Clinical trial NCT00741481: PET Evaluation of Response After 1 Course of Chemotherapy as Predictor of Treatment Outcome.
Official title: Evaluation of Prognostic and Predictive Value of PETSCAn in ColoRectal Cancer (CRC)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Colorectal Cancer Metastatic
Early Response Evaluation
Fdg-PET
Keywords: metastatic colorectal cancer
fdg pet
response evaluation
Lead sponsor: Jules Bordet Institute
Sponsor class: OTHER
First posted: 2008-08-26
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients \>18 yrs old advanced evaluable colorectal cancer beginning a new line of chemotherapy

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.

Eligibility criteria: Inclusion Criteria:

* advanced colorectal cancer
* evaluable disease
* signed informed consent

Exclusion Criteria:

* no other cancer
* no other life-threatening condition
* unwillingness or inability to sign informed consent
* active cerebral metastasis

Primary outcomes:
measure: compare fdg-pet variations after 1 course of chemotherapy to chemotherapy outcome measured by time to disease progression
timeFrame: Time to Disease progression
Secondary outcomes:
measure: compare fdg-pet variations after 1 course of chemotherapy to chemotherapy outcome measured by tumour response rate following RECIST criteria.
timeFrame: response rate
Other outcomes:
Locations:
city: Brussels
country: Belgium
facility: Institut Jules Bordet, Université Libre de Bruxelles
Study officials:
affiliation: Institut Jules Bordet, Université Libre de Bruxelles, Brussels
name: Alain - Hendlisz, MD
role: PRINCIPAL_INVESTIGATOR
References: