RESUMO
BACKGROUND: With the increasing demand for breast conservation surgery, the probability of recurrent tumour within the breast increases. Traditionally x-ray mammography (XMM) was used to assess the post-surgical breast, but post-surgery and radiotherapy changes have reduced the accuracy of this method. Scintimammography (SMM) has also been proposed and appears to be more accurate than XMM. MATERIAL AND METHODS: A total of 101 women received (Tc99m) MIBI SMM and 88 had a subsequent XMM. There were 142 sites suspected of loco-regional recurrence breast cancer. During the study the patients did not receive any treatment other then hormonotherapy. SMM was performed by the standard Diggles-Khalkhali method and XMM was performed using standard 2 views. Analysis was performed and the results of each type of imaging compared with histology. In the ROC curve analysis 5 points of certainty were used: from 1 being definitely normal to 5 being definitely cancer; grades 4 and 5 were counted as positive. RESULTS: The overall sensitivity value of SMM was 84% and specificity was 85%, compared with a sensitivity of 52% for XMM and a specificity of 84%. Analysis of areas under ROC curves provides statistically significant difference between SMM and XMM (p < 0.05). Combining the two tests did not significantly improve the diagnostic accuracy of sequence imaging over SMM. CONCLUSION: ROC curve analysis demonstrates that scintimammography should be the primary investigation in suspected local recurrence following breast conservation surgery.
RESUMO
UNLABELLED: The purpose of this retrospective study was assessment of correlation between Tc-99m sestaMIBI uptake and some prognostic factors of breast cancer. The following prognostic factors have been included in this study: size of the tumour, age of the patients, axilla node involvement, oestrogen and progesterone receptor (ER, PR) status, grading system of Bloom-Richardson and Ki-67 antigen expression. METHODS: 79 patients were enrolled in this study, with 85 lesions confirmed as primary breast cancers. Mean age of patients was 53 years. Scintimammography (SMM) was performed after intravenous injection of 740MBq. At 5-10 min after injection standard planar images were obtained in prone lateral and anterior supine views. Assessment of correlation between known prognostic factors of breast cancer and uptake of MIBI (evaluated as a tumour to background ratio-TBR) was performed used non-parametric (Kendall-tau correlation) statistical analysis. RESULTS: There were 85 breast cancers (73 invasive ductal carcinomas, 11 DCIS (ductal carcinoma in situ) and 1 lobular carcinoma. There was positive correlation between TBR Tc-99m MIBI uptake and size of the tumour (t = 0.19, p = 0.01), presence of axilla node involvement (t = 0.2, p = 0.006) and also grade of the IDC tumours evaluated using Bloom-Richardson's criteria (t = 0.18, 0.03). There were negative correlation between TBR and presence of PR (t = -0.16, p = 0.02) and borderline negative correlation between TBR and age of patients (t = -0.137, p = 0.06) and also TBR and ER status (t = -0.135, p = 0.065). Patients who are younger and/or have PR or ER negative cancers have higher Tc-99m MIBI uptake. Patients who presented with high grade of malignancy (B-R) also have higher uptake of radiotracer. Also those with higher uptake of radiotracer often had axillary node involvement. This would suggest that more aggressive tumours have higher uptake of Tc-99m MIBI. Finally this study suggest correlation between in vivo uptake of MIBI and some of the known prognostic factors of breast cancer.
