Some children with cancer have had chemotherapy sessions delayed as more than half of specialist nurses in the field are off work in the Belfast Health Trust.
The trust confirmed to BBC News NI that seven members of staff are “unavailable for work due to planned and unplanned absences”.
About five children have been affected with one child having their treatment put back by five days.
The Belfast Health Trust said it was working hard to ensure “adequate and safe staffing levels” at the haematology and oncology departments within the Royal Belfast Hospital for Sick Children, and that no child has had to go outside Northern Ireland to receive treatment.
Sources have told BBC News NI that issues around staffing levels across the health trust have been raised, and specifically about the number of specialist nurses in the paediatric haematology and oncology departments.
A member of staff said staffing problems were not being addressed by senior management.
The trust said while nursing posts were fully recruited, unfortunately “the number of chemotherapy-trained nursing staff on the ward has temporarily decreased due to planned and unplanned absences”.
The number of nursing staff currently absent is seven out of a total staff of 12.
“As a result, the service is working hard to review all the nursing roles within the wider haematology and oncology departments to help cover the service and protect the most time critical treatments,” said the trust.
“Nurses working on the haematology ward require specialist training to a very high standard so they can safely provide chemotherapy.”
Specialist training for newly-qualified nurses can take up to two years.
The trust said the delays to treatment were not just down to staffing issues but also the clinical assessments of children, bed capacity and chemotherapy preparation availability during the weekend.
It added there had been “no negative clinical outcomes” and it had written to the parents of children affected to offer the opportunity to discuss their children’s care.
Another member of staff who contacted BBC News NI said while a spotlight has been shone on the building’s failings and repairs within the Belfast Trust, which are costing tens of millions of pounds, staff feel “frustrated” that money is being diverted away from much-needed front-line care.
The trust said that safety and delivery of timely treatment remains a high priority.
It said it is “actively working to improve the situation and staffing and service delivery is being closely monitored on a daily basis to ensure adequate and safe staffing levels”.
