bluuebunny/crossref_metadata_2025_split huggingface dataset:
RADT-08. ADJUVANT SBRT FOR RESECTED BRAIN METASTASES: THE EFFECT OF TIMING ON LONG-TERM INTENDED-FIELD CONTROL
Authors: Bander Evan , Yuan Melissa , Reiner Anne , Panageas Katherine , Brennan Cameron , Beal Kathryn , Tabar Viviane , Moss Nelson 
Published: December 2020

Abstract

INTRODUCTION
Adjuvant stereotactic body radiation therapy (SBRT) improves the local control of resected brain metastases (BrM). However, the dependency of long-term outcomes on SBRT timing relative to surgery remains unclear.

METHODS
Retrospective analysis of metastasectomy-plus-adjuvant-SBRT patients at Memorial Sloan Kettering (MSK) between 2013-2016 was conducted. Kaplan-Meier methodology was used to describe overall survival (OS) and cumulative incidence in a competing-risks setting recurrence at the surgical site, other SBRT-treated sites, and elsewhere in the brain as defined by RANO-BM criteria. Recursive partitioning analysis (RPA) and competing-risks regression modeling assessed prognostic variables and associated events of interest.

RESULTS
Two hundred eighty-two patients with BrM including non-small cell lung (34%), breast (16%), melanoma (13%), and other cancers were included. Median time-to-adjuvant-SBRT (TT-SBRT) was 34 days (IQR: 27-39). Median overall survival (OS) from SBRT was 1.5 years (95% CI: 1.2-2.1) with median follow-up of 49.8 months for survivors. Local surgical recurrence, other irradiated-site, and distant progression rates were 14.3% (95%CI: 10.1-18.5), 4.9% (95%CI: 2.3-7.5), and 47.5% (95%CI: 41.4-53.6) at 5 years, respectively. TT-SBRT as a continuous variable significantly associated with surgical-site recurrence (HR 1.05 [1.02-1.07], p=0.0003), but not with distant or other irradiated-site recurrence nor OS. RPA analysis demonstrated the greatest control rate advantage with TT-SBRT &lt; 39 days (HR for 39+ days: 2.81 [1.50-5.27], p=0.001). No association of TT-SBRT with radiation necrosis, wound complication, or development of leptomeningeal dissemination was identified.

CONCLUSIONS
Delays in initiation of post-operative SBRT can decrease its efficacy. Efforts must be made to minimize logistical, procedural, and socioeconomic factors responsible for these delays.
RADT-15. PREOPERATIVE SINGLE FRACTION RADIOSURGERY VERSUS POSTOPERATIVE FRACTIONATED RADIOSURGERY FOR RESECTED BRAIN METASTASES: A BI-INSTITUTIONAL ANALYSIS OF SAFETY AND CLINICAL OUTCOMES
Authors: Prabhu Roshan , Shi Siyu , Dhakal Reshika , Soltys Scott , Burri Stuart , Asher Anthony , Gephart Melanie , Ward Matthew , Li Gordon , Heinzerling John , Pollom Erqi 
Published: December 2020

Abstract

BACKGROUND
Preoperative single fraction radiosurgery (SRS) and postoperative fractionated SRS delivered over 3–5 fractions have been shown to have favorable outcomes compared to postoperative single fraction SRS for resected brain metastases. No study has directly compared these 2 treatment approaches.

METHODS
Records for patients with resected brain metastases treated with either single fraction preoperative SRS or fractionated (3-5 fractions) postoperative SRS were reviewed. Preoperative SRS was 10-20% dose reduced compared to standard and surgery generally followed within 48 hours. Eligibility criteria included solid tumor metastases, 1 brain metastasis resected, and no previous cranial RT. Fine-Gray and Cox multivariable (MVA) and propensity score matched (PSM) analyses were used.

RESULTS
A total of 330 patients (137 preoperative; 193 postoperative) were included. Median dose was 15 Gy in 1 fraction and 24 Gy in 3 fractions, respectively. In MVA, preoperative SRS was significantly associated with higher risk of cavity local recurrence (LR, hazard ratio (HR) 2.04, p=0.002) and lower risk of leptomeningeal disease (LMD, HR 0.41, p=0.05). There was no difference in adverse radiation effect (ARE) or overall survival (OS) between groups. In the PSM analysis (65 matched pairs), 1-year outcomes for preoperative vs. postoperative SRS were as follows - cavity LR: 22.9% vs. 3.1%, p&lt; 0.001, LMD: 4.2% vs. 15.5%, p=0.04, ARE: 3.2% vs. 7.9%, p=0.73, composite endpoint (cavity LR, symptomatic ARE, or LMD): 27.6% vs. 20.1%, p=0.33, OS: 56.3% vs. 62.3%, p=0.8.

CONCLUSIONS
Preoperative single fraction SRS and postoperative fractionated (3-5 fractions) SRS demonstrate distinct patterns of failure. Compared to postoperative SRS, preoperative SRS was associated with increased risk of cavity LR and lower risk of LMD in both multivariable and PSM analyses. There was no difference in risk of ARE or OS. Methods to reduce preoperative SRS cavity LR, such as with higher dose fractionated regimens, should be considered.
RADT-16. HYPOFRACTIONATED RADIOTHERAPY AND STEREOTACTIC RADIOSURGERY FOR VESTIBULAR SCHWANNOMAS: A SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: Tosi Umberto , Guadix Sergio , An Anjile , Wright Drew , Brandmaier Andrew , Knisely Jonathan , Pannullo Susan , Christos Paul , Ramakrishna Rohan 
Published: December 2020

Abstract

BACKGROUND
Vestibular schwannomas (VS) are tumors of the cerebellopontine angle with significant morbidity, causing hearing loss, tinnitus, and trigeminal and facial nerve compromise. Surgical resection is complex and often results in comorbidities, with radiation therapy being used to achieve tumor control. Both single dose stereotactic radiosurgery (SRS) and, in recent years, hypofractionated stereotactic radiotherapy (hSRT), where a total 18-25 Gy dose is given in approximately 3-5 fractions, have been utilized. It remains unclear, however, how each of these approaches fares compared to the other.

METHODS
Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Reviews were searched for studies either comparing hSRT with SRS or focusing on hSRT alone for the treatment of VS. Primary endpoints included tumor control, serviceable hearing, presence of tinnitus, and facial and trigeminal nerve symptoms. A random effects analysis was employed to compare pre- and post-treatment effects (hSRT alone) or SRS and hSRT outcomes (two-arm studies).

RESULTS
This analysis included 21 studies focusing on hSRT alone and 13 studies comparing SRS and hSRT. Significant heterogeneity was observed. Overall, when hSRT was analyzed alone, crude tumor control was achieved in 93% of 1571 patients at average follow-up of 49.9 months. There was no difference intra-group between pre- and post-treatment odds ratios (OR) of tinnitus, facial, or trigeminal impairment. However, serviceable hearing was diminished following hSRT (OR = 0.60, 95% CI: 0.44, 0.83, p = 0.002). Comparison with SRS showed no difference with respect to tumor control (p = 0.84), serviceable hearing (p = 0.65), trigeminal impairment (p = 0.96), or facial nerve impairment (p = 0.32).

CONCLUSIONS
hSRT achieved excellent tumor control and, with the exception of serviceable hearing, did not result in worse cranial nerve symptomatology. Analyzing two-arm studies showed that hSRT is a treatment modality comparable to SRS with respect to tumor control and cranial nerve comorbidities.
RADT-27. ASSOCIATION BETWEEN ADJUVANT RADIATION THERAPY AND OVERALL SURVIVAL IN PLEOMORPHIC XANTHOASTROCYTOMA
Authors: Khalafallah Adham , Rakovec Maureen , Mukherjee Debraj 
Published: December 2020

Abstract
Pleomorphic Xanthoastrocytoma (PXA) is a low-grade central nervous system (CNS) tumor with a generally favorable prognosis. However, due to its rarity, optimal adjuvant treatment guidelines have not been established by large scale studies. In this study, we investigated the effect of adjuvant radiation therapy (RT) on overall survival (OS) in adult patients with PXA to help address this unanswered question. The National Cancer Database (NCDB) was used to identify adult patients (age 18 years old) diagnosed with histologically confirmed PXA (2004-2016). Patient demographics, tumor characteristics, and treatment information were collected. Kaplan-Meier curves were generated to study OS, and factors that affected OS were identified using a multivariate Cox proportional hazards (CPH) model. A total of 546 patients were identified. The average age of patients at diagnosis was 36.6 years old, and overall median survival was 128.6 months. RT was used to treat 179 (33.3%) patients. Those who received RT had a shorter median OS (33.3 months) compared to those who did not (&gt; 128.6 months, p &lt; 0.001). Our multivariate model demonstrated receiving RT was independently associated with a significantly higher risk of death (hazard ratio [HR]=4.28, 95% confidence interval [CI] = 1.77-10.38, p = .0013). Patients ≥ 65 years of age also demonstrated significantly higher risk of death (HR = 2.20, CI = 1.54-4.16, p = 0.006) and had a decreased median OS (26.0 months). In adults with PXA, treatment with RT is independently associated with a significantly higher risk of mortality. The routine use of this modality in treating PXA warrants further study.
RADT-31. PATTERNS OF CARE IN THE USE OF ADJUVANT RADIOTHERAPY AND CHEMOTHERAPY IN LOW GRADE GLIOMA PATIENTS IN THE UNITED STATES FROM 2010-2016
Authors: Rehrer Warren , Odia Yazmin , Rubens Muni , Kalman Noah , Chuong Michael , Kotecha Rupesh , Mehta Minesh , Hall Matthew 
Published: December 2020

Abstract

PURPOSE
In 2016, RTOG 9802 reported an overall survival advantage with the addition of chemotherapy to adjuvant radiotherapy (CRT) in patients with high-risk low grade glioma (LGG). We used the National Cancer Database (NCDB) to measure trends in CRT use in LGG patients from 2010-2016, a period when no Level 1 evidence existed.

METHODS
The NCDB was queried for WHO Grade II glioma patients treated from 2010-2016 who met the inclusion criteria for RTOG 9802. Adjusted logistic regression was used to assess the association of treatment year with the annual percentage of patients who received adjuvant CRT. Relative percent change and average annual percentage change (AAPC) were compared to determine if a change (defined a priori as &lt; 0.01) occurred in the use of adjuvant CRT in LGG patients during this period.

RESULTS
The analytic cohort consisted of 5,039 patients; 64.3% of patients were 40 years or older and 35.7% were under 40 with subtotal resection. Use of adjuvant CRT increased from 18.9% to 49.7% (p&lt; 0.001) during 2013-2016, with no change observed before 2013. The AAPC in the use of CRT was +39.6% per year (p&lt; 0.001). Corresponding declines in patients treated with surgery alone (p&lt; 0.001) and surgery plus radiotherapy (p&lt; 0.001) were observed during 2013-2016. Logistic regression demonstrated patients who were under 40 years old were significantly less likely to receive adjuvant CRT than patients 40 years or older (Odds Ratio 0.561, 95% CI 0.475-0.663, p&lt; 0.001). Use of adjuvant CRT increased from 12.5% to 45.1% in patients with oligodendroglioma during 2013-2016 (p&lt; 0.001).

CONCLUSIONS
During 2013-2016, an increasing number of patients with LGG were treated with surgery followed by adjuvant CRT. Future studies may characterize the use of single agent vs. multiagent chemotherapy in this population and the adoption of trimodality therapy by mutation status.
RADT-33. RADIOSURGERY VERSUS COMBINATION RADIOSURGERY-BEVACIZUMAB FOR THE TREATMENT OF RECURRENT HIGH-GRADE GLIOMA: A SYSTEMATIC REVIEW
Authors: Kulinich Daniel , Sheppard John , Nguyen Thien , Kondajji Aditya , Unterberger Ansley , Enomoto Adam , Patel Kunal , Gopen Quinton , Yang Isaac 
Published: December 2020

Abstract

BACKGROUND
High-grade gliomas (HGG) comprise the most common primary adult brain cancers and universally recur. Combination re-radiation therapy (reRT) and bevacizumab (BVZ) therapy for recurrent HGG is common, but its reported efficacy is mixed.

OBJECTIVE
To assess clinical outcomes after reRT±BVZ in recurrent HGG patients receiving stereotactic radiosurgery (SRS), hypo-fractionated (HFSRT), or fully fractionated RT (FSRT).

METHODS
We performed a systematic review of PubMed, Web of Science, Scopus, Embase, and Cochrane databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We identified studies reporting outcomes for patients with recurrent HGG treated via reRT±BVZ. Cohorts were stratified by BVZ treatment status and reRT modality (SRS, HFSRT, and FSRT). Outcome variables were overall survival (OS), and progression-free survival (PFS).

RESULTS
34 of 1,742 identified articles survived inclusion criteria (2%) and reported data on 954 patients receiving reRT alone and 445 patients receiving reRT+BVZ. All patients initially underwent standard-of-care therapy for their primary HGG. In a multivariate analysis that adjusted for median patient age, WHO Grade, RT dosing, reRT fractionation regimen, time between primary and reRT, and reRT target volume, BVZ therapy was associated with significantly improved OS (2.51 [0.11, 4.92] months, P=.041) but no significant improvement in PFS (1.40 [-0.36, 3.18] months, P=.099). Patients receiving BVZ also had significantly lower rates of RN (2.2% vs 9.5%, P &lt; .001).

CONCLUSIONS
Combination reRT+BVZ may improve OS and reduce rates of RN in recurrent HGG, but further controlled studies are needed to confirm these effects.
RADT-40. TRENDS IN THE USE OF RADIATION FOR MENINGIOMA ACROSS THE UNITED STATES
Authors: Matani Hirsch , Abel Stephen , Xu Linda , Yu Alexander , Ranjan Tulika , Karlovits Stephen , Wegner Rodney 
Published: December 2020

Abstract

BACKGROUND
Meningiomas are tumors originating from arachnoid cap cells on the surface of the brain or spinal cord. Treatment differs by grade but can consist of surgery, radiation therapy or both. We utilized the national cancer database (NCDB) to compare trends in the use stereotactic radiosurgery (SRS) and external beam radiation therapy (EBRT) in the management of meningioma.

METHODS
We queried the NCDB from 2004-15 for meningioma patients (Grade 1-3) treated with radiation therapy, either SRS or EBRT. Multivariable logistic regression was used to identify predictors of each treatment and to generate a propensity score. Propensity adjusted Kaplan-Meier survival curve analysis and multivariable cox hazards ratios were used to identify predictors of survival.

RESULTS
We identified 5406 patients with meningioma meeting above criteria. Median follow up was 43 months. 45%, 44%, and 11% were Grade 1, 2, and 3, respectively. Predictors for SRS were distance from treatment facility and histology. Predictors of EBRT were tumor size and WHO grade 2 or 3 disease. Tumor size, treatment year, and receipt of chemotherapy were associated with improved survival. Five and ten year survival rates were 89.2% vs. 72.6% (p &lt; 0.0001) and 80.3% vs. 61.4% (p = 0.29) for SRS and EBRT respectively. After propensity matching 226 pairs were generated. For SRS, 5 year survival was not significantly improved at 88.2% (p = 0.056)

CONCLUSIONS
In the present analysis, predictors of SRS utilization in management of meningioma include distance from treatment facility and histology whereas conventional EBRT utilization was associated with tumor size and grade 2 or 3 disease. Despite a possible survival benefit with SRS, inherent selection bias may confound interpretation of the apparent survival benefit reflected in our study.
RADT-42. ADJUVANT RADIATION THERAPY FOR SUBTOTALLY RESECTED CEREBELLAR LIPONEUROCYTOMA
Authors: McClelland Shearwood , Gardner Ulysses , Shah Mitesh , Watson Gordon , Shiue Kevin 
Published: December 2020

Abstract

INTRODUCTION
Classified as a benign glioneural tumor, cerebellar liponeurocytoma is a rare disease (fewer than 80 reported cases) and was upgraded from WHO grade I to grade II in 2007 due to its high recurrence rate. The authors report a case of definitive radiation therapy for recurrent subtotally resected cerebellar liponeurocytoma.

METHODS
An 80-year-old man having undergone seven resections for his left cerebellar liponeurocytoma without adjuvant therapy over the previous decade at outside institutions was referred for radiation therapy two months following his eighth resection, where gross total resection was limited by the lesion proximity to his brainstem resulting in a 2 cm residual left cerebellar lesion. Pathology revealed tumor cells strongly positive for synaptophysin and a Ki-67 labeling index &lt; 1%. Due to the propensity of this disease to recur following resection, his entire resection cavity was treated with external beam radiation therapy (EBRT) to 46 Gy, followed by a 10 Gy boost to his residual disease yielding a total of 56 Gy to the residual disease.

RESULTS
Reimaging following the initial 46 Gy revealed the residual disease remained amenable (&lt; 3 cm) to stereotactic radiosurgery (SRS), which was delivered via linear accelerator (10 Gy to the 80% isodose line) in a single fraction. Following EBRT + SRS, the patient responded well. At last follow-up, he has demonstrated no evidence of disease progression, brainstem-related morbidity or surgical incision-related morbidity.

CONCLUSIONS
The first reported case of SRS treatment of cerebellar liponeurocytoma as the culmination of a coordinated definitive plan beginning with EBRT supports the applicability and feasibility of this treatment strategy following subtotal resection. This case indicates that a radiation treatment plan similar to that for central neurocytoma may be an optimal strategy, and suggests that adjuvant radiation therapy following operative resection of this rare disease may be underutilized.
RADT-43. TREATMENT OF RETROPERITONEAL LEIOMYOSARCOMA BRAIN METASTASES WITH STEREOTACTIC RADIOSURGERY
Authors: McClelland Shearwood , Gardner Ulysses , Langer Mark , Shiue Kevin 
Published: December 2020

Abstract

INTRODUCTION
Retroperitoneal leiomyosarcoma is a relatively rare disease, with infrequent metastatic spread to the CNS. We present the first report of radiosurgical treatment of this disease.

METHODS
A 49-year-old woman developed leiomyosarcoma of the inferior vena cava and retroperitoneum with lung metastases on diagnosis. Following multiple courses of systemic and operative treatment, she developed a tender ulcerating mass in the left upper maxillary incisor associated with numbness along the upper gum, lip, and premaxillary area. CT revealed a 3.0 cm left posterior alveolar ridge gum lesion with bone invasion, for which she elected to undergo palliative radiation therapy (30 Gy in 10 fractions). Due to potential maxillary nerve involvement altering the intended radiation therapy treatment fields, an orbit/face MRI was performed to better delineate the lesion. On this MRI, two frontal lobe lesions were visualized; subsequent dedicated brain MRI revealed a total of five metastases (0.9 cm right superior frontal gyrus, 0.9 cm left middle frontal gyrus, 0.9 cm right postcentral gyrus, 0.7 cm right occipital, and 1.6 cm left occipital). Consequently, the decision was made to treat the brain metastases with linear accelerator (LINAC) stereotactic radiosurgery (SRS) to allow simultaneous treatment of the maxillary lesion and brain metastases.

RESULTS
A single CT simulation was performed for her intracranial and extracranial disease, using the Encompass face mask to allow for simultaneous head immobilization and optimal SRS targeting accuracy. LINAC SRS was delivered simultaneously during maxillary lesion radiation therapy to all five lesions (22 Gy to the 80% isodose line) in a single fraction with a 0.2 cm planning target volume (PTV) margin for each lesion.

CONCLUSIONS
The first reported case of metastatic retroperitoneal leiomyosarcoma brain metastases treated with SRS demonstrates the flexibility of LINAC (rather than Gamma Knife) SRS in allowing for simultaneous treatment of intracranial and extracranial metastatic disease.
RADT-45. EFFECT OF DIFFERENT RADIOTHERAPY TECHNIQUES ON HEMATOLOGICAL TOXICITY OF CRANIOSPINAL IRRADIATION
Authors: Zhang Yangqiong , Yang Huajun , Deng Guanhua , Luo Rishun , Zhang Ping , Cai Linbo 
Published: December 2020

Abstract

OBJECTIVE
To investigate the effect of different radiotherapy techniques on hematological toxicity of craniospinal irradiation.

METHODS
A retrospective study involving changes in hematology during craniospinal irradiation were conducted. 79 patients were divided into observation group and control group. 36 patients in observation group received intensity modulated radiation therapy and 43 patients in control group received three-dimensional conformal radiotherapy. The prescribed dose of PTV in the two groups are 28.8-36 Gy, and the single dose are 1.6-2.0 Gy. The hematological toxicity changes and bone marrow suppression stage of the two groups of patients before, during and after radiotherapy were recorded and analyzed.

RESULTS
90% of patients showed different bone marrow suppression stage during and after radiotherapy. During radiotherapy, the toxicity of hemoglobin in the observation group was more serious than that in the control group (z=-2.272, p=0.023). After radiotherapy, the toxicity of hemoglobin and white blood cells in the observation group was more serious than that in the control group (z=-3.053, p=0.002; z=-3.163, p=0.002).

CONCLUSION
We should closely observe the changes of hematological toxicity for craniospinal irradiation patient treated with IMRT and take corresponding preventive measures to avoid serious bone marrow suppression stage.
RBIO-02. COMBINING RADIOTHERAPY WITH PI3K ISOFORM-SPECIFIC INHIBITOR DECREASES RADIORESISTANCE AND SUPPRESSES TUMOR GROWTH IN GLIOBLASTOMA CELLS
Authors: Youn Seol Mi , Yoon Hong In 
Published: December 2020

Abstract
Glioblastoma (GBM) is the most malignant tumor that occurs within the brain and shows the dismal prognosis. The phosphoinositide 3-kinase (PI3K)-AKT signaling pathway plays a principal role in GBM. Also, Activated PI3K-AKT signaling by irradiation induces radioresistance. But, the pan-PI3K inhibitors cause side-effects in clinical trial. Different PI3K isoforms play non-redundant roles in brain tumor growth and regulating radioresistance. So it is expected that selective inhibition of PI3K isoforms decrease side effects. We demonstrated whether combining radiotherapy with the PI3K isoform inhibitor reduces radioresistance and tumor growth in GBM. Glioma261 expressed luciferase (GL261-luc) cell lines were used to investigate the synergistic effects of combining radiotherapy with the PI3K isoform inhibitors. GL261-luc were irradiated 1Gy with or without PI3K isoform inhibitors. GL261-luc irradiated by 1Gy was suppressed cell proliferation about 70% compared to control (p&lt; 0.001). When irradiated with PI3K-isform inhibitor, each growth rate was about 18% (PI3K-pan, p&lt; 0.00001), 25% (PI3K-alpha, p&lt; 0.00001), 30% (PI3K-delta, p&lt; 0.00001), 45% (PI3K-gamma/delta, p&lt; 0.00001). Significant increase of DNA DSB and decrease of the migration ability were shown by combination radiotherapy with PI3K- isoform inhibitor. Especially, combining radiotherapy, PI3K-alpha inhibitor showed the effect similar to PI3K-pan inhibitor (In vitro). So, we analyzed combination therapy effects using PI3K-alphs inhibitor and radiotherapy in vivo. We demonstrated that combining radiotherapy with the PI3K-alpha isoform inhibitor markedly delayed tumor growth than radiotherapy only (p&lt; 0.0001). Also, we confirmed that survival rate of intracranial GBM mouse was increased by combination therapy (p&lt; 0.01). In addition, the expression of PD1, regulator of cancer immune system, in spleenocyte was increased by combination therapy (p&lt; 0.001) (In vivo). Our results demonstrate that combining radiotherapy with the PI3K-alpha isoform improve radiosensitivity, which result in significant tumor growth delay and improved survival.