Avoiding unnecessary sentinel lymph node biopsy with the use of superparamagnetic iron oxide mapping agents (Magtrace®) in breast surgery.

BACKGROUND: Superparamagnetic iron oxide (SPIO) (Magtrace®) is a non-radioactive liquid tracer that can stay in the sentinel lymph nodes for 30 days. Injection of SPIO at time of primary breast surgery where upfront sentinel lymph node biopsy (SLNB) is not immediately indicated allows for a return to theatre if pathology then identifies invasive disease. SLNB is associated with paraesthesia, pain, seroma formation and lymphoedema risk. Hence, our study aims to assess the use of SPIO to avoid upfront SLNB in breast surgery for ductal carcinoma in situ (DCIS) and prophylaxis. METHODS: Retrospective single-centre study of consecutive patients who underwent injection of SPIO tracer at time of primary breast surgery to avoid upfront SLNB at Chris O'Brien Lifehouse, Sydney, NSW, Australia over a 10-month period. RESULTS: SPIO was injected 38 times, with 34 at time of mastectomy and four cases at time of wide local excision. The indication for surgery was DCIS in 18 cases, risk reduction in 17 cases and other indications in three patients. Six cases (15.8%) required delayed SLNB (D-SLNB) due to the finding of invasive disease on post-operative histopathology. All patients who underwent D-SLNB had nodes successfully localized with SPIO. CONCLUSION: In our cohort, 84.2% of cases were able to avoid upfront SLNB, and hence avoid the associated complications of SLNB. SPIO injection was successful in localizing the SLN in all cases at time of surgery for D-SLNB. This technique was safe with few associated complications.

Novel Dual Tracer Indocyanine Green and Radioisotope Versus Gold Standard Sentinel Lymph Node Biopsy in Breast Cancer: The GREENORBLUE Trial.

BACKGROUND: The methods for sentinel lymph node (SLN) biopsy in breast cancer have been variable in type and number of tracers. Some units have abandoned the use of blue dye (BD) due to adverse reactions. Fluorescence-guided biopsy with indocyanine green (ICG) is a relatively novel technique. This study compared the clinical efficacy and costs between novel dual tracer ICG and radioisotope (ICG-RI) with "gold standard" BD and radioisotope (BD-RI). METHODS: Single-surgeon study of 150 prospective patients with early breast cancer undergoing SLN biopsy (2021-2022) using ICG-RI compared with a retrospective cohort of 150 consecutive previous patients using BD-RI. Number of SLNs identified, rate of failed mapping, identification of metastatic SLNs, and adverse reactions were compared between techniques. Cost-minimisation analysis performed by using Medicare item numbers and micro-costing analysis. RESULTS: Total number of SLNs identified with ICG-RI and BD-RI was 351 and 315, respectively. Mean number of SLNs identified with ICG-RI and BD-RI was 2.3 (standard deviation [SD] 1.4) and 2.1 (SD 1.1), respectively (p = 0.156). There were no cases of failed mapping with either dual technique. Metastatic SLNs were identified in 38 (25.3%) ICG-RI patients compared with 30 (20%) BD-RI patients (p = 0.641). There were no adverse reactions to ICG, whereas four cases of skin tattooing and anaphylaxis were associated with BD (p = 0.131). ICG-RI cost an additional AU$197.38 per case in addition to the initial cost for the imaging system. CLINICAL TRIAL REGISTRATION:  ACTRN12621001033831. CONCLUSIONS: Novel tracer combination, ICG-RI, provided an effective and safe alternative to "gold standard" dual tracer. The caveat was the significantly greater costs associated with ICG.

Xanthogranulomatous inflammation and spindle cell proliferation in response to silicone breast implant leakage.

This case study highlights the rare complications of silicone breast implants, as well as the diagnostic limitations of imaging. The patient initially presented with leakage of bilateral breast implants as discovered by a positron emission tomography (PET)-computerized tomography (CT) scan performed as part of a workup for small bowel Langerhans cell sarcoma metastases. The imaging results of the PET-CT scan revealed increased activity bilaterally with an enhancing, irregular, heterogeneously enhancing mass in the right breast. Given the clinical suspicion for breast implant-associated anaplastic large cell lymphoma, further investigation including surgical excision was undertaken. What initially was a concern for a serious complication of long-standing breast implants, fortuitously turned out to be a benign but exuberant xanthogranulomatous inflammatory reactive process. We hope that our report will add to the literature of this rare phenomenon and highlight it as a differential diagnosis of a mass in association with breast implants.

Trends in outcomes with adoption of indocyanine green angiography in postmastectomy reconstruction.

BACKGROUND: Indocyanine green angiography (ICGA) aims to reduce ischaemic complications by supplementing intraoperative perfusion assessment of mastectomy flaps. Learning curves for this technology have not been analysed. We evaluated changes in patient outcomes with increasing case volume after ICGA adoption in postmastectomy reconstruction. METHODS: Single-institution retrospective analysis of 320 implant-based reconstructions following mastectomy using ICGA from 2015, when it was introduced, to 2021. Cases chronologically divided into tertiles and complications amongst groups evaluated. Trends in ischaemic complications plotted using weighted moving average. CUSUM analysis determined after how many cases plateau was reached. Number of ischaemic complications prior to plateau calculated with AUC analysis. RESULTS: Ischaemic complications decreased over time (Group 1, 15.1%; Group 2, 11.2%; Group 3, 4.7%, P = 0.034). Cases of delayed reconstruction increased over time (Group 1, 6.6%; Group 2, 28%; Group 3, 22.4%; P < 0.001). Our institution reached plateau of 10% ischaemic complications after 160 cases. Mean incidence of ischaemic complications decreased from 16.9% during the first 160 cases to 3.8% after plateau was reached (P < 0.001). Eleven extra breasts (6.9%) experienced ischaemic complications, that may have been avoided if operated by surgeons after the first 160 cases. CONCLUSIONS: There was increased tendency towards a conservative approach of delaying reconstruction and decreased rates of ischaemic complications with increasing case volume after ICGA implementation. A significant number of cases were needed to reach plateau of minimal ischaemic complications. This data could encourage development of standardized protocols for this technology to shorten learning curves for improved patient outcomes.

Patterns of ischaemia and reperfusion in nipple-sparing mastectomy reconstruction with indocyanine green angiography.

BACKGROUND: Intraoperative assessment of mastectomy flaps and nipple-areola complex (NAC) with indocyanine green angiography (ICGA) for decision-making in delayed breast reconstruction after nipple-sparing mastectomy (NSM) remains to be fully elucidated. We evaluated patterns of ischaemia and reperfusion in NSM with delayed breast reconstruction and their outcomes. METHOD: Single-institution retrospective study of delayed implant-based breast reconstructions following NSM due to poor perfusion analysis on ICGA. Intraoperative ICGA perfusion values and fluorescence patterns during the delayed and subsequent reconstruction operations were analysed. RESULTS: Fifty-six (45 patients) delayed breast reconstructions following NSM were performed. The median time to reconstruction was seven days (range, 4-21 days). A total of 112 fluorescence images were reviewed. Four patterns of ischaemia were identified during initial mastectomy (Type I, diffuse ischaemia; Type II, geographic ischaemia; Type III, incisional ischaemia; Type IV, NAC only ischaemia). All, but 1 breast, had adequate reperfusion during delayed reconstruction. Obesity (BMI ≥ 30) was associated with Type I ischaemia (p < 0.001). Mean ICGA absolute and relative perfusion values during initial mastectomy were significantly lower than the perfusion values during delayed reconstruction (absolute value 6.7 versus 40.2 units, p < 0.001; relative value 10% versus 44%, p < 0.001, respectively). There were no cases of partial-thickness or full-thickness necrosis. CONCLUSIONS: Delaying breast reconstruction for NSM with ischaemia predicted by ICGA may allow blood supply to the flap and NAC to improve, reducing the risk for necrosis. Distinct patterns of ischaemia and low perfusion values with ICGA may be used in the decision to delay reconstruction.

Cost-effectiveness of indocyanine green angiography in postmastectomy breast reconstruction.

BACKGROUND: Mastectomy skin flap necrosis is a major complication of skin- or nipple-sparing mastectomy. Indocyanine green angiography (ICGA) is a novel technology that can identify flaps at risk of necrosis, but there is paucity of cost-effectiveness data particularly in the Australian context. We evaluated its cost-effectiveness in breast reconstruction surgery. METHODS: Single-institution retrospective study of 295 implant-based breast reconstructions using ICGA compared with 228 reconstructions without ICGA from 2015 to 2020. Costs were calculated using Medicare item numbers and micro-costing analysis. Break-even point analysis determined the number needed to break-even. Cost-utility analysis compared probabilities of ischaemic complications and utility estimates derived from surveys of surgeons to fit into a decision model. RESULTS: There were 295 breast reconstructions using ICGA with a total cost of AU$164,657. The average cost of treating an ischaemic complication was AU$21,375. Use of ICGA reduced the ischaemic complication rate from 14.9% to 8.8%. Ischaemic complications were prevented in 18 breasts resulting in gross cost savings of AU$384,745 and net savings of AU$220,088. Three hundred eighteen cases using ICGA are needed to break-even. The decision model demonstrated a baseline cost difference of AU$1,179, a quality-adjusted life-years (QALY) difference of 1.77, and an incremental cost-utility ratio (ICUR) of AU$656 per QALY favouring ICGA. CONCLUSIONS: Routine use of ICGA during implant-based breast reconstruction is a cost-effective intervention for the reduction of ischaemic complications in the Australian setting. ICGA use was associated with a gain of 1.77 additional years of perfect health at a cost of AU$656 more per year.