated. Patients treated with electrons were younger than those who received photons (5.1 years [range, 3.8-9.0 years] vs 9.6 years [range, 3.5-12.9 years]); however, there were no differences in other clinical characteristics, treatment, or follow-up between the groups. Spine growth rate for patients treated with electrons fit the predictive model (104% ± 5.2%), but patients treated with photons had growth that was faster than predicted by the model (150% ± 47%) and different from that observed with electrons. The differences between treatment the modalities were statistically significant (P = .03). For patients treated with photons, there were no statistical differences between the growth rate of the anterior vertebral body compared with the posterior aspect, but for patients treated with electrons, a faster spine growth in the anterior L1-L5 lumbar spine was observed compared with the posterior lumbar spine (3.90 vs 2.52 mm/year; P = .006) without differences in the cervical or thoracic spine.

CONCLUSIONS

The use of electrons to treat the craniospinal axis in children with medulloblastoma resulted in no significant difference in spine growth compared with the predicted spine growth on the basis of previously published models using photons, but with a clinically insignificant faster spine growth rate in the anterior lumbar spine.

Safety of Combined PD-1 Pathway Inhibition and Intracranial Radiation Therapy in Non-Small Cell Lung Cancer

INTRODUCTION

Intracranial metastases are a common cause of morbidity and mortality in patients with advanced NSCLC, and are frequently managed with radiation therapy (RT). The safety of cranial RT in the setting of treatment with immune checkpoint inhibitors (ICIs) has not been established.

METHODS

We identified patients with advanced NSCLC with brain metastases who received cranial RT and were treated with or without programmed cell death 1/programmed death ligand 1 inhibitors between August 2013 and September 2016. RT-related adverse events (AEs) were retrospectively evaluated and analyzed according to ICI treatment status, cranial RT type, and timing of RT with respect to ICI.

RESULTS

Of 163 patients, 50 (31%) received ICIs, whereas 113 (69%) were ICI naive. Overall, 94 (58%), 28 (17%), and 101 (62%) patients received stereotactic radiosurgery, partial brain irradiation, and/or whole brain RT, respectively. Fifty percent of patients received more than one radiation course. We observed no significant difference in rates of all-grade AEs and grade 3 or higher AEs between the ICI-naive and ICI-treated patients across different cranial RT types (grade ≥3 AEs in 8% of ICI-naive patients versus in 9% of ICI-treated patients for stereotactic radiosurgery [p = 1.00] and in 8% of ICI-naive patients versus in 10% of ICI-treated patients for whole brain RT [p = 0.71]). Additionally, there was no difference in AE rates on the basis of timing of ICI administration with respect to RT.

CONCLUSIONS

Treatment with an ICI and cranial RT was not associated with a significant increase in RT-related AEs, suggesting that use of programmed cell death 1/programmed death ligand 1 inhibitors in patients receiving cranial RT may have an acceptable safety profile. Nonetheless, additional studies are needed to validate this approach.

Consensus Contouring Guidelines for Postoperative Completely Resected Cavity Stereotactic Radiosurgery for Brain Metastases

PURPOSE

To propose contouring guidelines based on consensus contours generated by 10 international experts for cavity stereotactic radiosurgery (SRS), an emerging treatment option after surgical resection of brain metastases. No guidelines for contouring the surgical cavity volume have been previously reported.

METHODS AND MATERIALS

Ten postoperative completely resected cases with varying clinical scenarios and locations within the brain were selected. For each case, 10 experts independently contoured the surgical cavity clinical target volume (CTV). All the contours were analyzed, and agreement was calculated using the simultaneous truth and performance level estimation (STAPLE) with the kappa statistic. A follow-up survey was also completed by each investigator to summarize their contouring rationale for a number of different clinical scenarios. The results from the survey and the consensus STAPLE contours were both summarized to establish contouring guidelines.

RESULTS

A high level of agreement was found between the expert CTV contours (mean sensitivity 0.75, mean specificity 0.98), and the mean kappa was 0.65. The agreement was statistically significant at P<.001 for all cases. From these results and analyses of the survey answers, the recommendations for CTV include fusion of the preoperative magnetic resonance imaging scan to aid in volume delineation; contouring the entire surgical tract regardless of the preoperative location of the tumor; extension of the CTV 5 to 10 mm along the dura overlying the bone flap to account for microscopic disease extension in cases with preoperative dural contact; and a margin of ≤5 mm into the adjacent sinus when preoperative venous sinus contact was present.

CONCLUSIONS

Consensus contouring guidelines for postoperative completely resected cavity SRS treatment were established using expert contours and clinical practice. However, in the absence of clinical data supporting these recommendations, these guidelines serve as a baseline for further study and refinement.

Histopathological prognostic factors of recurrence following definitive therapy for atypical and malignant meningiomas

OBJECTIVE Patients with atypical and malignant (WHO Grade II and III) meningiomas have a worse prognosis than patients with benign (WHO Grade I) meningiomas. However, there is limited understanding of the pathological risk factors that affect long-term tumor control following combined treatment with surgery and radiation therapy. Here, the authors identify clinical and histopathological risk factors for the progression and/or recurrence (P/R) of high-grade meningiomas based on the largest series of patients with atypical and malignant meningiomas, as defined by the 2007 WHO classification. METHODS Patients diagnosed with WHO Grade II and III meningiomas between 2007 and 2014 per the WHO 2007 criteria and treated with both surgery and external beam radiation therapy were retrospectively reviewed for clinical and histopathological factors at the time of diagnosis and assessed for P/R outcomes at the last available follow-up. RESULTS A total of 76 patients met the inclusion criteria (66 Grade II meningiomas, 10 Grade III meningiomas). Median follow-up from the time of pathological diagnosis was 52.6 months. Three factors were found to predict P/R: Grade III histology, brain and/or bone invasion, and a Ki-67 proliferation rate at or above 3%. The crude P/R rate was 80% for patients with Grade III histology, 40% for those with brain and/or bone involvement (regardless of WHO tumor grade), and 20% for those with a proliferative index ≥ 3% (regardless of WHO tumor grade). The median proliferation index was significantly different between patients in whom treatment failed and those in whom it did not fail (11% and 1%, respectively). CONCLUSIONS In patients with atypical or malignant meningiomas, the presence of Grade III histology, brain and/or bone involvement, and a high mitotic index significantly predicted an increased risk of treatment failure despite combination therapy. These patients can be stratified into risk groups predicting P/R. Patients with high-risk features may benefit from more treatment and counseling than is typically offered currently.

Neurocognitive effects of proton radiation therapy in adults with low-grade glioma

To understand neurocognitive effects of proton radiation therapy (PRT) in patients with low-grade glioma, we evaluated 20 patients who received this therapy prospectively and over 5 years with a comprehensive neuropsychological battery. 20 patients were evaluated at baseline and at yearly intervals for up to 5 years with a battery of neuropsychological measures that assessed intellectual, attention, executive, visuospatial and memory functions as well as mood and functional status. We evaluated change in cognitive functioning over time. We analyzed the relationship between cognitive performance and tumor location and also examined whether patients' performance differed from that reported in a study of normative practice effects. Overall, patients exhibited stability in cognitive functioning. Tumor location played a role in performance; those with tumors in the left hemisphere versus in the right hemisphere were more impaired at baseline on verbal measures (p < .05). However, we found greater improvement in verbal memory over time in patients with left than with right hemisphere tumors (p < .05). Results of our study, the first to investigate, in depth, neurocognitive effects of PRT in adults with low-grade gliomas, are promising. We hypothesize that the conformal advantage of PRT may contribute to preservation of cognitive functioning, although larger sample sizes and a longer period of study are required. Our study also highlights the need to consider normative practice effects when studying neurocognitive functioning in response to treatment over time, and the need to utilize comprehensive neuropsychological batteries given our findings that differentiate patients with left and right hemisphere tumors.

Bathroom greywater recycling using polyelectrolyte-complex bilayer membrane: Advanced study of membrane structure and treatment efficiency

Polyelectrolyte-complex bilayer membrane (PCBM) was fabricated using biodegradable chitosan and alginate polymers for subsequent application in the treatment of bathroom greywater. In this study, the properties of PCBMs were studied and it was found that the formation of polyelectrolyte network reduced the molecular weight cut-off (MWCO) from 242kDa in chitosan membrane to 2.71kDa in PCBM. The decrease in MWCO of PCBM results in better greywater treatment efficiency, subsequently demonstrated in a greywater filtration study where treated greywater effluent met the household reclaimed water standard of <2 NTU turbidity and <30ppm total suspended solids (TSS). In addition, a further 20% improvement in chemical oxygen demand (COD) removal was achieved as compared to a single layer chitosan membrane. Results from this study show that the biodegradable PCBM is a potential membrane material in producing clean treated greywater for non-potable applications.

Alectinib Dose Escalation Reinduces Central Nervous System Responses in Patients with Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer Relapsing on Standard Dose Alectinib

The central nervous system (CNS) is an important and increasingly recognized site of treatment failure in anaplastic lymphoma kinase (ALK)-positive, non-small cell lung cancer (NSCLC) patients receiving ALK inhibitors. In this report, we describe two ALK-positive patients who experienced initial improvements in CNS metastases on standard dose alectinib (600 mg twice daily), but who subsequently experienced recurrences with symptomatic leptomeningeal metastases. Both patients were dose-escalated to alectinib 900 mg twice daily, resulting in repeat clinical and radiographic responses. Our results suggest that dose intensification of alectinib may be necessary to overcome incomplete ALK inhibition in the CNS and prolong the durability of responses in patients with CNS metastases, particularly those with leptomeningeal carcinomatosis.

Benign meningiomas (WHO Grade I) with atypical histological features: correlation of histopathological features with clinical outcomes

OBJECT

World Health Organization (WHO) Grade I (benign) meningiomas with atypical features may behave more aggressively than similarly graded tumors without atypical features. Here, the prognostic significance of atypical features in benign meningiomas was determined.

METHODS

Data from patients diagnosed with WHO Grade I benign meningiomas per the 2007 WHO criteria and who underwent surgery between 2002 and 2012 were retrospectively reviewed. Patients were stratified by the absence or presence of 1 to 2 atypical features with review of the clinical and histological factors.

RESULTS

A total of 148 patients met the inclusion criteria (n = 77 with atypia; n = 71 without atypia). The median follow-up duration after pathological diagnosis was 37.5 months. Thirty patients had progression/recurrence (P/R) after initial treatment, and 22 (73%) of 30 patients with P/R had 1–2 atypical features. The presence of atypical features was significantly associated with P/R (p = 0.03) and independent of the MIB-1 labeling index. The 1-year and 5-year actuarial rates of P/R were 9.6% versus 1.4% and 30.8% versus 13.8% fortumors with and without atypical features, respectively. Higher Simpson grade resection (II–IV vs I) was associated with the increased risk of P/R (p < 0.001). Stratification of patients into low-risk (Simpson Grade I), intermediate-risk (Simpson Grade II–IV with no atypical features), and high-risk groups (Simpson Grade II–IV with atypical features) was significantly correlated with increased risk of P/R (p < 0.001).

CONCLUSIONS

Patients with benign meningiomas with atypical features and those undergoing Simpson Grade II–IV resection are at significantly increased risk of P/R. Patients with these features may benefit from the consideration of additional surgery and/or radiation therapy.

Imaging and extent of surgical resection predict risk of meningioma recurrence better than WHO histopathological grade

BACKGROUND

Risk stratification of meningiomas by histopathological grade alone does not reliably predict which patients will progress/recur after treatment. We sought to determine whether preoperative imaging and clinical characteristics could predict histopathological grade and/or improve prognostication of progression/recurrence (P/R).

METHODS

We retrospectively reviewed preoperative MR and CT imaging features of 144 patients divided into low-grade (2007 WHO grade I; n = 118) and high-grade (2007 WHO grades II/III; n = 26) groups that underwent surgery between 2002 and 2013 (median follow-up of 49 months).

RESULTS

Multivariate analysis demonstrated that the risk factors most strongly associated with high-grade histopathology were male sex, low apparent diffusion coefficient (ADC), absent calcification, and high peritumoral edema. Remarkably, multivariate Cox proportional hazards analysis demonstrated that, in combination with extent of resection, ADC outperformed WHO histopathological grade for predicting which patients will suffer P/R after initial treatment. Stratification of patients into 3 risk groups based on non-Simpson grade I resection and low ADC as risk factors correlated with the likelihood of P/R (P < .001). The high-risk group (2 risk factors; n = 39) had a 45% cumulative incidence of P/R, whereas the low-risk group (0 risk factors; n = 31) had no P/R events at 5 years after treatment. Independent of histopathological grade, high-risk patients who received adjuvant radiotherapy had a lower 5-year crude rate of P/R than those without (17% vs 59%; P = .04).

CONCLUSIONS

Patients with non-Simpson grade I resection and low ADC meningiomas are at significantly increased risk of P/R and may benefit from adjuvant radiotherapy and/or additional surgery.

Immune Effects of Chemotherapy, Radiation, and Targeted Therapy and Opportunities for Combination With Immunotherapy

There have been significant advances in cancer treatment over the past several years through the use of chemotherapy, radiation therapy, molecularly targeted therapy, and immunotherapy. Despite these advances, treatments such as monotherapy or monomodality have significant limitations. There is increasing interest in using these strategies in combination; however, it is not completely clear how best to incorporate molecularly targeted and immune-targeted therapies into combination regimens. This is particularly pertinent when considering combinations with immunotherapy, as other types of therapy may have significant impact on host immunity, the tumor microenvironment, or both. Thus, the influence of chemotherapy, radiation therapy, and molecularly targeted therapy on the host anti-tumor immune response and the host anti-host response (ie, autoimmune toxicity) must be taken into consideration when designing immunotherapy-based combination regimens. We present data related to many of these combination approaches in the context of investigations in patients with melanoma and discuss their potential relationship to management of patients with other tumor types. Importantly, we also highlight challenges of these approaches and emphasize the need for continued translational research.

Survival patterns following brain metastases for patients with melanoma in the MAP-kinase inhibitor era

Survival with BRAF-mutant metastatic melanoma is prolonged with MAP-kinase pathway inhibitors (MAPKi). Among patients with brain metastases (BM), however, the clinical course of MAPKi-treated patients is not well described. We therefore explored these patients' survival patterns compared to contemporary patients not treated with MAPKi. We analyzed 106 patients who developed melanoma BM between 2007 and 2013. Of these, 37 (35%) received de novo MAPKi for BRAF-mutant disease, which preceded BM in 49%. Immunotherapy was given to 54% of MAPKi-treated patients and 94% of those who did not receive MAPKi. We evaluated the potential influence of patient characteristics, systemic therapies, and BM-directed treatments on time to appearance of new BM and overall survival. With a median follow-up of 8.0 months after initial BM, MAPKi use was an independent predictor of prolonged survival after BM diagnosis (median 14.1 vs 7.0 months, P = 0.03, adjusted hazard ratio 0.39). This survival advantage was driven by the 16.6-month median survival of patients who initiated MAPKi after BM were diagnosed, versus 5.6 months if initiated prior to BM development (P = 0.03). Median survival from the onset of any systemic metastases was 22 months regardless of the timing of MAPKi relative to BM appearance. Time to in-brain progression was longer among patients whose MAPKi course was started after BM diagnosis, but MAPKi initiation prior to BM diagnosis was associated with longer time to intracranial involvement. These findings are consistent with potential MAPKi activity in intracranial melanoma.

The orally active urotensin receptor antagonist, KR36676, attenuates cellular and cardiac hypertrophy

BACKGROUND AND PURPOSE

Blockade of the actions of urotensin-II (U-II) mediated by the urotensin (UT) receptor should improve cardiac function and prevent cardiac remodelling in cardiovascular disease. Here, we have evaluated the pharmacological properties of the recently identified UT receptor antagonist, 2-(6,7-dichloro-3-oxo-2H-benzo[b][1,4]oxazin-4(3H)-yl)-N-methyl-N-(2-(pyrrolidin-1-yl)-1-(4-(thiophen-3-yl)phenyl) ethyl)acetamide (KR36676).

EXPERIMENTAL APPROACH

Pharmacological properties of KR36676 were studied in a range of in vitro assays (receptor binding, calcium mobilization, stress fibre formation, cellular hypertrophy) and in vivo animal models such as cardiac hypertrophy induced by transverse aortic constriction (TAC) or myocardial infarction (MI).

KEY RESULTS

KR36676 displayed high binding affinity for the UT receptor (Ki : 0.7 nM), similar to that of U-II (0.4 nM), and was a potent antagonist at that receptor (IC50 : 4.0 nM). U-II-induced stress fibre formation and cellular hypertrophy were significantly inhibited with low concentrations of KR36676 (≥0.01 μM). Oral administration of KR36676 (30 mg·kg(-1) ) in a TAC model in mice attenuated cardiac hypertrophy and myocardial fibrosis. Moreover, KR36676 restored cardiac function and myocyte size in rats with MI-induced cardiac hypertrophy.

CONCLUSIONS AND IMPLICATIONS

A highly potent UT receptor antagonist exerted anti-hypertrophic effects not only in infarcted rat hearts but also in pressure-overloaded mouse hearts. KR36676 could be a valuable pharmacological tool in elucidating the complicated physiological role of U-II and UT receptors in cardiac hypertrophy.

Occurrence and intake of deoxynivalenol in cereal-based products marketed in Korea during 2007-2008

The occurrence of deoxynivalenol (DON) was investigated in 514 cereal-based products (corn-based, n = 125; barley-based, n = 96; wheat-based, n = 94; rice-based, n = 199) marketed in Korea during 2007-2008, and estimates of DON intake were determined. Samples were analysed by high-performance liquid chromatography (HPLC) with ultraviolet light (UV) detection after immunoaffinity clean-up. The limits of detection (LOD) and limits of quantification (LOQ) were 2.2 and 5.6 µg kg(-1), respectively. Recoveries and repeatability expressed as coefficients of variation (CV) were 82.3-100% and 2.4-15.3% in beer, bread and dried corn. The incidences and mean levels of DON were 56% and 68.9 µg kg(-1) for corn-based products, 49% and 24.1 µg kg(-1) for wheat-based products, 43% and 7.5 µg kg(-1) for barley-based products, and 16% and 3.4 µg kg(-1) for rice-based products, respectively. The estimated daily intake of DON from the consumption of rice-based, wheat-based, barley-based and corn-based products were 0.0038 µg kg(-1) bw day(-1), 0.0032 µg kg(-1) bw day(-1), 0.0015 µg kg(-1) bw day(-1) and 0.0002 µg kg(-1) bw day(-1), respectively. These values represent 0.38%, 0.32%, 0.25% and 0.01% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg kg(-1) bw day(-1). These results indicate that rice-based products are major contributors to DON exposure in Korea, even though the current exposure level is unlikely to cause adverse health effects.

Significance of targeted therapy and genetic alterations in EGFR, ALK, or KRAS on survival in patients with non-small cell lung cancer treated with radiotherapy for brain metastases

BACKGROUND

We determined the impact of genetic alterations in EGFR, ALK, or KRAS on survival after radiotherapy for brain metastases in non-small cell lung cancer (NSCLC).

METHODS

Of 172 genotyped NSCLC patients treated with radiotherapy for brain metastases in 2005-2012, 54 had cancers with EGFR mutations, 12 had ALK rearrangements, 38 had KRAS mutations, and 68 were wild-type (WT). Overall survival (OS) was determined.

RESULTS

Median follow-up was 8.6 months. Median OS was 13.6 months for patients with EGFR mutations and 26.3 months for patients with ALK rearrangements, in contrast to 5.7 months for KRAS-mutant patients and 5.5 months for WT patients (P = .001). On multivariate analysis, adjusting for receipt of targeted therapy after cranial radiotherapy, ALK rearrangements were associated with improved OS (HR, 0.31; 95% CI, 0.13-0.74; P = .008). EGFR mutations were not significantly associated with improved OS on multivariate analysis (HR, 0.71; 95% CI, 0.37-1.38; P = .3). KRAS mutations were also not associated with improved OS (HR, 0.93; 95% CI, 0.59-1.47; P = .8). Receipt of targeted therapy after cranial radiotherapy was independently associated with improved OS (HR, 0.30; 95% CI, 0.17-0.54; P < .001). Receipt of chemotherapy after cranial radiotherapy, number of brain metastases, extracranial metastases, age, and performance status were also associated with OS.

CONCLUSIONS

NSCLC patients with genetic alterations in ALK have improved survival outcomes after radiotherapy for brain metastases compared with EGFR, KRAS, or WT. Subsequent receipt of targeted therapy was associated with additional improvement in OS.

Efficiency gains for spinal radiosurgery using multicriteria optimization intensity modulated radiation therapy guided volumetric modulated arc therapy planning

PURPOSE

To evaluate plan quality and delivery efficiency gains of volumetric modulated arc therapy (VMAT) versus a multicriteria optimization-based intensity modulated radiation therapy (MCO-IMRT) for stereotactic radiosurgery of spinal metastases.

METHODS AND MATERIALS

MCO-IMRT plans (RayStation V2.5; RaySearch Laboratories, Stockholm, Sweden) of 10 spinal radiosurgery cases using 7-9 beams were developed for clinical delivery, and patients were replanned using VMAT with partial arcs. The prescribed dose was 18 Gy, and target coverage was maximized such that the maximum dose to the planning organ-at-risk volume (PRV) of the spinal cord was 10 or 12 Gy. Dose-volume histogram (DVH) constraints from the clinically acceptable MCO-IMRT plans were utilized for VMAT optimization. Plan quality and delivery efficiency with and without collimator rotation for MCO-IMRT and VMAT were compared and analyzed based upon DVH, planning target volume coverage, homogeneity index, conformity number, cord PRV sparing, total monitor units (MU), and delivery time.

RESULTS

The VMAT plans were capable of matching most DVH constraints from the MCO-IMRT plans. The ranges of MU were 4808-7193 for MCO-IMRT without collimator rotation, 3509-5907 for MCO-IMRT with collimator rotation, 4444-7309 for VMAT without collimator rotation, and 3277-5643 for VMAT with collimator of 90 degrees. The MU for the VMAT plans were similar to their corresponding MCO-IMRT plans, depending upon the complexity of the target and PRV geometries, but had a larger range. The delivery times of the MCO-IMRT and VMAT plans, both with collimator rotation, were 18.3 ± 2.5 minutes and 14.2 ± 2.0 minutes, respectively (P < .05).

CONCLUSIONS

The MCO-IMRT and VMAT can create clinically acceptable plans for spinal radiosurgery. The MU for MCO-IMRT and VMAT can be reduced significantly by utilizing a collimator rotation following the orientation of the spinal cord. Plan quality for VMAT is similar to MCO-IMRT, with similar MU for both modalities. Delivery times can be reduced by nominally 25% with VMAT.

Clinical discussion and review of the management of brain metastases

Brain metastases are common in patients with cancer and are associated with a poor prognosis. Optimal treatment requires an integrative multidisciplinary approach, and therapeutic options may include stereotactic radiosurgery, whole-brain radiation therapy, surgical resection, chemotherapy, and targeted agents. The goals of therapy are to prolong survival, preserve neurologic function, and palliate symptoms. This article outlines the various therapeutic modalities, factors that guide treatment decisions, and medical management of frequently encountered complications of brain metastases.

Radiation therapy in the management of pituitary adenomas

Radiation therapy in the form of fractionated treatment or radiosurgery has an important role in the management of pituitary adenomas. Radiation is a reliable way of gaining local control for radiographically progressing pituitary adenomas. For functioning adenomas that are biochemically recurrent or persistent, radiation therapy is less consistent in offering biochemical normalization and often requires a latency period of years or decades. The decision of when to use radiation therapy is a delicate balance between its benefits and late sequelae, especially in the context of benign disease. Recent technological advances in radiation oncology hold the potential to minimize dose to uninvolved normal tissue and therefore reduce the risk of toxicity.

Underutilization of radiation therapy in patients with glioblastoma: predictive factors and outcomes

BACKGROUND

Randomized trials have demonstrated that radiation improves survival in patients with glioblastoma. The purpose of this study was to characterize the risk factors and impact of omission of radiation therapy in such patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) program was used to identify 22,777 patients diagnosed with glioblastoma between 1988 and 2007. Multivariable logistic regression was employed to identify predictors associated with omission of radiation. Cox regression was used to characterize the impact of omitting radiation on all-cause mortality.

RESULTS

Among the entire cohort, 16,863 of 22,777 patients (74%) received radiation, whereas 5914 of 22,777 patients (26%) did not. Factors associated with omission of radiation included older age (OR=1.048 per year increase, 95% CI=1.046-1.051, P<.001), lower annual income (OR=0.93 per $10,000 increase, 95% CI=0.90-0.96, P<.001), African American race (reference=white, OR=1.19, 95% CI=1.03-1.37, P=.02), Hispanic race (OR=1.34, 95% CI=1.19-1.50, P< .001), Asian American race (OR=1.24, 95% CI=1.04-1.48, P<.001), unmarried status (OR=1.71, 95% CI=1.60-1.83, P< .001), and subtotal resection/biopsy (OR=1.82, 95% CI=1.69-1.96, P<.001). The use of radiation was significantly associated with improved overall survival (2-year survival: 14.6% versus 4.2%, P<.001; adjusted HR=2.09, 95% CI=2.02-2.16, P<.001). When the population was restricted to patients <50 years old, these findings remained largely unchanged.

CONCLUSIONS

Radiation therapy is associated with survival benefit in patients with glioblastoma, and sociodemographic factors play a significant role in the underutilization of radiation. The underlying causes for these disparities in care require further research.

Natural history and role of radiation in patients with supratentorial and infratentorial WHO grade II ependymomas: results from a population-based study

Patients with World Health Organization (WHO) grade II supratentorial ependymomas are commonly observed after gross total resection (GTR), although supporting data are limited. We sought to characterize the natural history of such tumors. We used the Surveillance, Epidemiology, and End Results program to identify 112 patients ages 0-77 diagnosed with WHO grade II ependymomas between 1988 and 2007, of whom 63 (56 %) and 49 (44 %) had supratentorial and infratentorial primaries, respectively. Inclusion criteria were strict to ensure patient homogeneity. Of 33 patients with supratentorial tumors after GTR, 18 (55 %) received adjuvant radiation therapy and 15 (45 %) did not. Ependymoma-specific mortality (ESM) was the primary endpoint. With a median follow up of 4.5 years, only 1 of 33 patients with supratentorial ependymoma died of their disease after GTR; the 5-year estimate of ESM in this population was 3.3 % (95 % CI 0.2-14.8 %). Among patients with infratentorial ependymomas after GTR, the 5-year estimate of ESM was 8.7 % (95 % CI 1.4-24.6 %). In patients with subtotally resected tumors, 5-year estimates of ESM in patients with supratentorial and infratentorial primaries were 20.1 % (95 % CI 8.0-36.2 %) and 12.3 % (95 % CI 2.9-28.8 %), respectively. Among the whole cohort, on both univariable and multivariable regression, extent of resection was predictive of ESM, while tumor location and use of radiation were not. After GTR, patients with WHO grade II supratentorial ependymomas have a very favorable natural history with low associated cancer-specific mortality. Observation, with radiation reserved as a salvage option, may be a reasonable postoperative strategy in this population.

Survival patterns following brain metastases for patients with melanoma in the targeted therapy era

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Background: Survival from metastatic melanoma (MM) has been significantly prolonged with the introduction of molecularly targeted therapy, including BRAF inhibitors (BRAFi) for patients (pts) with the V600E mutation. Here, we present the first data describing patterns of survival after diagnosis of brain metastases (BM) in a large cohort of these pts with long follow-up. Methods: A retrospective review of 191 MM pts accrued on multiple prospective trials between 2008–2012 was conducted. These trials assessed novel immunologic and targeted therapies in pts with both BRAF mutant (n=70) and wild type/unknown (n=121) tumors. We evaluated pt characteristics and the impact of systemic and BM-directed treatments. Results: Of 98 pts who developed BM, median follow-up after first BM was 7.7 months (15.5 months for the 25 living pts), and 33 were treated with BRAFi. Median duration of BRAFi use was 5.9 months (range 0.7–27.1), which preceded BM in 30%, was concurrent with first BM in 18%, and followed first BM in 52%. Ipilimumab or anti–PD-1/PD-L1 immunotherapy was given to 58% of pts who received a BRAFi and 95% of those who did not. Limited intracranial disease on initial BM presentation (defined as ≤3 lesions) occurred in 70% of BRAFi-treated pts and 74% of non-BRAFi pts, and 70% of BRAFi pts received at least one focal BM treatment (stereotactic radiosurgery or resection) compared to 75% of non-BRAFi pts. As shown in the Table, actuarial survival after BM diagnosis was prolonged among pts treated with a BRAFi. This is due primarily to the nearly 2-year median survival of pts for whom a BRAFi was initiated after BM were diagnosed. Conclusions: Survival for pts with BM from BRAF mutant MM can significantly exceed the often anticipated 4–6 months, particularly if a BRAFi is initiated after BM arise. This supports BRAFi activity in intracranial disease, and helps to inform trials currently under way testing BRAFi use among MM pts with previously diagnosed BM. [Table: see text]

Brain metastases after breast-conserving therapy and systemic therapy: incidence and characteristics by biologic subtype

The characteristics of brain metastases (BM) that develop after breast-conserving therapy (BCT) for early-stage breast cancer (BC) remain incompletely defined. We examined 1,434 consecutive patients with stage I/II invasive BC who received BCT from 1997 to 2006, 91 % of whom received adjuvant systemic therapy, according to BC subtype. Median follow-up was 85 months. Overall 5-year cumulative incidence of BM was 1.7 %; 0.1 % for luminal A, 3.3 % for luminal B, 3.2 % for luminal-HER2, 3.7 % for HER2, and 7.4 % for triple negative (TN). Women who developed BM were more likely at BC diagnosis to be younger (P < .0001) and have node-positive (P < .0001), grade 3 (P < .0001), hormone receptor-negative (P = .006), and HER2-positive (P = .01) tumors. Median time from BC diagnosis to BM was 51.4 months (range, 7.6-108 months), which was longer among luminal versus non-luminal subtypes (P = .0002; median, 61.4 vs. 34.5 months). Thirty-four percent of patients who developed distant metastases (DM) eventually developed BM. Median time from DM to BM was 12.8 months but varied by subtype, including 7.4 months for TN, 9.6 months for luminal B, and 27.1 months for HER2. Eighty-one percent of all BM patients presented with neurologic symptoms. Median number of BM at diagnosis was two, and median BM size was 15 mm, with TN (27 mm) and luminal B (16 mm) exhibiting the largest median sizes. In conclusion, the risk of BM after BCT varies significantly by subtype. Given the large size and symptomatic presentation among luminal B and TN subtypes, earlier BM detection might improve quality of life or increase eligibility for non-invasive treatments including stereotactic radiosurgery. Women with DM from these two BC subtypes have a high incidence of BM with a short latency, suggesting an ideal target population for trials evaluating the utility of MRI screening.

Outcomes of multidisciplinary management in pediatric low-grade gliomas

PURPOSE

To evaluate the outcomes in pediatric low-grade gliomas managed in a multidisciplinary setting.

METHODS AND MATERIALS

We conducted a single-institution retrospective study of 181 children with Grade I-II gliomas. Log-rank and stepwise Cox proportional hazards models were used to analyze freedom from progression (FFP) and overall survival (OS).

RESULTS

Median follow-up was 6.4 years. Thirty-four (19%) of patients had neurofibromatosis Type 1 (NF1) and because of their favorable prognosis were evaluated separately. In the 147 (81%) of patients without NF1, actuarial 7-year FFP and OS were 67 ± 4% (standard error) and 94 ± 2%, respectively. In this population, tumor location in the optic pathway/hypothalamus was associated with worse FFP (39% vs. 76%, p < 0.0003), but there was no difference in OS. Age ≤5 years was associated with worse FFP (52% vs. 75%, p < 0.02) but improved OS (97% vs. 92%, p < 0.05). In those with tissue diagnosis, gross total resection (GTR) was associated with improved 7-year FFP (81% vs. 56%, p < 0.02) and OS (100% vs. 90%, p < 0.03). In a multivariate model, only location in the optic pathway/hypothalamus predicted worse FFP (p < 0.01). Fifty patients received radiation therapy (RT). For those with less than GTR, adjuvant RT improved FFP (89% vs. 49%, p < 0.003) but not OS. There was no difference in OS between patient groups given RT as adjuvant vs. salvage therapy. In NF1 patients, 94% of tumors were located in the optic pathway/hypothalamus. With a conservative treatment strategy in this population, actuarial 7-year FFP and OS were 73 ± 9% and 100%, respectively.

CONCLUSIONS

Low-grade gliomas in children ≤5 years old with tumors in the optic pathway/hypothalamus are more likely to progress, but this does not confer worse OS because of the success of salvage therapy. When GTR is not achieved, adjuvant RT improves FFP but not OS. Routine adjuvant RT can be avoided and instead reserved as salvage.

Combined-modality therapy with gemcitabine and radiation therapy as a bladder preservation strategy: long-term results of a phase I trial

PURPOSE

A Phase I trial of twice-weekly gemcitabine and concurrent radiation therapy (RT) was performed in patients with muscle-invasive bladder cancer. We present the final analysis of bladder-intact survival (BIS), disease-specific survival (DSS), and overall survival (OS).

METHODS AND MATERIALS

Eligible patients had muscle-invasive transitional cell carcinoma (cT2-3) and were candidates for cystectomy. Patients underwent maximal transurethral resection of bladder tumor followed by twice-weekly gemcitabine with concurrent RT to the bladder (total of 60 Gy over 6 weeks). Gemcitabine doses ranged from 10 to 33 mg/m(2).

RESULTS

Median follow-up was 5.6 years (range, 0.6-9.5 years). Twenty-three of 24 patients were evaluable for response. All patients were clinical stage T2. Locoregional failure occurred in seven patients (30%), which were successfully salvaged by radical cystectomy (n = 5) or intravesical therapy (n = 2). Four local failures occurred > 5 years after therapy. Most local failures were noninvasive tumors (Ta or Tis, n = 6). Ten patients (43%) experienced optimal outcome (no failures and bladder intact). The 5-year actuarial estimates of survival are BIS 62%, OS 76%, and DSS 82%.

CONCLUSION

Twice-weekly gemcitabine with concurrent RT is well tolerated and provides rates of survival and bladder preservation that are comparable to the existing literature. All locoregional failures were successfully salvaged by either radical cystectomy or intravesical therapy. Given the high proportion of late local failures, we recommend long-term monitoring when using this regimen. Future studies comparing the safety and efficacy of gemcitabine- vs. platinum-based bladder preservation protocols are pending.

Hyperthermal neutral beam sources for material processing

Hyperthermal neutral beams have a great potential for material processes, especially for etching and thin film deposition for semiconductor and display fabrication as well as deposition for various thin film applications. Plasma-induced damage during plasma etching is a serious problem for manufacturing deep submicron semiconductor devices and is expected to be a problem for future nanoscale devices. Thermal and plasma-induced damage is also problematic for thin film depositions such as transparent conductive oxide films on organic light emitting diodes or flexible displays due to high temperature processes in plasma environments. These problems can be overcome by damage-free and low-temperature processes with hyperthermal neutral beams. We will present the status of the hyperthermal neutral beam development and the applications, especially, in semiconductor and display fabrication and introduce potential applications of thin film growing for optoelectronic devices such as light emitting diodes.