Is it usual to start radiotherapy/chemo without trying to debulk the tumour?

Difficult to give any advice as you are booked to go in next week. Since you have asked I can provide some general info not at all specific to your case, so it does not constitute medical advice.

It is always a very difficult decision to operate or not, because the brain is not easy. The size and location of the tumour dictates how "easy" a surgical procedure might be. It greatly depends on the surgeon, because it is his personal skills and risk taking that will determine if he wants to undertake the procedure and how "aggressive" he will be during the procedure. For such delicate areas they usually do it while you are awake so they ask you to move leg and arm and talk and basically have a chat to make sure they are not going to cut in something very vital. The surgeon will not have a good day if the patient walks into the theatre but comes out on a wheelchair, they do try to avoid that. Even if the patient asks for, the surgeon will refuse to leave him paralysed. They cannot just tell by looking at the MRI and they sometimes use "functional" MRI, they stick you in the machine and ask you to move limps while it is checking your brain to map out exactly where the movement fibres and centres are. They may also ask you to "think" if they are looking to map out areas of memory, logic etc. For delicate tumour locations there are surgeons specialising in awake surgeries and a patient could seek opinions from other neurosurgeons. Anecdotally and with no categorical proof to back it up, one might suggest that "biopsy" could be a synonym for "take out what we can". Again, a chat to the surgeon might help clear things out.

Thank you for your help-I will try to contact them on Monday to clear this up before I have the biopsy on Tuesday.

A little update: I’ve had the biopsy-just a small biopsy-no de bulking -and will receive results on Tuesday. I also have a second opinion booked for the following week, if anything to get reassurance that I’m going down the correct route -as a friend told me, “it’s the man and tools that make a difference”. He may be more experienced in this type of surgery. I’m sure this isn’t the way it was supposed to come across and I can’t fault all the lovely staff at the hospital  but I do feel like surgery has just written off before I’ve had a chance to discuss fully the pros and cons.