RT Journal Article
SR Electronic
T1 Influence of Vitamin C on Salivary Absorbed Dose of <sup>131</sup>I in Thyroid Cancer Patients: A Prospective, Randomized, Single-Blind, Controlled Trial
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 618
OP 623
DO 10.2967/jnumed.109.071449
VO 51
IS 4
A1 Bin Liu
A1 Anren Kuang
A1 Rui Huang
A1 Zhen Zhao
A1 Yu Zeng
A1 Jiantao Wang
A1 Rong Tian
YR 2010
UL http://jnm.snmjournals.org/content/51/4/618.abstract
AB In this study, vitamin C was administered at various times as a sour stimulant to thyroid cancer patients, and the effect on salivary absorbed dose of therapeutic radioiodine (131I) was investigated. Methods: Patients with differentiated thyroid cancer who had been prepared for thyroid remnant ablation after total thyroidectomy were prospectively recruited and, using a random-number table, were divided into 4 groups. In the hypothyroid condition, the patients in groups A, B, C, and D began sucking vitamin C (100 mg every 4 h in the daytime over 6 d) at 1, 5, 13, and 25 h, respectively, after receiving 3.7 GBq of 131I. Scintigraphic images of the head and neck were serially acquired after 131I administration to assess biokinetics in the salivary glands. Calculation of salivary absorbed dose was based on the MIRD schema of the Society of Nuclear Medicine. Results: Seventy-two patients (18, 18, 19, and 17 patients from groups A, B, C, and D, respectively) were eligible for the analysis of salivary dosimetry. Differences in absorbed doses to the parotid salivary gland (0.18 ± 0.11, 0.16 ± 0.07, 0.16 ± 0.09, and 0.16 ± 0.12 mGy/MBq in groups A, B, C, and D, respectively; P = 0.37) and submandibular salivary gland (0.19 ± 0.05, 0.17 ± 0.05, 0.18 ± 0.07, and 0.17 ± 0.06 mGy/MBq, respectively; P = 0.28) were not statistically significant among groups. Salivary cumulated activities arising from the first 24 h after 131I administration accounted for 86.08% ± 7.89% (range, 75%−98%) of total cumulated activities. Differences in salivary absorbed dose during the first 24 h were not statistically significant among the 4 groups either (P = 0.32 and 0.24, respectively, for the parotid and submandibular salivary glands). Conclusion: Salivary stimulation with vitamin C at any time after 131I administration has only a limited effect on salivary absorbed dose in thyroid cancer patients.