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.

Diagnostic ultrasound of the chest wall in the symptomatic patient after mastectomy

BACKGROUND

Lack of standardized imaging recommendations among mastectomy patients has led to variability in how recurrences are detected.

OBJECTIVE

To describe the findings and assess the diagnostic efficacy of ultrasound in the evaluation of symptomatic post-mastectomy patients.

MATERIALS AND METHODS

This single institution, retrospective study included 749 consecutive diagnostic chest wall ultrasound examinations performed in mastectomy patients, from January 2016 to June 2017. Chest wall ultrasound evaluated the mastectomy bed with or without reconstruction. Electronic health records were queried for the primary breast cancer histology prior to mastectomy, clinical symptoms prompting the diagnostic ultrasound, ultrasound findings, subsequent cytology and pathology, and follow-up data. Excluded were patients with a known recurrence, asymptomatic patients, and those with <2 years of clinical or imaging follow-up. Descriptive and comparative statistical analyses were performed.

RESULTS

Among the 749 ultrasounds performed, 58 malignancies were identified for a 7.7% (58/749) malignancy rate, with a median tumor size of 20 mm. Patients diagnosed with a malignancy most often presented with a palpable abnormality (79.3%, 46/58) or skin changes (13.8%, 8/58) and rarely with pain (1.7%, 1/58). Patients who underwent a biopsy yielding a benign result most often presented with a palpable abnormality (41.5%, 287/691), pain (25.6%,177/691), or postoperative swelling/suspected fluid collection (17.8%, 123/691). Diagnostic ultrasound yielded a 91.4% sensitivity (95% CI 81.0, 97.1), 96.1% specificity (95% CI 94.4, 97.4), 66.3% PPV₃ (95% CI 57.4, 74.1), and 99.3% negative predictive value (95% CI 98.3, 99.7) for cancer detection. There were 5 false negative ultrasound cases after a skin punch biopsy was performed due to clinically suspicious skin changes.

CONCLUSIONS

Chest wall ultrasound has a high sensitivity and negative predictive value for detection of breast cancer recurrence in symptomatic patients after mastectomy. Skin changes remain an important clinical manifestation of a cancer recurrence.