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

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.

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