BEYOND THE DVH --SPATIAL AND BIOLOGICAL RADIOTHERAPY TREATMENT PLANNING by BO ZHAO August 2010 Advisor: Dr. Jay Burmeister Co-Advisor: Dr. Michael C. Joiner Major: Medical Physics Degree: Doctor of Philosophy Purpose: Both spatial and biological information are necessary in order to perform true optimization of a treatment plan and for predicting clinical outcome. The goal of this work is to de...

Introduction: Chemoradiation is a well-established protocol for management of localized esophageal cancer. However, some early and late toxicities are associated with this therapy. Plan evaluation in term of normal tissue complication probability (NTCP) may help clinicians to tailor this therapy more individually. Given the variety of present radiobiological models, the choice...

Radiotherapy treatment plan evaluation relies on an implicit estimation of the tumor control probability (TCP) and normal tissue complication probability (NTCP) arising from a given dose distribution. A potential application of radiobiological modeling to radiotherapy is the ranking of treatment plans via a more explicit determination of TCP and NTCP values. Although the limited predictive capa...

Introduction: In 3DCRT the number of therapeutic fields has dramatic impact on treatment results especially in stomach cancer. Traditionally, for radiotherapy of stomach cancer the therapeutic procedure was using two fields (AP- PA or AP Lateral with wedge) to achieve smooth and homogeneous dose distribution in tumor. But nowadays, adding lateral or oblique fields to aforement...

BACKGROUND Modern radiotherapy offers various possibilities for image guided verification of patient positioning. Different clinically relevant IGRT (image guided radiotherapy) scenarios were considered with regard to their influence on dosimetric plan quality and normal tissue complication probability (NTCP). METHODS This study is based on treatment plans of 50 prostate patients. We evaluate...

Normal tissue complication probability (NTCP) results were detailed in the July 2001 issue of Seminars in Radiation Oncology for conventionally fractionated radiation therapy. After 7 years, an extensive collection of stereotactic ablative body radiotherapy (SABR) or stereotactic body radiation therapy (SBRT) dose-tolerance limits was presented in the October 2008 issue of Seminars in Radiation...

Introduction: The ultimate goal of radiation treatment planning is to yield a high tumor control probability (TCP) with a low normal tissue complication probability (NTCP). Historically  dose volume histogram (DVH) with only volumetric dose distribution was utilized as a popular tool for plan evaluation  hence present study aimed to compare the radiobiological effectiveness of the cobalt-60 (Co...

BACKGROUND Pre-treatment magnetic resonance imaging (MRI) can give patient-specific evaluation of suspected pathologically involved volumes in the seminal vesicles (SV) in prostate cancer patients. By targeting this suspicious volume we hypothesize that radiotherapy is more efficient without introducing more toxicity. In this study we evaluate the concept of using MRI-defined target volumes in ...

Radiobiological models are essential components of modern radiotherapy. They are increasingly applied to optimize and evaluate the quality of different treatment planning modalities. They are frequently used in designing new radiotherapy clinical trials by estimating the expected therapeutic ratio of new protocols. In radiobiology, the therapeutic ratio is estimated from the expected gain in tu...

Introduction: Presence of dental filling material (DFM) such as amalgam in treatment patient with nasopharyngeal cancer (NPC) is common. Streaking artifact Arising from this high density material in computed tomography (scan), may lead to perturbation in dose calculation and dose delivery. Widespread performance of intensity-modulated radiotherapy (IMRT) for NPC using anterior...