To ablate remnant tissue after complete thyroidectomy(initially had multiple noduls, 1-ca node), what maximum dose of radioactive iodine be taken?

Depends: The dose is related to the risk of recurrent disease. The larger the primary tumor, the higher the risk. In your age group (under 45 yo) the risk is relatively low, even with having a positive lymph node. The recommended dose would be as low as 30 mci or as high as 100.

RAI: The RAI dose is directed by post operative risk stratification based on tumor size, margins, and cell type. This can be found in the #ATA 2015 Thyroid Nodule and Cancer Guidelines: Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, Pacini F, Randolph GW, Sawka AM, Schlumberger M, Schuff KG, Sherman SI, Sosa JA, Steward DL, Tuttle RM, Wartofsky L. 2015 American Thyroid Associat