Latency Of Early Effects

Latency refers to the delay in side effects appearing after a dose sufficient to cause them has been delivered. The delay is due to the turnover time of the tissue. Although the stem cells have been killed, the transit cells may continue to divide and differentiate, maintaining the surface epithelium for a time. This may lead to side effects appearing after radiation has finished – for instance dysphagia occurring in the week after completing palliative radiotherapy to the thoracic spinal cord.