Thermotherapy

Thermotherapy is a focal medical procedure that uses heat to kill retinoblastoma cells. Focal procedures seek to treat the effected cells without damaging surrounding healthy cells. The heat may be transmitted to the area of the eye that has tumors using ultrasound, microwave, or infrared rays.

Thermotherapy can be used as the sole method of treatment for small tumors, or in conjunction with other treatment methods for larger tumors or if treatment is not entirely successful in eliminating pediatric retinoblastoma. The heat often seems to increase the effectiveness of chemotherapy and radiation therapy. Thermotherapy is less invasive than some forms of treatment for pediatric retinoblastoma, but carries the risk of side effects and complications.

Retinoblastoma Thermotherapy Procedure

The exact procedure that is used can vary slightly depending on the size and location of the retinoblastoma, and whether other treatment methods will be used. Thermotherapy is given when the patient is under anesthesia, and sessions are often not longer than ten minutes. The procedure typically shrinks tumors little by little, so several sessions may be required. Physicians will usually wait about a month between sessions to allow the patient ample recovery time, and to allow the body to gather natural defenses against the retinoblastoma.

Chemothermotherapy

If thermotherapy is being combined with chemotherapy, called chemothermotherapy, the heat given will typically be a slightly lower temperature. These thermotherapy sessions are often longer due to the lowered heat. Treatment will begin a few hours after chemotherapy has been given, to allow the greatest possible impact from the combined treatment methods. This type of combined treatment can be effective in treating tumors that are attached to the optic nerve, which photocoagulation or radiation therapy would damage and cause significant visual impairment.

Thermotherapy Side Effects

Thermotherapy can cause visual impairment from a number of factors, including:

• Scarring of the eye
• Burns or damage to the retina
• Shrinking of the iris
• Swelling of the eye or eyelid
• Clouding of the eye lens

Despite these risks, thermotherapy is a safer method of treatment than surgery and can often preserve eyesight with no scarring or damage to vision. Thermotherapy is also effective, causing tumor regression in almost all cases in which it is used. In data taken from 91 cases of retinoblastoma in which the tumor was smaller than 1.5 millimeters, thermotherapy alone was sufficient to eliminate the tumor.