Interstitial laser thermotherapy (ILT) of breast cancer - Methodology and immunological responce

Interstitial laser thermotherapy (ILT) is an attractive form of local therapy against cancer because of its anti-tumor immune activity. The aim of this work was to evaluate ILT in breast cancer with respect to technique, changes in tissue immunocompetent cells and effect on prognosis. The method is dependent on accurate assessment of the tumor, and another aim was therefore to evaluate if MRI is better than ultrasound (US) for imaging. Twenty-four patients were treated with ILT, followed by surgical resection about two weeks later. Pre-treatment US estimated the average tumor diameter to be 14 (range 5-35) mm. ILT was performed at 48Cº for 30 minutes under local anesthesia. Three patients were radically treated with ILT and the average tumor necrosis was 33% (0-100). Microscopic examination of the resected specimen showed that the average tumor diameter was 23 (range 7-55) mm. US underestimation of tumor size contributed to the rather poor local efficacy. ILT-induced changes in tissue immunocompetent cells were assessed by comparing findings in pre-treatment core biopsies and post-treatment pathologic specimens (paired comparisons). Changes in regional lymph nodes were assessed by comparison with a control group undergoing surgery only. ILT induced a significant increase of mature dendritic cells, B lymphocytes and macrophages at the tumor border and of cytotoxic T lymphocytes and macrophages within the tumor. In the lymph nodes there was a significant decrease in T regulatory cells. Most of these changes are considered to have a favorable prognostic value. Follow up after ILT was 116 (91-136) months. No patient had local recurrence of disease. Five patients developed distant metastases, and three of them have died. The number of cytotoxic T cells within the tumor was higher in patients with recurrence than in patients without recurrence. Patients with recurrent disease had a lower number of NK cells in tumor-free lymph nodes than patients without recurrence. Possible clinical benefit of ILT should be examined in a larger and less heterogenous patient population. MRI has been used preoperatively in most patients (68%) with breast cancer in Iceland during 2007-2009, in addition to mammography and US. Invasive tumor was measurable on all imaging methods in 267 patients. The study revealed that MRI and US both under- and overestimated size. Routine MRI was not shown to be a better radiological method than US for estimating tumor size in local ablative therapy

Tumor Size of Invasive Breast Cancer on Magnetic Resonance Imaging and Conventional Imaging (Mammogram/Ultrasound): Comparison with Pathological Size and Clinical Implications.

In Landspitali University Hospital, magnetic resonance imaging is used non-selectively in addition to mammogram and ultrasound in the preoperative assessment of breast cancer patients. The aim of this study was to assess invasive tumor size on imaging, compare with pathological size and evaluate the impact of magnetic resonance imaging on the type of surgery performed

Interstitial laser thermotherapy (ILT) of breast cancer.

AIM: To find out if ILT can be used as radical treatment of breast cancer. METHOD: Twenty-four patients, aged 39-84 (mean 61), with invasive breast cancer were treated with ILT. All underwent mammography, ultrasound and core biopsy before treatment. The tumour was an invasive ductal carcinoma in 15 patients, a lobular carcinoma in eight and lobular-ductal cancer in one. Average tumour diameter was 14mm on ultrasound (5-35). Patients were treated in the outpatient clinics under local anaesthesia. Probes were placed under ultrasound guidance, in 19 patients, and ILT was performed with a diode laser at a steady-state temperature of 48 degrees C for 30min using temperature feedback control. Standard surgical excision was performed 12 (4-23) days after ILT and was preceded by Doppler ultrasound. RESULTS: Treatment-induced necrosis of invasive cancer was 33% (range 0-100) and was complete in three patients. At follow-up before surgery, the extent of laser damage could not be judged with ultrasound, although abolished tumour blood flow was demonstrated after treatment resulting in large necroses. Efficacy of treatment varied negatively with tumour size. The inefficacy of ILT was mainly due to the underestimation of tumour size by mammography and ultrasound and the shortcomings of these methods to demonstrate tumour borders, tumour irregularity and carcinoma in situ (CIS). ILT was well tolerated. Five patients had breast tenderness, and three patients had pain, during the first day after treatment. Small skin necroses were observed in two patients. CONCLUSION: Small breast cancers can be treated radically with ILT. The method may become useful in the treatment of breast cancer but needs further refinement, even for small well-defined breast cancers, if it is going to be employed for radical treatment