Liver metastases

Liver metastases are a frequent, often fatal complication in the natural history of many types of cancer, particularly in the digestive tract. When they are multiples and diffuse to both lobes of the liver, there is at present no valid cure as surgical resection is impossible, traditional radiotherapy is contraindicated because of the risk of irreversible radiation damage of the liver, and chemotherapy is usually ineffective. Other palliative therapeutic approaches, such as local ablation techniques, despite an apparent focal control, rarely demonstrate a survival benefit. Therefore, there is an urgent need to elaborate and apply new curative strategies for multiple liver metastases. For these clinical situations we proposed and performed in two patients a radio-surgical procedure based on an extracorporeal BNCT of the isolated, blood-deprived and chilled liver, which is previously treated with a ¹⁰B compound. This method is intended for young patients with a liver-only disease after a radical resection of the primary tumor (colon-rectum carcinoma) and in a good state of health. The advantages of this new approach are that the diseased organ can be directly and entirely exposed to a homogeneous neutron flux so that the dose of the absorbed radiation is the same in any known or unknown tumor nodule, and even single cells, depending merely on the B content that was accumulated. Any interference of irradiation with other tissues and organs is avoided; endothelial damage of vessels is reduced to a minimum. Difficulties and limitations are also present. From the surgical point of view, the procedure imposes a liver auto-transplantation, which is not an easy task. Early in the follow-up of both patients, a post-irradiation syndrome appeared; it lasted some weeks and caused dramatic even if reversible effects. Recurrences occurred in our long-surviving patient at 33 months and caused his death 44 months after BNCT. All these aspects of our clinical experience are presented and discussed, together with the technical issues we faced during the physical and biological preparatory phases of the project.