Clip and wire localization of locally advanced malignant breast masses in patients undergoing neoadjuvant chemotherapy and breast conservation therapy

Photoacoustic/ultrasound dual-modality imaging for marker clip localization in neoadjuvant chemotherapy of breast cancer

Significance

To ensure precise tumor localization and subsequent pathological examination, a metal marker clip (MC) is placed within the tumor or lymph node prior to neoadjuvant chemotherapy for breast cancer. However, as tumors decrease in size following treatment, detecting the MC using ultrasound imaging becomes challenging in some patients. Consequently, a mammogram is often required to pinpoint the MC, resulting in additional radiation exposure, time expenditure, and increased costs. Dual-modality imaging, combining photoacoustic (PA) and ultrasound (US), offers a promising solution to this issue.

Aim

Our objective is to localize the MC without radiation exposure using PA/US dual-modality imaging.

Approach

A PA/US dual-modality imaging system was developed. Utilizing this system, both phantom and clinical experiments were conducted to demonstrate that PA/US dual-modality imaging can effectively localize the MC.

Results

The PA/US dual-modality imaging can identify and localize the MC. In clinical trials encompassing four patients and five MCs, the recognition rate was ∼ 80 % . Three experiments to verify the accuracy of marker position recognition were successful.

Conclusions

We effectively localized the MC in real time using PA/US dual-modality imaging. Unlike other techniques, the new method enables surgeons to pinpoint nodules both preoperatively and intraoperatively. In addition, it boasts non-radioactivity and is comparatively cost-effective.

Assessment of Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Carcinoma Using Image-Guided Clip Placement

Background The present study aims to evaluate the response of locally advanced breast carcinoma (LABC) to neoadjuvant chemotherapy (NACT) using image-guided clip placement based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Methods Thirty-four patients with LABC were included in the study. Consent for three-dimensional titanium clip placement (400/300/200 mm Liga clips) under local anesthesia with USG guidance was obtained. Serial sonographic/X-ray evaluations of tumor bed size were conducted before every cycle of NACT. All data were recorded in millimeters of concentric tumor regression/non-regression. Tumor regression in a concentric or Swiss cheese pattern and non-responders were evaluated. Assessment of the response to NACT was performed using RECIST criteria, dividing it into four categories. Tumor response was confirmed with computerized tomography (CT) conducted before and after the completion of NACT. Patients underwent surgical management, mostly modified radical mastectomy (MRM), as they had locally advanced breast carcinoma. Following MRM, the clips in the specimen guided the original site of the tumor for histopathological evaluation and response to chemotherapy. Results Tumor response was classified into four types: complete response (CR), partial response (PR), progressive disease (PD), and stable disease. RECIST 1.1 criteria were elaborated and defined. Data for all patients were entered into an Excel sheet (Microsoft Corporation, Redmond, Washington) to prepare a master chart, and the following observations were made and analyzed using SPSS software. The duration of chemotherapy for the study population ranged from 32 to 206 days, with a mean (±SD) of 111.82 (± 52.64) days and a median (IQR) of 81 (63, 158) days. The mean period between clip insertion and completion of NACT was 111.82 days. The baseline sum diameters and post-NACT diameters of the tumors were 70.50 (±13.60) mm before NACT and 17.75 (±17.20) mm after NACT. Hence, the mean size of the lump was statistically significantly lower after NACT, with a mean difference of 52.75 (p<0.05). The mean rate of reduction in tumor diameter was found to be 74.32% (±23.44%) based on RECIST 1.1 criteria. Pathological response was observed in all patients except for 8.8% of the patients. Clinical complete response was seen in 35.29% of patients, and partial response was observed in 52.92% of the patients based on RECIST 1.1 criteria. The study thus demonstrates the effectiveness of NACT in LABC, with a mean reduction in tumor diameter of 74.32%, assessed with the help of RECIST 1.1 criteria. Conclusion NACT for patients with LABC has shown a significant reduction in tumor size. NACT should be the initial mode of management for patients with LABC. RECIST 1.1 criteria are effective and can be used to assess tumor response to NACT. This has aided in the stratification of the response of NACT for further management through systemic therapy (adjuvant chemotherapy) after the surgical excision of the tumor.

Does Tumor Marking Before Neoadjuvant Chemotherapy Helps Achieve Better Outcomes in Patients Undergoing Breast Conservative Surgery? A Systematic Review

Patients with breast cancer are increasingly being offered breast conserving surgery (BCS) following neoadjuvant chemotherapy (NACT). We aimed to conduct a systematic review to assess the advantage of tumor marking in patients undergoing BCS after NACT. After registering the protocol for a systematic review with PROSPERO, a systematic search was conducted through September 30, 2020, for all studies involving patients undergoing BCS post NACT after tumor marking. Margin status on final histology was the primary outcome. Oxford Centre for Evidence Based Medicine (OCEBM) levels were used to assess internal validity. A total of 636 records from Medline/PubMed, 1381 from Embase, and 1422 from Cochrane library were extracted. After screening, 15 articles (1520 patients) were included for data synthesis. For marking, 6 studies used metallic markers and 5 used ¹²⁵I-radioactive seeds (RSL) followed by skin tattoo and radio-guided occult lesion localization using ^99mTc (ROLL) in one study each. Most studies used a single marker at the center except for two (143 patients), who practiced the bracketing technique. Incidence of unsatisfactory margins (positive/close) ranged from 5 to 23.5%. After excluding patients with complete pathological response, the "adjusted unsatisfactory margin" rate was found to be 19.3% (10.4-33%). Overall 20.6 recurrences (locoregional/distant) were reported per 1000 patient-years follow-up. Overall survival (OS) was only reported by one study as 96.6% and 84.7% in patients with and without marker placement (p = .01). Re-excision and secondary mastectomy rates (reported by nine studies) were 7.3% and 5.7% respectively. There is limited evidence that tumor marking before neoadjuvant chemotherapy improves the rate of unsatisfactory margins or survival outcomes in a patient undergoing BCS after NACT.