To Observe the Local Tumor Recurrence Rate of Adding Intraluminal Brachytherapy With Balloon Applicator After Standard Definitive Concurrent Chemoradiotherapy (CCRT) on Local-regional Thoracic Esophageal Cancer Patients Who Refused Surgery

American Brachytherapy Society (ABS) provided guidelines for brachytherapy in esophageal cancer in 1997, which defines the general principle for brachytherapy used in definitive CCRT. (1) Patients with unifocal thoracic adeno- or squamous cancers < or = 10 cm in length, with no evidence of intra-abdominal or metastatic disease.

(2) Contraindications include tracheal or bronchial involvement, cervical esophagus location, or stenosis that cannot be bypassed.

(3) The esophageal brachytherapy applicator should have an external diameter of 6-10 mm.

(4) If 5FU-based chemotherapy and 45-50-Gy EBRT are used, recommended brachytherapy is HDR 5-10 Gy in one to two weekly fractions of 5 Gy each and should not be given concurrently with chemotherapy In the esophageal cancer treatments, tumor recurrence in the primary tumor site approaches 50% in most non-surgical CCRT series reported. Brachytherapy has the advantages of introducing higher doses to the tumor site to improve tumor control, but it is like the double edge of the sword, higher dose may bring higher risk of serious side effect, such as fistula formation in the esophagus noted over previous studies. The innovative Braxx applicator can maximize the therapeutic efficacy by reducing dose inhomogeneity in the esophageal wall (3mm to surface: 136-175%), which will translate into less over-dosing and less risk of the side effects of fistula or stenosis as noted in traditional brachytherapy using NG tube (3mm to surface: 160%-265%). Without much changing the user's habits in performing brachytherapy, the innovative applicator is expected to be easier to be accepted for use.

* Screening Phase: All non-T4b or M1 (non-nodal organ involvement) stage esophageal cancer participants who received neoadjuvant/ definitive chemoradiation first, which includes radiotherapy dosage between 4140-5040cGy concurrently with chemotherapy of carboplatin + paclitaxel or cisplatin + 5FU.