(Pictured above: anatomy of the thyroid gland. Image source: Wikipedia.org.)
In the June 2016 issue of Neuro-Oncology, researchers from M.D. Anderson Cancer Center in Houston reported findings that craniospinal irradiation with proton therapy led to a decreased incidence of hypothyroidism in the long-term.
Craniospinal irradiation (CSI), or radiation treatment that focuses its energy on the head, neck, and spinal column, is often prescribed for brain tumors like medulloblastoma, as well as head and neck cancers.
There are many critical structures in our skulls and necks that could be negatively affected by radiation, such as the thyroid gland. The thyroid gland regulates our bodies’ metabolism by converting the nutrient iodine into hormones necessary for human biological function. If the thyroid gland is radiated, it may lead to hypothyroidism, a glandular condition which creates symptoms such as reduced metabolism, sluggishness, high cholesterol, weight gain, and depression.
M.D. Anderson’s researchers performed a retrospective meta-analysis, studying the outcomes of 96 medulloblastoma patients treated with CSI from 1997 to 2014. Of the patients, 54 had received photon CSI, while 42 received proton radiation therapy for CSI.
Time and again, proton therapy led to better thyroid outcomes than photon therapy did. Proton therapy deposits radiation right at the targeted tumor, sparing surrounding healthy tissue. In the case of CSI, this means less radiation deposited in the nearby thyroid, which could destroy thyroid function. As a result, hypothyroidism developed in 46 percent of those treated with photon radiation, while it only developed in 19 percent (i.e. 8 patients) treated with proton therapy.
Ackerman Cancer Center treats a variety of brain tumors and oral, head, and neck cancers with the precision of proton therapy. Our practice also provides treatment for thyroid disease and thyroid cancer, both in the administration of radioactive iodine and the prescription of Synthroid, a synthetic form of thyroid hormones that allows patients to live with a normal quality of life.
To read the full text of the study published in Neuro-Oncology, click here.
To learn more about cancers treated with proton therapy, visit the Proton Therapy section of this website.