Dose-volume relationships between enteritis and irradiated bowel volumes during 5-fluorouracil and oxaliplatin based chemoradiotherapy in locally advanced rectal cancer

Figures & data

Table I.  NCI CTC grading of diarrhea.

Diarrhea	Grade 0	Grade 1	Grade 2	Grade 3	Grade 4
Patients without colostomy	none	increase of <4 stools/day over pre-treatment	increase of 4–6 stools/day, or nocturnal stools	Increase of ≥7 stools/day or incontinence; or need for parenteral support for dehydration	Physiologic consequences requiring intensive care; or hemodynamic collapse
Patients with a colostomy	none	mild increase in loose, watery colostomy output compared with pretreatment	moderate increase in loose, watery colostomy output compared with pretreatment, but not interfering with normal activity	Severe increase in loose, watery colostomy output compared with pretreatment, interfering with normal activity	Physiologic consequences, requiring intensive care; or hemodynamic collapse

Figure 1.  Delineated bowel volumes: 1) Small bowel (red structure), 2) Large bowel (green), and 3) “Whole abdomen” (blue).

Figure 2.  Dose-volume histograms for small bowel (a), large bowel (b), and “whole abdomen” (c), divided by diarrhea grade 0–1 vs. grade 2–3. Dots indicate volumes of normal tissue in individual patients receiving >5, >10, >15,…,>50 Gy. Lines indicate median volumes as a function of dose level. Mann-Whitney U-test was used.

Table II.  Association between grade 2 +  diarrhea and patient and treatment associated factors using Fisher's exact test.

Parameter	No. of patients	Grade II+ Diarrhea	p-value
Age			0.46
< median	13	4 (31%)
≥ median	15	7 (47%)
Gender			0.44
Male	18	6 (33%)
Female	10	5 (50%)
Tumor			0.2
Primary	20	6 (30%)
Locally recurrent	8	5 (63%)
Fractionation schedule*			0.25
1.8 Gy	15	4 (27%)
2.0 Gy	13	7 (54%)
Prior chemotherapy			1.0
Yes	16	6 (38%)
No	12	5 (42%)
Enterostomy			0.25
Yes	15	4 (27%)
No	13	7 (54%)
BMI			0.25
< 25	13	7 (54%)
> 25	15	4 (27%)
Hypertension*			1.0
Yes	7	3 (43%)
No	21	8 (38%)

*1.8 vs. 2.0 Gy fractions to 50.4 and 50 Gy respectively.

Table III.  Number of patients with diarrhea grade 0–1 and grade 2–3, respectively, related to whether more or less than 150 cc of the small bowel volume received >15 Gy, p = 0.049 (two sided Fischer's exact test).

	Grade 0–1	Grade 2–3	Total
V15Gy ≤150 cm^3	8	1	9
V15Gy >150 cm^3	9	10	19
Total	17	11	28