Post on 20-Jan-2016
DETECTION OF CELLULAR BORON IN HUMAN
GLIOBLASTOMA BIOPSIES AFTER INFUSION OF BPA
A Detta, NP Lockyer, S Green, G Cruickshank
Dept Neurosurgery, QEHB & School of Cancer Sciences, University of Birmingham
Dept Medical Physics, QEHB & Dept Physics, University of Birmingham
Surface Analysis Research Centre, University of Manchester
Why GBM?
Most aggressive tumour known Incurable Causes greatest life-years-lost of any
oncological disease Causes costly morbidity
Why measure cellular boron?
Identify engagement of boronated drug with target tissue
Microscopic locus of boron dictates site of damage
Need 10-fold LESS boron intracellularly than extracellularly to cause cell death
Quantify microdosimetry
Why use SIMS
Best technique available for visualising cellular/subcellular boron
Generates visual images of isotopic composition and distribution
SIMS
High vacuum imaging technique Requires fastidious cryogenic procedures
to preserve chemical and structural integrity of tissue
Cryogenic procedure must obviate processing steps that would cause disturbance of native compartmentalisation of diffusible ions
However, detection limit is ~10ppm
Patient cohorts
1) Intravenous BPA x3 2) Intravenous BPA + BBB-D with
mannitol x3 3) Intracarotid BPA x3 4) Intracarotid + BBB-D with mannitol x1
Needle biopsy taken at 1-2h post BPA of Tumour & BAT
Not readily cryosectionableImprint tissue on Si or glass substrate
Liquid propane: unacceptable riskCryopreserve in isopentane-LN2
SIMS: frozen or freeze-dried
Histology
Bulk 10B quantification:ICP-MS
Store -80 oC
<30s
Pt 1 (IV BPA)Boron Na K
1h BAT 1h Tumour
Pt 1 (IV BPA)
2h BAT 2h Tumour
Pt 2 (IV BPA)
2h BAT 2h Tumour
Pt 3 (IV BPA)
2h Tumour
Pt 4 (IV BPA + BBB-D)
2h BAT 2h Tumour
Pt 5 (IV BPA + BBB-D)
2h BAT 2h Tumour
Pt 6 (IV BPA + BBB-D)
2h BAT 2h Tumour
Pt 7 (IA BPA)
2h BAT 2h Tumour
Pt 8 (IA BPA)
2h BAT 2h Tumour
Pt 9 (IA BPA)
2h BAT 2h Tumour
Pt 10 (IA BPA + BBB-D)
Analysis pending
Patients/Groups
Pt No. Age/gender
Diagnosis BPA infusion module
1 73/M OAII? IV
2 54/F GBM IV
3 55/M GBM IV
4 66/F GBM IV+BBBD
5 70/M GBM IV+BBBD
6 51/M GBM IV+BBBD
7 57/M GBM IA
8 72/M GBM IA
9 57/M GBM IA
10 71/M GBM IA+BBBD
Preliminary ResultsBPA infusion module
SIMS B:C ratio ICP-MS (ppm)
T BAT T BAT
1. IV 0.04 (1)
0.03 (1)
6.6 5.2
2. IV 0.08 (3)
0.08 (3)
47 18
3. IV 0.04 (2)
NA 8.6 9.4
4. IV+BBBD 0.03 (2)
0.02 (2)
23.2 14.4
5. IV+BBBD 0.04 (1)
0.01 (1)
22.2 9.9
6. IV+BBBD 0.04 (1)
0.02 (1)
18.4 16.9
7. IA 0.08 (2)
0.10 (2)
32.2 13.7
8. IA 0.05 (2)
0.02 (2)
22.1 13.9
9. IA 0.04 (3)
0.03 (3)
17.8* 10.4
Results summary 1BPA
infusion
module
SIMS B/C ratio
T B
ICP-MS (ppm)
T B
IV 0.05+ 0.02
0.06+ 0.035
20.7+ 22.8
10.9+ 6.5
IV+BBBD
0.05+ 0.026
0.02+ 0.006
21.3+ 2.5
13.7+ 3.5
IA0.06+ 0.02
0.05+ 0.04
24.0+ 7.4
12.7+ 2.0
Results summary 2BPA infusion
moduleT:B SIMS boron
T:B ICP-MS boron
IV 0.8 1.9
IV+BBBD 2.5 1.6
IA 1.2 1.9
Conclusions
Cell-level boron can be measured in human GBM biopsies with SIMS
IA route possibly route of choice for optimal target engagement at tissue and cell-level dimensions
Tumour : BAT boron levels independent of route of infusion
SIMS suggests tumour boron levels a little higher than BAT whereas ICP-MS shows ~2-fold difference