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DE-CT in Lung Cancer Proton Therapy (DE-CT)

This study is not yet open for participant recruitment. (see Contacts and Locations)
Verified August 2016 by Maastricht Radiation Oncology
Information provided by (Responsible Party):
Maastricht Radiation Oncology Identifier:
First received: July 19, 2016
Last updated: August 2, 2016
Last verified: August 2016
Dose distribution calculations for proton therapy are more accurate when based on DE-CT than on SE-CT. It is however unclear what the quantitative benefit of repeated DE-CT calculations is for lung cancer patients.

Condition Intervention
Non Small Cell Lung Cancer
Procedure: DE-CT's and SE-CT

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Official Title: DE-CT vs. SE-CT as Optimal Imaging During Treatment for Adaptive Proton Therapy in Stage III Non Small Cell Lung Cancer (NSCLC)

Resource links provided by NLM:

Further study details as provided by Maastricht Radiation Oncology:

Primary Outcome Measures:
  • Dose distribution on the CTV (measured in Gy) [ Time Frame: Measured during 2nd and 4th week of radiation treatment ]
    Dose distribution on the CTV (clinical target volume) of the tumour and the lymph nodes of DE-CT vs. SE-CT

  • Dose distribution on the OAR (measured in Gy) [ Time Frame: Measured during 2nd and 4th week of radiation treatment ]
    Dose distribution on the OAR (organs at risk), lungs, heart, aorta, pulmonary artery, superior vena cava, oesophagus, spinal cord, vertebral body, of DE-CT vs. SE-CT

Estimated Enrollment: 10
Study Start Date: September 2016
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: September 2017 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Scans
Patients included in the trial will receive DE-CT in stead of SE-CT's.
Procedure: DE-CT's and SE-CT
Patients included in the trial will receive 3 extra DE-CT's and 3 extra SE-CT's

Detailed Description:

In order to calculate the dose distribution of protons adequately, accurate estimations of the stopping power ratio (SPR) medium to water, are required. Using a conversion from single energy CT (SE-CT) images results in an uncertainty in the SPR of at least 3-4%. This uncertainty results in in the use of larger margins around the clinical target volume (CTV) and hence more dose to the organs at risk (OAR). It also effects in the conservative use of beam directions, which are often sub-optimal, to avoid irradiating normal tissues.

Dual energy CT (DE-CT) improves the accuracy of the SPR and therefore the proton range estimation.

An evaluation of the proton range for several tissues using SE-CT and DE-CT as input to Monte Carlo (MC) simulations showed on average improvements in range prediction from 0.1% to 2.1% when using DECT instead of SECT, but in several phantoms and also versus proton-CT, the errors on SE-CT based proton stopping power ratios are reported to be more than 7 %.

A limitation of these studies is that most of them were performed in phantoms. In the first clinical data set on five patients with base of skull tumours, it was reported that although the SPR estimation was indeed better for DE-CT than for SE-CT, its clinical relevance was unclear. However, in the same study, phantom measurements showed a large uncertainty of the SPR in the lung. This is due to the large heterogeneity of the lungs and the huge difference in the density of the lungs compared to the mediastinum, the tumour and the chest cavity.

It is therefore important to study the SPR differences of SE-CT compared to DE-CT in lung cancer patients and the impact on the dose distribution especially in the context of adaptive radiotherapy. As during the course of concurrent chemotherapy and radiotherapy, which is the standard treatment in the majority of stage III lung cancer patients, important anatomical changes may occur, it is also of clinical relevance to determine the influence of repeated dose calculations on DE-CT.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Histologically or cytologically confirmed locally advanced stage IIIA or III B (T0-4 N2-3M0) NSCLC, or M1 oligometastatic disease according to 7th TNM classification.
  • Scheduled to receive concurrent chemotherapy and radiotherapy to a dose of at least 60 Gy, as decided at the multidisciplinary tumour board
  • Able to give written informed consent
  • Able to have adequate contraception in woman with child bearing potential

Exclusion Criteria:

  • Not able to give written informed consent
  • Not able to comply with adequate contraception in woman with child bearing potential
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02844140

Contact: Chantal Overhof-Wedick +31 88 44 55 686
Contact: Ann Claessens +31 44 55 686

MAASTRO clinic Not yet recruiting
Maastricht, Limburg, Netherlands, 6229 ET
Contact: Chantal Overhof-Wedick    +31 88 44 55 686   
Principal Investigator: Dirk De Ruysscher, MD, PhD         
Sponsors and Collaborators
Maastricht Radiation Oncology
Principal Investigator: Dirk De Ruysscher, MD, PhD Maastro Clinic, The Netherlands
  More Information

Responsible Party: Maastricht Radiation Oncology Identifier: NCT02844140     History of Changes
Other Study ID Numbers: DE-CT
Study First Received: July 19, 2016
Last Updated: August 2, 2016
Individual Participant Data  
Plan to Share IPD: No

Additional relevant MeSH terms:
Lung Neoplasms
Carcinoma, Non-Small-Cell Lung
Respiratory Tract Neoplasms
Thoracic Neoplasms
Neoplasms by Site
Lung Diseases
Respiratory Tract Diseases
Carcinoma, Bronchogenic
Bronchial Neoplasms processed this record on March 29, 2017