Palmer, Joshua D

Abstract Background Although there are data describing the onset of neurocognitive toxicity following radiation for patients with brain metastases, less is known about the potential for functional cognitive recovery (CR). This study sought to evaluate CR following neurocognitive function failure (NCF) in patients treated with stereotactic radiosurgery (SRS), whole-brain radiotherapy (WBRT), and hippocampal avoidance (HA)-WBRT. Methods A pooled analysis of 3 (NCCTG N107C/CEC.3, NCCTG N0574, and NRG CC001) clinical trials was performed. Patients with trial-defined NCF and longitudinal cognitive testing were included. The primary endpoint was time to CR, defined as patients no longer exhibiting a 1 or more standard deviation decline from baseline on any cognitive test. Results A total of 288 patients were included, with a median follow-up of 12.2 months. The cumulative incidence of CR was 38% (95% confidence interval [CI] = 32.5% to 43.9%) at 6 months after NCF. Incidence of CR was significantly improved with post-op SRS vs WBRT (hazard ratio [HR] = 2.68, 95% CI = 1.43 to 5.03, P = .002) and with SRS vs SRS+WBRT (HR = 2.35, 95% CI = 1.16 to 4.79, P = .008). On multivariable analysis, SRS was highly prognostic of CR compared with WBRT (HR = 2.42, 95% CI = 1.70 to 3.45, P < .0001). Meta-analysis demonstrated that conformal RT techniques (SRS or HA-WBRT) conferred a significantly higher rate of CR compared with WBRT (pooled HR = 2.12, 95% CI = 1.49 to 3.02, P < .001); 68% of patients had long-term sustained CR. Conclusions A sizeable proportion of patients who experience NCF following brain radiation eventually attain full and sustained CR, thereby highlighting that neurocognitive decline may not be permanent. The use of conformal radiation techniques results in greater rates of neurocognitive recovery.

Abstract The role of radiation therapy in the management of brain metastasis is evolving. Advancements in machine learning techniques have improved our ability to both detect brain metastasis and our ability to contour substructures of the brain as critical organs at risk. Advanced imaging with PET tracers and magnetic resonance imaging-based artificial intelligence models can now predict tumor control and differentiate tumor progression from radiation necrosis. These advancements will help to optimize dose and fractionation for each patient’s lesion based on tumor size, histology, systemic therapy, medical comorbidities/patient genetics, and tumor molecular features. This review will discuss the current state of brain directed radiation for brain metastasis. We will also discuss future directions to improve the precision of stereotactic radiosurgery and optimize whole brain radiation techniques to improve local tumor control and prevent cognitive decline without forming necrosis.

Background and purpose: A bolus is required when treating scalp lesions with photon radiation therapy. Traditional bolus materials face several issues, including air gaps and setup difficulty due to irregular, convex scalp geometry. A 3D-milled bolus is custom-formed to match individual patient anatomy, allowing improved dose coverage and homogeneity. Here, we describe the creation process of a 3D-milled bolus and report the outcomes for patients with scalp malignancies treated with Volumetric Modulated Arc Therapy (VMAT) utilizing a 3D-milled bolus. Materials and methods: Twenty-two patients treated from 2016 to 2022 using a 3D-milled bolus and VMAT were included. Histologies included squamous cell carcinoma (n = 14, 64%) and angiosarcoma (n = 8, 36%). A total of 7 (32%) patients were treated in the intact and 15 (68%) in the postoperative setting. The median prescription dose was 66.0 Gy (range: 60.0–69.96). Results: The target included the entire scalp for 8 (36%) patients; in the remaining 14 (64%), the median ratio of planning target volume to scalp volume was 35% (range: 25–90%). The median dose homogeneity index was 1.07 (range: 1.03–1.15). Six (27%) patients experienced acute grade 3 dermatitis and one (5%) patient experienced late grade 3 skin ulceration. With a median follow-up of 21.4 months (range: 4.0–75.4), the 18-month rates of locoregional control and overall survival were 75% and 79%, respectively. Conclusions: To our knowledge, this is the first study to report the clinical outcomes for patients with scalp malignancies treated with the combination of VMAT and a 3D-milled bolus. This technique resulted in favorable clinical outcomes and an acceptable toxicity profile in comparison with historic controls and warrants further investigation in a larger prospective study.

Abstract Background Surgery is the mainstay of treatment for meningioma, the most common primary intracranial tumor, but improvements in meningioma risk stratification are needed and current indications for postoperative radiotherapy are controversial. Recent studies have proposed prognostic meningioma classification systems using DNA methylation profiling, copy number variants, DNA sequencing, RNA sequencing, histology, or integrated models based on multiple combined features. Targeted gene expression profiling has generated robust biomarkers integrating multiple molecular features for other cancers, but is understudied for meningiomas. Methods Targeted gene expression profiling was performed on 173 meningiomas and an optimized gene expression biomarker (34 genes) and risk score (0 to 1) was developed to predict clinical outcomes. Clinical and analytical validation was performed on independent meningiomas from 12 institutions across 3 continents (N = 1856), including 103 meningiomas from a prospective clinical trial. Gene expression biomarker performance was compared to 9 other classification systems. Results The gene expression biomarker improved discrimination of postoperative meningioma outcomes compared to all other classification systems tested in the independent clinical validation cohort for local recurrence (5-year area under the curve [AUC] 0.81) and overall survival (5-year AUC 0.80). The increase in area under the curve compared to the current standard of care, World Health Organization 2021 grade, was 0.11 for local recurrence (95% confidence interval [CI] 0.07–0.17, P < 0.001). The gene expression biomarker identified meningiomas benefiting from postoperative radiotherapy (hazard ratio 0.54, 95% CI 0.37–0.78, P = 0.0001) and re-classified up to 52.0% meningiomas compared to conventional clinical criteria, suggesting postoperative management could be refined for 29.8% of patients. Conclusions A targeted gene expression biomarker improves discrimination of meningioma outcomes compared to recent classification systems and predicts postoperative radiotherapy responses.

Background: Racial/ethnic (R/E) minorities with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared to White patients. While disparities in patient outcomes for R/E minorities have been well documented, the specific drivers of the inferior outcomes remain poorly understood. Patients and Methods: This was a population-based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database (NCDB) from 2000–2016. Patient outcomes were stratified by R/E groups including White, Black, Hispanic, Native American/Other, and Asian. The main outcome in this study was overall survival (OS). Univariate time-to-event survival analyses were performed using the Kaplan–Meier product limit estimates and the log-rank test to evaluate the differences between strata. Results: There were 304,138 patients with HNSCC identified in this study, of which 262,762 (86.3%) were White, 32,528 (10.6%) were Black, 6191 were Asian (2.0%), and 2657 were Native American/Other (0.9%). Black R/E minorities were more likely to be uninsured (9% vs. 5%, p < 0.0001), have Medicaid insurance (22% vs. 8%, p < 0.0001), be in a lower income quartile (<30,000, 42% vs. 13%, p < 0.0001), have metastatic disease (5% vs. 2%, p < 0.001), and have a total treatment time 6 days longer than White patients (median 107 vs. 101 days, p < 0.001). The 5-year OS for White, Black, Native American/Other, and Asian patients was 50.8%, 38.6%, 51.1%, and 55.8%, respectively. Among the oropharynx HNSCC patients, the 5-year OS rates in p16+ White, Black, and Asian patients were 65.7%, 39.4%%, and 55%, respectively. After a multivariate analysis, Black race was still associated with an inferior OS (HR:1.09, 95% CI: 1.03–1.15, p = 0.002). Conclusions: This large cohort study of HNSCC patients demonstrates that Black race is independently associated with worse OS, in part due to socioeconomic, clinical, and treatment-related factors.

Brain metastases are a devastating sequela of common primary cancers (e.g., lung, breast, and skin) and have limited effective therapeutic options. Previously, systemic chemotherapy failed to demonstrate significant benefit in patients with brain metastases, but in recent decades, targeted therapies and more recently immune checkpoint inhibitors (ICIs) have yielded promising results in preclinical and clinical studies. Furthermore, there is significant interest in harnessing the immunomodulatory effects of radiotherapy (RT) to synergize with ICIs. Herein, we discuss studies evaluating the impact of RT dose and fractionation on the immune response, early studies supporting the synergistic interaction between RT and ICIs, and ongoing clinical trials assessing the benefit of combination therapy in patients with brain metastases.

Brain metastases (BMs) account for a disproportionately high percentage of cancer morbidity and mortality. Historically, studies have focused on improving survival outcomes, and recent radiation oncology clinical trials have incorporated HRQOL and cognitive assessments. We are now equipped with a battery of assessments in the radiation oncology clinic, but there is a lack of consensus regarding how to incorporate them in modern clinical practice. Herein, we present validated assessments for BM patients, current recommendations for future clinical studies, and treatment advances that have improved HRQOL and cognitive outcomes for BM patients.

Abstract Background Global incidence for brain tumors varies substantially without explanation. Studies correlating radon exposure and incidence are inconclusive. Particulate pollution has been linked to increased tumor incidence. Particulates may disrupt the blood-brain barrier allowing intracranial exposure to oncogenic radon. We investigated the relationship between exposure to residential radon, particulate pollution, and brain tumor incidence in the United States (US). Methods County-level median radon testing results and annual air quality index values were obtained and divided into tertiles. Counties without both values were excluded. Four groups of counties were generated: high particulate/high radon (high/high), high/low, low/high, and low/low. Using incidence data from the Central Brain Tumor Registry of the US (provided by CDC’s National Program of Cancer Registries and NCI’s SEER), annual age-adjusted incidence rates (AAAIRs) by group were generated by behavior. Incidence rate ratios were calculated to examine for significant differences (α = .05). Poisson regression accounting for possible confounders was conducted. Results Counties with available data included 83% of the US population. High/high exposure was significantly associated with increased AAAIR of all non-malignant tumors (up to 26% higher, including most meningiomas) even after accounting for potential confounders. An increased AAAIR was noted for all malignant tumors (up to 10% higher), including glioblastoma, but was negated after accounting for demographic/socioeconomic differences. Conclusions We present the first report suggesting increased non-malignant brain tumor incidence in regions with high particulate and radon exposure. These findings provide insight into unexplained variation in tumor incidence. Future studies are needed to validate these findings in other populations.

BackgroundThe standard of care for elderly or frail patients with glioblastoma (GBM) is 40 Gy in 15 fractions of radiotherapy. However, this regimen has a lower biological effective dose (BED) compared with the Stupp regimen of 60 Gy in 30 fractions. It is hypothesized that accelerated hypofractionated radiation of 52.5 Gy in 15 fractions (BED equivalent to Stupp) is safe and efficacious.MethodsElderly or frail patients with GBM treated with 52.5 Gy in 15 fractions were pooled from 3 phase 1/2 studies and a prospective observational study. Overall survival (OS) and progression‐free survival (PFS) were defined time elapsing between surgery/biopsy and death from any cause or progression of disease.ResultsSixty‐two newly diagnosed patients were eligible for this pooled analysis of individual patient data. The majority (66%) had a Karnofsky performance status (KPS) score <70. The median age was 73 years. The median OS and PFS were 10.3 and 6.9 months, respectively. Patients with KPS scores ≥70 and <70 had a median OS of 15.3 and 9.5 months, respectively. Concurrent chemotherapy was an independent prognostic factor for improved PFS and OS. Grade 3 neurologic toxicity was seen in 2 patients (3.2%). There was no grade 4/5 toxicity.ConclusionsThis is the only analysis of elderly/frail patients with GBM prospectively treated with a hypofractionated radiation regimen that is isoeffective to the Stupp regimen. Treatment was well tolerated and demonstrated excellent OS and PFS compared with historical studies. This regimen gives the elderly/frail population an alternative to regimens with a lower BED. Randomized trials are needed to validate these results.

Radiotherapy (RT) is one of the cornerstones in the current treatment paradigm for glioblastoma (GBM). However, little has changed in the management of GBM since the establishment of the current protocol in 2005, and the prognosis remains grim. Radioresistance is one of the hallmarks for treatment failure, and different therapeutic strategies are aimed at overcoming it. Among these strategies, nanomedicine has advantages over conventional tumor therapeutics, including improvements in drug delivery and enhanced antitumor properties. Radiosensitizing strategies using nanoparticles (NP) are actively under study and hold promise to improve the treatment response. We aim to describe the basis of nanomedicine for GBM treatment, current evidence in radiosensitization efforts using nanoparticles, and novel strategies, such as preoperative radiation, that could be synergized with nanoradiosensitizers.