Hiya Feisty and welcome.  I would suggest that you ask the doctor treating you who will (a) have been asked the question before and (b) will know how it would react with your planned treatment.  I realise you are not asking my opinion on taking cannabis (so I won't give it!) but please make sure you are clear on what it might do to the effectiveness of your treatment.  Best wishes and I hope your treatment goes smoothly for you.  Annie