Long-term effects may include scarring, loss of organ function, or even secondary cancers. In many cases, the cancer can be cured with no long-term effects. Combining radiation and chemotherapy can cause more acute and late side effects. Combination therapy is more likely to cause permanent damage to the bone marrow and secondary cancers. Superficial electron beam radiation is usually free of serious side effects.
Implanted radiation tends to cause local reactions.
There can be some late complications, such as scarring. Radioactive iodine in the usual doses rarely causes any problems.