RAI and salivary stimulants (after)
The ONLY reasonably-performed study documented the worsening of salivary dysfunction consequent to using lemon candies to stimulate salivary flow during the first 24 hours of radioactive iodine therapy. On the other hand, AFTER 24 hours there is such a severe decrease of the level of radioactive iodine in the circulating blood, that the need for further treatments (of any sort) for the salivary glands is essentially moot. For that reason, I do not advocate ANY use of salivary stimulants at ANY time during or after radioactive iodine therapy. This differs from the recommendations of the study's authors who state that they might suggest use of lemon candy after 24 hours from the I-131 treatment.
The abstract for the study is: Nakada, K., T. Ishibashi, et al. (2005). "Does lemon candy decrease salivary gland damage after radioiodine therapy for thyroid cancer?" J Nucl Med 46(2): 261-6. Salivary gland dysfunction is one of the common side effects of high-dose radioiodine therapy for thyroid cancer. The purpose of this study was to determine whether an early start of sucking lemon candy decreases salivary gland injury after radioiodine therapy. METHODS: The incidence of the side effects of radioiodine therapy on the salivary glands was prospectively and longitudinally investigated in 2 groups of patients with postsurgical differentiated thyroid cancer with varying regimens for sucking lemon candy. From August 1999 to October 2000, 116 consecutive patients were asked to suck 1 or 2 lemon candies every 2-3 h in the daytime of the first 5 d after radioiodine therapy (group A). Lemon candy sucking was started within 1 h after radioiodine ingestion. From November 2000 to June 2002, 139 consecutive patients (group B) were asked to suck lemon candies in a manner similar to that of group A. In the group B, lemon candies were withheld until 24 h after the ingestion of radioiodine. Patients with salivary gland disorders, diabetes, collagen tissue diseases, or a previous history of radioiodine therapy or external irradiation to the neck were excluded.
Thus, 105 patients in group A and 125 patients in group B were available for analysis. There were no statistical differences in the mean age (55.2 y vs. 58.5 y), average levels of serum free thyroxine (l-3,5,3',5'-tetraiodothyronine) (0.40 ng/dL vs. 0.47 ng/dL), and the mean dose of (131) I administered (3.96 GBq vs. 3.87 GBq) between the 2 groups. The onset of salivary side effects was monitored during hospital admission and regular follow-up on the basis of interviews with patients, a visual analog scale, and salivary gland scintigraphy using (99m)Tc-pertechnetate. When a patient showed a persistent (>4 mo) dry mouth associated with a nonfunctioning pattern on salivary gland scintigraphy, a diagnosis of xerostomia was established. RESULTS: The incidences of sialoadenitis, hypogeusia or taste loss, and dry mouth with or without repeated sialadenitis in group A versus group B were 63.8% versus 36.8% (P < 0.001), 39.0% versus 25.6% (P < 0.01), and 23.8% versus 11.2% (P < 0.005), respectively. Permanent xerostomia occurred in 15 patients in group A (14.3%) and 7 patients in group B (5.6%) (P < 0.05). In both groups, bilateral involvement of the parotid gland was the most frequently seen and was followed by bilateral involvement of the submandibular gland. CONCLUSION: An early start of sucking lemon candy may induce a significant increase in salivary gland damage. Lemon candy should not be given until 24 h after radioiodine therapy.
ThyroidCancerHelp, November, 2007RAI and sour candy (dont use)
The facts are this: the only reasonably-performed clinical trial of salivary stimulants demonstrated that sour candies severely worsen salivary damage from radioactive iodine. Additionally, enhanced liquid consumption during radioactive iodine therapy will demonstrably diminish the benefits of radioactive iodine and put one at risk for dilutional hyponatremia, based on classic radiobiology and physiology. There is no doubt that these concepts are not understood or affirmed by some physicians; however, they're just mostly wrong or ignorant. Medical/biological reality is not subject to alteration by polling or voting. Much of the information on the ThyCa website was originally provided by me, but much has been altered and that of some other contributors is not correct.
ThyroidCancerHelp, November, 2007