Determination of radiotherapeutic target zones for thoracic esophageal squamous cell cancer with lower cervical lymph node metastasis according to CT-images

Abstract

Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related deaths worldwide. And radical synchronized chemoradiotherapy has become an important treatment measures for this disease. It is necessary to define the therapeutic target zone based on computer tomography(CT)-images for precise radiotherapy. Therefore, we retrospectively analyzed the regularity of lymph node metastasis in lower cervical section of thoracic esophageal cancer based on CT-images and discussed the range of radiotherapy in supraclavicular zone. The lower cervical lymphatic drainage area was divided into cervical tracheoesophageal groove (CTG), medial supraclavicular zone (MSC zone) and lateral supraclavicular zone (LSC zone) based on CT-images. We found that the rate of lymph node metastasis to medial CTG and MSC zone was relatively high. And rate of lymph node metastasis to the above two zones from middle thoracic section was on an increasing trend with the progress of T stage. Patients at stage T3 and T4 with lymph node metastasis in tracheoesophageal groove in middle thoracic section showed a higher rate of lymph node metastasis in MSC zone. These results demonstrated that the CTG and MSC zone should be clinically included in the supraclavicular target zone for radical radiotherapy, and the T-stage and tumor location should be considered simultaneously.

Hypofractionated Radiotherapy in Combination With Chemotherapy Improves Outcome of Patients With Esophageal Carcinoma Tracheoesophageal Groove Lymph Node Metastasis

“…However, TGLN metastasis after surgery is the major cause of treatment failure of EC, with an incidence of 12–80% ( 2 – 5 ), especially the right lymph node metastasis ( 16 , 17 ). The diagnosis of TGLN metastasis is mainly relied on CT and PET-CT scans ( 6 , 18 – 21 ), where there is a presence of a short diameter ≥0.5 cm and/or high uptake of 18F-PDG ( 22 ). In clinical practice, lymph node metastasis may induce injury of laryngeal nerve, which results in hoarseness and bucking and a poor prognosis.…”

“…Furthermore, TGLN is also a negative prognostic factor for patients with EC. Radiotherapy is a major treatment option for TGLN metastasis in EC patients ( 6 ). Recently, the application of intensity-modulated radiation therapy (IMRT) contributes to target conformance and dose homogeneity, which reduces the dose of radiation to normal tissues and increases the local control and survival rate ( 7 ).…”

Comparative study of computed tomography (CT) and pathological diagnosis toward mediastinal lymph node metastasis in esophageal carcinoma

“…Kato et al 20 considered that EC-tracheoesophageal groove lymph node metastasis can occur in any locations, lesions and tumor cell invasion ranges of primary tumor. Li et al 21 believed that the rate of lymph node metastasis to cervical tracheoesophageal groove and medial supraclavicular zone from middle thoracic section of esophageal cancer was increased with later T stages. Schmidt et al 22 considered that general people have lymph nodes in their tracheoesophageal groove, with an average of 3.24 and 5.52 lymph nodes in the left and right tracheoesophageal grooves, respectively.…”

Esophageal cancer N staging study with endoscopic ultrasonography

“…It may be speculated that this phenomenon was caused by surgical difficulties. However, lymph nodes located in the tracheal and esophageal groove were frequently subject to metastasis, which may indicate an association between location and metastatic capacity (18). The present study determined the optimized critical value of long diameter (>7.5 mm) and short diameter of lymph nodes (>5.5 mm).…”