Pillai M.R.A. | Bhabha Atomic Research Centre (original) (raw)
Papers by Pillai M.R.A.
EJNMMI Radiopharmacy and Chemistry, 2024
The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentar... more The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readershipon trends in the field of radiopharmaceuticals development.
Nuclear Medcine and Biology, 1999
Novel polydentate amine-pyrrole and amine-thiophene ligands were synthesized and charac- terized ... more Novel polydentate amine-pyrrole and amine-thiophene ligands were synthesized and charac-
terized by 1H and 13C NMR spectroscopy. Radiochemical studies with 99mTc were carried out at 0.1–100
mM of technetium. Complexation yields were estimated from thin layer chromatography (TLC), paper
electrophoresis, and solvent extraction studies. The 99mTc complexes formed were found to be neutral and
lipophilic. Complexes with the corresponding imine-ligands were formed in lower yields. Biodistribution
studies of the 99mTc complexes of these ligands showed no significant uptake in brain or heart, and the
clearance was mainly through the hepatobiliary system.
A short histroy of my life as radiopharmaceutical scientist
Nuclear Medicine and Biology, 2017
In 1975, the ‘15th Conférence Générale des Poids et Mesures’ adapted Becquerel as SI (The Interna... more In 1975, the ‘15th Conférence Générale des Poids et Mesures’
adapted Becquerel as SI (The International System of Units, in French:
Système international d'unités) unit of radioactivity through a resolution
which stated - “…. by reason of the need to make as easy as possible the
use of the units for non-specialists, takinginto considerationalsothe grave
risks of errors in therapeutic work, adopts the following special name for
the SI unit of activity: becquerel, symbol Bq, equal to one reciprocal second”
[1]. The authors of this letter with forty odd years of experience
working with radioactive materials, isotope production and nuclear
medicine feel that the purpose of adapting Bq unit for radioactivity did
not achieve the objectives highlighted in the 1975 resolution as rationalized
below and hence suggesting the need for a review.
This paper discusses the benefits of obtaining 99mTc from non-fission reactor-produced low specif... more This paper discusses the benefits of obtaining 99mTc from non-fission reactor-produced low specific activity 99Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of 99mTc separated from reactor-produced 99Mo by (n,) activation of natural/enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of 99mTc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of 99mTc over a period of two weeks; with three extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of 99Mo once every four days can provide 1.3-3.3 TBq (40-90 Ci) of 99mTc daily. This model can use research reactors operating in the US to supply current 99Mo needs by using natural natMo targets. Molybdenum-99 production capacity enhancement can be accomplished by using 98Mo enriched targets. The proposed model reduces the loss of 99Mo by decay
![Research paper thumbnail of Preparation of [177Lu]PSMA-617 Using Carrier Added (CA) 177Lu for Radionuclide Therapy of Prostate Cancer](https://attachments.academia-assets.com/111059267/thumbnails/1.jpg)
](Journal of Nuclear Medicine & Radiation Therapy, 2016
A group of functionalized triamine chelants and their derivatives that form complexes with radioa... more A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2015
This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-spec... more This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo...
Radiochimica Acta, 2014
The work reported in this paper provides a systematic study towards the development of an optimiz... more The work reported in this paper provides a systematic study towards the development of an optimized strategy for preparation of a clinically relevant dose of 90Y-labeled dimeric RGD peptide derivative, DOTA-E[c(RGDfK)]2 [DOTA-(RGD)2] for in vivo targeted therapy utilizing 90Y obtained from a novel electrochemical 90Sr/90Y generator. The performance of the generator was evaluated to ensure its suitability for providing 90Y in adequate quantity and purity required for formulation of clinically relevant dose for PRRT. 90Y-DOTA-(RGD)2 was synthesized in high yield (86.2 ± 2.5%) and radiochemical purity (98.4 ± 0.5%) using clinically relevant dose (∼3.8 GBq) of 90Y. In vitro stability studies revealed that the radiolabeled conjugate retained its radiochemical purity in normal saline and human serum. Preliminary biodistribution studies carried out in C57/BL6 mice bearing melanoma tumors showed that the preparation exhibited significant tumor uptake (5.30 ± 0.78% of injected activity at 30...
Cancer Biotherapy and Radiopharmaceuticals, 2014
The present article describes the preparation, characterization, and biological evaluation of Thu... more The present article describes the preparation, characterization, and biological evaluation of Thulium-170 ((170)Tm) [T1/2 = 128.4 days; Eβmax = 968 keV; Eγ = 84 keV (3.26%)] labeled tin oxide microparticles for its possible use in radiation synovectomy (RSV) of medium-sized joints. (170)Tm was produced by irradiation of natural thulium oxide target. 170Tm-labeled microparticles were synthesized with high yield and radionuclidic purity (> 99%) along with excellent in vitro stability by following a simple process. Particle sizes and morphology of the radiolabeled particles were examined by light microscope, dynamic light scattering, and transmission electron microscope and found to be of stable spherical morphology within the range of 1.4-3.2 μm. The preparation was injected into the knee joints of healthy Beagle dogs intraarticularly for biological studies. Serial whole-body and regional images were taken by single-photon-emission computed tomography (SPECT) and SPECT-CT cameras up to 9 months postadministration, which showed very low leakage (< 8% of I.D.) of the instilled particles. The majority of leaked radiocolloid particles were found in inguinal lymph nodes during the 9 months of follow-up. All the animals tolerated the treatment well; the compound did not show any possible radiotoxicological effect. These preliminary studies showed that 170Tm-labeled microparticles could be a promising nontoxic and effective radiopharmaceutical for RSV applications or later local antitumor therapy.
EJNMMI Radiopharmacy and Chemistry, 2021
Background The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highligh... more Background The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highlight commentary to describe trends in the field. Results This commentary of highlights has resulted in 19 different topics selected by each member of the Editorial Board addressing a variety of aspects ranging from novel radiochemistry to first in man application of novel radiopharmaceuticals. Conclusion Trends in radiochemistry and radiopharmacy are highlighted demonstrating the progress in the research field being the scope of EJNMMI Radiopharmacy and Chemistry.
Polyhedron, 1991
The syntheses of a new, bifunctional ligand, 3-[N-(4-aminobenzyl)]amino-3methyl-Zbutanone oxime, ... more The syntheses of a new, bifunctional ligand, 3-[N-(4-aminobenzyl)]amino-3methyl-Zbutanone oxime, ligand I, and a non-bifunctional analogue 3-benzylamino-3methyl-Zbutanone oxime, ligand II, the former for labelling proteins with "'Rh complexes for internal radiotherapy applications are reported. The rhodium complex of ligand II was isolated and characterized by 'H NMR, IR spectroscopy and X-ray crystallography. The crystal structure consists of discrete mononuclear, neutral and slightly distorted octahedral molecules. The octahedron around rhodium consists of two trans-chlorine atoms and four nitrogen atoms from the two bidentate amine oxime ligands. The complex formed in situ with the bifunctional ligand I gives up to 95% yield with losRh in pH 9 bicarbonate buffer. This complex was converted to the isothiocyanate derivative with thiophosgene and extracted into CHC13 (91%). Conjugation yields of greater than 90% could be obtained with human y-globulin. The protein conjugation method described is suitable for the preparation of "'Rh labelled antibodies with specific activities of 1.6-9.3 mCi mg-'.
Radiochimica Acta , 2014
The work reported in this paper provides a systematic study towards the development of an optimiz... more The work reported in this paper provides a systematic study towards the development of an optimized strategy for preparation of a clinically relevant dose of 90Y-labeled dimeric RGD peptide derivative, DOTA-E[c(RGDfK)]2 [DOTA-(RGD)2] for in vivo targeted therapy utilizing 90Y obtained from a novel electrochemical 90Sr/90Y generator. The performance of the generator was evaluated to ensure its suitability for providing 90Y in adequate quantity and purity required for formulation of clinically relevant dose for PRRT. 90Y-DOTA-(RGD)2 was synthesized in high yield (86.2 ± 2.5%) and radiochemical purity (98.4 ± 0.5%) using clinically relevant dose (∼3.8 GBq) of 90Y. In vitro stability studies revealed that the radiolabeled conjugate retained its radiochemical purity in normal saline and human serum. Preliminary biodistribution studies carried out in C57/BL6 mice bearing melanoma tumors showed that the preparation exhibited significant tumor uptake (5.30 ± 0.78% of injected activity at 30 min post-injection) with good tumor to background ratio. The optimized radiolabeling protocol seems to be an attractive strategy which is largely viewed as a springboard to realize scope of developing 90Y labeled cyclic RGD peptides for targeted therapy of tumors over-expressing integrin-αvβ3 receptors.
![Research paper thumbnail of A cost effective method for the preparation of sodium fluoride [ 18 F]NaF for PET-CT imaging by using an in-house designed module](https://attachments.academia-assets.com/96729658/thumbnails/1.jpg)
](We report the development of a manual module for the preparation of [ 18 F]NaF for metastatic bon... more We report the development of a manual module for the preparation of [ 18 F]NaF for metastatic bone cancer imaging. By using this simple module, [ 18 F]NaF production can be carried out inexpensively without using commercially available kits. The module can be used for making [ 18 F]NaF from freshly irradiated H 2 18 O water or with left over activity in the target after [ 18 F]FDG production. The product meets all quality control parameters.
![Research paper thumbnail of Preparation of Patient Doses of [ 177 Lu]Lu-DOTATATE and [ 177 Lu] Lu-PSMA-617 with Carrier Added (CA) and No Carrier Added (NCA) 177 Lu](https://attachments.academia-assets.com/92108232/thumbnails/1.jpg)
](Purpose [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 used for targeted radionuclide therapy are ... more Purpose [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 used for targeted radionuclide therapy are very often prepared in the hospital radiopharmacy. The preparation parameters vary depending upon the specific activity of the 177 Lu used. The aim of this study was to develop optimized protocols to be used in the nuclear medicine department for the preparation of patient doses of the above radiopharmaceuticals. Method 177 Lu (CA and NCA) were used for radiolabeling DOTATATE and PSMA-617. Parameters studied are 177 Lu of different specific activity and different peptide concentrations and two different buffer systems. Paper and thin layer chromatography systems were used for estimating the radiochemical yield as well as radiochemical purity. Solid-phase extraction was used for the purification of the labeled tracers. Results [ 177 Lu]Lu-DOTATATE was prepared with CA 177 Lu (n = 13) and NCA 177 Lu (n = 6). Four batches each of [ 177 Lu] Lu-PSMA-617 were prepared using CA and NCA 177 Lu. Radiochemical yields > 80% and final product with less than < 1% radiochemical impurity could be obtained in all batches which were used for therapy. Conclusion Robust protocols for the preparation of clinical doses of [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 were developed and used for the preparation of clinical doses. The quality of the SPECT images of both the tracers are consistent with the expected uptake in respective diseases.
Nuclear Medciine and Biology, 1993
When eluates from expired %"Mo/ *"Tc generators were used to form the neutral lipophilic complexe... more When eluates from expired %"Mo/ *"Tc generators were used to form the neutral lipophilic complexes of PnAO and its derivatives, degradation of these chelates occurred on standing to form secondary ""Tc-species. It was determined that the conversion of the primary complexes to secondary complexes was due to the impurities present in the %TcO; eluate. The stability was found to be improved by extraction of the complexes into CHCl, and reconstituting in buffer after evaporation of CHCl,, indicating that the impurities are non extractable into CHCl,. Purification of the %TcO, eluate from the generator by MEK extraction and its use for the preparation of the PnAO complex produced products which showed practically no degradation for a 6 h period of storage. All the secondary %"Tc complexes of PnAO are converted back to primary complex, when the solution was heated in a boiling water bath for lo-20 min.
![Research paper thumbnail of Experience of 6-L-[ 18 F]FDOPA Production Using Commercial Disposable Cassettes and an Automated Module](https://attachments.academia-assets.com/83306490/thumbnails/1.jpg)
](Nuclear Medcine and Molecualr Imaging, 2022
Purpose The clinical demand of 6-L-[ 18 F] FDOPA is gaining rapidly for imaging neurodegenerative... more Purpose The clinical demand of 6-L-[ 18 F] FDOPA is gaining rapidly for imaging neurodegenerative diseases by using positron emission tomography. Hence, large-scale production of 6-L-[ 18 F] FDOPA is necessary. This paper describes our experience on the production of 6-L-[ 18 F]FDOPA via nucleophilic synthesis using NEPTIS module and a commercially available cassette based chemistry. Method 6-L-[ 18 F]FDOPA production could be completed in three synthetic steps by using ABX nitro precursor. The precursor is first labeled with 18 F by replacing a-NO 2 leaving group followed by purification using a solid phase cartridge. In the subsequent step, the radiolabeled precursor is oxidized using meta chloroperoxy benzoic acid hydrolyzed to remove the four different protecting groups. The product is finally purified in a series of solid phase cartridges to yield radiochemically pure 6-L-[ 18 F]FDOPA. Results Total 36 batches of 6-L-[ 18 F]FDOPA were produced. The decay uncorrected yield were 5.5 ± 1.5% (n = 33) which corresponds to a decay corrected yield of 11.8 ± 3.2% (n = 33). The radiochemical purity of the product obtained is always > 95%. Conclusion The yields obtained are low and hence there is a need to improve synthetic chemistry. In order to understand the efficiency of each step, a detailed analysis using the radioactive traces obtained from the automated module was carried out. The radiolabeling yield of precursor is only about 50% and there is subsequent reduction in activity in the oxidation as well as hydrolysis steps. Despite the low radiochemical yields, the product obtained was suitable for imaging.
EJNMMI Radiopharmacy and Chemistry, 2024
The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentar... more The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readershipon trends in the field of radiopharmaceuticals development.
Nuclear Medcine and Biology, 1999
Novel polydentate amine-pyrrole and amine-thiophene ligands were synthesized and charac- terized ... more Novel polydentate amine-pyrrole and amine-thiophene ligands were synthesized and charac-
terized by 1H and 13C NMR spectroscopy. Radiochemical studies with 99mTc were carried out at 0.1–100
mM of technetium. Complexation yields were estimated from thin layer chromatography (TLC), paper
electrophoresis, and solvent extraction studies. The 99mTc complexes formed were found to be neutral and
lipophilic. Complexes with the corresponding imine-ligands were formed in lower yields. Biodistribution
studies of the 99mTc complexes of these ligands showed no significant uptake in brain or heart, and the
clearance was mainly through the hepatobiliary system.
A short histroy of my life as radiopharmaceutical scientist
Nuclear Medicine and Biology, 2017
In 1975, the ‘15th Conférence Générale des Poids et Mesures’ adapted Becquerel as SI (The Interna... more In 1975, the ‘15th Conférence Générale des Poids et Mesures’
adapted Becquerel as SI (The International System of Units, in French:
Système international d'unités) unit of radioactivity through a resolution
which stated - “…. by reason of the need to make as easy as possible the
use of the units for non-specialists, takinginto considerationalsothe grave
risks of errors in therapeutic work, adopts the following special name for
the SI unit of activity: becquerel, symbol Bq, equal to one reciprocal second”
[1]. The authors of this letter with forty odd years of experience
working with radioactive materials, isotope production and nuclear
medicine feel that the purpose of adapting Bq unit for radioactivity did
not achieve the objectives highlighted in the 1975 resolution as rationalized
below and hence suggesting the need for a review.
This paper discusses the benefits of obtaining 99mTc from non-fission reactor-produced low specif... more This paper discusses the benefits of obtaining 99mTc from non-fission reactor-produced low specific activity 99Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of 99mTc separated from reactor-produced 99Mo by (n,) activation of natural/enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of 99mTc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of 99mTc over a period of two weeks; with three extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of 99Mo once every four days can provide 1.3-3.3 TBq (40-90 Ci) of 99mTc daily. This model can use research reactors operating in the US to supply current 99Mo needs by using natural natMo targets. Molybdenum-99 production capacity enhancement can be accomplished by using 98Mo enriched targets. The proposed model reduces the loss of 99Mo by decay
Journal of Nuclear Medicine & Radiation Therapy, 2016
A group of functionalized triamine chelants and their derivatives that form complexes with radioa... more A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2015
This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-spec... more This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo...
Radiochimica Acta, 2014
The work reported in this paper provides a systematic study towards the development of an optimiz... more The work reported in this paper provides a systematic study towards the development of an optimized strategy for preparation of a clinically relevant dose of 90Y-labeled dimeric RGD peptide derivative, DOTA-E[c(RGDfK)]2 [DOTA-(RGD)2] for in vivo targeted therapy utilizing 90Y obtained from a novel electrochemical 90Sr/90Y generator. The performance of the generator was evaluated to ensure its suitability for providing 90Y in adequate quantity and purity required for formulation of clinically relevant dose for PRRT. 90Y-DOTA-(RGD)2 was synthesized in high yield (86.2 ± 2.5%) and radiochemical purity (98.4 ± 0.5%) using clinically relevant dose (∼3.8 GBq) of 90Y. In vitro stability studies revealed that the radiolabeled conjugate retained its radiochemical purity in normal saline and human serum. Preliminary biodistribution studies carried out in C57/BL6 mice bearing melanoma tumors showed that the preparation exhibited significant tumor uptake (5.30 ± 0.78% of injected activity at 30...
Cancer Biotherapy and Radiopharmaceuticals, 2014
The present article describes the preparation, characterization, and biological evaluation of Thu... more The present article describes the preparation, characterization, and biological evaluation of Thulium-170 ((170)Tm) [T1/2 = 128.4 days; Eβmax = 968 keV; Eγ = 84 keV (3.26%)] labeled tin oxide microparticles for its possible use in radiation synovectomy (RSV) of medium-sized joints. (170)Tm was produced by irradiation of natural thulium oxide target. 170Tm-labeled microparticles were synthesized with high yield and radionuclidic purity (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 99%) along with excellent in vitro stability by following a simple process. Particle sizes and morphology of the radiolabeled particles were examined by light microscope, dynamic light scattering, and transmission electron microscope and found to be of stable spherical morphology within the range of 1.4-3.2 μm. The preparation was injected into the knee joints of healthy Beagle dogs intraarticularly for biological studies. Serial whole-body and regional images were taken by single-photon-emission computed tomography (SPECT) and SPECT-CT cameras up to 9 months postadministration, which showed very low leakage (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 8% of I.D.) of the instilled particles. The majority of leaked radiocolloid particles were found in inguinal lymph nodes during the 9 months of follow-up. All the animals tolerated the treatment well; the compound did not show any possible radiotoxicological effect. These preliminary studies showed that 170Tm-labeled microparticles could be a promising nontoxic and effective radiopharmaceutical for RSV applications or later local antitumor therapy.
EJNMMI Radiopharmacy and Chemistry, 2021
Background The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highligh... more Background The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highlight commentary to describe trends in the field. Results This commentary of highlights has resulted in 19 different topics selected by each member of the Editorial Board addressing a variety of aspects ranging from novel radiochemistry to first in man application of novel radiopharmaceuticals. Conclusion Trends in radiochemistry and radiopharmacy are highlighted demonstrating the progress in the research field being the scope of EJNMMI Radiopharmacy and Chemistry.
Polyhedron, 1991
The syntheses of a new, bifunctional ligand, 3-[N-(4-aminobenzyl)]amino-3methyl-Zbutanone oxime, ... more The syntheses of a new, bifunctional ligand, 3-[N-(4-aminobenzyl)]amino-3methyl-Zbutanone oxime, ligand I, and a non-bifunctional analogue 3-benzylamino-3methyl-Zbutanone oxime, ligand II, the former for labelling proteins with "'Rh complexes for internal radiotherapy applications are reported. The rhodium complex of ligand II was isolated and characterized by 'H NMR, IR spectroscopy and X-ray crystallography. The crystal structure consists of discrete mononuclear, neutral and slightly distorted octahedral molecules. The octahedron around rhodium consists of two trans-chlorine atoms and four nitrogen atoms from the two bidentate amine oxime ligands. The complex formed in situ with the bifunctional ligand I gives up to 95% yield with losRh in pH 9 bicarbonate buffer. This complex was converted to the isothiocyanate derivative with thiophosgene and extracted into CHC13 (91%). Conjugation yields of greater than 90% could be obtained with human y-globulin. The protein conjugation method described is suitable for the preparation of "'Rh labelled antibodies with specific activities of 1.6-9.3 mCi mg-'.
Radiochimica Acta , 2014
The work reported in this paper provides a systematic study towards the development of an optimiz... more The work reported in this paper provides a systematic study towards the development of an optimized strategy for preparation of a clinically relevant dose of 90Y-labeled dimeric RGD peptide derivative, DOTA-E[c(RGDfK)]2 [DOTA-(RGD)2] for in vivo targeted therapy utilizing 90Y obtained from a novel electrochemical 90Sr/90Y generator. The performance of the generator was evaluated to ensure its suitability for providing 90Y in adequate quantity and purity required for formulation of clinically relevant dose for PRRT. 90Y-DOTA-(RGD)2 was synthesized in high yield (86.2 ± 2.5%) and radiochemical purity (98.4 ± 0.5%) using clinically relevant dose (∼3.8 GBq) of 90Y. In vitro stability studies revealed that the radiolabeled conjugate retained its radiochemical purity in normal saline and human serum. Preliminary biodistribution studies carried out in C57/BL6 mice bearing melanoma tumors showed that the preparation exhibited significant tumor uptake (5.30 ± 0.78% of injected activity at 30 min post-injection) with good tumor to background ratio. The optimized radiolabeling protocol seems to be an attractive strategy which is largely viewed as a springboard to realize scope of developing 90Y labeled cyclic RGD peptides for targeted therapy of tumors over-expressing integrin-αvβ3 receptors.
We report the development of a manual module for the preparation of [ 18 F]NaF for metastatic bon... more We report the development of a manual module for the preparation of [ 18 F]NaF for metastatic bone cancer imaging. By using this simple module, [ 18 F]NaF production can be carried out inexpensively without using commercially available kits. The module can be used for making [ 18 F]NaF from freshly irradiated H 2 18 O water or with left over activity in the target after [ 18 F]FDG production. The product meets all quality control parameters.
Purpose [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 used for targeted radionuclide therapy are ... more Purpose [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 used for targeted radionuclide therapy are very often prepared in the hospital radiopharmacy. The preparation parameters vary depending upon the specific activity of the 177 Lu used. The aim of this study was to develop optimized protocols to be used in the nuclear medicine department for the preparation of patient doses of the above radiopharmaceuticals. Method 177 Lu (CA and NCA) were used for radiolabeling DOTATATE and PSMA-617. Parameters studied are 177 Lu of different specific activity and different peptide concentrations and two different buffer systems. Paper and thin layer chromatography systems were used for estimating the radiochemical yield as well as radiochemical purity. Solid-phase extraction was used for the purification of the labeled tracers. Results [ 177 Lu]Lu-DOTATATE was prepared with CA 177 Lu (n = 13) and NCA 177 Lu (n = 6). Four batches each of [ 177 Lu] Lu-PSMA-617 were prepared using CA and NCA 177 Lu. Radiochemical yields > 80% and final product with less than < 1% radiochemical impurity could be obtained in all batches which were used for therapy. Conclusion Robust protocols for the preparation of clinical doses of [ 177 Lu]Lu-DOTATATE and [ 177 Lu]Lu-PSMA-617 were developed and used for the preparation of clinical doses. The quality of the SPECT images of both the tracers are consistent with the expected uptake in respective diseases.
Nuclear Medciine and Biology, 1993
When eluates from expired %"Mo/ *"Tc generators were used to form the neutral lipophilic complexe... more When eluates from expired %"Mo/ *"Tc generators were used to form the neutral lipophilic complexes of PnAO and its derivatives, degradation of these chelates occurred on standing to form secondary ""Tc-species. It was determined that the conversion of the primary complexes to secondary complexes was due to the impurities present in the %TcO; eluate. The stability was found to be improved by extraction of the complexes into CHCl, and reconstituting in buffer after evaporation of CHCl,, indicating that the impurities are non extractable into CHCl,. Purification of the %TcO, eluate from the generator by MEK extraction and its use for the preparation of the PnAO complex produced products which showed practically no degradation for a 6 h period of storage. All the secondary %"Tc complexes of PnAO are converted back to primary complex, when the solution was heated in a boiling water bath for lo-20 min.
Nuclear Medcine and Molecualr Imaging, 2022
Purpose The clinical demand of 6-L-[ 18 F] FDOPA is gaining rapidly for imaging neurodegenerative... more Purpose The clinical demand of 6-L-[ 18 F] FDOPA is gaining rapidly for imaging neurodegenerative diseases by using positron emission tomography. Hence, large-scale production of 6-L-[ 18 F] FDOPA is necessary. This paper describes our experience on the production of 6-L-[ 18 F]FDOPA via nucleophilic synthesis using NEPTIS module and a commercially available cassette based chemistry. Method 6-L-[ 18 F]FDOPA production could be completed in three synthetic steps by using ABX nitro precursor. The precursor is first labeled with 18 F by replacing a-NO 2 leaving group followed by purification using a solid phase cartridge. In the subsequent step, the radiolabeled precursor is oxidized using meta chloroperoxy benzoic acid hydrolyzed to remove the four different protecting groups. The product is finally purified in a series of solid phase cartridges to yield radiochemically pure 6-L-[ 18 F]FDOPA. Results Total 36 batches of 6-L-[ 18 F]FDOPA were produced. The decay uncorrected yield were 5.5 ± 1.5% (n = 33) which corresponds to a decay corrected yield of 11.8 ± 3.2% (n = 33). The radiochemical purity of the product obtained is always > 95%. Conclusion The yields obtained are low and hence there is a need to improve synthetic chemistry. In order to understand the efficiency of each step, a detailed analysis using the radioactive traces obtained from the automated module was carried out. The radiolabeling yield of precursor is only about 50% and there is subsequent reduction in activity in the oxidation as well as hydrolysis steps. Despite the low radiochemical yields, the product obtained was suitable for imaging.
IAEA Radioisotope and Radiopharmaceuticals Series 9, 2023
This IAEA publication provides a broad overview of the current status of radiopharmaceuticals for... more This IAEA publication provides a broad overview of the current status of radiopharmaceuticals for bone pain palliation for cancer patients with metastases to the bone. Production of radionuclides, identification of bone seeking carrier molecules, preparation of stable complexes, in vitro and in vivo evaluations, and dosimetry studies, which are part of the development of these radiopharmaceuticals for clinical use, are covered in the book. Details on the production and quality control of the currently available products are also provided here. This publication will appeal to scientists involved in the development of radiopharmaceuticals for bone pain palliation.
D.Sc Thesis, INCT, 2011
Thesis submitted to the Institute of Nuclear Chemistry and Technology (INCT) Poland for habilitat... more Thesis submitted to the Institute of Nuclear Chemistry and Technology (INCT) Poland for habilitation.
This is the full text of a thesis of the D.Sc submitted to the Institute of Chemistry and Nuclear... more This is the full text of a thesis of the D.Sc submitted to the Institute of Chemistry and Nuclear Technology (INCT), Poland in 2010 based on which the degree was awarded in 2011.
The thesis describes authors work on the development of several therapeutic radionuclides and radiopharmaceuticals; and written based on published work by the author from 1987-2010.
A general introduction on the evolution of therapeutic radiopharmaceutical is described in Chapter 1. Chapter 2 describes the principles behind the development of therapeutic radiopharmaceuticals. Chapter 3 gives a comprehensive description on different radionuclides used and potentially usable for targeted therapy. Chapter 4-10 gives the work done by the author with different radionuclides. Chapter 11 is an epilogue and future directions.
A general lecture on the activities of Molecular Group with an intial introduction to cyclotron.
A General lecture on Cancer and the role of nuclear medicine
Discusses the relative safety issues with commonly used radioisotopes in a nuclear medicine depar... more Discusses the relative safety issues with commonly used radioisotopes in a nuclear medicine department.
BRICS Forum
Paper presented at the BRICS International Forum for Nuclear Medicine
A presentation on the metallic radionuclides that are useful for targeted radiotherapy
ICNM Seminar at PGIMER, 2024
A review of radiopharmaceuticals development and the need to select small molecules as targeting ... more A review of radiopharmaceuticals development and the need to select small molecules as targeting vectors.
Lecture given on National Science Day, Bhabha Atomic Research Centre, Mumbai, 01.03.24.
Describes the initiatives taken by private industry in radiopharmaceuticals production in India.
Training Workshop on 'Cyclotron Produced PET Radiopharmaceuticals Production, Sri Lanka
Training Workshop on "Cyclotron Produced PET Radiopharmaceuticals Production, Sri Lanka 2023
Training Workshop on Cyclotron Produced PET Radiopharmaceuticals Production, Colombo, Sri Lanka
Training Workshop on Cyclotron based PET radiopharmaceuticals production
Training Workshop on Cyclotron production of PET radiopharmaceuticals
Training Workshop on 'Cyclotron Produced PET Radiopharmaceuticals Production'
Training Workshop-Sri Lanka, 2023
Experience in setting up of a medical cyclotron project is discussed.
Training Workshop on "Cyclotron Produced PET Radiopharmaceuticals"
Indian Analytical Science Congress 2023- 24-03-, 2023
Invited talk at "Master class in Theranostics" at MIOT, Chennai, 2023
Story of the genesis of PSMA tracers
KMCH Nuclear Medicine Course, 2021
Introductory lecture on Cyclotron
Lecture given in a Regional Training Course on "Cyclotron and PET Radiopharmaceuticals Production... more Lecture given in a Regional Training Course on "Cyclotron and PET Radiopharmaceuticals Production" 29th June to 2nd July 2021
Details about the design of a new Cyclotron PET radiopharmaceuticals production facility complyin... more Details about the design of a new Cyclotron PET radiopharmaceuticals production facility complying with GMP. Lecture given in an IAEA training Workshop.