The Late Effects of Normal Tissue (LENT) conference in 1992 developed the Subjective, Objective, Management criteria with Analytic laboratory/imaging procedures, or SOMA classification, for normal tissues that were known to develop late effects.
For each tissue, there are numerous scoring criteria:
- Subjective Criteria are symptoms reported by patients
- Objective Criteria are clinical signs that can be assessed by a medical practitioner
- Management Criteria are interventions that have been instigated to help the patient manage symptoms
- Analytical tools are investigations that can be performed to determine the presence or severity of late effects. These are listed separately to allow SOMA scores to be calculated when access to investigations is limited.
Each criterion is graded from 0 to 5 (similar to early effect grading systems), where:
- Grade 0 is not present, not detectable or not requiring treatment
- Grade 1 are occasional symptoms,