The Role of redo-Sentinel Lymph Node Biopsy in Patients With Prior Ipsilateral Breast Cancer Surgery.

BACKGROUND: Sentinel Lymph Node Biopsy (SLNB) is used to stage the axilla, but there is limited data in patients with prior ipsilateral breast cancer. This study compares redo-SLNB (reSLNB) and Axillary node sample (ANS) in this sub-cohort of patients. MATERIALS AND METHODS: This is a retrospective study looking at patients with a new ipsilateral primary or recurrence with history of breast-conserving surgery. Planned and performed surgery, patient demographics and previous treatments were recorded. Node positivity and success rate of reSLNB was analyzed. RESULTS: A total of 86 patients were identified that had mastectomy for ipsilateral recurrent disease with radiologically negative axilla. Out of the 48 that had reSLNB, 35(72.9%) were successful. Nineteen percent of the reSLNB had positive axillae and 20% of the ANS patients. reSLNB success rate was significantly lower amongst patients with previous axillary surgery (P = .014) and previous positive nodes(P = .001). CONCLUSION: reSLNB should be considered to restage the axilla in patients with previous history of ipsilateral cancer especially that there is growing evidence showing good identification rate.

SeHCAT retention values as measured with a collimated and an uncollimated gamma camera: a method comparison study.

TauroH-23-(Se) selena-25-homocholic acid retention values are used in the diagnosis of bile acid malabsorption. The standard method for measuring values is with an uncollimated gamma camera, which can create some logistic difficulties, with other background sources of activity, which are irrelevant when a collimator is used, becoming significant. In this study we compare the retention values obtained with a collimated and an uncollimated gamma camera in phantoms and in 23 patients. Bland-Altman plots were created using the data, which showed a mean bias in retention of 0.10% in the phantom study and 0.55% in the patient study between methods. A Wilcoxon signed-rank test with the null hypothesis of zero median difference between uncollimated and collimated methods was not statistically significant to P values less than 0.05 in the patient and phantom studies. In the patient study, on using a fixed boundary of retention (10%) between positive and negative status, the status of one patient was changed from negative (12%) to positive (9%). We conclude that measurement of retention with a collimated gamma camera is similar but not identical to that of uncollimated values. The clinical significance of this shift is unclear, as the threshold of significance and the method of integrating this measure with other clinical factors into management remain unclear.