The Clinical Physics Research of Image Guided Adaptive Radiation Therapy for Esophagus Cancer

The purpose of this study is to evaluate the benefit of adaptive radiation therapy (adaptive radiation therapy, ART) for esophageal cancer, using dose tracking technique with online images and deformable registration.

The aim of study is to evaluate the benefit of adaptive radiation therapy(ART) for esophageal cancer. 80 patients with locally advanced esophageal cancer will be treated with 3D-CRT(three dimensional conformal radiotherapy, 3D-CRT)/IMRT(intensity modulated radiotherapy, IMRT), dividing to experimental group and control group (40 patients each). All patients are kVCT(kilo-voltage computed tomography, kVCT) scanned weekly(the fifth fraction in a week) and CBCT (cone beam computed tomography, CBCT) scanned per fraction before treatment. Irradiated dose distribution of each patient is calculated using the CBCT images corrected with validated modelling and accumulate the volumetric dose for all PTV(planning target volume,PTV) and OARs(organs at risk, OAR) using deformable registration algorithm. For the experimental group, replan the treatment when the target volume is not covered by the prescribed dose or OARs is overdose beyond the action level to achieve an optimal dose distribution. Conversely, no action is taken in the control group and the original plan will be used for the full treatment course. Dosimetric parameters (such as the ratio of target coverage, the mean dose of OARs, etc) ,treatment toxicities (such as radiation pneumonitis and esophagitis), PFS（Progress Free Survival,PFS）and OS（Overall Survival, OS）of the two groups will be analyzed and compared in the study.

40 patients treated with ART, using dose adaptation method to match the change of PTV and movement of OARs and achieve an optimal dose distribution using online CBCT images.

Replanning the treatment to adapt the change of PTV and movement of OARs to achieve an optimal dose distribution using online CBCT images.

Evaluating the treatment toxicity weekly during treatment course and at the time of one year after treatment according to the NCI CTCAE 4.0 (The National Cancer Institute Common Terminology Criteria for Adverse Events,NCI-CTCAE, Version 4.0).

From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 100 months.

The survival time from the start of treatment to death or the time of the last follow-up of this study.

Inclusion Criteria: Diagnosed with locally advanced esophageal cancer ECOG(Eastern Cooperative Oncology Group, ECOG) physical status score：0-2 Charlson complications index score≤4 First second forced expiratory volume ≥1 liter Patients and their families agreed and signed the informed consent Exclusion Criteria: Previous treatment with other malignant tumor Had anti-tumor treatment, including (chemotherapy, radiotherapy, surgery) Any taboo disease or condition of radiotherapy and chemotherapy With malignant pleural effusion and pericardial effusion Participated to other clinical test within 30 days before this experiment With uncontrolled seizures or loss of mental self-control Drug takers, chronic alcoholism, and HIV/AIDS patients Has a history of severe allergic or specific physique Researchers think that is unfavorable to the test

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