BNCT IN AN EXPERIMENTAL MODEL OF LUNG METASTASES IN BDIX RATS V.A. Trivillin 1,2 , M.A. Garabalino 1 , L.L. Colombo 2,3,4 , E.C.C. Pozzi 1 , A. Monti Hughes 1 , P Curotto 1 , S Thorp 1 , R.O. Farías 1,2 , S.J. González 1,2 , S. Bortolussi 5 , S. Altieri 5 , M.E. Itoiz 1,6 , R.F. Aromando 6 , D.W. Nigg 7 , A.E. Schwint 1,2 1 Comisión Nacional de Energía Atómica (CNEA); 2 CONICET; 3 Instituto de Oncología Angel H Roffo; 4 Universidad Abierta Interamericana (UAI), Argentina; 5 Dipartimento di Fisica Nucleare e Teorica dell’ Università, Pavia and Istituto Nazionale di Fisica Nucleare (INFN), Pavia, Italia; 6 Facultad de Odontología, Universidad de Buenos Aires (UBA), Argentina; 7 Idaho National Laboratory, EE.UU.
Transcript
BNCT IN AN EXPERIMENTAL MODEL OF LUNG
METASTASES IN BDIX RATS V.A. Trivillin1,2, M.A. Garabalino1, L.L. Colombo2,3,4, E.C.C. Pozzi1,
A. Monti Hughes1, P Curotto1, S Thorp1, R.O. Farías1,2, S.J. González1,2, S. Bortolussi5, S. Altieri5, M.E. Itoiz1,6, R.F. Aromando6,
D.W. Nigg7, A.E. Schwint1,2
1 Comisión Nacional de Energía Atómica (CNEA); 2CONICET; 3Instituto de Oncología Angel H Roffo; 4 Universidad Abierta Interamericana (UAI), Argentina; 5Dipartimento di Fisica Nucleare e Teorica dell’ Università, Pavia and Istituto Nazionale di Fisica Nucleare (INFN), Pavia, Italia; 6 Facultad de Odontología, Universidad de Buenos Aires (UBA), Argentina; 7
Idaho National Laboratory, EE.UU.
BNCT has been proposed for the treatment of non resectable, diffuse tumors in lung.
The lung is the most frequent (and sometimes unique) site of metastases for several tumor types.
Surgical resection is not an option when metastases are multiple, and chemotherapy is often ineffective. In these cases the short-term mortality rate is 100%.
The aim of the present study was to perform BNCT studies in an experimental model of lung metastases to assess therapeutic efficacy and potential toxicity.
Based on the work of Bortolussi et al. (ARI 2011), we adapted an experimental model of disseminated lung metastases in rats to perform experimental BNCT studies devoted to optimizing the therapeutic advantage of ex-situ or in-situ BNCT for lung tumors.
This work is part of the multi-institutional project (CNEA, Maimonides Univ., Inst. A. Roffo and Favaloro Foundation) whose primary objective is to study the feasibility of applying BNCT ex-situ to patients with multiple metastases in both lungs.
At different times post-injection of the tumor cells, the animals were sacrificed, the lungs were removed and fixed in Bouin's solution.
2 Weeks
Between 1 to 6 x 106 DHD/K12/TRb colon
carcinoma cells in 0.5 ml of F10-DMEM were
injected in the jugular vein. The selected tumor
cell load was 3 x 106 cells.
The colon carcinoma cells DHD/K12/TRb were maintained in vitro in culture medium F10-DMEM supplemented with 10% fetal bovine serum.
3 Weeks 4 Weeks 5 Weeks
Experimental Model: different experimental conditions were
tested to optimize the model for biodistribution studies and
for in vivo BNCT studies.
Syngeneic inoculation of colon cancer cells
(DH/DK12/TRb) in BDIX rats in the jugular vein
Development of lung
metastases
Administration of boron
compounds
Irradiation in the RA-3 Nuclear
Reactor
Sacrifice of the group T0
Sacrifice of the experimental
groups
Parameters evaluated:
*Body weight
*Lung mass
*Histology
*Surface with metastatic nodules
(ongoing work)
3 weeks
Diagram BNCT in vivo study
3 h.
2 weeks
The general state of the animals was evaluated in terms of body weight, neurological symptoms and clinical signs throughout the process.
• Without boron compound administration.• Irradiation at RA-3 Nuclear Reactor. • Sacrificed 5 weeks post-inoculation and 2 post therapy.
Experimental Groups: 1. Control groups
In all groups (except NORMAL), BDIX rats were inoculated with 3 * 106 cells (DH/DK12/TRb).
• Sacrificed 3 weeks post inoculation (pre-treatment).
• Without boron compound administration.• Same manipulation without irradiation.• Sacrificed 5 weeks post inoculation.
Beam only
T0
Sham
• Without inoculation of cancer cells.• Without boron compound administration.• Euthanized to assess normal lung mass.
NORMAL
• Administration of BPA (46.5 mg 10B/Kg) iv.• Irradiation at RA-3 Nuclear Reactor. • Sacrificed 5 weeks after inoculation and 2 post
therapy.
• Administration of BPA (31 mg 10B/Kg) + GB-10 (34.5 mg 10B/Kg) iv.• Irradiation at RA-3 Nuclear Reactor.• Sacrificed 5 weeks after inoculation and 2 post therapy.
BPA-BNCT
LD
(BPA+GB-10) -BNCT
Low dose: minimum absorbed dose to tumor 4 Gy.
High dose: minimum absorbed dose to tumor 8 Gy.
HD
LD
Low dose: minimum absorbed dose to
tumor 4 Gy.
High dose: minimum absorbed dose to tumor 8 Gy.
HD
Experimental Groups: 2. BNCT
groups
In all groups, BDIX rats were inoculated with 3 * 106 cells (DH/DK12/TRb).
Thermal column
Shutter External Shield
Irradiation position
Feasibility of BNCT for experimental lung metastases in the RA-3 Nuclear Reactor
Based on potentially useful administration protocols assayed in previous biodistribution studies (Trivillin et al., 2013), dosimetric calculations were
performed to carry out irradiations at RA-3. It was necessary to design and build a shield to protect the animal body while the lung is exposed through an opening.
Razetti et al. designed, constructed and characterized an adequate thermal neutron shield of lithium carbonate (enriched in lithium-6).
Design, construction and application of a neutron shield for the treatment of diffuse lung cancer in rats using BNCT. A. Razetti, R.O. Farías, S.I. Thorp, V.A. Trivillin, E.C.C. Pozzi, P. Curotto, A.E. Schwint, S.J. González. Applied Radiation and Isotopes (in press).
Diagram of the thermal column of the RA-3
Lithium Carbonate Shield
Restrictions in clinical radiotherapy with photonsOrgan Condition Vol. Crit
Percentage of lung mass / body weight for different protocols (mean ± SD).
BNCT corresponds to data pooled for BPA-BNCT and (BPA+GB-10)-BNCTStatistical significance vs. Sham , *p<0.05 **p<0.01 ***p<0.001; Normal vs. T0 **p<0.01
**
****
**
*** ***
Normal
TOSham
Beam Only LD
(Low dose
)
BPA-BNCT LD
(BPA+GB-10)-B
NCT LD
BNCT LD (p
ooled)
Beam Only HD (H
igh dose)
BPA-BNCT HD
(BPA+GB-10)-B
NCT HD
BNCT HD (pooled)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Lung
mas
s (g
r.)
Lung mass for different protocols (mean ± SD).
BNCT corresponds to data pooled for BPA-BNCT and (BPA+GB-10)-BNCTStatistical significance vs. Sham , *p<0.05 **p<0.01 ***p<0.001; Normal vs. T0 **p<0.01
Beam only (5 weeks post-inoculation, 2 weeks post-treatment)
Representative examples of the macroscopic appearance of left lung lobes
Representative example of metastatic dissemination in lung (low magnification)
Sham: viable tumor nodule with glandular differentiation
BNCT: tumor nodule exhibiting areas of viable cells, areas of necrosis and/or fibrosis and
pleomorphic cells with radioinduced damage
Representative examples of the microscopic appearance
Discussion and Conclusions BNCT induced a partial, consistent and significant control of
lung metastases, 2 weeks post-irradiation, with no associated toxicity.
The BNCT groups did not exhibit significant differences with T0, revealing that BNCT halted tumor growth.
No clinical, macroscopic or histological changes were observed in normal lung in any of the groups.
One problem so far is that we do not have a system for noninvasive monitoring of lung metastases. That is why we worked with the T0 group, to have a representative value of pretreatment lung mass.
BNCT allows the treatment of all nodules and scattered cells, without the need to know the exact number, distribution or shape (Bortolussi, 2011). Furthermore, the application of BNCT in lung tumors has the advantage that it is not necessary to adjust for the movement of breathing associated with the organ.
Acknowledgements
This study was partially supported by grants from the Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. GB-10 was kindly provided by Dr. David W. Nigg of Idaho National Laboratory, USA.
ACKNOWLEDGMENTS
Thanks !!!
Prescribed absorbed dose for different protocols for the low dose level.
