Coolsculpting only affects and treats the subcutaneous fat which is held within the applicator during treatment. It would not be expected to affect deeper tissues. If you have had external beam radiation, it would be wise to consult with your urologist and radiation oncologist. Radiation can cause changes to blood vessels and decrease blood supply to various tissues. If you had radiation treatment of the lymph nodes near the aorta, then you need further evaluation from your treating physicians. If you have never had radiation for your cancer, or if the radiation was limited to your testicular area, then coolsculpting would not be expected to be a problem.
I doubt that there is much data on this subject. However, if you're not Coolsculpting over the area where you had your vaccine, I don't think there would be any reason to avoid Coolsculpting. Maximum cell death occurs during the first 30 to 90 days after Coolsculpting. At that rate, I don't think that you will have a problem with clearing the breakdown products of your fat cells in connection with your vaccine. The amount of vaccine is very small and will have been passed along through your lymphatic system by the time fat cells die. Furthermore the dying/dead fat cells will pass through several lymphatic drainage areas in most cases.