Breast conserving surgery and irradiation: the importance of demarcating the excision cavity with surgical clips.
OBJECTIVE
To determine whether or not the surgical scar and surgical induration are suitable landmarks for localizing the boost field in the treatment of patients undergoing breast conservation surgery and irradiation.


METHODS
Thirty-five patients had surgical clips placed in the excision cavity at the time of tumor excision. The boost field locations for these patients were determined by encompassing the surgical induration with a minimum 2 cm margin or, when there was no induration, by encompassing the incision scar with a 3 cm margin. Simulator radiographs were taken with the boost field margins marked with solder wire.


RESULTS
The simulator radiographs showed that the excision cavity clips were at or outside the boost field margins in 19 patients, 54% of the entire group. An unexpected finding was that, in six of the 23 patients with the surgical scar 2 cm medial or lateral to the areola, the excision cavity clips were inadequately covered by tangential fields even though the fields appeared to be adequate based on external landmarks.


CONCLUSIONS
(a) This study suggests that the skin incision and surgical induration are not reliable landmarks for boost field localization. (b) Without surgical clips, part of the excision cavity would have underdosed by the tangential fields in 23% of patients with medial or lateral surgical scars.
Bedwinek
J
J
Cancer Care Center, St. Joseph Hospital, St. Louis, MO 63122.
D001943:Breast Neoplasms / Q000453:epidemiology / Q000532:radiotherapy / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D012189:Retrospective Studies; D013523:Surgical Equipment