A stratified sampling method for the efficient repeated computation of dose-volume histograms (DVHs) in brachytherapy is presented as used for anatomy based brachytherapy optimization methods. The aim of the method is to reduce the number of sampling points required for the calculation of DVHs for the body and the PTV. From the DVHs are derived the quantities such as Conformity Index COIN and C...

BACKGROUND AND PURPOSE High dose rate (HDR) brachytherapy is a clinically used procedure in prostate cancer treatment. The purpose of this study was to present the influence of using different optimization algorithms in 3D-CBRT planning on the treatment plan quality. MATERIALS AND METHODS Treatment plans were calculated for 15 patients--three plans for each patient using: geometrical optimiza...

The analysis of semivolatiles in the parts-per-trillion range presents challenges due to analyte activity, background contamination, and instrument sensitivity. Method requirements vary worldwide, with the least sensitive specifying 1-μL injections and full scan data acquisition. Lower level calibrations can be achieved using large volume injection (LVI) with a programmable temperature vaporizi...

BACKGROUND Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. OBJECTIVE In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planni...

BACKGROUND Dosimetric comparison of two dimensional (2D) radiography and three-dimensional computed tomography (3D-CT) based dose distributions with high-dose-rate (HDR) intracavitry radiotherapy (ICRT) for carcinoma cervix, in terms of target coverage and doses to bladder and rectum. MATERIALS AND METHODS Sixty four sessions of HDR ICRT were performed in 22 patients. External beam radiothera...

The purpose of this study is to investigate the effectiveness of the HIPO planning and optimization algorithm for real-time prostate HDR brachytherapy. This study consists of 20 patients who underwent ultrasound-based real-time HDR brachytherapy of the prostate using the treatment planning system called Oncentra Prostate (SWIFT version 3.0). The treatment plans for all patients were optimized u...

While the Periotest continues to be used in assessing the integrity of implants, there are numerous reports of its inconsistencies. To understand more precisely what the Periotest is actually measuring, a mathematical model was developed that illustrates the effect that various geometric and clinical parameters have on the Periotest value (PTV). In addition, the model was validated with an in v...

Recently we introduced interactive dose shaping (IDS) as a new IMRT planning strategy. This planning concept is based on a hierarchical sequence of local dose modification and recovery operations. The purpose of this work is to provide a feasibility study for the IDS planning strategy based on a small set of six prostate patients. The IDS planning paradigm aims to perform interactive local dose...

The sparing of the parotid glands in the treatment of head and neck cancers is of clinical relevance as high doses to the salivary glands may result in xerostomia. Xerostomia is a major cause of decreased quality of life for head and neck patients. This paper explores the relationship between the overlap of the target volumes and their expansions with the parotid glands for helical delivery pla...

This study compared field-in-field (FIF) radiotherapy with conformal radiotherapy with physical wedges for the treatment of unilateral cervical malignant lymphoma. Two treatment plans, the FIF technique and conformal RT, were generated for each of 32 patients with unilateral cervical malignant lymphoma. To compare the 2 treatment plans, dose-volume histograms of the planning target volume (PTV)...