Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources

Ghorbani, Mahdi; Mehrpouyan, Mohammad; Davenport, David; Ahmadi Moghaddas, Toktam

doi:10.1515/raon-2016-0019

Figures & Tables

2D anisotropy function values for (A) 125I, (B) 103Pd, (C) 169Yb and (D) 192Ir sources at r = 0.5 cm (a), 5.0 cm (b), and 15.0 cm (c) distances.

Percentage differences (%) between the 2D anisotropy function obtained from National Nuclear Data Center (NNDC) and other references of energy spectra for (A) 125I, (B) 103Pd, (C) 169Yb, and (D) 192Ir sources.

Isodose curves for (A) 125I, (B) 103Pd, (C) 169Yb, and (D) 19 2Ir sources obtained by different photon energy spectra. The contours for various spectra are not clearly distinguishable due to their overlapping.

Air kerma strength, dose rate constant, and dose rate at 1 cm for 125I, 103Pd, 169Yb, and 192Ir sources based on different photon energy spectra reported by other studies, LBNL, and NNDC databases

Source	Other studies^{1, 16-18}	LBNL¹⁹	NNDC^20-23	Diff. (%) Other study-NNDC	Diff. (%) LBNL-NNDC
Source	Air kerma strength (cGycm2/h)
¹²⁵I	1.035	1.169	1.121	-7.67	4.28
¹⁰³Pd	1.132	1.428	1.404	-19.37	1.71
¹⁶⁹Yb	1.094	1.094	1.097	-0.27	-0.27
¹⁹²Ir	3.622	3.631	3.496	3.60	3.86
	Dose rate constant (cGy/hU)
¹²⁵I	1.115	0.961	1.013	10.07	-5.13
¹⁰³Pd	0.830	0.658	0.669	24.06	-1.64
¹⁶⁹Yb	1.222	1.226	1.222	0.00	0.33
¹⁹²Ir	1.117	1.117	1.117	0.00	0.00
	Dose rate at 1 cm (cGy/hmCi)
¹²⁵I	1.154	1.123	1.136	1.60	-1.07
¹⁰³Pd	0.939	0.940	0.939	0.00	0.09
¹⁶⁹Yb	1.338	1.341	1.341	-0.23	0.00
¹⁹²Ir	4.045	4.054	3.904	3.59	3.84

Radial dose function for 125I, 103Pd, 169Yb, and 192Ir sources based on different photon energy spectra reported by other studies1,16-18, Lawrence Berkeley National Laboratory (LBNL)19, and National Nuclear Data Center (NNDC)20-23 databases

Source	r (cm)	Other studies (A)	LBNL (B)	NNDC (C)	Diff. (%) A-C	Diff. (%) B-C	Source	Other studies (A)	LBNL (B)	NNDC (C)	Diff. (%) A-C	Diff. (%) B-C Pd
¹²⁵I	0.5	0.996	0.996	0.996	0.00	0.00	¹⁰³Pd	1.196	1.196	1.196	0.00	0.00
	1	1.000	1.000	1.000	0.00	0.00		1.000	1.000	1.000	0.00	0.00
	1.5	0.955	0.955	0.954	0.11	0.10		0.789	0.789	0.789	0.00	0.00
	2	0.890	0.890	0.890	0.00	0.00		0.609	0.609	0.608	0.16	0.16
	2.5	0.816	0.815	0.816	0.00	-0.12		0.465	0.465	0.464	0.22	0.22
	3	0.740	0.740	0.740	0.00	0.00		0.352	0.352	0.352	0.00	0.00
	3.5	0.667	0.666	0.667	0.00	-0.15		0.265	0.265	0.264	0.38	0.38
	4	0.596	0.596	0.595	0.17	0.17		0.199	0.199	0.198	0.50	0.51
	4.5	0.530	0.530	0.530	0.00	0.00		0.150	0.150	0.149	0.67	0.68
	5	0.470	0.469	0.470	0.00	-0.21		0.112	0.112	0.112	0.00	0.00
	5.5	0.415	0.415	0.415	0.00	0.00		0.084	0.084	0.083	1.20	1.21
	6	0.365	0.365	0.365	0.00	0.00		0.063	0.062	0.062	1.61	0.00
	6.5	0.320	0.319	0.319	0.31	0.00		0.047	0.047	0.047	0.00	0.00
	7	0.279	0.279	0.279	0.00	0.00		0.035	0.035	0.035	0.00	0.00
	10	0.120	0.120	0.120	0.00	0.00		0.0066	0.0066	0.0065	1.54	1.54
	15	0.029	0.029	0.029	0.00	0.00		0.0010	0.0010	0.0010	0.00	0.00
¹⁶⁹Yb	0.5	0.950	0.949	0.951	-0.11	-0.21	¹⁹²Ir	0.996	0.996	0.996	0.00	0.00
	1	1.000	1.000	1.000	0.00	0.00		1.000	1.000	1.000	0.00	0.00
	1.5	1.042	1.041	1.041	0.10	0.00		1.003	1.003	1.003	0.00	0.00
	2	1.079	1.079	1.077	0.19	0.19		1.006	1.006	1.006	0.00	0.00
	2.5	1.113	1.111	1.110	0.27	0.09		1.008	1.008	1.008	0.00	0.00
	3	1.136	1.137	1.133	0.27	0.35		1.010	1.010	1.009	0.10	0.10
	3.5	1.157	1.156	1.155	0.17	0.09		1.011	1.011	1.010	0.10	0.01
	4	1.169	1.171	1.168	0.09	0.26		1.011	1.011	1.010	0.10	0.10
	4.5	1.183	1.181	1.180	0.25	0.09		1.010	1.010	1.010	0.00	0.00
	5	1.189	1.185	1.185	0.34	0.00		1.008	1.008	1.007	0.10	0.10
	5.5	1.193	1.191	1.191	0.17	0.00		1.005	1.005	1.005	0.00	0.00
	6	1.195	1.189	1.190	0.42	-0.08		1.002	1.002	1.001	0.10	0.10
	6.5	1.189	1.185	1.186	0.25	-0.08		0.998	0.998	0.998	0.00	0.00
	7	1.182	1.181	1.181	0.09	0.00		0.995	0.994	0.994	0.10	0.00
	10	1.089	1.091	1.090	-0.09	0.09		0.949	0.949	0.949	0.00	0.00
	15	0.860	0.865	0.862	-0.23	0.35		0.836	0.836	0.835	0.12	0.12

Information on photon energy spectra of the 125I and 103Pd, 169Yb, and 192Ir radionuclides reported by different databases

	¹²⁵I			103Pd
Reference	TG-43 U1¹	LBNL¹⁹	NNDC²⁰	Rivard¹⁶	LBNL¹⁹	NNDC²¹
Energy range (keV)	27.202-35492	3.335-35.4919	3.77-35.4925	22.074-497.054	2.377-497.08	2.7-487.08
Total photons per disintegration	1.4757	1.60482	1.5767	0.7713825	0.851569801	0.857582605
Average energy (keV)	28.370	27.541	26.059	21.319	19.038	18.889
	¹⁶⁹Yb			192Ir
Reference	Cazeca et al.17	LBNL¹⁹	NNDC²²	Medich and Munro¹⁸	LBNL¹⁹	NNDC²³
Energy range (keV)	49.77-307.74	6.341-781.64	7.18-781.64	61.49-884.54	7.822-1378.3	9.44-1378.50
Total photons per disintegration	3.322	3.779	3.771	2.301	2.359	2.214
Average energy (keV)	92.797	82.622	82.781	354.356	346.736	369.525

Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources

Figures & Tables

Air kerma strength, dose rate constant, and dose rate at 1 cm for 125I, 103Pd, 169Yb, and 192Ir sources based on different photon energy spectra reported by other studies, LBNL, and NNDC databases

Radial dose function for 125I, 103Pd, 169Yb, and 192Ir sources based on different photon energy spectra reported by other studies1,16-18, Lawrence Berkeley National Laboratory (LBNL)19, and National Nuclear Data Center (NNDC)20-23 databases

Information on photon energy spectra of the 125I and 103Pd, 169Yb, and 192Ir radionuclides reported by different databases

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