Pu YM, et al. - This research determined if oral squamous cell carcinoma (OSCC) patients with only micrometastasis required postoperative radiotherapy. Using HE staining, experts detected and selected OSCC patients with negative, only micrometastasis and macrometastasis. Higher T stage and inferior worst pattern of invasion (WPOI) were discovered in patients with only micrometastasis but they had longer overall survival (OS), metastasis-free survival (MFS), and disease-free survival (DFS) than macrometastasis patients. Nonetheless, a comparable survival time of only micrometastasis patients with or without postoperative radiotherapy was determined, even in patients with inferior WPOI. Yet, radiotherapy could only be advantageous for patients with IV/V levels of micrometastasis. Yielded results demonstrated that postoperative radiotherapy was dispensable for only micrometastasis OSCC patients.