Mine is about that height which is how high they usually get so it should stop as mine appears to have done. (slow growers)
Pruning is not necessary but if you do bear in mind you might not keep its pyramid shape and may introduce disease. They do not always survive hard winters, may not be long lived? If it were mine I would leave it alone.

I had variegated Pittosporum tenuifolium Irene Paterson in my garden some years ago - I used to cut it back every spring to about 6 feet, keeping the pyramidal shape, so I'd wait till spring and reduce it then.

I love these plants and have a lot of them, i cut mine back and form them into 6' pyramid shaped plants.
Here in the south west i've not found them to be anything other than tough !

But they can be temperamental in colder areas!

I hae pittosporum 'Garnettii' which gets to about 15 feet. A few years ago, I had it reduced (in both height and girth) by a professional Kew-trained tree surgeon in April. It looked tatty for about a month and then grew back quite happily. It's getting to the stage of needing doing again