It has emerged that a number of chemotherapy sessions at CHI at Crumlin, previously known as Our Lady's Children's Hospital, Crumlin, were postponed earlier this month due to bed shortages.
In a statement, the hospital said the postponements were regrettable and said it was very cognisant of the impact it had on patients with cancer and their families.
The hospital said five patients were affected in December and all have since received the necessary treatment.
Three patients had their chemotherapy delayed by one day and two had to wait two days before receiving treatment.
The hospital said the decision to postpone the treatments was not taken lightly.
It said it was due to an increase in numbers attending the emergency department with flu and the winter vomiting bug.
In a statement, the Irish Hospital Consultants Association said the postponed treatments is "one of the more troubling effects of this Government's failure to invest in adequate bed capacity across our acute public hospitals".
The IHCA said the lack of beds has left hospitals "unable to provide for both planned essential care, such as chemotherapy for cancer, and the annual predictable increase in patients' requirements for hospital care due to illnesses such as respiratory conditions or flu".