Comparison of a Novel Curvilinear Approach to Conventional Rectilinear Approach for Prostate Seed Implant

Purpose: To evaluate dosimetric benefit of curvilinear distribution of seeds for low-dose-rate (LDR) prostate brachytherapy with I-125 isotopes. American Association of Physicists in Medicine (AAPM) 52nd Annual Meeting July 18-22, Philadelphia, P

Effects of EGFR Expression on Anti-tumor Efficacy of Vandetanib or Cediranib Combined with Radiotherapy (RT) in U87 Human Glioblastoma (GBM) Xenografts

Introduction: Vandetanib is a receptor tyrosine kinase inhibitor (RTKI) with activity against vascular endothelial growth factor receptor-2 (VEGFR-2) and epidermal growth factor receptor (EGFR). Cediranib is a highly potent VEGF RTKI that inhibits all three VEGF receptors. In this study we investigated the effect of exogenous overexpression of EGFR on sensitivity of human GBM U87 xenografts to vandetanib or cediranib, alone or in combination with RT. American Association for Cancer Research (AACR) 101st Annual Meeting April 17-21, Washington, DC

Effect of Cediranib, Temozolamide and Radiotherapy in U87 GBM wtEGFR and EGFRvIII-expressing Xenografts

Introduction: Glioblastomas (GBM) frequently overexpress the epidermal growth factor receptor (wtEGFR) or its mutant, EGFRvIII contributing to radioresistance. New treatment strategies for GBM include blockade of EGFR signaling and angiogenesis. Cediranib (CD) is a highly potent VEGFR-2 RTKI that inhibits all three VEGF receptors. This study investigated the radiosensitizing potential of CD in combination with temozolamide (TMZ) in U87 GBM xenografts expressing wtEGFR or EGFRvIII. Radiation Research Society (RRS) 8th Annual Meeting September 25-29, Maui, H

Evolving Role of Vorinostat Combined with Radiation Therapy in the Treatment of Brain Tumors, from the Lab to the Clinic

Purpose/Objective(s): Radiation therapy (RT) is a critical element in the treatment of both brain metastases and glioblastoma (GBM). Temozolomide (TMZ) has an established role in the upfront treatment of GBM. Down-regulated mismatch repair (MMR) is a known mechanism of resistance to TMZ. Vorinostat (SAHA), an HDAC inhibitor, has successfully been combined with a number of cytotoxic agents, including ionizing radiation (IR). We performed a series of preclinical and clinical studies to examine the role of SAHA in the treatment of brain tumors. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

Toxicity of Phase I Radiation Oncology Trials: Worldwide Experience

Introduction: Informed consent involves understanding the risks and benefits of trial enrollment. This is challenging in the phase I setting since true quantitative information is never known. We therefore performed an analysis of published radiation oncology (RO) phase I trials emphasizing patient outcomes. To our knowledge, no such systemic analysis has previously been published. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

The GUCY2C Tumor Suppressor is the Nexus of a Paracrine Hormone Axis Preventing Radiotherapy-Induced Gastrointestinal (GI) Toxicity

Purpose/Objective: Radiation-induced GI toxicity is the primary dose limitation compromising therapy in cancer patients treated with radiation therapy. GUCY2C is the intestinal receptor for diarrheagenic bacterial enterotoxins and the endogenous paracrine hormones guanylin and uroguanylin. Following genomic insult, cyclic (c)GMP produced by ligand activation of GUCY2C enhances DNA damage sensing and repair in intestinal cells. Here, we show that the GUCY2C-cGMP axis mediates p53-dependent radioprotection of intestinal epithelial cells. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

Functional Antagonism Between Vorinostat and Temozolomide when Combined with Ionizing Radiation (IR) in Glioblastoma

Background: Glioblastoma is the most common primary adult brain tumor. Surgery followed by radiation therapy in combination with temozolomide (Tmz) produces a median survival of 14.6 months. Tmz is a DNA akylating agent that leads to the mispairing of guanine residues with thymine. An intact mismatch-repair mechanism (MMR) converts the mispaired thymine into a lethal double-strand DNA break. Vorinostat (SAHA), an HDAC inhibitor, has been shown to act as a radiosensitizer, possibly through inhibition of DNA repair. SAHA has successfully been combined with a number of cytotoxic agents. We hypothesized that SAHA would further potentiate the radiosensitizing properties of Tmz in glioblastoma. American Association for Cancer Research (AACR) 101st Annual Meeting April 17-21, Washington, D

Chart Rounds in the Digital Age: A Survey of North American Institutions

Purpose/Objective(s): In light of public concerns regarding the quality of radiation treatment delivery, we surveyed the utilization of “chart rounds” or peer-review quality assurance meetings, within North American academic institutions. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

Dosimetric Comparison of VMAT, IMRT and Proton Therapy for Post- Prostatectomy Radiation Therapy for Prostate Cancer

Purpose/Objectives: Radiation therapy (RT) for the treatment of prostate cancer after radical prostatectomy (RP) is widely accepted. With technological advances, radiation treatment technique and dosimetry may vary. The purpose of this study is to quantify dosimetric difference of proton therapy versus VMAT and IMRT focusing on bladder and rectal dose sparing and target coverage. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C