My father is 74 yrs old, he has benign enlarged prostate, every 3 months monitoring of the size of his prostate, recently his prostate was 104 grams and his psa was 1.3, is the result ok for his age? thanks?

PSA at age 70 & over should be below 4, thus your father's PSA is super normal. But why is his enlarged prostste monitored every 3 months, this only befits whoever is billing every 3 months for an unnecessary examination. Father only needs treatment if experiencing urinary incontinence, retention, prosttitis or UTIs, initially with medication & failing that surgery by experienced urologist.