"Unsatisfactory waiting time for check cystoscopy."

i am asked to attend for a six monthly cystoscopy following a grade 3 bladder cancer tumour removed in 2012 and plan my holidays around these, especially as I cannot get travel insurance since this diagnosis, but the appointment is always delayed and the current delay is four months. I'm sure this must be stressful for all those waiting and suggest the appointments should be given at the previous appointment for patients peace of mind and also maybe to highlight the inadequacy of the system.