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M.M.G. Rossi
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P3.14 - Radiotherapy (ID 730)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Radiotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.14-005 - Treatment Response Measured on Conebeam-CT During Concurrent Chemoradiation for NSCLC Patients (ID 9814)
09:30 - 09:30 | Author(s): M.M.G. Rossi
- Abstract
Background:
The management of NSCLC-patients has evolved towards a more personalized care approach. Currently, the outcomes of concurrent chemoradiation (CCRT) in NSCLC patients are evaluated after the end of treatment, while individual treatment response during treatment is not taken into account. To pursue adaptive radiotherapy, it is important to distinguish responses during treatment and correlate this with outcome. Therefore, the aim was to identify subgroups that show a distinct treatment response during CCRT and correlate this with treatment outcome.
Method:
NSCLC-patients treated with CCRT between 2007-2013 were included. Treatment consisted of 66Gy/24 fractions with concurrent daily Cisplatin. Deformable image registration of the planning-CT to all Conebeam-CTs acquired during treatment was performed, and the gross tumor volumes on the ConeBeam-CTs were measured. Latent Class Growth Modeling was used to identify subgroups showing a distinct treatment response of the primary tumor during CCRT. Cox survival analysis was performed to assess the association of subgroup ‘membership’ with overall survival (OS) and progression free survival (PFS).
Result:
402 patients were included. Median follow-up was 63 months and median OS was 23 months (95%CI 20-26 months) and median PFS was 18 months (95%CI 15–21 month). Six different patterns of treatment response were identified (Figure1). Group 1&2 showed a relatively stable pattern during treatment. Group 5 showed tumor progression in the first week followed by sharp decrease in tumor volume. All other groups showed a decrease in tumor volume from start of treatment. Remarkably, the groups 1&5, that didn’t show a decrease in tumor volume from the beginning of treatment, had a significantly improved OS and PFS. Figure 1
Conclusion:
Six groups showing a distinct treatment response during CCRT were identified. This is an important finding to be able to pursue adaptive radiotherapy. First analyses revealed an association between tumor response during treatment and OS and PFS. In-depth analyses are warranted.
