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M. Burns
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P2.05 - Early Stage NSCLC (ID 706)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Early Stage NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 10/17/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P2.05-006 - Credentialing of Radiotherapy Centres in Australasia for a Phase III Clinical Trial on SABR (TROG 09.02 CHISEL) (ID 9985)
09:30 - 09:30 | Author(s): M. Burns
- Abstract
Background:
A randomised phase III clinical trial comparing Stereotactic Ablative Body Radiotherapy (SABR) with conventional radiotherapy for early stage lung cancer in peripheral location has been conducted in Australia and New Zealand under the auspices of the Trans Tasman Radiation Oncology Group (TROG). As SABR technology at the commencement of the trial was new to most centres in our region and the techniques used are complex and technologically challenging a credentialing program was developed for centres wishing to join the trial.
Method:
The credentialing program used a prospective risk management approach with high risk elements considered to be (i) the ability to create a plan that meets all dosimetric constraints, (ii) the dose calculation in the presence of inhomogeneities and (iii) the management of motion. Participating centres were asked to develop treatment plans for two test cases made available in DICOM format, and inhomogeneity corrections and dose delivery was assessed during a site visit using a phantom with moving inserts (modified Modus Quasar).
Result:
Site visits were conducted in 17 Australian and 3 New Zealand radiotherapy facilities. All centres were able to produce acceptable plans for both test cases, in particular after the protocol was amended to allow delivery of 48Gy in 4 fractions for lesions close to the chest wall in addition to the original trial arm of 54Gy in 3 fractions. The tests conducted during site visit with lung and air inhomogenieties confirmed known shortcomings of the AAA algorithm for dose calculation behind the inhomogeneity. The dose was assessed using an ionisation chamber and radiochromic film in a stationary and moving cylinder (sinusoidal motion, 1cm amplitude, 4s period) in the phantom for a typical treatment delivery including at least one non-coplanar beam. The measurements confirmed in an end-to-end test that all participating centres were able to deliver SABR with the required accuracy. Overall, the site visit took 3 hours of time on the treatment unit and was well received by participating staff. For several facilities it proved to be a useful step in the process of developing a SABR program.
Conclusion:
The credentialing process including a site visit documented that participating centres were able to deliver dose to a phantom as required in the trial protocol. It also gave an opportunity to provide education about the trial and discuss technical issues such as 4D CT, small field dosimetry and patient immobilisation with staff in participating centres.
