Definition
Chronic progressive radiation myelopathy (CPRM) is a clinical syndrome that manifests with spinal cord signs and symptoms. These can be severe and result in pain, paraesthesia, sensory deficits, paralysis, Brown-Sequard syndrome, and bowel/bladder incontinence.r
Incidence/prevalence
CPRM is an uncommon development, but usually occurs when portions of the spinal cord are included in radiation therapy treatment fields. This may occur when treating malignancies in the thoracic region, head and neck, abdomen and pelvis.
Onset/duration
CPRM is a serious late effect of radiation treatment and can occur 6-24 months following RT.r
Risk factors
The risk of CPRM is related to the total dose of radiation delivered to the spinal cord. When conventional fractionation is used at doses of 1.8 to 2 Gy per fraction to the full thickness of the spinal cord, the estimated risk of myelopathy is 0.2% for a total dose of 50 Gy, 6% for a total dose of 60 Gy and 50% for a total dose of 69 Gy.r There is also a strong correlation between increased risk and a higher dose per fraction.r