Ultrasound-guided boost irradiation of tumor cavity after lumpectomy in breast cancer

Background: Aer breast conserving surgery, most recurrences occur around the primary tumor site. This jusfies the use of boost radiotherapy to the primary site of tumor. Surgical scar is not always a good surrogate for the locaon of the lumpectomy cavity. The aim of this study was to evaluate ultrasonic guidance for detecon of the lumpectomy cavity aer breast conserving surgery for electron beam boost field planning. Materials and Methods: 35 breast cancer paents who treated with whole breast irradiaon aer breast conserving surgery underwent ultrasonic evaluaon for measurement of depth and size of lumpectomy cavity. Results of ultrasonic imaging were used to define electron boost field size and depth of treatment. These results were compared with clinical measurements that made by two expert radiaon oncologists. Results: The operave bed was well visualized in all of the paents. In only 21 paents (60%) cavity was located on the scar. Depth determined by ultrasonography was not significantly correlated with depth determined by clinical impression (r=0.304, P<0.01). This means that the results of the two methods are quite different (these results are also true for other variables). In 88% of paents, the depth of treatment and electron beam energy that were selected by clinical measurements were changed. Conclusion: Ultrasound is found useful tool for measurement of depth and size of lumpectomy cavity and could be used for boost planning. It is easily available, non-invasive and inexpensive.