Liver Cancer (cont.)

Cryoablation is similar to RFA in that a single tumor is identified and then targeted by a radiologist with a needle inserted through the skin directly into the cancer. However, instead of using heat, cryoablation sues a probe filled with liquid nitrogen to freeze the tumor and kill it that way. This is probably as effective as RFA but can be used in some tumor locations where heat might accidentally damage adjacent organs (like when the gallbladder or colon is too close to the tumor).

Stereotactic radiosurgery (SRS) is a new technique directing radiation (high-powered X-ray beams) directly to the tumor. Previously, radiation could not generally be used for liver cancer, because the normal liver was more sensitive to dying from radiation than the cancer was. SRS uses computer planning and CT scans to model the exact size, shape, and location of the cancer. It then directs the radiation machine, which can move around the patient in all three dimensions, to give many individual beams of radiation designed to converge just on the tumor, thus sparing much of the normal liver from the cumulative high doses. This appears to be very effective against solitary tumors.

This technique is able to deliver high doses of radiation to a defined local area. Proton beam therapy is used in the treatment of other solid tumors as well. There are not much data yet regarding the efficacy of this treatment in liver cancer. The ideal patient is one with only a small (<5 cm) solitary lesion. To have this procedure done, the patient actually is fitted with a body cast so that he or she can be placed in the identical position for each session. Therapy is conducted daily for 15 days. Preliminary data from the U.S. suggest similar effectiveness as seen with TACE or ablation therapy. It is not known, however, whether this type of radiation treatment prolongs the life of the patient.

How do these various medical treatment procedures compare to each other?

We really don't know because there are no head-to-head studies comparing chemotherapy, chemoembolization, ablation techniques, and proton beam therapy to each other. Most reports deal with a heterogeneous group of patients who have undergone only one specific treatment procedure or another. Therefore, selection of a treatment option for a particular patient will depend primarily on the expertise of the doctors in the patient's area. Studies are also needed to evaluate combinations of these procedures (for example, proton beam and TACE). Decisions are generally made by a multidisciplinary team of liver cancer specialists who are knowledgeable and expert in all of these techniques, so that the team can choose the best method for an individual patient depending upon overall health and liver function as well as the size, number, and location of the tumors.

Source: MedicineNet.com
http://www.medicinenet.com/liver_cancer/article.htm