A mammogram is the best way for men to detect testicular cancer?

That is not correct.

A mammogram is an x-ray of the mammaries (breasts) and is used to detect abnormal growths in the breast that may be a sign of breast cancer. Checking for cancer of the testicles is done by physical inspection with your fingers for lumps, bumps and changes in the size, shape or consistency of the testicles. If anything not normal is noticed, you should see a urologist or your family doctor.