Estimation of relative biological effectiveness of 225Ac compared to 177Lu during [225Ac]Ac-PSMA and [177Lu]Lu-PSMA radiopharmaceutical therapy using TOPAS/TOPAS-nBio/MEDRAS

EJNMMI Physics

Table 3 Estimated fit parameters for ¹⁷⁷Lu

Cell geom.	Intern.		\(b_{{{\text{init}}}} , {\text{DSB}}s \, {\text{Gy}}^{ - 1}\)	\(b_{{{\text{repair}}}} , {\text{DSB}}s\,{\text{ Gy}}^{ - 1}\)	\(a_{{{\text{repair}}}} ,{\text{ DSB}}s\,{\text{ Gy}}^{ - 2}\)
1	int.	2D	76.75 ± 0.82	16.84 ± 1.57	0.30 ± 0.91
1	membr.	2D	77.17 ± 0.86	17.00 ± 1.68	0.00 ± 1.23
2	int.	2D	79.13 ± 1.02	15.91 ± 1.91	1.36 ± 1.33
2	membr.	2D	78.00 ± 1.13	15.42 ± 2.08	1.06 ± 1.88
3	int.	2D	79.31 ± 1.23	17.13 ± 2.53	0.00 ± 2.58
3	membr.	2D	77.18 ± 1.35	11.63 ± 2.35	4.51 ± 2.95
4	int.	2D	78.28 ± 1.13	14.84 ± 2.01	2.67 ± 2.15
4	membr.	2D	76.40 ± 1.13	9.43 ± 2.08	6.89 ± 2.01
5	int.	2D	78.78 ± 1.11	16.54 ± 2.17	0.43 ± 2.26
5	membr.	2D	75.57 ± 1.03	14.27 ± 2.26	1.87 ± 2.82
1	int.	3D	77.69 ± 0.43	16.31 ± 0.81	1.21 ± 0.12
1	membr.	3D	78.28 ± 0.44	15.50 ± 0.99	1.45 ± 0.16
2	int.	3D	76.89 ± 0.47	15.05 ± 1.10	1.32 ± 0.16
2	membr.	3D	78.93 ± 0.39	14.87 ± 0.88	1.49 ± 0.14
3	int.	3D	76.94 ± 0.44	14.41 ± 0.96	1.49 ± 0.14
3	membr.	3D	76.59 ± 0.43	16.35 ± 0.94	1.11 ± 0.14
4	int.	3D	77.19 ± 0.43	14.48 ± 1.09	1.48 ± 0.16
4	membr.	3D	77.57 ± 0.37	15.73 ± 0.85	1.30 ± 0.12
5	int.	3D	77.41 ± 0.43	14.86 ± 1.09	1.48 ± 0.16
5	membr.	3D	77.20 ± 0.49	15.10 ± 1.10	1.32 ± 0.17

\(a_{{{\text{repair}}}}\) denote \(a_{{{}_{{}}^{177} {\text{Lu}}}}\) defined in Methods for the post-repair damage
\(b_{{{\text{init}}}}\) and \(b_{{{\text{repair}}}}\) denote \(b_{{{}_{{}}^{177} {\text{Lu}}}}\) described in Methods for the initial damage and the post-repair damage, rescpectively