Ultrasound-guided hepatic cryosurgery in the treatment of metastatic colon carcinoma. Preliminary results

Abstract

Cryosurgery, the in situ freezing of cancer, has been proposed in the past as a possible treatment for unresectable hepatic tumors. Its advantage lies in the fact that it is a very focal treatment sacrificing less normal tissue than surgical resection, allowing treatment of multiple lobes. Because cryosurgery does not affect large vessels, tumors in difficult locations, such as adjacent to the inferior vena cava (IVC), can be treated. With the use of intraoperative ultrasound to place the cryoprobes and monitor the freezing process, 18 patients with unresectable metastatic colon carcinoma confined to the liver were treated. Of the 18 patients treated, 4 (22%) are in complete remission as determined by computed tomography (CT) scans and carcinoembryonic antigen (CEA) levels, with a mean follow-up of 28.8 months. Four patients (22%) were not adequately treated at the time of cryosurgery. The number of lesions frozen in each patient ranged from 1 to 12, with a mean of 6 lesions. Fourteen patients had bilobar disease; three patients had previous right lobectomies with recurrences in their remaining left lobes prior to cryosurgery, and one patient had unilobar disease. Mean survival of the 14 cases with recurrence was 21.4 months, with 2 of the 14 still alive. Ultrasound-guided hepatic cryosurgery appears to be an effective treatment for metastatic colon carcinoma to the liver that is unresectable (including patients with bilobar and multiple lesions). These preliminary results indicate that the procedure warrants further study.

Surgical treatment of colorectal metastases to the liver

“…36 Patients had as many as 12 tumors within the liver, but none were found to have extrahepatic tumor. Mean survival for this group was 21 months.…”

Microwave ablation for unresectable hepatic tumours: Clinical results using a novel microwave probe and generator

“…A tumour diameter of 30mm or greater and close proximity to major vascular structures are both well documented risk factors for tumour recurrence (6)(7)(8)(9)(10)(11)(12)(13). It is possible that the larger size of one of these tumours may be connected to its recurrence though many larger lesions were successfully treated in this series.…”

Treatment of cancer with cryochemotherapy

“…The thermal parameters employed in this study were chosen because they are typical of non-lethal freezing thermal parameters most relevant to the problems of cryosurgery. The cooling rate of 18C/min is typical to 'low' cooling rates Shitzer, 1976, 2000), the temperature of 7148C is a typical temperature in which cell survival was observed and in which the mechanism of damage is chemical (Revoire et al, 1996;Rui et al, 1999;Rubinsky, 2000) and the time of exposure of 30 min is typical to how long a cryosurgical procedure takes (Onik et al, 1984(Onik et al, , 1991. Table 1 demonstrates that bleomycin has the ability to significantly increase cell damage at thermal conditions typical to those on the outer rim of a cryosurgical lesion.…”

“…Deep in the body it is performed with needle-like cryogen cooled probes, inserted in the tumour. The extent of freezing is controlled by imaging (Onik et al, 1984(Onik et al, , 1991Rubinsky, 2000). The frozen tissue is left to thaw in situ and is disposed by the body immune system.…”