Image Guided Adaptive Radiotherapy in the Head-and-neck Region

Study Overview
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Brief Summary
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Aim of this study is the clinical evaluation of an image-guided adaptive radiotherapy concept. This involves the adaption of the radiotherapy treatment plan according to changes in tissues and variations in patients position and posture during a radiotherapy treatment course, based on repeat CT scans. It is investigated, if dosimetric improvements can be achieved using this approach and if the method using the software-package ReDeform can be implemented in clinical Routine.

Detailed Description
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Aim of this study is the clinical evaluation of an image-guided adaptive radiotherapy (ART) concept. This involves the adaption of the radiotherapy treatment plan according to changes in tissues and variations in patients position and posture during a radiotherapy treatment course, based on repeat CT scans. It is prospectively investigated, if dosimetric improvements can be achieved using this approach and if the method using the software-package ReDeform can be implemented in clinical Routine. For that purpose 2 repeat CT scans are acquired during the radiotherapy course (week 3 and week 5 of radiotherapy). The Initial CT scan is matched to the follow-up CT-scan by means of deformable image registration.

Official Title
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Image Guided Adaptive Radiotherapy Based on Elastic Image Registration for Improved Tumor Coverage and Reduction of Side Effect in Normal Tissues

Conditions
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Head and Neck Neoplasms

Intervention / Treatment
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* Radiation: Follow-up CT scans during week 3 and week 5 of treatment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with histo-pathologically verified malignancies in the head-and-neck without clinical signs of dissemination, who consented in radiotherapy or radio-chemotherapy. Exclusion Criteria: previous radiation therapy for head-and-neck

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Adaptive Radiotherapy<br>Follow-up CT scans during week 3 and week 5 of Treatment Image-guided adaptive Radiotherapy arm: Follow-up CT scans are performed on a conventional CT-simulator. Deformable Image Registration between the planning-CT and the follow-up CT (fCT) is done using a dedicated Software package. Delineations for target volumes and organs at risk are transferred to the fCT based on the Deformation vector fields calculated during deformable Image registration. Volumetric changes in target volumes and organs-at-risk are assessed. The initial treatment plan is transferred to the fCT scan. Dosimetric consequences of morphologic changes are analysed with the Focus on target dose coverage for the planning target volume. Adaption and plan re-optimisation are performed. | Radiation: Follow-up CT scans during week 3 and week 5 of treatment<br>* Scheduled follow-up planning CT scan and re-optimisation of the intensity modulation radiation therapy (IMRT)-based radiotherapy Treatment plan. Dosimetric Evaluation and assessment of morphologic changes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Planning Target Volume (PTV) Coverage Parameter D98% | Dose coverage of the planning target volume: Number of participants with a decrease in the planning target volume (PTV) coverage (D98%) above 5%. The Parameter D98% denotes the minimum dose to 98% of the volume according to the ICRU (International Commission on Radiation Units & Measurements) Report No. 62. It is a widely accepted classification index for dose coverage. The Planing Target Volume is a volume, consisting of the clinical target volume and additional safety margins, that should receive a certain radiation dose. | week 5 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Volumetric Changes | Percent changes in the volume of the Planning Target Volume (PTV). The Planning Target Volume is a volume, consisting of the clinical target volume and additional safety margins, that should receive a certain radiation dose. The volumetric changes of the PTV throughout the course of Radiation therapy are evaluated. A significant change in the volume of the PTV (measured in ccm) might be an indicator for possible undesireable dosimetric alterations. | week 5 |