Fig. 2: Clinical decision-making flowchart, based on the two-step risk stratification model.

After first-line immunochemotherapy, patients with a Model I score ≥ two are classified as resistant patients and modification of the treatment strategy is recommended. Those scoring < two proceed to Model II. In Model II, patients with a score of two are considered durable responders and advised to receive immunotherapy maintenance alone, while those with a score < two are identified as partial responders and LRRT is recommended. NPC nasopharyngeal carcinoma, LRRT locoregional radiotherapy, LDH lactate dehydrogenase, EBV Epstein-Barr virus, SD stable disease, PD progressive disease. Depth of response (DpR) was defined as the percentage of tumor shrinkage from the baseline tumor burden to the timepoint of assessment.