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E. Lyn
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MO23 - Radiotherapy II: Lung Toxicity, Target Definition and Quality Assurance (ID 107)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Radiation Oncology + Radiotherapy
- Presentations: 2
- Moderators:M.M. Tin, F. Macbeth
- Coordinates: 10/30/2013, 10:30 - 12:00, Bayside 204 A+B, Level 2
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MO23.04 - Is pre-trial quality assurance (QA) effective? A comparison of pre-trial QA versus ongoing QA for the CONVERT Trial. (ID 1809)
10:30 - 12:00 | Author(s): E. Lyn
- Abstract
- Presentation
Background
CONVERT is an international randomised phase III trial comparing 45Gy in 30 fractions twice-daily and 66Gy in 33 fractions once-daily (given concurrently with cisplatin/etoposide) for good performance status patients with limited stage small cell lung cancer. A QA programme was set-up to standardise radiotherapy (RT) delivery across all centres.Methods
The pre-trial QA exercise (PQE) involved completion of a questionnaire and treatment planning exercise. Each participating clinician was asked to select a previously treated patient, who fitted the entry criteria for the trial, and provide disease and organs at risk (OAR) outlines and a treatment plan for both arms of the trial. QA guidelines, including an atlas for OAR outlining, were distributed to participating centres. Additionally, at least one RT plan per centre was randomly collected during the trial (ongoing QA exercise-OQE). A comparison was made between the PQE and OQE for each centre, including a review of eligibility criteria, OAR and gross tumour volume (GTV) outlining, expansion to clinical target volume (CTV) and planning target volume (PTV).Results
Twenty nine clinicians from 28 centres who had completed both the pre-trial QA and the ongoing QA were included in the analysis. From the pre-trial questionnaire it was reported that 3 centres were using beam energies of 10MV or more which was not permitted as per protocol. Subsequently the PQE showed that these all used acceptable beam energies. Four clinicians submitted ineligible patients for the PQE and none for the OQE. Twenty five clinicians (86.2%) used the correct GTV to CTV and CTV to PTV expansions for the PQE and OQE. Table 1 shows a comparison of adherence to protocol regarding OAR outlining between the PQE and OQE. Table 1
Organ at risk doses were found to be within the tolerances specified in the trial protocol for both PQE and OQE.Oesophagus outline Spinal canal outline Heart outline Lung-PTV outline PQE-OAR outline as per protocol (n=29) 19 (65.5%) 14 (48.3%) 4 (13.8%) 20 (68.9%) OQE-OAR outline as per protocol (n=29) 21 (72.4%) 18 (62.1%) 8 (27.6%) 20 (68.9%) Conclusion
A PQE improves clinicians’ compliance to trial protocol, and has been found in the OQE to reduce deviations across the participating centres that may confound the results of the study. Despite the fact that consistency of OAR outlining remained an issue in both the PQE and the OQE an overall improvement was seen following the PQE.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.05 - Changes in lung radiotherapy techniques during the CONVERT Trial. A survey of participating centres. (ID 1820)
10:30 - 12:00 | Author(s): E. Lyn
- Abstract
- Presentation
Background
CONVERT is an international randomised phase III trial, comparing 45Gy in 30 fractions twice-daily or 66Gy in 33 fractions once-daily (given concurrently with cisplatin/etoposide) for good performance status patients with limited stage small cell lung cancer. A survey was sent out to 69 clinicians who had randomised patients into the trial with the aim of establishing how radiotherapy techniques for lung cancer have changed over the 5 years since the trial opened.Methods
As part of the pre-trial quality assurance process each centre was asked to complete a facility questionnaire giving details of treatment planning, delivery and verification techniques. Recruitment to the trial began in April 2008 and in January 2013, a further facility questionnaire was sent to centres. The survey was completed using an on-line survey tool.Results
This analysis includes answers from the 34 clinicians who responded to the questionnaire. Changes in treatment planning techniques and verification since the beginning of the trial are summarised in table 1. Table 1 Figure 1 *Note that some centres reported using more than one beam arrangement, beam energy, planning algorithm or treatment verification technique. Out of the 34 clinicians who answered the questionnaire, 14 (41.1%) are currently using 4DCT, 3 (8.8%) are using breathold techniques and 16 (47.1%) are not using any technique to account for respiratory motion for simulation and treatment planning of lung patients. Data on management of respiratory motion were not available in 2008.Conclusion
During the 5 years the CONVERT Trial has been open there have been significant advances in radiotherapy treatment technology. Major changes include the use of Type B treatment planning algorithms and PET CT for planning, IMRT for treatment and CBCT for treatment verification of patients with small cell lung cancer.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
