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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.

Local management for vestibular schwannoma (VS) is associated with excellent local control with focus on preserving long-term serviceable hearing. Fractionated proton radiation therapy (FPRT) may be associated with greater hearing preservation because of unique dosimetric properties of proton radiotherapy.To investigate hearing preservation rates of FPRT in adults with VS and secondarily assess local control and treatment-related toxicity.A prospective, single-arm, phase 2 clinical trial was conducted of patients with VS from 2010 to 2019. All patients had serviceable hearing at baseline and received FPRT to a total dose of 50.4 to 54 Gy relative biological effectiveness (RBE) over 28 to 30 fractions. Serviceable hearing preservation was defined as a Gardner-Robertson score of 1 to 2, measured by a pure tone average (PTA) of ≤50 dB and a word recognition score (WRS) of ≥50%.Twenty patients had a median follow-up of 4.0 years (range 1.0-5.0 years). Local control at 4 years was 100%. Serviceable hearing preservation at 1 year was 53% (95% CI 29%-76%), and primary end point was not yet reached. Median PTA and median WRS both worsened 1 year after FPRT (P.0001). WRS plateaued after 6 months, whereas PTA continued to worsen up to 1 year after FPRT. Median cochlea D90 was lower in patients with serviceable hearing at 1 year (40.6 Gy [RBE] vs 46.9 Gy [RBE]), trending toward Wilcoxon rank-sum test statistical significance (P = .0863). Treatment was well-tolerated, with one grade 1 cranial nerve V dysfunction and no grade 2+ cranial nerve dysfunction.FPRT for VS did not meet the goal of serviceable hearing preservation. Higher cochlea doses trended to worsening hearing preservation, suggesting that dose to cochlea correlates with hearing preservation independent of treatment modality.

Purpose The quality of life (QoL) impact of multidisciplinary treatment for patients with nonfunctioning pituitary macroadenomas (NFPMA) is unclear. We sought to investigate associations between patient factors, clinical data, and patient-reported QoL in patients with NFPMA. Methods Patients with treated NFPMA and > 1 year of follow up after transsphenoidal surgery (TSS) and with no evidence of progressive disease were evaluated utilizing the following patient-reported outcome measures: RAND-36-Item Health Survey, Multidimensional Fatigue Inventory, Cognitive Failures Questionnaire. Results 229 eligible patients completed QoL questionnaires a median of 7.7 years after initial transsphenoidal surgery (TSS). 25% of participants received radiation therapy (RT) a median of 2.0 years (0.1–22.5) after initial TSS. Patients who received RT were younger (median age 46 v 58, p Conclusion Hypopituitarism, radiation therapy after TSS, and financial stressors are associated with more impaired QoL in patients with NFPMA. Awareness of these factors can better guide use and timing of radiation therapy in addition to identifying patients who can benefit from multidisciplinary surveillance.

GBM8 and GBM24 growth in culture.

Tumor genotypes and CTC frequency

DNA-FISH analysis of non-EGFR-amplified GBM CTCs.

Immunohistologic and DNA-FISH analysis of tumor cells and CTCs from a patient with metastatic GBM.

Methods and Supplementary Figure Legends

STEAM cocktail staining specifically identifies GBM cells.

Clinical association of CTC frequency

Unsupervised hierarchical clustering analysis of patient and xenograft single cell qRT-PCR expression data.

Purpose:Perineural invasion (PNI) is associated with aggressive tumor behavior, recurrence, and metastasis, and can influence the administration of adjuvant treatment. However, standard histopathologic examination has limited sensitivity in detecting PNI and does not provide insights into its mechanistic underpinnings.Experimental Design:A multivariate Cox regression was performed to validate associations between PNI and survival in 2,029 patients across 12 cancer types. Differential expression and gene set enrichment analysis were used to learn PNI-associated programs. Machine learning models were applied to build a PNI gene expression classifier. A blinded re-review of hematoxylin and eosin (H&E) slides by a board-certified pathologist helped determine whether the classifier could improve occult histopathologic detection of PNI.Results:PNI associated with both poor overall survival [HR, 1.73; 95% confidence interval (CI), 1.27–2.36; P < 0.001] and disease-free survival (HR, 1.79; 95% CI, 1.38–2.32; P < 0.001). Neural-like, prosurvival, and invasive programs were enriched in PNI-positive tumors (Padj < 0.001). Although PNI-associated features likely reflect in part the increased presence of nerves, many differentially expressed genes mapped specifically to malignant cells from single-cell atlases. A PNI gene expression classifier was derived using random forest and evaluated as a tool for occult histopathologic detection. On a blinded H&E re-review of sections initially described as PNI negative, more specimens were reannotated as PNI positive in the high classifier score cohort compared with the low-scoring cohort (P = 0.03, Fisher exact test).Conclusions:This study provides salient biological insights regarding PNI and demonstrates a role for gene expression classifiers to augment detection of histopathologic features.

Supplementary Data Legends

Supplementary Figure S1

Supplementary Table 1

PDF file, 138K, High-throughput profiling of survival following exposure to �-radiation.

PDF file, 109K, Clonogenic survival of lung SqCC after radiation (S1); High-throughput profiling of lung SqCC after radiation (S2); Mutations in NFE2L2 and KEAP1 in lung SqCC cell lines (S3); MSigDB Gene Sets from Fig S5 (S4); TP53 alterations, LOH, and mRNA levels in lung SqCC cell lines (S5).

PDF file, 282K, Clonogenic survival following exposure to �-radiation.

PDF file, 103K, NFE2L2 is frequently activated in human cancers.

PDF file, 76K.

PDF file, 156K.

PDF file, 86K, ssGSEA identifies gene sets that correlate with radiation resistance (left) and sensitivity (right). Top 15 gene sets are listed.

PDF file, 20K, High-throughput profiling of lung cancer cell lines.

PDF file, 1002K, ssGSEA identifies gene sets that correlate with radiation resistance (left) and sensitivity (right). Top 50 gene sets are listed.

BACKGROUND: Decreased peripheral lymphocyte counts are associated with outcome after RT in several solid tumors, though appear late during or after the radiation course and often correlate with other clinical factors. Here we investigate if absolute lymphocyte counts (ALC) are independently associated with recurrence in pediatric medulloblastoma early during RT. METHODS: We assessed 202 medulloblastoma patients treated between 2000 and 2016 and analyzed ALC throughout therapy, focusing on both early markers (ALC during week 1 – ALC(wk1); grade 3+ Lymphopenia during week 2 – Lymphopenia(wk2)) and late markers (ALC nadir). Uni- and multivariable regressions were used to assess association of clinical and treatment variables with ALC and of ALC with recurrence. RESULTS: Thirty-six recurrences were observed, with a median time to recurrence of 1.6 years (Range 0.2–10.3) and 7.1 years median follow-up. ALC during RT was associated with induction chemotherapy (p

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal and treatment-refractory cancer. Molecular stratification in pancreatic cancer remains rudimentary and does not yet inform clinical management or therapeutic development. Here, we construct a high-resolution molecular landscape of the cellular subtypes and spatial communities that compose PDAC using single-nucleus RNA sequencing and whole-transcriptome digital spatial profiling (DSP) of 43 primary PDAC tumor specimens that either received neoadjuvant therapy or were treatment naive. We uncovered recurrent expression programs across malignant cells and fibroblasts, including a newly identified neural-like progenitor malignant cell program that was enriched after chemotherapy and radiotherapy and associated with poor prognosis in independent cohorts. Integrating spatial and cellular profiles revealed three multicellular communities with distinct contributions from malignant, fibroblast and immune subtypes: classical, squamoid-basaloid and treatment enriched. Our refined molecular and cellular taxonomy can provide a framework for stratification in clinical trials and serve as a roadmap for therapeutic targeting of specific cellular phenotypes and multicellular interactions.

PURPOSE The optimal timing of adjuvant radiation therapy (RT) in the management of atypical meningiomas remains controversial. We compared the outcomes of atypical meningiomas managed with upfront adjuvant RT versus postoperative surveillance. METHODS AND MATERIALS Patients with intracranial atypical meningiomas who underwent resection between 2000 and 2015 at a single institution were identified. Patients receiving adjuvant RT (n = 51), defined as RT within the first year of surgery before tumor progression/recurrence (P/R), were compared with those undergoing initial surveillance (n = 179). The primary endpoints were radiographic evidence of P/R and time to P/R from surgery. RESULTS A total of 230 patients were identified. Fifty-one (22%) patients received upfront adjuvant RT, and 179 (78%) underwent surveillance. Compared with the surveillance group, patients who received adjuvant RT had larger tumors (5.2 cm vs 4.6 cm; P = .04), were more likely to have undergone subtotal resection (65% vs 26%; P < . 01), and more often had bone invasion (18% vs 7%; P = .02). On multivariable analysis, receipt of adjuvant RT was associated with a lower risk of P/R compared with surveillance (hazard ratio, 0.21; 95% confidence interval, 0.11-0.41; P < .01). Patients who initially underwent surveillance and then received salvage RT at time of P/R had a shorter median time to local progression after RT compared with patients who developed local P/R after upfront adjuvant RT (19 vs 64 months, respectively; P < . 01). CONCLUSION Upfront adjuvant RT was associated with improved local control in atypical meningiomas irrespective of extent of initial resection compared with surveillance. Early adjuvant RT should be strongly considered after gross total resection of atypical meningiomas.

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.

With increasing attention on the essential roles of the tumour microenvironment in recent years, the nervous system has emerged as a novel and crucial facilitator of cancer growth. In this Review, we describe the foundational, translational, and clinical advances illustrating how nerves contribute to tumour proliferation, stress adaptation, immunomodulation, metastasis, electrical hyperactivity and seizures, and neuropathic pain. Collectively, this expanding knowledge base reveals multiple therapeutic avenues for cancer neuroscience that warrant further exploration in clinical studies. We discuss the available clinical data, including ongoing trials investigating novel agents targeting the tumour-nerve axis, and the therapeutic potential for repurposing existing neuroactive drugs as an anti-cancer approach, particularly in combination with established treatment regimens. Lastly, we discuss the clinical challenges of these treatment strategies and highlight unanswered questions and future directions in the burgeoning field of cancer neuroscience.

Objective To assess the efficacy and toxicity of proton radiotherapy in vestibular schwannoma. Study design Retrospective chart review and volumetric MRI-analyses. Setting Tertiary referral center. Patients Vestibular schwannoma patients treated with protons between 2003 and 2018. Intervention Proton radiotherapy. Main outcome measures Tumor control was defined as not requiring salvage treatment. Progressive hearing loss was defined as a decrease in maximum speech discrimination score below the 95% critical difference in reference to the pretreatment score. Hearing assessment includes contralateral hearing and duration of follow-up. Dizziness and/or unsteadiness and facial and trigeminal nerve function were scored. Patients who had surgery prior to proton radiotherapy were separately assessed. Results Of 221 included patients, 136 received single fraction and 85 fractionated proton radiotherapy. Actuarial 5-year local control rate was 96% (95% CI 90-98%). The median radiological follow-up was 4.5 years. Progressive postirradiation speech discrimination score loss occurred in 42% of patients with audiometric follow-up within a year. Facial paresis was found in 5% (usually mild), severe dizziness in 5%, and trigeminal neuralgia in 5% of patients receiving protons as primary treatment. Conclusions Proton radiotherapy achieves high tumor control with modest side effects aside from hearing loss in vestibular schwannoma patients. Limited and heterogeneous outcome reporting hamper comparisons to the literature. Potential sequelae of radiation therapy impacting vestibular function, cognitive function, and quality of life warrant further evaluation. Subgroups that benefit most from proton radiotherapy should be identified to optimize allocation and counterbalance its costs.

INTRODUCTION High-grade meningiomas are associated with significant neuro-cognitive morbidity and a poor prognosis. Systemic therapies, to date, have demonstrated minimal efficacy. We recently found that high-grade meningiomas harbor an immunosuppressive tumor microenvironment and that programmed cell death-ligand 1 (PD-L1) expression may contribute to the aggressive phenotype of these tumors. Therefore, we conducted a single-arm, open-label phase II trial evaluating efficacy of pembrolizumab, a PD-1 inhibitor, in a cohort of 24 patients with recurrent and progressive grade II and III meningiomas. METHODS The primary endpoint was the rate of progression-free survival at 6 months. The trial distinguished between 6-month PFS (PFS-6) rates of 26% vs. 52%. If at least 10 patients demonstrated a 6-month PFS, among the 24 patients, the agent would be considered worthy of further study. This design has at least 88% power using an exact binomial test with a one-sided significance level of 0.1. RESULTS Between November 2017 to December 2019, twenty-four patients were enrolled. The majority of the patients in our cohort were heavily pre-treated; prior to enrolling to the study, twenty patients underwent more than one surgical resection and twelve patients had received more than one round of radiotherapy. Our study met its primary endpoint and achieved a 6-month progression-free survival rate of 0.50 (90% exact CI: 0.32-0.68) and a median PFS of 8.3 months (90% CI: 4.1-12.9 months). For the twelve patients who achieved the PFS-6 primary endpoint, median PFS from the start of treatment was 17.3 months (90% CI: 9.7 – 24.3 months). Four patients had grade-3 or higher adverse events that were at least possibly treatment-related, including colitis, skin infection, encephalopathy and transaminitis. CONCLUSION Our study achieved its primary endpoint. These results suggest that pembrolizumab exerts promising activity on these tumors and results in prolonged PFS compared to historical controls.

Background Rathke cleft cysts (RCCs) are sellar-based cystic lesions that are often found incidentally but occasionally become symptomatic with significant visual and/or endocrine deficits. The standard of treatment is surgery, but rare cases of multiply recurrent RCCs can be refractory to surgical drainage, leading to significant morbidity. Objective To demonstrate the safety and feasibility of fractionated stereotactic radiotherapy (SRT) as salvage therapy in multiply recurrent RCCs refractory to surgical drainage. Methods An IRB-approved retrospective review at a single institution was conducted to identify and describe patients with multiply recurrent RCCs refractory to surgical drainage who underwent SRT. Results From 1994 to 2015, 6 patients (5 female) who underwent SRT for recurrent RCCs were identified. A total of 4 presented with visual deficits, and 2 presented with endocrine dysfunction and severe headaches prior to their initial drainage. All patients had initial postoperative improvement but then developed multiple, symptomatic recurrences. Median number of surgical drainage procedures prior to radiotherapy was 3. A total of 3 patients underwent LINAC-based SRT, and 3 had proton-based SRT. Treatment doses were 45 Gy over 25 fractions (n = 5) and 50.4 Gy over 28 fractions (n = 1). Median follow-up after radiation therapy was 69 mo (range 24-154 mo). In the follow-up period, stabilization of the RCC was achieved, although 2 patients required additional drainage procedures. Only 1 patient developed new hypothyroidism and hypoadrenalism after SRT. Conclusion In rare cases of multiply recurrent RCCs refractory to repeat surgical drainage, stereotactic fractionated radiation therapy is a safe and effective salvage therapy.

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., Three randomized trials have shown a striking overall survival benefit with adjuvant procarbazine, lomustine, and vincristine (PCV) chemotherapy and radiotherapy for the treatment of patients with high‐risk lower grade gliomas, however the majority of patients currently receive temozolomide (TMZ) instead of PCV chemotherapy. This review article examines the best available evidence to inform the choice of PCV or TMZ for the treatment of high‐risk lower grade gliomas.

Histopathological grading of meningiomas is insufficient for optimal risk stratification. The purpose of the present study was to determine the prognostic value of atypical histopathological features across all nonmalignant meningiomas (World Health Organization [WHO] grade I-II).The data from 334 patients with WHO grade I (n = 275) and grade II (n = 59) meningiomas who had undergone surgical resection from 2001 to 2015 at 2 academic centers were pooled. Progression/recurrence (P/R) was determined radiographically and measured from the date of surgery.The median follow-up was 52 months. The patients were stratified by the number of atypical features: 0 (n = 151), 1 (n = 71), 2 (n = 66), 3 (n = 22), and 4 or 5 (n = 24). The risk of P/R increased with an increasing number of atypical features (log-rank test, P = 0.001). The 5-year actuarial rates of P/R stratified by the number of atypical features were as follows: 0, 16.3% (95% confidence interval [CI], 10.7-24.4); 1, 21.7% (95% CI, 12.8-35.2); 2, 28.2% (95% CI, 18.4-41.7); 3, 30.4% (95% CI, 13.8-58.7); and 4 or 5, 51.4% (95% CI, 31.7-74.5). On univariate analysis, the presence of high nuclear/cytoplasmic ratio (P = 0.007), prominent nucleoli (P = 0.007), and necrosis (P0.00005) were associated with an increased risk of P/R. On multivariate analysis, the number of atypical features (hazard ratio [HR], 1.30; 95% CI, 1.03-1.63; P = 0.03), ≥4 mitoses per high-power fields (HR, 2.45; 95% CI, 1.17-5.15; P = 0.02), subtotal resection (HR, 3.9; 95% CI, 2.5-6.3; P0.0005), and the lack of adjuvant radiotherapy (HR, 2.40; 95% CI, 1.19-4.80; P = 0.01) were associated with an increased risk of P/R.An increased number of atypical features, ≥4 mitoses per 10 high-power fields, subtotal resection, and the lack of adjuvant radiotherapy were independently associated with P/R of WHO grade I-II meningiomas. Patients with these features might benefit from intensified therapy.

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.

Background Patients with low-grade gliomas (LGG) can survive years with their illness. Proton radiotherapy (PRT) can reduce off-target dose and decrease the risk of treatment-related morbidity. We examined long-term morbidity following proton therapy in this updated prospective cohort of patients with LGG. Methods Twenty patients with LGG were enrolled prospectively and received PRT to 54 Gy(RBE) in 30 fractions. Comprehensive baseline and longitudinal assessments of toxicity, neurocognitive and neuroendocrine function, quality of life, and survival outcomes were performed up to 5 years following treatment. Results Six patients died (all of disease) and six had progression of disease. Median follow-up was 6.8 years for the 14 patients alive at time of reporting. Median progression-free survival (PFS) was 4.5 years. Of tumors tested for molecular markers, 71% carried the IDH1-R132H mutation and 29% had 1p/19q co-deletion. There was no overall decline in neurocognitive function; however, a subset of five patients with reported cognitive symptoms after radiation therapy had progressively worse function by neurocognitive testing. Six patients developed neuroendocrine deficiencies, five of which received Dmax ≥20 Gy(RBE) to the hypothalamus–pituitary axis (HPA). Most long-term toxicities developed within 2 years after radiation therapy. Conclusions The majority of patients with LGG who received proton therapy retained stable cognitive and neuroendocrine function. The IDH1-R132H mutation was present in the majority, while 1p/19q loss was present in a minority. A subset of patients developed neuroendocrine deficiencies and was more common in those with higher dose to the HPA.

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 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.

Patients undergoing cranial irradiation are at high risk for development of subsequent pituitary deficiencies. Patients with meningiomas can expect to live many years after treatment and are therefore particularly vulnerable to long-term sequalae of radiation therapy (RT). The purpose of this study was to determine the rates and timing of onset of pituitary dysfunction across each hypothalamic-pituitary axis in patients with meningiomas in the sellar region.Data from 74 patients with meningiomas in the sellar or perisellar region who underwent RT between 2001 and 2017 at a single academic center were analyzed. Dose-volume histograms were generated to determine the dose of radiation to the pituitary gland. Pituitary function tests were evaluated before and after completion of RT.There was a 20% risk for new hypopituitarism across any hypothalamic-pituitary axis after RT at a median follow-up of 43 months. Identified rates of dysfunction across each axis were 24% for thyroid and adrenal, 19% for growth hormone, and 10% for gonadal. Median time to develop deficiencies ranged from 11 months for growth hormone deficiency to 32 months for adrenal insufficiency. Deficiencies were likely to be correlated, with increased risk for thyroid dysfunction in patients with adrenal, gonadal, or prolactin deficiencies (P .05). On univariate analysis, mean dose to the pituitary gland and male sex were associated with increased risk for post-RT thyroid deficiency (P = .01 and P = .004, respectively). There was no difference in rates of hypothyroidism after protons compared with photons (P = .14).Cranial irradiation for sellar meningiomas carries a risk for subsequent hypopituitarism that appears to be dose dependent and may occur years after completion of RT. Growth hormone deficiency and gonadal dysfunction were likely underestimated here secondary to a lack of routine testing. Given the favorable tumor prognosis in this patient population, early and long-term endocrine follow-up is warranted.

BACKGROUND: Recurrent atypical and malignant meningiomas have poor outcomes with surgical therapy alone. Neither adjuvant chemotherapy nor postoperative radiation therapy remedies this problem. OBJECTIVE: To evaluate our experience with the treatment of 15 patients treated with I-125 or Cs-131 brachytherapy radiation seeds as an adjuvant in these difficult cases. METHODS: Patients with high-grade recurrent meningioma who underwent resection and intraoperative placement of brachytherapy seeds at our institution from 2002 to 2014 were identified and studied by retrospective chart review. RESULTS: Fifteen patients with median age of 68.8 yr were treated with I-125 (n = 13) or Cs-131 (n = 2) brachytherapy seeds for cases of recurrent, grade II (n = 8), or grade III (n = 7) meningioma at our institution from 2002 to 2014. These lesions originated from a variety of locations including, convexity (3), falcine (3), frontal (2), occipital (1), parietal (2), 2 sphenoid wing (2), and temporal (2), based recurrent meningiomas. Patients had a median of 2 prior open surgical interventions and received local radiation therapy with a median dose of 55 Gy prior to brachytherapy. Survival at 2.5 yr was 56% for grade II and 17% for grade III lesions. Survival was significantly associated with patient age but not tumoral pathology. Forty percent of patients required reoperations for wound complications following brachytherapy. CONCLUSION: Brachytherapy with implantation of permanent radiation seeds provides a viable alternative treatment for recurrent meningioma while carrying a significant clinical risk of wound infection and need for reoperation.

Cancer therapy-induced adverse effects on the brain are a major challenge in neuro-oncology. Brain tissue necrosis (treatment necrosis [TN]) as a consequence of brain directed cancer therapy remains an insufficiently characterized condition with diagnostic and therapeutic difficulties and is frequently associated with significant patient morbidity. A better understanding of the underlying mechanisms, improvement of diagnostic tools, development of preventive strategies, and implementation of evidence-based therapeutic practices are pivotal to improve patient management. In this comprehensive review, we address existing challenges associated with current TN-related clinical and research practices and highlight unanswered questions and areas in need of further research with the ultimate goal to improve management of patients affected by this important neuro-oncological condition.

Background Patients with metastatic HER2/neu-positive (HER2/neu +) breast cancer (BC) often experience treatment resistance, disease recurrences and metastases. Thus, new approaches for improving the treatment of HER2/neu + BC to prevent metastatic dissemination are urgently needed. Our previous studies have shown that losartan, an angiotensin receptor blocker, increases tumor perfusion and decreases hypoxia in a number of tumor models. Hypoxia reduces the efficacy of radiation and increases metastases. We therefore hypothesized that by modifying tumor stroma and increasing oxygenation, losartan will improve the outcome of radiotherapy and inhibit disease progression in a highly metastatic HER2/neu + murine BC model. Methods We established a metastatic HER2/neu + murine BC line (MCa-M3C) and used it to generate mammary fat pad isografts in syngeneic female FVB/N mice. Starting on day 3 after orthotopic tumor implantation, we administered a 7-day losartan treatment (40 mg/kg BW, gavage daily); or a 7-day losartan treatment followed by 20 Gy single dose local irradiation (S-IR) on day 10 (tumor size ~ 100 mm3), or 20 Gy local fractionated (5 × 4 Gy daily) irradiation (F-IR) on days 10–14. We analyzed tumor-growth delay (TGD), development of spontaneous lung metastases, animal survival, tumor vascular density, and tumor hypoxia. Results Treatments with S-IR, F-IR, Losartan + S-IR, or Losartan + F-IR resulted in a significantly increased TGD (8–16 days) in MCa-M3C tumors versus controls. However, the combination of Losartan + S-IR and Losartan + F-IR further enhanced tumor response to radiation alone by increasing TGD an additional 5 to 8 days for both single and fractionated dose irradiation (P vs. Control, P vs. Control, P = 0.0303). In addition, losartan treatment significantly increased tumor vascularity (P = 0.0314) and decreased pimonidazole positive (hypoxic) area (P = 0.0002). Conclusions Combining losartan with local irradiation significantly enhanced tumor response, at least in part via reduced tumor hypoxia presumably due to increased tumor perfusion. Our findings suggest that combining losartan with radiotherapy is a potential new treatment strategy for local control and inhibiting metastasis in HER2 + BC.

PURPOSE/OBJECTIVE(S) Management for vestibular schwannoma (VS) achieves excellent local control, and advances have increasingly focused on long-term serviceable hearing preservation. Fractionated stereotactic radiation therapy (FSRT) is associated with better hearing preservation compared to stereotactic radiosurgery (SRS). Fractionated proton beam radiation therapy (FPRT) may be associated with greater hearing preservation due to unique dosimetric properties of proton radiotherapy. MATERIALS/METHODS A single institution, prospective, single-arm, phase 2 clinical trial was designed for patients with VS between 2010-2019. All patients received FPRT to a total dose of 50.4-54Gy relative biological effectiveness (RBE) over 28-30 fractions. The primary endpoint was serviceable hearing preservation, defined as Gardner-Robertson (GR) score 1-2, defined as Pure Tone Average (PTA) ≤50dB and Word Recognition Score (WRS) ≥50%, at 5 years compared to a historical rate of serviceable hearing preservation of 65% in patients treated with photon radiation therapy. Other audiometric measures included Otoacoustic Emissions (OAE) and Auditory Brainstem Response (ABR). Preliminary analysis was performed for 20 patients accrued with a minimum follow up of 1.0 year. RESULTS Twenty patients were accrued with median follow up of 4.0 years (range 1.0-5.0 years), with a median age of 64 years, median RT dose of 50.4 Gy (RBE). Serviceable hearing preservation at 1 year was 53%, primary endpoint was not yet met. Local control at 4 years was 100%. Median cochlea D90 was lower for patients with serviceable hearing at 1 year (median 40.5 Gy (RBE) vs 46.9 Gy (RBE), P = 0.0863). V90, Dmean, Dmin, and other cochlea dosimetric measures were also generally lower, but the associations with hearing preservation at 1 year were not statistically significant. Median PTA at 1-year worsened from 42dB at baseline to 62dB (P < 0.0001), and median WRS at 1-year worsened significantly from 85% to 48% (P < 0.0001); PTA worsening developed earlier than WRS worsening. The rate of OAE absence significantly worsened from 60% at baseline to 100% at 1-year (P = 0.0156). Other audiometric measures, including contralateral PTA, ABR, tympanometry, were not independently associated with hearing preservation. Treatment was well tolerated, with low levels of acute and late-term toxicity; one patient incurred grade one CN V dysfunction, with no grade two or higher CN dysfunction. CONCLUSION FPRT for vestibular schwannoma results in high rates of local control with comparable serviceable hearing preservation compared to historical RT series. Audiometric analyses suggest radiation-associated hearing dysfunction is manifested as early PTA worsening followed by WRS worsening.

Purpose/objective(s) Nelson's syndrome is a rare disorder that may arise as a complication of treating Cushing's disease through bilateral adrenalectomy. It is characterized by growth of remaining pituitary adenoma and elevation of adrenocorticotropic hormone (ACTH) levels. Prior studies have established radiation therapy (RT) as a method of treating Nelson's syndrome. In this study, we evaluated the efficacy of proton stereotactic radiosurgery (PSRS) on decreasing ACTH levels and achieving disease remission in patients with Nelson's syndrome treated with SRS. Materials/methods A retrospective analysis of eight patients with Nelson's syndrome who received PSRS between 2007 and 2017 at our institution was conducted. All patients previously underwent bilateral adrenalectomy for treatment of Cushing's disease. Patients received PSRS at a total dose of 15 or 20 Gy(RBE) delivered in one fraction. The median clinical target volume was 5.7 cc (range 3.7-9.0 cc). ACTH levels, disease status, and post-treatment complications were followed post-SRS to assess for endocrine remission. Results The median follow-up was 80 months (range 35-126 months) from the end of SRS treatment. The median ACTH level decreased from 761.5 pg/mL pre-SRS to 38 pg/mL post-SRS at time of latest follow-up. Endocrine remission was achieved among six patients (75%) at a median time of 47 months (range 12 -126 months) from SRS. Three patients (38%) developed pituitary deficits (two with TSH and gonadal deficiency and one with pan-pituitary deficiency) post-SRS. Conclusion SRS can be an effective treatment to achieve endocrine remission in patients with Nelson's syndrome. SRS can lead to pituitary deficits in some patients and longer follow-up is warranted to assess long-term disease control and treatment toxicity. Author disclosure D.W. Kim: None. G. Lee: None. E. Cai: None. B. Swearingen: None. P.H. Chapman: None. M.R. Bussiere: Consultant; American College of Radiology. A. Klibanski: None. J.S. Loeffler: None. H.A. Shih: Employee; Dartmouth Hitchcock. Research Grant; AbbVie, NIH. Honoraria; UpToDate. Consultant; Cleveland Clinic. Speaker's Bureau; prIME Oncology. advisory; The Radiosurgery Society. director of clinical operations; Massachusetts General Hospital. clinical operational leader; Massachusetts General Hospital.