Impact of radioguided occult lesion localization on the correct excision of malignant breast lesions: effect of histology and tumor size.

摘要

AIM: To evaluate the impact of radioguided occult lesion localization (ROLL) in the correct location and excision of malignant breast lesions, and analyze if these results are affected by the histology and tumor size. MATERIALS AND METHODS: A total of 105 patients with occult breast lesions were studied. The mean age was 55 years. An intralesional dose of 18.5 MBq of 99mTc-labeled macroaggregated human albumin (AMA) was administered using stereotaxic mammography or ultrasound. Surgical resection was carried out with the help of a gammadetector probe. In the histological study, disease-free margin was defined by a distance between the tumor lesion and the surgical margin of more than 1 mm. The possible influence of tumor histology and lesion diameter with respect to free/affected margins was analyzed. RESULTS: Correct radiotracer placement was achieved in 100/105 of the cases (95.2%). In the remaining 5 cases (4.8%), radiotracer placement was incorrect, with 2 of them being malignant lesions that were found by macroscopic inspection, and the other 3 having benign pathology. Among the malignant lesions (44 cases), correct placement of the radiotracer was achieved in 42 cases (95.5%). Of these 42 malignant lesions, in which the ROLL was correctly performed, free surgical margins were obtained in 24 cases (57.1%), while the other 18 (42.9%) had infiltrated surgical margins. The most common histological type among the malignant lesions was invasive ductal carcinoma (71.4%). The histological types with an increased frequency of infiltration of surgical margins were invasive and microinvasive cancer (94.4%). All the affected margins were in lesions greater than 10 mm, and the highest incidence was in those between 20 and 30 mm (55.5%). CONCLUSION: In our experience, the advantages of the ROLL technique are a precise localization of malignant breast lesions (95.5%) and an increased probability of a complete excision with free margins in more than one half of them. Nevertheless, special consideration should be taken when dealing with invasive and microinvasive cancers and in those exceeding 10 mm because of their higher incidence of infiltrated margins.