Analysis of the Movement of Surgical Clips Implanted in Tumor Bed during Normal Breathing for Breast Cancer Patients

Lee, Rena; Chung, Eunah; Suh, HyunSuk; Lee, Kyung ja; Lee, Jihye

Abstract

PURPOSE: To evaluate the movement of surgical clips implanted in breast tumor bed during normal breathing.
MATERIALS AND METHODS
Seven patients receiving breast post-operative radiotherapy were selected for this study. Each patient was simulated in a common treatment position. Fluoroscopic images were recorded every 0.033 s, 30 frames per 1 second, for 10 seconds in anterior to posterior (AP), lateral, and tangential direction except one patient's images which were recorded as a rate of 15 frames per second. The movement of surgical clips was recorded and measured, thereby calculated maximal displacement of each clip in AP, lateral, tangential, and superior to inferior (SI) direction. For the comparison, we also measured the movement of diaphragm in SI direction.
RESULTS
From AP direction's images, average movement of surgical clips in lateral and SI direction was 0.8+/-0.5 mm and 0.9+/-0.2 mm and maximal movement was 1.9 mm and 1.2 mm. Surgical clips in lateral direction's images were averagely moved 1.3+/-0.7 mm and 1.3+/-0.5 mm in AP and SI direction with 2.6 mm and 2.6 mm maximal movement in each direction. In tangential direction's images, average movement of surgical clips and maximal movement was 1.2+/-0.5 mm and 2.4 mm in tangential direction and 0.9+/-0.4 mm and 1.7 mm in SI direction. Diaphragm was averagely moved 14.0+/-2.4 mm and 18.8 mm maximally in SI direction.
CONCLUSION
The movement of clips caused by breathing was not as significant as the movement of diaphragm. And all surgical clip movements were within 3 mm in all directions. These results suggest that for breast radiotherapy, it may not necessary to use breath-holding technique or devices to control breath.