pet vs ct

I am a 62 yo male with hypertension controlled by 20/25mg hctz.
iam 5 11 174lbs active my mother died at 90 father a smoker @63
i would like to have a pet scan q3 years to track improvements related
to diet , xercise, and meds. the pet clinic is very close to home.
any reason why coronary ct angiography would be a better choice.
tx john r.n. are they both worth the radiation risks i know they are short lived substances in both.

[Cleveland Clinic]

I am not really sure why you need any of these tests to begin with.  You didn't tell me whether you had any chest pain or shortness of breath or any previously noted CAD.  If I were you I would not do either of these tests done.  The radiation exposure is not worth it and it is significant.