The phrase NED is a bit of a reach and a stretch for many brain tumors because NED implies “no evidence for disease”, whereas in reality, after radiotherapy, there is almost always a visible tumor that needs to be monitored to ensure that it is not growing.
The follow-up guidelines vary based on the actual diagnosis and the time that has elapsed since completing radiotherapy. In general, for almost all patients, it is common practice to evaluate patients approximately 1 month after completing radiotherapy to ensure that any acute or immediate side effects have resolved. Thereafter, the frequency of follow-up varies based on several parameters. For example, for benign tumors such as meningioma, vestibular schwannoma, etc., it is not uncommon to see the patient at 6 monthly intervals for the first year, with MR imaging and then annually thereafter. For patients with low gradeglioma, the initial follow-up is a little more frequent, such as every 4 months or so but is then progressively lengthened.
For malignant tumors, the opposite is true, in that the follow-up is more rigorous and more frequent. For example, for patients with brain metastases treated with radiosurgery alone, the initial imaging and follow-up is frequent, such as for example at months 1, 3, 6, etc, and the reason for this is to identify any new lesions that may develop as a consequence of withholding whole brain radiotherapy. For patients with malignant glioma, such as glioblastoma, the follow-up and imaging is often co-ordinated with the chemotherapy doctor (medical or neuro-oncologist), and typically occurs every 2 to 3 months to follow things like tumor response, pseudoprogression, tumor progression, etc. These follow-up visits are also important for the purposes of tapering steroids, adjusting the doses of seizure medications, etc. In patients treated with mostly a palliative intent, the follow-up visits are minimized to reduce the burden on the patient, and visits and imaging is often performed on an “as needed” basis.
A corollary question is when do you stop following? There are no good guidelines for this part of the question, since this is not a question that has been studied prospectively; for patients with benign tumors, some physicians stop imaging (and sometimes follow-up) after 5 years, but relapses/recurrences have been described 15 years and beyond, and so there is no categorical answer for this. For patients who decline because their disease is progressing, and if no further therapeutic options are available, frequent visits and scans may only increase the burden on the patients, and this should be wisely considered.
Question by: glenmjones
(Survivor (10 - 20 years))