Table 3.

Typical estimated values of biologically weighted dose components and their achievable total values for californium-252 (²⁵²Cf) brachytherapy combined with boron neutron capture therapy (Cf-BNCT) with a balloon catheter filled with light water (LWB) and Cf-BNCT with a balloon catheter filled with heavy water (HWB) to a 432-μg ²⁵²Cf, and for conventional boron neutron capture therapy (BNCT) at MIT, Petten institutions taken on BNCT facilities, considering an irradiation field directed towards the tumour at the same depth (d) referent to infiltrations I₁ and I₂ positions, boron concentration on tumour ($C_{\text{B}}^{\text{T}}$) and brain ($C_{\text{B}}^{\text{b}}$)

BNCT type	d	$C_{\text{B}}^{\text{T}}$/$C_{\text{B}}^{\text{b}}$ (ppm)	Biologically weighted dose components (Gy) and weighting factors					Biologically weighted total dose (Gy)		Exposure time (min)
			DB		DγwF; DG wF = 0.5	Dn wn 3.2	DN wN 3.2	Brain	Tumour
			$w_{\text{B}}^{\text{b}}$ 1.3	$w_{\text{B}}^{\text{T}}$ 3.8
M67-MITa	I1	–/15	0.5		1.8	0.25	0.1	2.65		100
	I2		0.15		1.2	0.15	0.03	1.53
MITb	I1	65/18	0.8	4.2	0.55; 0.06	0.03	0.21	1.65	5.05	1
	I2		–	–	–	–	–	–	–
Pettenc	I1	30 (blood)	2.9		3.15	0.12	0.1	6.27		74.77
	I2		0.6		1.8	0.05	0.05	2.50
Cf-LWBd	I1	52.5/15	0.54	7.04	0.09; 0.11e	1.73	0.49	2.96	9.45	60
	I2		0.22	1.04	0.02; 0.01e	0.20	0.07	0.52	1.34
Cf-HWBf	I1	52.5/15	0.54	5.96	0.04; 0.10e	2.86	0.41	4.21	9.63	60
	I2		0.22	2.18	0.02; 0.01e	0.42	0.15	0.84	2.80

Cf, ²⁵²Cf brachytherapy.

^aM67 epithermal neutron beam at BNCT facilities in MIT Nuclear Reactor Laboratory (MITR-II) in Boston, MA.⁹

^bMIT fission converter operating at 83 kW.²⁹

^cPetten, calculated with the Idaho National Engineering and Environmental Laboratory treatment planning software.³⁰

^dWeighted dose from Cf-BNCT-HWB; emitting 10⁹ p s⁻¹ evaluated per neutron emitted by source.

^eAdjusted by the difference of gamma and neutron emitting.

^fWeighted dose from Cf-BNCT-LWB; emitting 10⁹ p s⁻¹ evaluated per neutron emitted by source.