The role of breast scintigraphy with breast-specific gamma-camera (BSGC) in the preoperative identification of residual disease following neoadjuvant therapy

Objectives Breast scintigraphy with BSGC has proved a very effective diagnostic tool in the detection of primary breast cancer (BC). In the present study we assessed the role of the above procedure in the preoperative identification of residual disease in BC patients following neoadjuvant therapy.

Methods We prospectively studied 33 consecutive female BC patients, aged 26 to 82 yrs, scheduled to surgery following neoadjuvant chemo (26 cases) or hormone (7 cases) therapy. Ten min. after the i.v. injection of 740 MBq of 99mTc-tetrofosmin, all patients underwent breast scintigraphy in both cranio-caudal and medio-lateral oblique views (600 sec/view) with mild breast compression during acquisition using a high resolution BSGC. Scintigraphic data were correlated with surgical histopathological findings in all cases.

Results Residual disease was ascertained at surgery in 27/33 (81.8%) patients, while the remaining 6/33 (18.2%) patients had a pathological complete remission without any evidence of residual breast cancer. BSGC scintigraphy resulted positive in 26/27 patients with residues (sensitivity: 96.3%), including 2 of 3 patients with residues evident only at microscopic pathological examination. A precise definition of breast quadrant localization was also given in all positive cases in association with a correct tumor extension. The procedure was false negative in only one patient who had microscopic tumor foci scattered in a fibrotic area. BSGC scintigraphy was true negative in all 6 patients with pathological complete remission (specificity: 100%).

Conclusions In our series, BSGC scintigraphy proved a very highly sensitive diagnostic tool in the preoperative identification of residual breast carcinomas following neoadjuvant therapy, in absence of false positive findings. Moreover, scintigraphy gave an accurate tumor localization and extension. A wider employment of this procedure is thus suggested before surgery to guide the surgeon to the most appropriate surgical treatment.

Research Support Fondazione Banco di Sardegna. Regione Sardegna (Legge n.7/2007)