Biomedical subjects

David Rajasekar

Publications and source records attributed to David Rajasekar.

3 recordsLinked to original sources

PubMed2004

A graphical user interface for automatic image registration software designed for radiotherapy treatment planning.

Medical imaging forms a vital component of radiotherapy treatment planning and its evaluation. The integration of the useful data obtained from multiple imaging modalities for radiotherapy planning is achieved by image registration softwares. In radiotherapy planning systems, normally the computed tomography (CT) slices are kept as a standard upon which other modality images (magnetic resonance imaging [MRI], single photon emission computed tomography [SPECT], positron emission tomography [PET], etc.) are aligned--automatically or interactively. Following validation of successful registration, they are resampled and reformatted, as per the requirements. This paper defines the minimum requirements of automatic image registration software for 3-dimensional (3D) radiotherapy planning and describes the implementation of a suitable graphical user interface developed in Visual Basic (version 5). The automatic image registration (AIR) routines freely available from Dr. Roger P. Woods, UCLA, (USA) were used in this software. This software could be easily implemented and was easy to use for image processing suitable for radiotherapy planning systems.

Algorithms↗

PubMed2004

Improvement of radiotherapy facilities in developing countries: a three-tier system with a teleradiotherapy network.

Incidence of cancer has been projected to rise worldwide by around 50% in the next 20 years, most of which will be in developing countries. To face this unprecedented global health problem, it is essential to plan effective health-care strategies. Radiotherapy-a main component of the multidisciplinary therapeutic approach for cancer-involves a huge capital investment that can pose difficulties for developing countries. Limited resources should therefore be used effectively to meet the projected requirements and to find ways to offer quality-assured radiotherapy to patients. Taking advantage of the global explosion of telecommunication technology, we present a proposal for creation of an integrated three-tier radiotherapy service, which consists of primary, secondary, and tertiary radiotherapy centres in developing countries-coordinated through a teleradiotherapy network. Such a network could be cost effective, help to bridge the gap, and give all patients access to the state-of-the-art technology in radiotherapy.

Cancer Care Facilities↗

PubMed2003

Problems in reporting doses and volumes during multiple high-dose-rate intracavitary brachytherapy for carcinoma cervix as per ICRU Report 38: a comparative study using flexible and rigid applicators.

OBJECTIVE: The objective was to evaluate the extent of geometric and positional variations of two different applicators during multiple high-dose-rate (HDR) intracavitary brachytherapy (ICBT) in carcinoma cervix and its implication on reporting as per International Commission on Radiation Units and Measurement (ICRU) Report 38. METHODS: Fifty patients, following teletherapy, were randomly allocated to two groups of 25 each. They received a dose of 6 Gy to point A during each of the three HDR ICBT applications by either a flexible Ralstron or a rigid geometry Rotterdam applicator. The various applicator components related to its geometry and their Cartesian coordinates were evaluated from orthogonal films. The doses to ICRU bladder, rectal, pelvic, lymphatic trapezoid points, and dimensions of 6-Gy ICRU height, width, thickness, and volume were estimated for each application. RESULTS: Significant variation was observed with the three HDR ICBT applications for each group, for all components and for both applicators, although it was relatively more with the flexible Ralstron applicator. The average shift in each of the coordinates of os, uterine tip, and ovoids was around 10 mm for both groups. These resulted in significant variations in all the ICRU Report 38 reporting parameters for three insertions in any given patient and across 25 patients of both groups. CONCLUSIONS: Multiple HDR ICBT applications led to significant variation in the applicator geometry and its positions in pelvis, irrespective of the applicator rigidity. This results in uncertainties in reporting as per ICRU Report 38 guidelines, and thus calls for its revision.

Brachytherapy↗