The toxicity endpoints considered were as follows : total number of days with grade 1 proctitis ( G1 ) ; total number of days with grade 2 proctitis ( G2 ) ; G1 and G2 proctitis lasting at least 3 and 5 consecutive days starting from week 4 ( G1 +3 d , G2 +3 d ) ; damaging effects of RT on rectal mucosa as measured by endoscopy .