Comparison of conformal radiation therapy techniques within the dynamic radiotherapy project 'Dynarad'

The objective of the dynamic radiotherapy project 'Dynarad' within the Euro pean Community has been to compare and grade treatment techniques that are currently applied or being developed at the participating institutions. Cer vical cancer was selected as the tumour site on the grounds that the involv ed organs at risk, mainly the rectum and the bladder, are very close to the tumour and partly located inside the internal target volume. In this work, a solid phantom simulating the pelvic anatomy was used by institutions in Belgium, France, Greece, Holland, Italy, Sweden and the United Kingdom. The results were evaluated using both biological and physical criteria. The ma in purpose of this parallel evaluation is to test the value of biological a nd physical evaluations in comparing treatment techniques. It is demonstrat ed that the biological objective functions allow a much higher conformality and a more clinically relevant scoring of the outcome. Often external beam treatment techniques have to be combined with intracavitary therapy to giv e clinically acceptable results. However, recent developments can reduce or even eliminate this need by delivering more conformal dose distributions u sing intensity modulated external dose delivery. In these cases the reliabi lity of the patient set-up procedure becomes critical for the effectiveness of the treatment.