Publications by authors named "Kevin S Oh"

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

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

Study Design: Retrospective cohort.

View Article and Find Full Text PDF

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

Methods: NRG Oncology/RTOG1205 is a prospective, phase II, randomized trial of re-RT and BEV versus BEV alone.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Purpose: Cranial irradiation results in cognitive decline, which is hypothesized to be partially attributable to hippocampal injury and stem cell loss. Recent advances allow for targeted reduction of radiation dose to the hippocampi while maintaining adequate dose coverage to the brain parenchyma and additional increasing dose to brain metastases, a approach called hippocampal avoidance whole brain radiation therapy with a simultaneous integrated boost (HA-WBRT + SIB.) We review our early clinical experience with HA-WBRT + SIB.

View Article and Find Full Text PDF

The paradigm for post-operative cavity radiation therapy has shifted to more targeted, less morbid approaches. Single-fraction or hypofractionated radiation therapy is a common approach to treating the postoperative cavity but is associated with a local failure rate 20-40%. We employed an alternative treatment strategy involving fractionated partial brain radiation therapy to the surgical cavity.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: 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).

Methods: 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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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

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

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Purpose: 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.

View Article and Find Full Text PDF

Introduction: Concurrent radiotherapy and temozolomide (TMZ) is associated with radiographic pseudoprogression (PsP) in glioblastoma. The occurrence of PsP and other treatment effects is less well understood in low-grade gliomas (LGG). The purpose of this study is to evaluate whether the addition of TMZ to radiotherapy increases the incidence of PsP in adults with LGG treated with proton radiotherapy (PRT).

View Article and Find Full Text PDF

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

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

Methods: The American College of Surgeons, National Surgical Quality Improvement Program was used to identify patients that underwent operative intervention for metastatic disease.

View Article and Find Full Text PDF

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

View Article and Find Full Text PDF

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

Methods And Materials: This was a single institution retrospective review of children who were treated with CSI for medulloblastoma. Spine growth was measured on magnetic resonance imaging scans at defined locations on the basis of a published predictive model of spine growth after CSI.

View Article and Find Full Text PDF

Immunotherapy (IT) is increasingly incorporated in the management of metastatic melanoma patients with brain metastases, but the impact of timing of IT with stereotactic radiosurgery (SRS) remains unclear. The aim of this study was to determine the temporal significance of IT in melanoma patients treated with cranial radiation therapy (RT) with respect to patterns of intracranial progression, overall survival (OS), and toxicity. We retrospectively reviewed consecutive melanoma patients with brain metastases undergoing cranial RT and IT between 2008 and 2015.

View Article and Find Full Text PDF

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

Methods: We identified patients with advanced NSCLC with brain metastases who received cranial RT and were treated with or without programmed cell death 1/programmed death ligand 1 inhibitors between August 2013 and September 2016.

View Article and Find Full Text PDF

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

Methods And Materials: Ten postoperative completely resected cases with varying clinical scenarios and locations within the brain were selected.

View Article and Find Full Text PDF

Purpose: Stereotactic radiation therapy (SRT) enables focused, short course, high dose per fraction radiation delivery to brain tumors that are less ideal for single fraction treatment because of size, shape, or close proximity to sensitive structures. We sought to identify optimal SRT treatment regimens for maximizing local control while minimizing morbidity.

Methods And Materials: We performed a retrospective review of patients treated with SRT for solid brain metastases using variable dose schedules between 2001 and 2011 at 3 academic hospitals.

View Article and Find Full Text PDF

OBJECTIVE Patients with atypical and malignant (WHO Grade II and III) meningiomas have a worse prognosis than patients with benign (WHO Grade I) meningiomas. However, there is limited understanding of the pathological risk factors that affect long-term tumor control following combined treatment with surgery and radiation therapy. Here, the authors identify clinical and histopathological risk factors for the progression and/or recurrence (P/R) of high-grade meningiomas based on the largest series of patients with atypical and malignant meningiomas, as defined by the 2007 WHO classification.

View Article and Find Full Text PDF

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

View Article and Find Full Text PDF

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

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

View Article and Find Full Text PDF

To understand neurocognitive effects of proton radiation therapy (PRT) in patients with low-grade glioma, we evaluated 20 patients who received this therapy prospectively and over 5 years with a comprehensive neuropsychological battery. 20 patients were evaluated at baseline and at yearly intervals for up to 5 years with a battery of neuropsychological measures that assessed intellectual, attention, executive, visuospatial and memory functions as well as mood and functional status. We evaluated change in cognitive functioning over time.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionepjg80ekcg8i77fdmv831udumidkauev): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once