Effect of internal port on dose distribution in post-mastectomy radiotherapy for breast cancer patients after expander breast reconstruction.

BACKGROUND

In patients with expander-based reconstruction a few dosimetric analyses detected radiation therapy dose perturbation due to the internal port of an expander, potentially leading to toxicity or loss of local control. This study aimed at adding data on this field.

MATERIALS AND METHODS

A dosimetric analysis was conducted in 30 chest wall treatment planning without and with correction for port artifact. In plans with artifact correction density was overwritten as 1 g/cm. Medium, minimum and maximum chest wall doses were compared in the two plans. Both plans, with and without correction, were compared on an anthropomorphic phantom with a tissue expander on the chest covered by a simulating the skin. dosimetry was carried out on the phantom and three patients by using film strips during one treatment fraction. Estimated doses and measured film doses were compared.

RESULTS

No significant differences emerged in the minimum, medium and maximum doses in the two plans, without and with correction for port artifacts. and analyses showed a good correspondence between detected and calculated doses without and with correction.

CONCLUSIONS

The port did not significantly affect dose distribution in patients who will receive post-mastectomy radiation therapy.