Image-guided radiofrequency excision biopsy of breast lesions

Breast abnormalities may be benign or malignant. Diagnosis is based on clinical findings, imaging and tissue sampling. Tissue sampling is usually by fine needle aspiration for cytology, or by needle core biopsy for histology. Histology allows for differentiation between benign tumours such as fibroadenomas (typically between 1 cm and 3 cm in size), and others such as non-invasive ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). Open surgical biopsy or image-guided vacuum-assisted core biopsy may also be used to establish tumour type and grade.

Breast cancer is the most common cancer in women in the UK. If cancer is diagnosed, treatment depends on the type, stage and grade of the tumour.

In general terms, the more tissue retrieved with multiple core samples or larger tissue samples, the more accurate the diagnosis is likely to be. With this procedure, the whole lesion can be removed.

Image-guided radiofrequency (RF) excision biopsy of breast lesions aims to achieve minimally invasive retrieval of an intact specimen for histological examination, while minimising the risk of bleeding and haematoma formation. This procedure is not indicated currently for the therapeutic removal of known cancers unless there are no surgical options.

The procedure is carried out with the patient under local anaesthesia. Using image guidance, a small incision is made in the breast. A probe with a unipolar RF cutting tip is advanced to the site of the lesion. Small wires and capturing arms are extended from the tip of the probe to surround the lesion, which is then dissected using the RF cutting tip. The sample is captured in the arms of the device and withdrawn.

Probes of various diameters and expandable RF cutting tips can be used, depending on the diameter of the sample to be captured.

In a case series of 742 breast lesions (absolute number of patients not reported), 34 lesions were initially identified as atypical ductal hyperplasia (benign lesions) after RF excision biopsy. Following subsequent surgery and histological examination 9% (3 out of 34) of these results were false negatives; the lesions were subsequently diagnosed as either DCIS or IDC. Similarly, 5% (6 out of 119) of lesions initially diagnosed as DCIS following RF excision biopsy were subsequently diagnosed as IDC after surgical excision and biopsy.

In a case series of 100 patients (106 lesions) with breast lesions diagnosed as fibroadenomas based on imaging findings, who were subsequently managed by RF excision biopsy, 93% (79 out of 85) of patients showed no physical or imaging evidence of residual lesions at follow-ups of between 4 and 6 months.

The Specialist Advisers listed key efficacy outcomes for this procedure, when used for benign lesions, as intact removal of the lesion and patient acceptability/cosmetic appearance. The Specialist Advisers listed additional efficacy outcomes, when used in early breast cancer, as delivery of an evaluable lesion for histology, and both local recurrence and survival.

The case series of 742 lesions (absolute number of patients not stated) reported that infection (not otherwise defined) occurred in less than 1% (1 out of 742) of biopsies (resolved with oral antibiotics; follow-up not stated). The case series of 100 patients (106 lesions) recorded a mean pain score during the procedure of less than 1 point (using a visual analogue scale from 0 [no pain] to 10 [severe pain]).

In the case series of 100 patients (106 lesions), bleeding occurred in 2% (2 out of 106) of excision procedures but this was controlled by 'conservative measures' (not otherwise defined).

The Specialist Advisers listed adverse events reported in the literature as haematoma, infection, skin burns and failure to deliver an adequate sample. They considered theoretical adverse events to include seeding of tumour cells along the biopsy tract, haemorrhage, pain (temporary) and fat necrosis due to thermal damage.