QUANTITATIVE PLANNING OF NEUTRON CAPTURE THERAPY ACCORDING TO THE KINETICS DATA OF Gd (III) COMPLEXES WITH MAGNETIC RESONANCE IMAGING

Neutron capture therapy (NCT) with thermal neutron beams of high flux density is the most promising method of therapy for inoperable malignant brain tumors using Gd in stable acetate complexes with possibility of visualization by magnetic resonance imaging (MRI). The effectiveness of NCT is determined by the maximum dose that is created in tumor cells by products of the capture of thermal neutrons by Gd atoms. Analyzing the kinetics of direct absorption and inverse diffusion of Gd complexes in brain tumor tissue by MRI, we were able to show that it is linear in all cases and Gd concentration in the tumor at the moment T is defined as С_tum(Т) = k_pl-tum ∙ ∫ С_pl(t)∙exp(–k_tum-pl (T–t))dt. At the same time, the value of the direct transport factor k_plasma-tumor=5.87±0.31 is an order of magnitude higher than the rate of reverse diffusion k_tumor-plasma=0.91±0.23. Then, according to the data of a single diagnostic dynamic study, it is possible to calculate the optimal regimen of Gd administration to achieve the therapeutic effect of a neutron beam of known flux density for NCT, while avoiding the release of Gd in healthy tissues.

1. Тюрин И.Е. Лучевая диагностика в Российской Федерации 2012 // Лучевая диагностика и терапия. — 2013. — № 4(4). — С. 116–120.

2. Корякин С.Н., Ульяненко С.Е., Савина Е.П. и др. Использование меченного радиоактивным йодом меркаптододекабората натрия для планирования нейтрон-захватной терапии // Мед. радиология и мед. безопасность. — 2005. — Т. 50, № 2. — С. 56–60.

3. Шимановский Н.Л. Контрастные средства / Руководство по рациональному применению. — М. : ГЭОТАР Медиа, 2009. — 485 с.

4. Гутер Р.С., Янпольский А.Р. Дифференциальные уравнения. — М. : Высшая школа, 1976. — 304 с.

5. Усов В.Ю., Бородин О.Ю., Величко О.Б. и др. Оценка эндотелиальной проницаемости опухолей мозга методом динамической магнитно-резонансной томографии с контрастированием Магневистом на низкопольном МР-томографе // Вестн. рентгенологии и радиологии. — 2001. № 3. — С. 22–29.

6. Peters A.M., Glass D.M., Bird N.J. Extracellular fluid volume and glomerular filtration rate: their relation and variabilities in patients with renal disease and healthy individuals // Nucl. Med. Commun. — 2011. — Vol. 7, No. 32. — P. 649–653.