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Frederic Lacroix-Poisson
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P1.03 - Chemotherapy/Targeted Therapy (ID 689)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Chemotherapy/Targeted Therapy
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.03-020 - Detection of Hypoxia Using EF5 PET/CT in 10 Patients with Advanced NSCLC Receiving Chemotherapy with and without Bevacizumab (ID 8084)
09:30 - 16:00 | Presenting Author(s): Frederic Lacroix-Poisson
- Abstract
Background:
Hypoxia is associated with increased resistance to radiation and chemotherapy treatments and may be an important prognostic factor in non-small cell lung cancer (NSCLC). Antiangiogenic drugs such as bevacizumab can have the paradoxical effect of transiently improving perfusion by normalizing blood vessels and reducing interstitial pressure, which may improve chemotherapy delivery and tumor cell killing. The aim of this study was to non-invasively assess tumor hypoxia with [18]F-EF5 PET/CT imaging in patients with advanced-stage NSCLC prior to systemic therapy and to compare changes during and after chemotherapy treatments with and without bevacizumab. [18]F-EF5 is a 2-nitroimidazole-based PET tracer reported as a good surrogate for hypoxia.
Method:
Eligibility included patients with incurable stage III/IV NSCLC who were to receive first-line platinum-based doublet chemotherapy alone or in combination with bevacizumab; prior radiation therapy was not allowed. 10 patients completed the study; 5 were treated with standard chemotherapy alone and 5 with chemotherapy plus bevacizumab. Each patient had three [18]F-EF5 PET/CT studies: one baseline pre-treatment, one at day 15 after the first cycle and one post-treatment study after 4-6 cycles of therapy. The investigators reading the PET/CT studies were blinded as to whether patients were treated with bevacizumab or not and no clinical information was available. [18]F-EF5 PET/CT images were acquired from shoulders to upper abdomen and analyzed by calculating tumor-to-muscle (T/M) uptake ratios. A ratio ≥1.50 was considered positive for hypoxia.
Result:
A total of 64 lesions were analyzed on baseline [18]F-EF5 PET/CT scans: 42 in the bevacizumab group and 22 in the control group. 51 of these lesions were positive for hypoxia (79.7%): 37 in the bevacizumab group (88.1%) and 14 in the control group (63.6%). Using a Dunn’s multiple comparisons test, there was a significant decrease in [18]F-EF5 uptake only on post-treatment study versus baseline in the group treated with chemotherapy alone (p=0.009). On the other hand, in the group treated with chemotherapy plus bevacizumab, T/M ratios obtained after one cycle of chemotherapy and after treatment completion were statistically lower when compared to baseline (p<0.0001).
Conclusion:
Preliminary data suggest that many advanced NSCLC are hypoxic and that the combination of bevacizumab and chemotherapy leads to a greater decrease in [18]F-EF5 accumulation compared to chemotherapy alone in primary tumors and metastatic lymph nodes. Further studies are necessary to understand the clinical significance of this finding and to explore this as a potential predictive marker for the use of bevacizumab.
