Bruce J. Barron

Generally, a child’s medical condition is reviewed prior to administering contrast. Chronic renal failure and severe disability may cause reactions from contrast. There should be no side effects in your son’s case. The has been some concern about the contrast staying around for a long time, but definite causality of problems has not been established.

Nuclear medicine has long been able to treat certain cancers with radioisotopes. The old standard is using radioiodine to treat thyroid cancer. We also use radiolabeled beads to infuse into liver tumors, with some degree of success. Recently radiolabeled receptor agents have been used to treat neuroendocrine tumors with some success. Newer cancer agents commune and immune stimulating factor with a chemotherapy agent. Some are tagged with a therapeutic radioisotope. With the exceptions listed above, other nuclear medicine therapies are often non-specific and can kill normal tissue as well. Unfortunately, there is no magic bullet.

Radioactive iodine is the ideal therapeutic agent for well differentiated thyroid cancer. The iodine (I-131) is administered as a capsule. The iodine goes to the thyroid (normal and cancerous) and kills the cells. The dose of I-131 is dependent on the specifics of the tumor and whether or not there is metastatic disease elsewhere. After thyroidectomy, thyroid hormone is suspended for a while or the patient may receive two intramuscular injections of a thyroid stimulating hormone. A small dose of I-131 is administered to see how much and where thyroid tissue is left. After receiving radioactive iodine, there are some quarantine issues to prevent exposure to others.

Radioactive iodine (I-131) is a beta emitter and when taken up preferentially by the thyroid gland or cancer kills the cells. It is a useful treatment if the cancer is well differentiated. Dose depends on specifics of tumor histology, presence of normal thyroid, or distal metastatic disease.

Radioactive seeds are placed into the prostate gland where the emit their radiation. They remain in the gland after the radiation if finished. If possible, a better option might be IMRT or directed radiation to the prostate from an external beam. This requires up to 30 visits for treatments. Side effects include those related to colon and bladder. He should also have a baseline bone scan.