Prescribed Activity of 131I Therapy in Differentiated Thyroid Cancer

As authors, practitioners, or readers of these studies, we are receiving a wake-up call to be more thoughtful and critical in our assessment of publications in general and our interpretation of these studies in particular. Is 1.11 GBq as effective as, or as ineffective as, 3.7 GBq or more for adjuvant treatment? Does an absence of evidence in two different patient populations equate to evidence of an absence between two treatments?In the end, everything is about our patients and our commitment to them. Physicians must individually decide what their 131I activity recommendations will be for adjuvant treatment and distantmetastasis treatment in each of their DTC patients. For my patients, I generally recommend an 131I activity approaching 5.55 GBq for adjuvant treatment. For patients with distant metastasis,I explore local treatment options first, and if the decision is to proceed with 131I, I thoroughly discuss with the patient the potential benefits and risks of empiric and dosimetrically guided 131I activit . In addition, and regardless of 131I activity for therapy,I recommend and educate for aggressive preventive management to reduce the frequency and severity of side effects. If I were the patient and initial local treatments were not an option, I would proceed with approximately 5.55 GBq of 131I for adjuvant treatment. For distant metastasis, I would proceed with dosimetrically guided 131I activity with no fractionation of the 131I and adherence to a strict low-iodine diet. Whether to undergo preparation with thyroid hormone withdrawal or recombinant human thyroid-stimulatin hormone injections would depend on my clinical situation at the time of treatment.