Indications for breast magnetic resonance imaging at a referral center for the diagnosis and treatment of breast cancer in Brazil.

OBJECTIVE: To describe the indications for breast magnetic resonance imaging (MRI) at a referral center for breast cancer in Brazil. MATERIALS AND METHODS: This was a retrospective study in which we reviewed the clinical records, including physician requests and patient questionnaires, of women who underwent breast MRI between 2014 and 2018 at a referral center for the diagnosis and treatment of breast cancer in the city of Belo Horizonte, Brazil. RESULTS: The most common indication for breast MRI was as a complement to mammography/ultrasonography (in 43.6% of cases), followed by breast cancer staging (in 25.1%), the screening of patients at high risk (in 17.4%), the evaluation of breast implants (in 10.1%), and the evaluation of the response to neoadjuvant chemotherapy (in 3.8%). CONCLUSION: Although there is strong evidence supporting the use of breast MRI, mainly for the screening of high-risk patients, the imaging method is underutilized in Brazil.

OBJETIVO: Este estudo tem como objetivo descrever o perfil de indicações de ressonância magnética (RM) das mamas em um hospital referência em câncer de mama. MATERIAIS E MÉTODOS: Estudo descritivo retrospectivo de solicitações médicas de exames e questionários de mulheres que realizaram RM das mamas em um centro de referência no diagnóstico e tratamento do câncer de mama no período de 2014 a 2018. RESULTADOS: A indicação mais frequente foi complemento de mamografia/ultrassonografia (43,6%), seguida por estadiamento do câncer de mama (25,1%), rastreamento de pacientes de risco elevado (17,4%), avaliação de implantes (10,1%) e avaliação de resposta a tratamento por quimioterapia neoadjuvante (3,8%). CONCLUSÃO: Embora existam fortes evidências em favor do uso da RM das mamas, principalmente para rastreamento em pacientes de alto risco, o método ainda é subutilizado no nosso meio.

Indications for breast magnetic resonance imaging at a referral center for the diagnosis and treatment of breast cancer in Brazil / Indicações de exames de ressonância magnética das mamas em um centro de referência no diagnóstico e tratamento de câncer de mama no Brasil

Abstract Objective: To describe the indications for breast magnetic resonance imaging (MRI) at a referral center for breast cancer in Brazil. Materials and Methods: This was a retrospective study in which we reviewed the clinical records, including physician requests and patient questionnaires, of women who underwent breast MRI between 2014 and 2018 at a referral center for the diagnosis and treatment of breast cancer in the city of Belo Horizonte, Brazil. Results: The most common indication for breast MRI was as a complement to mammography/ultrasonography (in 43.6% of cases), followed by breast cancer staging (in 25.1%), the screening of patients at high risk (in 17.4%), the evaluation of breast implants (in 10.1%), and the evaluation of the response to neoadjuvant chemotherapy (in 3.8%). Conclusion: Although there is strong evidence supporting the use of breast MRI, mainly for the screening of high-risk patients, the imaging method is underutilized in Brazil.

Resumo Objetivo: Este estudo tem como objetivo descrever o perfil de indicações de ressonância magnética (RM) das mamas em um hospital referência em câncer de mama. Materiais e Métodos: Estudo descritivo retrospectivo de solicitações médicas de exames e questionários de mulheres que realizaram RM das mamas em um centro de referência no diagnóstico e tratamento do câncer de mama no período de 2014 a 2018. Resultados: A indicação mais frequente foi complemento de mamografia/ultrassonografia (43,6%), seguida por estadiamento do câncer de mama (25,1%), rastreamento de pacientes de risco elevado (17,4%), avaliação de implantes (10,1%) e avaliação de resposta a tratamento por quimioterapia neoadjuvante (3,8%). Conclusão: Embora existam fortes evidências em favor do uso da RM das mamas, principalmente para rastreamento em pacientes de alto risco, o método ainda é subutilizado no nosso meio.

Intratumoral Intensity in T2-weighted MRI and the Association With Histological and Molecular Prognostic Factors in Women With Invasive Breast Cancer.

OBJECTIVE: To compare the intratumoral T2 signal intensity on MRI and histopathological and molecular expression of biomarkers of aggressiveness (histological grade, hormonal status, HER2, and Ki-67). METHODS: This retrospective study included all women with invasive breast cancer undergoing MRI from January 2014 to October 2016. The intratumoral T2 signal as interpreted at consensus by two radiologists was compared to histopathological and molecular prognostic factors from the surgical specimen. Statistical analyses used Pearson χ 2 test with a confidence level of 95% (P ≤ 0.05). RESULTS: Fifty patients with 50 lesions met study criteria (mean age 65.8 ± 13.5 years). Mean lesion size was 28 mm ± 15.7 mm (range, 15 to 76 mm). Cancer types were invasive ductal (35/50, 70%), invasive lobular (10/50, 20%), and mixed (5/50, 10%). Most lesions were histological grade 1 or 2 (41/50, 82%) and luminal type (45/50, 90%). On T2 images, lesions were hypointense in 62% (31/50), isointense in 20% (10/50), and hyperintense in 18% (9/50) of cases. Among hypointense lesions, 94% (29/31) were low or intermediate grade tumors (P = 0.02), low HER2 overexpression (30/31, 97%) (P = 0.005), and high ER status (30/31, 97%) (P = 0.006), high PR (26/31, 84%) (P = 0.02), and low incidence of necrosis (2/31, 6%). The difference in Ki-67 tumoral expression between groups was not significant. CONCLUSION: Intratumoral T2 hypointensity in invasive breast cancer is associated with better prognostic tumors, such as histological low-grade high hormone receptor status.