To establish the proportion of patients in whom an initial radiotherapy plan does not provide similar, or improved coverage, on a repeat planning procedure after 15 fractions. To implement adaptive radiotherapy.
ID
Source
Brief title
Condition
- Respiratory tract neoplasms
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
1.To establish the proportion of patients in whom an initial radiotherapy plan
does not provide similar or improved coverage on a repeat planning procedure
after 15 fractions.
2. To indentify the characteristics of this sub-population of patients and
design adaptiveimaging protocols to account for time trends.
3. Establish the magnitude of reduction in toxicity risk to lung and esophagus
in patients for whom reductions in PTV are possible
Secondary outcome
nvt
Background summary
Conventional radiotherapy for locally-advanced lung cancer is typically
delivered using once-daily fractions of between 2-2.6 Gy over a period ranging
from 4.5 to 6.5 weeks. The use of 4-dimensional CTscans permit the use of
smaller radiation fields to encompass the tumor. A treatment plan is generated
and treatment delivery is based on the assumption that the pre-treatment
planning target volume (PTV) is representative for the entire course of
treatment. However, the tumor volume and/or location can change during a 4-6
week course of radiotherapy due to so called *time trends* .
A repeat of the initial 4DCT (or CT-PET scan) after 3 weeks of treatment* can
identify time trends. This facilitates implementation of 'adaptive IGRT*, an
approach which has the potential to both improve treatment accuracy and further
reduce normal tissue toxicity in locally advanced lung cancer. The proposed
studies are a first step in acquiring this information.
Study objective
To establish the proportion of patients in whom an initial radiotherapy plan
does not provide similar, or improved coverage, on a repeat planning procedure
after 15 fractions.
To implement adaptive radiotherapy.
Study design
Number of patients: 40 patients, at least 25 of whom will be undergoing
concurrent chemo-radiotherapy.
Timing of repeat 4DCT or CT-PET: Directly after the 15th fraction of radiation
Analysis:
1.The repeat 4D imaging study will be co-registered with the initial 4D study
2.The PTV will be rapidly reconstructed on repeat 4DCT
3.Geometric differences between the initial and second PTV will be evaluated
4.The initial treatment plan will be projected upon the new PTV to assess
dosimetric coverage.
5.The treating clinician will decide if the plan will have to be modified in
accordance with the criteria specified below (intervention)
Intervention
The treating clinician will decide if the plan will have to be modified in
accordance with the following criteria. Geometric displacement will always be
corrected. Reductions in field sizes for primary lung tumors will only be
performed in cases where the risk of radiation pneumonitis is high (i.e. an
initial V20 greater than 35%) and with a low risk of having microscopic
extension in the distal tumour margins, e.g. based upon endobronchial tumor
extent and/or the findings of FDG-PET scans.
Study burden and risks
Patients will undergo a repeat scan immediately after the 15th fraction (3
weeks after starting radiation therapie). Consequently patients will have to
stay longer in the hospital for a maximum of one hour.
Patients receive a relatively small extra radiation dose (CTDI 52.7 mGy), which
is minor compared to the therapeutic radiation dose received during treatment,
typically in the range 5000 to 6600 cGy.
De Boelelaan 1117, Postbus 7057
1007 MB Amsterdam
Nederland
De Boelelaan 1117, Postbus 7057
1007 MB Amsterdam
Nederland
Listed location countries
Age
Inclusion criteria
Eligible patients who will undergo a 4DCT or 4DCT-PET planning scan, and in whom (i) a pre-treatment GTV can be identified and (ii) will receive a minimum dose of 46 Gy in 4 weeks
Exclusion criteria
Patients who will be irradiated after a complete response to chemotherapy or after a complete surgical resection
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL14671.029.06 |