Table 8.

Postshielding peripheral dose in the region of the pubic symphysis, expressed as a percentage of the monitor units and as a percentage of the prescribed dose.

Collimator size (mm)	Distance (cm)	Postshielding peripheral dose (cGy)	Postshielding peripheral dose (%MU)	Postshielding peripheral dose (%TD)	Monitor units	Prescribed dose (cGy)	Isodose line (%)
12.5	63	1.24	0.04	0.06	3483	2200	80
25	71	3.94	0.04	0.20	10355	2000	70
20, 20, 10	72	5.75	0.04	0.36	12911	1600	70
12.5, 12.5, 10	70.5	4.62	0.03	0.36	13271	1300	70
20, 20, 7.5	71	5.66	0.04	0.40	14289	1400	70
15	67	5.34	0.04	0.36	14621	1500	70
35	83	6.66	0.04	0.37	15061	1800	70
12.5, 12.5, 7.5	82	7.26	0.04	0.40	20391	1800	70
10	87	6.23	0.03	0.35	20789	1800	70
5, 5, 5	68	4.64	0.02	0.23	20798	2000	70
7.5	82	8.06	0.04	0.37	20969	2200	70
10, 10, 5	74	9.18	0.04	0.44	24249	2100	70
5	76	7.26	0.03	0.40	24680	1800	80
10, 12.5, 20	70	10.04	0.04	0.63	26656	1600	75
5, 5, 10	74	11.76	0.04	0.65	29230	1800	70
5, 10, 12.5	73	11.52	0.04	0.61	29833	1900	70
5, 5, 5	80	11.64	0.04	0.55	32202	2100	70
7.5, 12.5, 20	69	13.08	0.04	0.65	33130	2000	70
5, 7.5, 12.5	73.5	18.66	0.04	1.04	42177	1800	70
7.5, 12.5, 12.5	88	13.89	0.03	0.51	43623	2700	75

MU: Monitor Units

TD: Prescribed Dose