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

DE-CT vs. SE-CT as Optimal Imaging During Treatment for Adaptive Proton Therapy in Stage III Non Small Cell Lung Cancer (NSCLC)

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.

Study Overview

• Status: Withdrawn
• Conditions: Non Small Cell Lung Cancer
• Intervention / Treatment: Procedure: DE-CT's and SE-CT

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.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands, 6229 ET
      • Maastro clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Maastricht Radiation Oncology
• Investigators: Principal Investigator: Dirk De Ruysscher, MD, PhD, Maastro Clinic, The Netherlands

Study record dates

Study Major Dates

• Study Start: September 1, 2016
• Primary Completion (Anticipated): September 1, 2017
• Study Completion (Anticipated): December 1, 2017

Study Registration Dates

• First Submitted: July 19, 2016
• First Submitted That Met QC Criteria: July 21, 2016
• First Posted (Estimate): July 26, 2016

Study Record Updates

• Last Update Posted (Actual): April 14, 2017
• Last Update Submitted That Met QC Criteria: April 13, 2017
• Last Verified: August 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Neoplasms; Lung Diseases; Neoplasms by Site; Respiratory Tract Neoplasms; Thoracic Neoplasms; Carcinoma, Bronchogenic; Bronchial Neoplasms; Lung Neoplasms; Carcinoma, Non-Small-Cell Lung
• Other Study ID Numbers: DE-CT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO