Screening chest wall ultrasound in the mastectomy patient

Background: While there are clear guidelines regarding chest wall ultrasound in the symptomatic patient, there is conflicting evidence regarding the use of ultrasound in the screening of women post-mastectomy. Objective: To assess the utility of screening chest wall ultrasound after mastectomy and to assess features of detected malignancies. Methods: This IRB approved, retrospective study evaluates screening US examinations of the chest wall after mastectomy. Asymptomatic women presenting for screening chest wall ultrasound from January 2016 through May 2017 were included. Cases of known active malignancy were excluded. All patients had at least one year of clinical or imaging follow-up. 43 exams (8.5 %) were performed with a history of contralateral malignancy, 465 exams (91.3 %) were performed with a history of ipsilateral malignancy, and one exam (0.2 %) was performed in a patient with bilateral prophylactic mastectomy. Results: During the 17-month period, there were 509 screening US in 389 mastectomy patients. 504 (99.0 %) exams were negative/benign. Five exams (1.0 %) were considered suspicious, with recommendation for biopsy, which was performed. Out of 509 exams, 3 (0.6 %) yielded benign results, while 2 (0.39 %) revealed recurrent malignancy, with a 95 % confidence interval (exact binomial) of 0.05 % to 1.41 % for screening ultrasound. Both patients who recurred had previously recurred, and both had initial cancer of lobular histology. Conclusion: Of 509 chest wall screening US exams performed in mastectomy, 2 malignancies were detected, and each patient had history of invasive lobular carcinoma and at least one prior recurrence prior to this study, suggesting benefit of screening ultrasound in these populations.