Letter to the Editor “The dynamic changes and precise classification of parathyroid function within one year after thyroid cancer surgery”

Dear Editor, I read with great interest the recent article by Ning et al entitled “Dynamic changes and precise classification of parathyroid function within one year after thyroid cancer surgery”[1]. This retrospective cohort study represents a significant and commendable endeavor to evaluate parathyroid function after thyroidectomy. The study’s central thesis is that parathyroid function follows a biphasic pattern with a “shock phase” and a “plateau phase,” which is a valuable conceptual model. And the introduction of two specific metrics, the “vvPTH” (lowest value) and the “nbPTH” (new baseline), is a pragmatic approach to quantify this recovery. Furthermore, the proposed five-type classification system (I, II, IIIA, IIIB, and IIIC) is an ambitious and potentially useful tool for stratifying patient risk and guiding long-term management strategies. However, an aspect of the classification system invites scholarly debate and requires further validation. The choice of thresholds (15 and 25 pg/mL) for vvPTH and nbPTH, while data-driven from this cohort, may not be universally applicable. A PTH-based classification system utilizing relative changes from preoperative levels may enhance generalizability across diverse clinical settings, as absolute PTH values can vary significantly between institutions. This adjustment would enhance the model’s external validity and facilitate multi-institutional validation, a necessary step for widespread adoption. One additional point deserves mention. The identification of parathyroid autotransplantation (PA) as an independent risk factor for a lower vvPTH is statistically accurate, as the procedure inherently involves gland devascularization[2]. However, this finding must be interpreted within its full clinical context to avoid misleading conclusions. In modern thyroid surgery, PA is not merely a risk factor but a proactive, gland-preserving rescue strategy intended to mitigate the risk of permanent hypoparathyroidism[3]. The model effectively captures its short-term “shock” effect but does not assess its long-term benefit on the nbPTH. In conclusion, this work represents an important advance in the thyroid field. It provides a data-rich model for describing parathyroid recovery. And a prospective, multi-institutional, well-controlled study is warranted to validate these results. Refining this system through prospective validation will solidify its role as an indispensable tool in optimizing outcomes for thyroidectomy patients. Sincerely,