Post operative/radiotherapy treatment MRI scan apperance

[Tsu]

In April i had a massive and unclassified tumour operated on in my right frontal lobe. 99% of the tumour was removed and a month later i started my radiotherapy - 33 treatments with 70 "greys" used on the remaining tumour and the surrounding areas.
Eight weeks later the radiation burns and sickness is gone and i am coming off the medication as prescribed but i had my first MRI scan. To my shock I was shown a large mass (larger than the original tumour) of highly luscent cells (glowing whitely) - regardless of the fact the scan was not done with contrast, 99% of the tumour had been removed and I have lost all of the symptoms I originally presented with.
I'm curious if this is a KNOWN post radiotherapy artifact, water swelling or clumping of the dead tissue or a known presentation of tissue after radiotherapy on MRI. The registrar that presented the MRI's to me seemed to never have seen a post treatment/operative MRI of the brain after the radical treatment I have had. If anyone can answer this question or direct me to the books I would be most thankfull.

[Tsu]

Thankyou so much :)

[CCF-Neuro-M.D.-JT]

There is a well known entity called radiation necrosis that appears mass-like on an MRI after someone has had radiation therapy for tumor. It can sometimes be difficult to distinguish from recurrent tumor and if there's a question as to what the MRI shows, then special imaging studies such as PET or SPECT scanning may be needed to look for active components. You should definitely have your surgeons look at the films themselves as well as your neurooncologist (if you have one) and an experienced neuroradiologist. This is a very common finding that your surgeon should be able to recognize. GOod luck.