This study was conducted to evaluate the variability of gross tumor volume (GTV) using 11C-Choline and 18F-FDG PET/CT images for nasopharyngeal carcinomas boundary definition. Assessment consisted of inter-observer and inter-modality variation analysis. Four radiation oncologists were invited to manually contour GTV by using PET/CT fusion obtained from a cohort of 12 patients with nasopharyngea...

PURPOSE To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients. MATERIALS AND METHODS We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume w...

Due to respiratory motion, lung tumor can move up to several centimeters. If respiratory motion is not carefully considered during the radiation treatment planning, the highly conformal dose distribution with steep gradients could miss the target. To address this issue, the common strategy is to add a population-derived safety margin to the gross tumor volume (GTV). However, during a free breat...

Our objective was to determine if protons allow for the expansion of treatment volumes to cover high-risk nodes in patients with regionally advanced non-small-cell lung cancer. In this study, 5 consecutive patients underwent external-beam radiotherapy treatment planning. Four treatment plans were generated for each patient: 1) photons (x-rays) to treat positron emission tomography (PET)-positiv...

This paper presents an overview of the first HEad and neCK TumOR (HECKTOR) challenge, organized as a satellite event 23rd International Conference on Medical Image Computing Computer Assisted Intervention (MICCAI) 2020. The task challenge is automatic segmentation head neck primary Gross Tumor Volume in FDG-PET/CT images, focusing oropharynx region. data were collected from five centers for tot...

A digital phantom was created from a CT scan of patient’s head and employed together with GATE 8.2 Monte Carlo modeling linear accelerator nominal 6 MV energy to simulate an irradiation geometry for typical tumor volume centrally within the brain region. Although simplistic in arrangement, this setup considered appropriate demonstrate dose enhancements that may be expected megavoltage external ...

Purpose: This study investigates the feasibility of personalizing radiotherapy prescription schemes (treatment margins and fractional doses) for glioblastoma (GBM) patients and their potential benefits using a proliferation and invasion (PI) glioma model on phantoms. Methods and Materials: We propose a strategy to personalize radiotherapy prescription schemes by simulating the proliferation and...

BACKGROUND Current staging systems have limited ability to adjust optimal therapy in advanced nasopharyngeal carcinoma (NPC). This study aimed to delineate the correlation between tumor volume, treatment outcome and chemotherapy cycles in advanced NPC. METHODS A retrospective review of 110 patients with stage III-IV NPC was performed. All patients were treated first with neoadjuvant chemother...

Hepatoid variant of yolk sac tumor of ovary is an unusual tumor with an aggressive behavior. It is usually observed in young females, presents with abdominal complaints and is associated with raised α-fetoprotein (AFP) levels. It should be differentiated from other hepatoid tumors involving the ovary. A complete patient evaluation with gross, microscopy, and immunohistochemistry can identify th...

OBJECT This study evaluated the efficacy of postoperative Gamma Knife surgery (GKS) to the tumor cavity following gross-total resection of a brain metastasis. METHODS A retrospective review was conducted of 700 patients who were treated for brain metastases using GKS. Forty-seven patients with pathologically confirmed metastatic disease underwent GKS to the postoperative resection cavity foll...