PET Evaluation of Response After 1 Course of Chemotherapy as Predictor of Treatment Outcome.
- Conditions
- Colorectal Cancer MetastaticEarly Response EvaluationFdg-PET
- Interventions
- Procedure: FDG-PET imaging
- Registration Number
- NCT00741481
- Lead Sponsor
- Jules Bordet Institute
- Brief Summary
Study hypothesis : early decrease in fdg-pet measured SUV max after 1 cycle of chemotherapy can accurately predict response of chemotherapy as assessed by conventional radiology after 3 cycles of chemotherapy.
FDG-PET imaging will be done at J0 and J14 of a new line of chemotherapy treatment in metastatic colorectal cancer.
SUV max will be recorded and delta SUVmax will be compared to the results of conventional radiological evaluation after 3 courses of chemotherapy. Results will also be compared to the time to disease progression.
- Detailed Description
statistical hypothesis : Sample size calculation for FDG-PET in metastatic patients.
In the paper of Cascini et al. \[1\], they have 18 patients with a TRG response (TRG = Tumor Regression Grade) and 15 patients with no response.
SUV mean was measured at baseline and at day 12 in all 33 patients. All 33 patients showed a reduction in SUV-mean from baseline to day 12. The median reduction in SUV-mean was 63% (mean 66%) in responding tumors and 22% (mean 22%) for non responding tumors. Using a cutoff level of 52% a perfect accuracy could be obtained, i.e. all responding tumors had a SUV-mean reduction higher than 52% and all non responding tumors had a SUV-mean reduction lower than 52%.
(Standard deviation of the SUV-mean reduction was 25.) All 33 patients showed also a reduction in SUV-max from baseline to day 12. The median reduction in SUV-max was 62% in responding tumors and 28% in non responding tumors. (No information about mean or standard deviation of SUV-max available in \[1\].) Based on the data of SUV-mean we can do a power calculation based on the Wilcoxon test: In order to demonstrate an absolute difference in the mean of ΔSUV-mean of 44% between responding and non responding patients, with an estimated standard deviation of 25, using 35 patients (50% response, 50% no response), at a significance level of 5%, we obtain a power of 0.98.
For SUV-max, if we assume that the difference in the means is similar to the difference in the medians, i.e. 34% and the standard deviation is similar to the one of SUV-mean, i.e. 25, we obtain a power of 0.93 If we, to be safe, are a little bit less optimistic and estimate that the difference in the mean of ΔSUV-max between responding and non responding tumors would be a little lower than in \[1\]: 35%, and the standard deviation a little bit higher: 30, then we need 40 patients at a power of 0.90
Référence 1 : Cascini GL, Avallone A, Delrio P, Guida C, Tatangelo F, Marone P et al.: F-18-FDG PET is an early predictor of pathologic tumor response to preoperative radiochemotherapy in locally advanced rectal cancer. Journal of Nuclear Medicine 2006, 47: 1241-1248.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 40
- advanced colorectal cancer
- evaluable disease
- signed informed consent
- no other cancer
- no other life-threatening condition
- unwillingness or inability to sign informed consent
- active cerebral metastasis
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description 1 FDG-PET imaging all study population
- Primary Outcome Measures
Name Time Method compare fdg-pet variations after 1 course of chemotherapy to chemotherapy outcome measured by time to disease progression Time to Disease progression
- Secondary Outcome Measures
Name Time Method compare fdg-pet variations after 1 course of chemotherapy to chemotherapy outcome measured by tumour response rate following RECIST criteria. response rate
Trial Locations
- Locations (1)
Institut Jules Bordet, Université Libre de Bruxelles
🇧🇪Brussels, Belgium