bluuebunny/crossref_metadata_2025_split huggingface dataset:
RADT-07. RADIOGRAPHIC “NECROSIS" FOLLOWING SINGLE-FRACTION SRS AND IMMUNE CHECKPOINT INHIBITION IS ASSOCIATED WITH IMPROVED SURVIVAL IN PATIENTS WITH BRAIN METASTASES: AN INTERNATIONAL MULTICENTER STUDY
Authors: Lehrer Eric , Ahluwalia Manmeet , Gurewitz Jason , Bernstein Kenneth , Kondziolka Douglas , Wei Zhishuo , Niranjan Ajay , Lunsford L Dade , Fakhoury Kareem , Rusthoven Chad , Mathieu David , Trudel Claire , Malouff Timothy , Ruiz-Garcia Henry , Bonney Phillip , Hwang Lindsay , Yu Cheng , Zada Gabriel , Patel Samir , Deibert Christopher , Picozzi Piero , Franzini Andrea , Attuati Luca , Prasad Rahul , Raval Raju , Palmer Joshua , Lee Cheng-Chia , Yang Huai-che , Jones Brianna , Green Sheryl , Sheehan Jason , Trifiletti Daniel 
Published: November 2022

Abstract

OBJECTIVE
Immune checkpoint inhibitors (ICI) and stereotactic radiosurgery (SRS) are commonly utilized in the management of brain metastases. Treatment-related imaging changes (TRIC) are a frequently observed clinical manifestation and are commonly classified as radiographic radiation necrosis. However, these findings are not well characterized and may predict for response to SRS and ICI.

METHODS
The diagnosis-specific graded prognostic assessment was used to guide variable selection. TRIC were determined based upon MRI, PET/CT, or MR spectroscopy and a consensus by local clinical providers was required.

RESULTS
The analysis included 697 patients with 4,536 brain metastases across 11 institutions in 4 countries. The median follow-up after SRS was 13.6 months. The median age was 66 years, 54.1% of patients were male, and 57.3%, 36.3%, and 6.4% were non-small cell lung cancer, melanoma, and renal cell carcinoma (RCC) histology, respectively. TRIC were observed in 9.8%. On univariable analysis, Karnofsky Performance Status (KPS) (hazard ratio [HR]: 0.98; p &lt; 0.001), presence of TRIC (HR: 0.67; p = 0.03), female sex (HR: 0.67; p &lt; 0.001), and prior resection (HR: 0.60; p = 0.03) were associated with improved OS. On multivariable analysis, KPS (HR: 0.98; p &lt; 0.001) and the presence of TRIC (HR: 0.66; p = 0.03) were associated with improved OS. A V12 Gy ≥ 10 cm3 (Odds Ratio [OR]: 2.78; p &lt; 0.001), prior whole brain radiation therapy (OR: 3.46; p = 0.006), and RCC histology (OR: 3.10; p = 0.01) were associated with an increased probability of developing TRIC. The median OS in patients with and without TRIC was 29.0 and 23.1 months, respectively (log-rank p = 0.03).

CONCLUSION
TRIC following ICI and SRS are associated with a median OS benefit of approximately 6 months. Further prospective study is warranted to further elucidate the role and etiology of this common clinical scenario.
RADT-10. THE LOST METASTASES: DEEP LEARNING’S POTENTIAL IN RADIOSURGERY QUALITY ASSURANCE
Authors: Bang Charmin , Chartrand Gabriel , Pawlowski Sophie , Emiliani Ramon , Markel Daniel , Bahig Houda , Samak Alexandre , Rajakesari Selvan , Lavoie Jérémi , Ducharme Simon , Roberge David 
Published: November 2022

Abstract

Introduction
Identifying, segmenting, measuring, and following multiple brain metastases treated with radiosurgery can be time consuming and error prone. Machine learning has shown promise for automated detection and segmentation. Recently, a U-Net inspired model combining volume aware loss functions and volume aware sampling methods was trained in an industrial-academic partnership. A total of 530 clinically annotated T1 gadolinium MRIs were used. Initial validation showed a high sensitivity (91%) with an average of 0.66 false positives per MRI. The goal of the present work was to characterize those “false positives” which may represent clinically undetected metastases.

METHODS
The images used for model development were clinically annotated for radiosurgery planning. Lesions had first been identified by a radiologist, second by clinicians during tumor board review, third by the treating radiation oncologist and the treating neurosurgeon (potentially after segmentation by a trainee) and finally by fellow radiation oncologists during quality assurance rounds. Despite these multiple checks, 10 patients (2%) had brain lesions considered potential clinical misses when all “false positives” were manually reviewed by a single investigator. Further detailed review including prior and subsequent imaging was used to arbitrate the nature of these lesions.

RESULTS
Among the 10 cases, four were confirmed as undetected metastases: two lesions required subsequent radiosurgery and 2 patients died prior to further imaging. The six other lesions were adjudicated as true “false positives” (typically vascular).

CONCLUSION
The multi-tier radiosurgery workflow at our institution left very few unidentified brain metastases (0.8%). Despite this low error rate, our AI algorithm still detected two lesions that required further treatment. Future investigations will focus on potential roles of AI in simplifying and accelerating our workflow. It also remains to be established if more undetected metastases would be seen in community settings where workflows include fewer sequential imaging reviews.
RADT-17. A CASE OF RECURRENT GLIOBLASTOMA EFFECTIVELY TREATED WITH TUMOR-TREATING-FIELDS(TTFS)
Authors: Geng Xin , Ji Hongming , Cheng Rui 
Published: November 2022

Abstract
The patient was admitted to our hospital due to sudden headache in February 2021, and the head MRI showed "right frontal mass". On February 8, 2021, a large right forehead mass resection was performed under general anesthesia. The postoperative pathology showed: Glioblastoma (WHO grade IV). Regular chemotherapy with temozolomide was given postoperatively. In June 2021, the re-examination of the head MRI examination considered the possibility of recurrence, and tumor-treating-fields(TTFs) was started. Subsequently, the head MRI was reviewed every 2 months, and it was seen that the lesions gradually shrank. At present, the patient is generally in good condition without headache and other discomfort, and has obtained 15 months of PFS since the operation.
RADT-19. CHEMORADIATION (CRT) TREATMENT WITH OR WITHOUT CONCURRENT TUMOR-TREATING FIELDS (TTFIELDS) IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (GBM)
Authors: Cappelli Louis , Kayne Allison , Pan Peter , Cordova James , Huang Jiayi , Wang Tony , Alnahhas Iyad , Shi Wenyin 
Published: November 2022

Abstract

OBJECTIVES
Standard of care for newly diagnosed glioblastoma after resection includes concurrent temozolomide (TMZ) and radiation therapy followed by adjuvant TTF with maintenance TMZ. Preclinical studies suggest TTF and radiotherapy work synergistically. We evaluate the benefit of concurrent TTF with CRT vs adjuvant TTF with TMZ after CRT.

METHODS
Concurrent TTF with CRT patients were enrolled in a single-arm pilot study (clinicaltrials.gov Identifier: NCT03477110). For the comparison control of adjuvant TTF, adult patients with newly diagnosed GBM that had a KPS ≥ 60 who received treatment with CRT and adjuvant TMZ + TTF from three institutions were included. The adjuvant TTF cohort excluded patients who progressed during CRT or did not receive TMZ. PFS and OS were compared between groups.

RESULTS
A total of 87 patients were included in this study, of which 30 received concurrent TTF with CRT. Median patient age was 58 in the concurrent TTF group and 59 in the adjuvant TTF group. The median KPS in both groups was. MGMT methylation was present in 33.3% of the concurrent TTF and 32.0% in the adjuvant TTF group. 40% received GTR in the concurrent group and 38% received GTR in the adjuvant group. Multifocal disease was appreciated in 40% of patients in the concurrent TTF group. There was no significant difference in median OS (p=0.38) or PFS (p=0.76).

CONCLUSIONS
There was no difference in OS or PFS between concurrent or adjuvant TTF treatment groups. However, the adjuvant TTF group is expected to be a better prognosis due to the elimination of patients that progressed or declined after initial CRT. The current study suggested concurrent TTF treatment achieved outcomes to that of a better prognosis group. The survival benefit of concurrent TTF with CRT vs adjuvant TTF is being tested in the phase 3 TRIDENT EF-32 clinical trial (NCT04471844).
RADT-22. RISING UTILIZATION AND REDUCED MEDICARE SPENDING OF SHORT-COURSE RADIATION THERAPY FOR PRIMARY CNS TUMORS IN ELDERLY ADULTS
Authors: Tringale Kathryn , Miller Alexandra , Beal Kathryn , Yang Jonathan , Pike Luke , Imber Brandon 
Published: November 2022

Abstract

INTRODUCTION
For elderly/frail glioma patients, shortening radiotherapy from 6 to 3 weeks (short-course RT [SC-RT]) is non-inferior to standard long course (LC-RT) though usage is estimated to be &lt; 20%. We analyzed real-world utilization of SC-RT with/without systemic therapy in Medicare beneficiaries treated with RT for primary CNS tumors using CMS data on radiation episodes.

METHODS
Radiation modality, year, age (65-74, 75-84, ≥ 85), and site-of-care (freestanding vs hospital-affiliated) were evaluated. Utilization of SC-RT (11-20 fractions) vs LC-RT (21-30 fractions) and systemic therapy was evaluated by multivariable logistic regression. Medicare spending over the 90-day episode was analyzed using multivariable linear regression (adjusted β coefficients reported).

RESULTS
From 2015-2019, 9,572 episodes were included (2,966 [31%] SC-RT). SC-RT utilization increased (27% in 2015, 34% in 2019; OR 1.2 per year [95%CI:1.1-1.2]) and was associated with older age (age ≥ 85 vs 65-74, OR 7.0 [95%CI:5.7-8.7], hospital-affiliated sites (OR 1.2 [95%CI:1.1-1.4]), conventional RT (vs IMRT OR 2.8 [95%CI 2.4-3.3]), and lack of systemic therapy (OR 1.2 [95%CI:1.1-1.3]; p &lt; 0.001 for all). Rise in SC-RT was concentrated in hospital-affiliated sites (interaction p = 0.005). Most (6,629, 69%) received systemic therapy with no differences by site-of-care (p = 0.34). Systemic therapy utilization increased over time (67% in 2015, 71% in 2019; OR 1.1 per year [95%CI:1.1-1.1]) and was less likely for older patients, conventional RT, and SC-RT (p-value &lt; 0.001 for all). SC-RT significantly reduced spending vs LC-RT (β=$8,416, 95%CI:8,317-8,515), while spending modestly increased with systemic therapy usage (β=$316, 95%CI:220-409).

CONCLUSIONS
While most Medicare beneficiaries received LC-RT for primary brain tumors, SC-RT utilization increased in hospital-affiliated centers; despite high-level evidence, discrepancy in SC-RT implementation by site-of-care persists and necessitates further investigation. Given RT course length had a greater impact on Medicare spending than systemic therapy, increased use of SC-RT in appropriate populations reflects an opportunity to increase high value care.
RADT-31. 68GA-DOTATATE PET VERSUS MRI-BASED TREATMENT PLANNING FOR POST-OPERATIVE AND INTACT MENINGIOMA: A DOSIMETRIC ANALYSIS
Authors: Perlow Haley , Prasad Rahul , Siedow Michael , Gokun Yevgeniya , McElroy Joseph , Matsui Jennifer , Cadieux Catherine , Eiler Daniel , Odou Sean , Addington Mark , Ivanidze Jana , Bovi Joseph , Kleefisch Christopher , Zoller Wesley , Palmer Joshua 
Published: November 2022

Abstract

Background
Nearly all meningiomas express somatostatin receptor 1/2 (SSTR1/SSTR2); therefore, SSTR ligands such as 68Ga-DOTATATE can be utilized for meningioma radiotherapy treatment planning. Incorporation of 68Ga-DOTATATE PET assists with target delineation and may reduce the dose to organs-at-risk (OARs). We hypothesize that 68Ga-DOTATATE PET-based treatment plans will reduce dose to OARs when compared to MRI-based plans.

METHODS
All treatment plans were rendered on computed tomography (CT) planning datasets, using RapidArc and 6MV photon energy. Two arcs were positioned on the coplanar axis with alternated collimator settings of 0 and 90 degrees to promote MLC sparing with a third unique vertex arc chosen independently to spare normal brain tissue and associated organs at risk (OAR). For MRI structures, a 1 cm expansion from the gross tumor volume (GTV) created a clinical treatment volume (CTV)60. A 2 cm expansion created a CTV54. For PET structures, a 1 cm expansion from the GTV created a CTV60. A 3 mm isotropic expansion created planning treatment volumes (PTVs). Plans were optimized such that Dmax to brainstem remained limited to 60Gy or less and Dmax to optic structures was limited to 54Gy or less.

RESULTS
18 meningioma patients were included (9 post-operative, 9 intact). The mean PTV volume using MRI was 258 ccs (306 ccs for post-operative, 210 ccs for intact), and the mean PTV volume using PET was 60 ccs (97 ccs for post-operative, 91 ccs for intact). The mean radiation dose to both optic nerves, the optic chiasm, both hippocampi, and the brainstem was reduced favoring PET-based treatment plans for both post-operative and intact patients.

CONCLUSION
Our study shows that incorporation of 68Ga-DOTATATE PET can reduce dose to OARs for post-operative and intact patients, and this difference may translate to reduced toxicity. 68Ga-DOTATATE PET guided radiation treatments are worthy of future prospective investigation.
RADT-33. INTRATUMORAL HEMORRHAGE IN VESTIBULAR SCHWANNOMAS FOLLOWING GAMMA KNIFE STEREOTACTIC RADIOSURGERY
Authors: Bin-Alamer Othman , Fogg David , Wei Zhishuo , Duehr James , Mallela Arka , Niranjan Ajay , Lunsford L Dade , Abou-Al-Shaar Hussam 
Published: November 2022

Abstract

INTRODUCTION
Intratumoral hemorrhage (ITH) is a rare occurrence in vestibular schwannomas (VS) resulting in worsening vestibular and cranial nerve deficits. Scarce data described the occurrence, management, and outcomes of ITH after stereotactic radiosurgery (SRS).

OBJECTIVE
The aim of this study is to delineate the incidence, presentation, management, and outcomes of ITH in VS patients following SRS.

METHODS
A total of 2058 patients with VS underwent Gamma Knife radiosurgery (GKRS) at the University of Pittsburgh Medical Center between 1987 and 2022. The authors identified patients with ITH. Their presentation, management, clinical, and imaging outcomes are reported and analyzed.

RESULTS
A total of 1902 VS patients had sufficient clinical and imaging follow-up data. Five Koos III (n = 1) and IV (n = 4) VS patients developed ITH after GKRS, resulting in a cumulative incidence rate of 0.26%. The age at presentation ranged from 62 to 79 years, and 3 of the patients were males. The time from VS diagnosis to GKRS ranged from 1-13 months, and the time from GKRS to ITH ranged from 2-130 months. Three patients had bleeding risk factors. One patient required urgent surgical intervention due to the ITH volume, while the other four patients initially were observed. Three remained stable and required no delayed intervention. Histopathological analysis revealed multiple fragments of S-100–positive cells, hemorrhage, and hemosiderin-laden macrophages. At last follow-up, 4 patients had clinically improved, and one remained stable.ConclusionVS ITH following SRS is a rare complication with a cumulative incidence rate of 0.26%. Patient-tailored management is vital based on patient presentation, acuity, and ITH size and characteristics.
RADT-36. MANAGEMENT OF PATIENTS WITH METASTATIC CENTRAL NERVOUS SYSTEM (CNS) GERMINOMA; A LITERATURE REVIEW
Authors: Abu-Arja Mohammad , Shatara Margaret , Okcu M Fatih , McGovern Susan , Su Jack M , Abdelbaki Mohamed 
Published: November 2022

Abstract

BACKGROUND
No consensus exists on the optimal irradiation volume/dose for patients with metastatic CNS germinoma. We reviewed the literature for a potential association between different treatment modalities and survival.

METHODS
We searched PubMed for studies on patients with primary metastatic CNS germinoma including detailed survival outcome data. We used the Kaplan-Meier method to estimate event-free survival (EFS) rates and log-rank test for comparison among treatment modalities.

RESULTS
We identified 124 patients from 38 studies published between 1990 and 2021. The median age of presentation was 15 years (range: 1.5–47 years). Treatment modalities included: chemotherapy only (n = 5), radiotherapy only (n = 31), and radio-chemotherapy (n = 88). Radiotherapy modalities included: craniospinal irradiation (CSI) (n = 69), whole-brain irradiation (WBI) (n = 19), whole ventricular irradiation (WVI) (n=16), focal and spine irradiation (n = 5), focal irradiation only (n = 9), and not specified (n = 1). The median focal irradiation dose was 36.6 Gy (range:19.5-59.8 Gy). The median doses for CSI, WBI, and WVI were 24 Gy (range: 10.8-49 Gy). Eighteen patients relapsed, 111 were alive without disease, 2 were alive with disease, and 12 died of disease. The median follow-up time was 5 years in survivors. Four patients who received only chemotherapy relapsed. Five-year EFS rates were similar in patients who received chemo-radiotherapy and radiotherapy alone (89%, 95%CI 81-97%, vs 88%, 95%CI 74-100%, p = 0.6). Patients who were treated with CSI had a longer 5-year EFS compared to patients treated with other modalities (92%, 95%CI 84-100% vs 80%, 95%CI 64-94% p = 0.03). EFS was similar in patients treated with CSI whether they received ≥ 24 Gy or less.

CONCLUSION
CSI is required to achieve prolonged relapse-free survival (RFS). CSI dose of &lt; 24 Gy may be sufficient to achieve sustained RFS. Future trials are needed to evaluate the potential role of neoadjuvant chemotherapy in reducing the dose/volume of irradiation in patients with metastatic CNS germinoma.
RADT-38. INCIDENCE OF HEARING IMPAIRMENT AFTER DEFINITIVE PROTON BEAM THERAPY FOR MALIGNANCIES OF THE BRAIN AND BASE OF SKULL
Authors: Gaito Simona , Hwang Eunji , Aznar Marianne , Ahern Verity , Twaithes David , France Anna , Sitch Peter , Indelicato Daniel J , Holtzman Adam , Pan Shermaine , Smith Ed , Whitfield Gillian 
Published: November 2022

Abstract

AIM
Aim of the project is to report the incidence of moderate/severe (G ≥ 3) long-term hearing impairment (HI) and to identify risk factors in patients treated for malignancies of the brain and base of skull with definitive Proton Beam Therapy (PBT) within the Proton Overseas Programme (POP).

METHODS
Clinical and treatment-related data from patients’ files stored in a national database and curated by a dedicated outcomes unit were extracted and analysed. Clinical toxicity data from the POP were graded as per Common Terminology Criteria for Adverse Events (CTCAE 4.0). Dosimetric data (Dmean to the cochlear structures) were extracted from the Treatment Planning System Proknow. For the purpose of this analysis, patients with radical definitive PBT only were selected.

RESULTS
Between 2008 - 2018, 229 UK patients received radical PBT overseas for Craniopharyngioma (104 patients;45.4%), Chordoma (60; 26.2%), Chondrosarcoma (53;23.1%), Meningioma (7;3%), Pituitary Adenoma (5;2.1%). Median age was 17 years (1-77). Median prescription dose was 55.8 Gy (45-75.8). Median dose to the Left and Right cochleas were 14.18 Gy (0-85.15) and 12.55 Gy (0-77.50), respectively. Eight patients developed G ≥ 3 HI (3.5%). Of those, 7 had received dose escalated treatments for radioresistant tumours (chordomas or condrosarcomas). In 4/8, the HI was bilateral. The median cochlear dose for the structures who developed G ≥ 3 HI was 48.99 Gy (10-76.87).

CONCLUSIONS
Incidence of G ≥ 3 HI in this patient population compares with historical cohorts, and, as expected, is higher in patients who receive dose escalated treatments for radioresistant tumours of the base of skull. Median dose in those who developed HI supports the use of dose constraints used in the clinical PBT practice.
RADT-41. IATROGENIC INFLUENCE ON PROGNOSIS OF RADIATION-INDUCED CONTRAST ENHANCEMENTS IN PATIENTS WITH GLIOMA WHO 1-3 FOLLOWING PHOTON AND PROTON RADIOTHERAPY
Authors: Eichkorn Tanja , Lischalk Jonathan , Deng Maximilian , Elisabetta Sandrini , Eva Meixner , Regnery Sebastian , Held Thomas , Bauer Julia , Bahn Emanuel , Semi Harrabi , Juliane Hoerner-Rieber , Klaus Herfarth , Juergen Debus , Laila Koenig 
Published: November 2022

Abstract
Radiation-induced contrast enhancement (RICE) is a common side effect following radiotherapy for glioma, but both diagnosis and handling are challenging. Due to the potential risks associated with RICE and its challenges in differentiating RICE from tumor progression, it is critical to better understand how RICE prognosis depends on iatrogenic influence. We identified 99 patients diagnosed with RICE who were previously treated with either photon or proton therapy for World Health Organization (WHO) grade 1-3 primary gliomas. Post-treatment brain MRI-based volumetric analysis and clinical data collection was performed at multiple time points. The most common histologic subtypes were astrocytoma (50%) and oligodendroglioma (46%). In 67%, it was graded WHO grade 2 and in 86% an IDH mutation was present. RICE first occurred after 16 months (range: 1 - 160) in median. At initial RICE occurrence, 39% were misinterpreted as tumor progression. A tumor-specific therapy including chemotherapy or re-irradiation led to a RICE size progression in 86% and 92% of cases, respectively and RICE symptom progression in 57% and 65% of cases, respectively. A RICE-specific therapy such as corticosteroids or Bevacizumab for larger or symptomatic RICE led to a RICE size regression in 81% of cases with symptom stability or regression in 62% of cases. RICE progression went along with a worsening in progression-free survival (p = 0.04). While with chemotherapy and re-irradiation a RICE progression was frequently observed, anti-edematous or anti-VEGF treatment frequently went along with a RICE regression. For RICE, correct diagnosis and treatment decisions are challenging and critical and should be made interdisciplinarily.