Image-Guided Breast Interventions: Biopsy and Beyond

Breast interventions primarily comprise of biopsy of the suspicious breast lesions to obtain accurate pathological diagnosis. Generally, image-guided breast biopsy is required for nonpalpable lesions, however, even in palpable lesions, image-guided biopsy should be performed as it improves the accuracy of diagnosis. Image-guided breast interventions have progressed well beyond biopsy, making the radiologist an important part of the multidisciplinary management of breast cancer. Preoperative localization of nonpalpable abnormalities guides optimal surgical excision to obtain negative margins without sacrificing the normal tissue. Ablative procedures for breast cancer treatment such as radiofrequency ablation (RFA) and high-intensity focused ultrasound ablation can sometimes replace surgery in older patients with comorbidities. This article enumerates and describes the expanding spectrum of image-guided interventions performed by breast radiologist.

Magnetically Guided Localization Using a Guiding-Marker System® and a Handheld Magnetic Probe for Nonpalpable Breast Lesions: A Multicenter Feasibility Study in Japan

Accurate pre-operative localization of nonpalpable lesions plays a pivotal role in guiding breast-conserving surgery (BCS). In this multicenter feasibility study, nonpalpable breast lesions were localized using a handheld magnetic probe (TAKUMI) and a magnetic marker (Guiding-Marker System®). The magnetic marker was preoperatively placed within the target lesion under ultrasound or stereo-guidance. Additionally, a dye was injected subcutaneously to indicate the extent of the tumor excision. Surgeons checked for the marker within the lesion using a magnetic probe. The magnetic probe could detect the guiding marker and accurately localize the target lesion intraoperatively. All patients with breast cancer underwent wide excision with a safety margin of ≥5 mm. The presence of the guiding-marker within the resected specimen was the primary outcome and the pathological margin status and re-excision rate were the secondary outcomes. Eighty-seven patients with nonpalpable lesions who underwent BCS, from January to March of 2019 and from January to July of 2020, were recruited. The magnetic marker was detected in all resected specimens. The surgical margin was positive only in 5/82 (6.1%) patients; these patients underwent re-excision. This feasibility study demonstrated that the magnetic guiding localization system is useful for the detection and excision of nonpalpable breast lesions.

Intrathyroidal Thymus (Incidentaloma) Mimicking Thyroid Neoplasia in DICER1 Syndrome

<b><i>Introduction:</i></b> With the use of ultrasonography for the evaluation of thyroid and nonthyroid neck diseases, the incidental discovery of previously unsuspected thyroid nodules/nonpalpable lesions has increased. Intrathyroidal thymus arises due to aberrant thymic migration during embryogenesis. It is thought to be rare, fulfils the classic<i></i>criteria for diagnosis of an incidentaloma and it can be mistaken for a thyroid nodule. Multinodular goiter is the main endocrine manifestation of DICER1 syndrome, a tumor predisposition syndrome. Careful thyroid examination including ultrasound is thus necessary for DICER1 syndrome patients. <b><i>Case Report:</i></b> A 4-year-old prepubertal boy was referred to the pediatric endocrinology department following an earlier diagnosis of pleuropulmonary blastoma (PPB) type III, which is a hallmark component of DICER1 syndrome. The patient underwent surgery followed by chemotherapy. Genetic analysis identified a germline <i>DICER1</i> pathogenic variant (c.2062C&#x3e;T, p.R688*)<i></i>in the child and in 5 relatives. A second somatic <i>DICER1</i> RNase IIIb hotspot mutation<i></i>(c.5438A&#x3e;G, p.E1813G) was identified in DNA extracted from the proband’s PPB. He had no goiter on clinical examination, but a heterogenous, well-delineated, avascular, solid and hypoechogenic lesion with pseudomicrocalcifications was observed in the right lobe (4.1 × 3.1 × 2.6 mm), suggestive of thyroid neoplasia. Diagnostic work-up and a 3-year follow-up excluded thyroid neoplasia and confirmed the diagnosis of an intrathyroid benign thymic lesion. <b><i>Discussion and Conclusion:</i></b> This case exemplifies that thyroid incidentalomas in DICER1 syndrome patients should be viewed with great suspicion, but that not all thyroid disorders are indeed <i>DICER1</i>-related in these patients.

Single-Stage Localization and Thoracoscopic Removal of Nonpalpable Pulmonary Nodules in a Hybrid Operating Room

Objective We report our experience with simultaneous localization and thoracoscopic removal for nonpalpable undiagnosed pulmonary nodules. Methods All patients with nonpalpable lesions requiring video-assisted thoracoscopic surgery (VATS) wedge resection underwent localization of the targets and surgical removal in a hybrid operating room. Lesions were considered nonpalpable if they were small (<1 cm), deep (>1 cm from the surface), subsolid, or located within a dystrophic area. In all cases, intraoperative cone-beam computed tomography was performed for nodule localization and targeting, metal hookwires, or coils were alternatively used for intraoperative marking. Results From April 2016 to November 2019, 39 image-guided VATS (iVATS) were performed. The mean lesion size was 12 ± 6 mm. The mean distance from the deep edge of the lesion to the pleural surface was 24 ± 9 mm. The localization was performed with 20 hookwires and 19 coils. iVATS localization was successful in 36 patients (92.3%). Thirty-seven wedge resections were completed by VATS, 2 (5%) required conversion to thoracotomy. In 9 patients with intraoperative diagnosis of lung cancer, a lobectomy was performed (7 VATS and 2 thoracotomies). Mean length of iVATS localization was 30 ± 13 minutes. Median postoperative length of stay was 4 days (IQR 3 to 5). Conclusions iVATS seems to be a helpful tool for simultaneous localization and removal of nonpalpable nodules. A versatile approach using different devices seems advisable for the removal of targets in every clinical scenario reducing VATS conversion rate. Future research is required to compare iVATS with traditional preoperative localization techniques.

Magnetic resonance imaging in the diagnosis of nonpalpable breast cancer

Aim. To analyze sensitivity of magnetic resonance imaging (MRI) in the diagnosis of breast cancer when used after mammography and breast ultrasound.Methods. The study included 70 patients with nonpalpable breast lesions who had changes of breast tissue found at previous studies (mammography and breast ultrasound). MRI was performed with the use of Siemens Magnetom Avanto with magnetic field 1.5 Tl.Results. Most frequently nonpalpable lesions were diagnosed in 45 to 60-year old patients (60%), a little rarer - in 39 to 45-year old patients (22.9%), in patients at the age of 61 to 69 - in 10.0% (7 patients). 7.1% patients were over 70. All first detected nonpalpable lesions of breast were biopsied for morphological verification. With the combined use of mammography, sonography, MRI and stereotactic biopsy the diagnosis was made in 100% patients. MRI with contract enhancement showed no relation between sensitivity, specificity and reliability and density of breast tissues.Conclusions. MRI is considered a highly sensitive method of diagnosis and identification of changes found at mammography and breast ultrasound.

Magnetic Probe–Guided Excision of Nonpalpable Neck Lesions

Background: Reoperative neck surgery is technically more demanding because of the presence of scar tissue and distorted anatomy. We aimed to investigate the magnetic probe–guided excision of nonpalpable neck lesions in patients with previously operated neck compartments. Methods: This study included 9 patients with recurrent/persistent thyroid carcinoma, recurrent/persistent hyperparathyroidism with previously operated neck compartments. The pathologic lesions were localized by ultrasonography, and magnetic tracer (0.2 mL, iron oxide) was injected directly into the pathologic lesions. Careful dissection was carried out following the area of maximum magnetic activity until the nonpalpable lesions were identified and excised. Result: All neck lesions were removed in 9 patients. The median count from lesion was significantly higher than values from lesion bed (background activity; (9900/5 seconds vs 250/5 seconds, P < .001). During follow-up, all patients had negative ultrasonography. Conclusion: Magnetic probe–guided technique could provide access to nonpalpable lesion localization in centers without readily available access to nuclear medicine facilities.