Improving accuracy and therapeutioc ratio in radiation oncology
01 / 1998 - unknown
METIS Erasmus Universiteit Rotterdam
A key field of research in radiotherapy is the clinical application of conformal radiotherapy, where the treated volume is made to conform to the target volume, thereby limiting the volume of irradiated normal critical tissue. By reducing the probability of normal tissue toxicity, this approach allows for sparing of critical organs and/or radiation dose escalation and improved local tumor control. In collaboration with the Antonie van Leeuwenhoek Hospital in Amsterdam, a randomised clinical trial of dose escalation for prostate cancer is currently underway. Phase II studies of intensity modulated conformal radiotherapy are underway for lung cancer and head and neck cancer (to limit damage to the salivary glands and escalate dose). Studies of stereotactic irradiation for eye and brain tumours have been activated. The intraoperative brachytherapy research is focused on the treatment of tumours of the rectum, head and neck, and lung. A program of ultrasound and CT-assisted brachytherapy for prostate cancer is underway. In collaboration with the Thoraxcenter of the University Hospital Rotterdam, patients are being treated with endovascular brachytherapy in the context of ongoing clinical trials. In addition, two trials of radiotherapy for peripheral vascular disease and arteriovenous shunts are rapidly accruing patients. Finally for a number of clinical tumor sites radiation with concomitant chemotherapy radiation protectors is being studied. The current research in clinical physics is focused on the development and application of tools for conformal therapy. Improved electronic portal imaging (EPI) techniques are being developed and EPI has been clinically implemented for patient set-up verification and correction, in vivo dosimetry during conformal treatments and for quality assurance measurements of intensity modulated photon beams produced with dynamic multileaf collimation. The optimisation of dose distributions by intensity modulated radiotherapy beams is being actively pursued and algorithms for computer planning with photon and electron beams are being developed and tested. The research activities of molecular radiobiology are geared towards gaining an improved understanding of the mechanisms and biological relevance of double-strand DNA break repair in relation to genomic instability, carcinogenesis and radiotherapy by evaluating the relative contribution of two major repair pathways, homologous recombination and DNA end-joining. In a Dutch Cancer Society funded project, the phenotype of mice with defective homologous recombination repair is currently being analyzed. Recently, Dr. Kanaar has been granted a subsidy in the prestigious PIONEER program coordinated by the Netherlands National Research Council.