Table 1.

RTOG Toxicity Scoring Criteria

	Acute Toxicity (<120 days)	Late Toxicity (>120 days)
Grade 1	Increased frequency or change in quality of bowel habits not requiring medication Rectal discomfort not requiring analgesics	Mild diarrhea or cramping Bowel movement up to 5 times daily Slight rectal discharge or bleeding
Grade 2	Diarrhea requiring a parasympatholytic drug Mucous discharge not necessitating sanitary pads Rectal or abdominal pain requiring analgesics	Moderate diarrhea and colic Bowel movement >5 times daily Excessive rectal mucus or intermittent bleeding
Grade 3	Diarrhea requiring parenteral support Severe mucous or blood discharge needing sanitary pads Abdominal distention (flat plate radiograph demonstrates distended bowel loops)	Obstruction or bleeding requiring surgery
Grade 4	Acute or subacute obstruction, fistula, or perforation GI bleeding requiring transfusion Abdominal pain or tenesmus requiring tube decompression or bowel diversion	Necrosis Perforation Fistula