Welcome Olak. Anything is possible, and may be nothing, but any symptoms, especially if lasting more than 3 weeks, should be brought to the attention of his doctor(s), which was done. I had recurrences only one month after a clean scan, others less than a few months, so time is no indication it's not a recurrence, not saying it is, but he needs to have an MRI, as the doctor suggested, to start ruling out cancer, if not, there will always be wonder, and what may be treatable now, may not be by waiting too long. Good luck.