Invasion of pterygoid plates; an indicator for regional lymph node failure in maxillary sinus cancer

Abstract

Background: The aim of this study was to evaluate the long-term treatment results of combined superselective intraarterial chemotherapy and radiation therapy for advanced maxillary sinus cancer (MSC) and the incidence of regional lymph node failure, and to reveal the clinical and anatomical predictive factors for metastasis.Methods: We retrospectively evaluated 55 consecutive patients with locally advanced squamous cell carcinoma of the maxillary sinus who were treated with external radiotherapy and superselective intraarterial chemotherapy. Elective nodal irradiation (ENI) was performed only in the clinical node-positive (cN+) cases and not in the clinical node-negative (cN0) cases.Results: Thirty-eight patients were cN0, and 17 were cN+ at diagnosis. Regional lymph node metastases occurred in 7 of 38 patients with cN0, and 2 of 17 with cN+ during the median follow-up period of 36 months. There were more cases of high-grade (3 or 4) late adverse events in the ENI group than in the non-ENI group (13% vs. 41%, respectively; p = 0.03). In cN0 cases without ENI, invasion of the pterygoid plates (57% vs. 90%; p < 0.01) and oral cavity (35% vs. 92%, with invasion vs without invasion, respectively; p = 0.02) was significantly correlated with a low 5-year regional recurrence-free rate.Conclusions: Patients with MCS and invasion of the pterygoid plates and oral cavity can be considered appropriate candidates for ENI.

Radiologic Criteria of Retropharyngeal Lymph Node Metastasis in Maxillary Sinus Cancer

“…Furthermore, staging was performed on the basis of ndings from physical examinations, computed tomography (CT), MRI, and/or positron emission tomography-CT (PET-CT), in accordance with the Union for International Cancer Control (UICC, 7 th edition) (14). Treatment Details of de nitive external radiotherapy and super-selective IA chemotherapy were given in our previous report (7). In cN+ cases, the primary sites and metastatic LNs were irradiated with 60-70 Gy (median, 60 Gy, to iso-center by three-dimensional conformal radiation therapy (3DCRT), prescription dose > 50% of the target volume by IMRT) in 30-35 fractions over 6-7 weeks, and the prophylactic regional area (ENI) was irradiated with 46 Gy in 23 fractions by 3DCRT or 50 Gy in 25 fractions by IMRT (median, 46 Gy).…”

“…In this setting, we have performed elective nodal irradiation (ENI) only for patients with regional LN metastasis (cN+). From the results of a metaanalysis, the guidelines of the National Comprehensive Cancer Network (NCCN) recommended ENI for patients with advanced MSC (6), but ENI is controversial because of reports of increased late adverse events comprising dysphagia and trismus (7). We reported that ENI increased the radiation dose in the pharyngeal contractile muscles and increased late aspiration pneumonia (8).…”