Clinical Diagnoses and Outcomes After Diagnostic Breast Ultrasound by Nurses and General Practitioner Physicians in Rural Rwanda

PURPOSE

To scale up early detection of breast cancer in low- and middle-income countries, research is needed to inform the role of diagnostic breast ultrasound performed by nonradiologists in resource-constrained settings. The authors examined 2-year clinical follow-up and outcomes among women who underwent diagnostic breast ultrasound performed by nonradiologist clinicians participating in a breast ultrasound training and mentorship program at a rural Rwandan hospital.

METHODS

Imaging findings, management plans, and pathologic results were prospectively collected during the training using a standardized form. Data on follow-up and outcomes for patients receiving breast ultrasound between January 2016 and March 2017 were retrospectively collected through medical record review.

RESULTS

Two hundred twenty-nine breast palpable findings (199 patients) met the study's eligibility criteria. Of 104 lesions initially biopsied, 38 were malignant on initial biopsy; 3 lesions were identified as malignant on repeat biopsy. All 34 patients ultimately diagnosed with cancer received initial recommendations for either biopsy or aspiration by trainees. The positive predictive value of trainee biopsy recommendation was 34.8% (95% confidence interval, 24.8%-45.0%). The sensitivity of trainees' biopsy recommendation for identifying malignant lesions was 92.7% (95% confidence interval, 84.2%-100%). Of 46 patients who did not receive biopsy and were told to return for clinical or imaging follow-up, 37.0% did not return.

CONCLUSIONS

Trained nonradiologist clinicians in Rwanda successfully identified suspicious breast lesions on diagnostic breast ultrasound. Loss to follow-up was common among patients instructed to return for surveillance, so lower biopsy thresholds, decentralized surveillance, or patient navigation should be considered for patients with low- or intermediate-suspicion lesions.

Breast lesions associated with mammographic architectural distortion: a study of 588 core needle biopsies

Architectural distortion (AD) on mammography is a localized alteration in the uniform texture of the breast characterized by lines radiating from a central point. Radiologic/pathologic correlation is challenging because the types of lesions associated with AD are not well defined and, thus, what signifies a discordant finding requiring excision is less clear. This retrospective case series was performed to elucidate the pathologic lesions associated with AD. Over a 6-year period, 588 core needle biopsies (CNBs) were performed for AD. Thirty-eight percent of the lesions were AD alone (single feature AD) and 62% had additional imaging features (multi-feature AD). Overall, 31% showed invasive carcinoma or ductal carcinoma in situ (DCIS), 37% showed benign lesions likely to correlate with AD, and 32% showed nonspecific benign findings. The invasive carcinomas tended to be low-grade (60%), ER-positive (98%), HER2-negative (98%), and often had lobular features (52%). Ninety-two percent were AJCC pathologic stage group I. Ninety-four cases of benign findings that correlated with AD without atypia underwent excision, and only one was found to have DCIS adjacent to the sclerosing lesion (1%). The remaining cases had benign findings without a clear correlate for AD. Sixty-eight cases without atypia underwent excision, and six multi-feature AD were upgraded to invasive carcinoma (9%). In conclusion, about one-third of CNBs for lesions associated with AD reveal carcinomas that are predominantly invasive, low-grade, ER-positive, HER2-negative, and low stage. Single-feature AD differed from multi-feature AD due to a lower number of carcinomas on CNB (18% vs 39%). For CNBs showing benign lesions on biopsy with a correlate for AD, the finding of malignancy on excision is low (1%). Radiologic/pathologic correlation and decisions to recommend excision will continue to be a challenge after CNB reveals nonspecific findings as some patients with multi-feature AD were found to have undetected invasive carcinomas.

Training Nonradiologist Clinicians in Diagnostic Breast Ultrasound in Rural Rwanda: Impact on Knowledge and Skills

OBJECTIVE

To assess the effectiveness of diagnostic breast ultrasound training provided for general practitioners and nurses in Rwanda via intensive in-person and subsequent online supervision and mentorship.

METHODS

Four breast radiologists from Brigham and Women's Hospital trained two general practitioner physicians and five nurses in Rwanda over 9 total weeks of in-person training and 20 months of remote mentorship using electronic image review with emailed feedback. Independently recorded assessments were compared to calculate the sensitivity and specificity of trainee assessments, with radiologist assessments as the gold standard. We compared performance in the first versus second half of the training.

RESULTS

Trainees' performance on written knowledge assessments improved after training (57.7% versus 98.1% correct, P = .03). Mean sensitivity of trainee-performed ultrasound for identifying a solid breast mass was 90.6% (SD 4.2%) in the first half of the training (period 1) and 94.0% (SD 6.7%) in period 2 (P = .32). Mean specificity was 94.7% (SD 5.4%) in period 1 and 100.0% (SD 0) in period 2 (P = .10). Mean sensitivity for identifying a medium- or high-suspicion solid mass increased from 79.2% (SD 11.0%) in period 1 to 96.3% (SD 6.4%) in period 2 (P = .03). Specificity was 84.4% (SD 15.0%) in period 1 and 96.7% (SD 5.8%) in period 2 (P = .31).

DISCUSSION

Nonradiologist clinicians (doctors and nurses) in a rural sub-Saharan African hospital built strong skills in diagnostic breast ultrasound over 23 months of combined in-person training and remote mentorship. The sensitivity of trainees' assessments in identifying masses concerning for malignancy improved after sustained mentorship. Assessment of impact on patient care and outcomes is ongoing.

Impact of In-Person and Electronic Training by Breast Radiologists on Rwandan General Practitioners' and Nurses' Skills in Diagnostic Breast Ultrasound

Background: Ultrasound (US) is a key tool in evaluation of palpable breast masses and can help refine the likelihood of malignancy and the need for further diagnostic studies. US technology is available in many low-resource settings, but there are few specialized radiologists. We launched a diagnostic breast ultrasound training program for general practitioner doctors (GPs) and nurses at a rural Rwandan district hospital that serves as a cancer referral facility. Aim: Assess GPs' and nurses' skill in diagnostic breast ultrasound over 23 months of intensive in-person and online supervision and mentorship. Methods: 4 rotating breast radiologists from Brigham and Women's Hospital trained 5 nurses and 4 doctors in Rwanda over 9 weeks of in-person training and 21 months of weekly remote case consultations and mentorship using electronic review of images with emailed feedback. During in-person trainings, trainees and radiologists evaluated patients separately, while radiologists' electronic assessments were based on emailed images and assessments from trainees. Among breast lesions with documented radiologist and trainee assessments, we compared written trainee and radiologist assessments to calculate the sensitivity of trainee assessments, with radiologist assessments as the gold standard. We used paired t-tests to examine whether the sensitivity varied between the first 14 months (stage I) and the last 9 months (stage 2), after the final in-person training. Results: Of 323 breast and axillary lesions assessed by trainees and radiologists, 279 were breast lesions. Of these, 114 (41%) were evaluated by radiologists in-person, and 165 (59%) through electronic evaluation. 237 (85%) were determined to be breast masses by the radiologists, with 164 of these solid masses, 25 complex solid/cystic lesions, 15 definite or probable simple cysts, 31 normal intramammary lymph nodes, and 2 other masses. Sensitivity of trainees' assessments for identifying a solid mass was 90.2% (95% CI 85.9-94.9) overall. Among trainees who scanned ≥ 10 lesions each, mean sensitivity was 90.6% in stage I, and 94.0% in stage 2 ( P = 0.3). In cases where both radiologists and trainees perceived solid masses (n=148), trainees' assessments had a sensitivity of 81.4% (95% CI 72.3-90.5) overall for detecting masses suspicious for malignancy, or probably benign but needing further evaluation (versus benign with no further evaluation needed). Among trainees who scanned ≥ 10 lesions each, sensitivity was 79.1% during stage I and 96.2% during the stage 2 ( P = 0.03). Conclusion: Nurses and GPs in a rural sub-Saharan African facility built strong skills in diagnostic ultrasound over 23 months of combined in-person training and distance learning via electronic case reviews. The sensitivity of their assessments for identifying masses concerning for malignancy showed significant improvement after sustained mentorship. Assessment of impact on patient care and outcomes is ongoing.

Acute myocardial infarction: contrast-enhanced multi-detector row CT in a porcine model

PURPOSE

To assess the role of contrast material-enhanced retrospectively electrocardiographically (ECG) gated multi-detector row computed tomography (CT) in the detection of acute myocardial infarction in a porcine model of total coronary occlusion.

MATERIALS AND METHODS

Seven Yorkshire farm pigs were studied with contrast-enhanced retrospectively ECG-gated multi-detector row CT 3 hours after total occlusion of the distal left anterior descending artery (n = 5) or the second diagonal branch (n = 2). Reformatted short-axis end-systolic and end-diastolic CT data sets were assessed for myocardial perfusion deficits, coronary occlusion, and abnormal myocardial wall motion. Perfusion deficits were compared with microsphere-determined blood flow and triphenyltetrazolium chloride (TTC)-stained tissue samples for infarct assessment by using Bland-Altman analysis and analysis of variance.

RESULTS

Myocardial perfusion deficits, occlusion of the left anterior descending artery or second diagonal branch, and akinesis of the infarcted segment were identified in all five animals that completed the study. One animal died, and one data set had nondiagnostic image quality. The CT end-diastolic (mean, 16.1% +/- 4.8 [SD]; range, 8.6%-22.2%) and end-systolic (mean, 17.0% +/- 6.4; range, 8.7%-26.8%) volume of perfusion deficit was similar to that of infarcted tissue at TTC staining (mean, 13.6% +/- 6.0; range, 7.8%-30.9%). Infarcted myocardium at CT demonstrated a 76.1% reduction in microsphere-determined blood flow and a significant reduction of myocardial CT attenuation compared with normal myocardium (P <.01). Myocardial wall motion analysis demonstrated absence of systolic wall thickening in infarcted myocardium.

CONCLUSION

Multi-detector row CT with retrospective ECG gating permits the detection and further characterization of acute myocardial infarction in a porcine model of complete coronary occlusion.