SINN Fein MLA has spoken for the first time about his battle with cancer in an effort to highlight the demands on the regional treatment unit.
Oliver McMullan (61) is undergoing intensive radiotherapy, having been diagnosed with prostate cancer two months ago.
He travels every day from Cushendall in north Antrim for treatment at the Belfast City Hospital-based cancer centre which treats up to 300 patients a day.
However, Mr McMullan, who is halfway through a seven-week radiotherapy course, said treatment is often delayed because machines break down.
A business case has already been accepted for a 10th radiotherapy machine which the East Antrim MLA says would ease delays.
"Since I have been here - I'm into my third week - I think I have encountered something like three to four breakdowns," the father-of-five says.
"Nobody complains. Staff don't complain. The patients don't complain - they realise it's a wonderful centre - but the machines breaking down could put a delay of about 40 minutes on."
The Belfast Health and Social Care Trust confirmed that a 10th machine is needed but said the final decision lies with the Department of Health.
"If the need is there with the rising numbers using the centre, the business case is answered already. Surely it should be done and dusted and get the machine in place," Mr McMullan says.
Mr McMullan, who is hopeful of making a full recovery, only received his diagnosis as a result of a routine check-up with his GP.
"I had no symptoms at all, none whatsoever," he says.
"It was a shock when I found out and this is where I would say to the public - don't wait until something happens."