Can I use ContEst just for tumor only sample?

Hi,

I want to use the ContEst to estimate my Exom-seq tumor sample. We do not have the normal control. Can I use these two vcf files in the command line? Thanks.
-B:pop,vcf example/hg19_population_stratified_af_hapmap_3.3.vcf \
-T Contamination -B:genotypes,vcf example/hg00142.vcf \

best

HY