The evaluation of results one-year study of accuracy of irradiation in the hollycross cancer centre

Abstract

Purpose

To study the accuracy of patients positioning treated with external beams in the Holycross Cancer Centre in Kielce.

Material and methods

Displacements between digitised reference-simulator film and portal film were measured with the Port-Pro and home made programme AutoPort. Based on the data obtained for patients treated in the Holycross Cancer Centre and those published reaction levels for every localisation were defined: 5 mm for patients treated in the pelvic region – and also 5 mm for lung, breast and brain cancer patients. If the reaction level was exceeded the analysis of the set-up procedure was performed and the portal control was repeated. All the results were presented to the radiotherapists during the check meeting once a week. Over one year 524 pairs of film were compared for in 307 patients.

Results

In 42 patients the action levels were exceeded during the last year. Twenty-four of them were irradiated in the pelvic region, 11 were irradiated for the breast, 3 were treated for brain tumours and the remaining 4 for lung cancer. In all cases portal verification was repeated. In 10 cases the difference larger than the action level was also observed so the simulation was performed once again.

Conclusions

The results showed that of patient preparation and implementation of radiotherapy provides a clinically acceptable reproducibility of patient set-up. The results stress the continuous need for paying attention to every patient's positioning and to the need of for the analysis of portal verification data collected over a long period of time. The data of the analysis showed the need for the implementation of specific control procedures for breast irradiation in our hospital.