2 The procedure

2.1 Indications

2.1.1 Interstitial laser therapy is used to treat small tumours of the breast. Standard treatments include lumpectomy or mastectomy (without preceding laser therapy), and minimally invasive techniques such as radiofrequency ablation or cryotherapy.

2.2 Outline of the procedure

2.2.1 Interstitial laser therapy is a minimally invasive technique for treating small breast cancers. After locating the tumour using stereotactic techniques or ultrasound, laser energy is delivered into the tumour via a needle probe. This destroys tumour tissue – the aim is to ablate the tumour entirely.

2.3 Efficacy

2.3.1 The evidence was limited to three small case series and one case report. One study of interstitial laser therapy followed by surgery reported that 98% (43/44) of patients were disease-free at follow-up. However, follow-up ranged from 2 to 26 months, and it was difficult to determine whether the results were attributable to the laser therapy or the surgery. This study also found no histological sign of laser damage in the tumours of 9% (4/44) of patients. For more details, refer to the Sources of evidence section.

2.3.2 The Specialist Advisors noted that it was still uncertain whether the procedure could achieve thermal ablation of all malignant tissue. They also noted that there were no data comparing outcomes of the procedure with those of wide excision and radiotherapy.

2.4 Safety

2.4.1 The following complications were reported in the identified studies: small skin burns 11% (4/35); necrosis of non-tumour tissue caused by incorrectly placed laser 10% (2/20); pain sufficient to stop treatment 7% (3/44); gaseous rupture of tumour 3% (1/35); and haemorrhage 2% (1/44). For more details, refer to the Sources of evidence section.

2.4.2 One Specialist Advisor considered that this procedure should not be used outside a clinical trial; another listed the potential adverse effects of the procedure as necrosis, haemorrhage, and liquefaction caused by overheating of the tissue.