Efficacy evaluation of different measurement methods for target lesions after neoadjuvant chemotherapy and radical radiotherapy in locally advanced hypopharyngeal carcinoma

Aim To assess the diagnostic efficacy in response evaluation of hypopharyngeal carcinoma (HPC) using different CT measurement methods. Methods and materials One hundred and three patients with locally advanced HPC receiving neoadjuvant chemotherapy (NACT) and radical radiotherapy (RT) were retrospectively enrolled. The long diameter, short diameter and largest axial area of the tumors and the largest metastatic cervical lymph node (LN) were measured before and after NACT, at the end of RT and 1 month after RT. Tumor regression ratios of the sum of the tumor's long diameter and LN's short diameter (LDTSDL), the sum of tumor and LN's short diameter (TTSDL), the sum of tumor and LN's largest axial area (AATML) were calculated. Analysis was conducted for overall survival (OS), metastasis‐free survival, regional recurrence‐free survival (RRFS), and local recurrence‐free survival (LRFS). Results Note that 35, 28, 23, and 16 patients suffered death, local recurrence, regional recurrence and distant metastasis, respectively. TTSDL‐defined effective group demonstrated better LRFS (p = .039) and RRFS (p = .047) after NACT and better OS since the end of RT (p = .037); AATML‐defined effective groups demonstrated better OS, LRFS, and RRFS since the end of RT (p = .015, .008, and .005). While LDTSDL‐defined groups showed differences in OS and LRFS until 1 month after RT (p = .013 and .014). Conclusions The regression rate of TTSDL and AATML can distinguish prognosis at an earlier time and demonstrated better reliability compared with LDTSDL. They were recommended for response evaluation in HPC. Diagnostic efficacy in therapeutic response by different imaging measurement of hypopharyngeal carcinoma with evaluated and proved diagnostic performance in different time point. The thickness and axial area distinguish prognosis better than RECIST 1.1. The thickness is the best for therapeutic response evaluation.