FIELD OF THE INVENTION
[001] The present invention generally relates to radiopharmaceuticals.
[002] More particularly, the present invention relates to process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake.
BACKGROUND FOR THE INVENTION:
[003] By reference to EP application no. EP0291281A1 by Amersham International PLC dated 1988-05-11, titled” Preparation of Tc-99m Radiopharmaceuticals” discloses Complexes useful as radiopharmaceuticals contain the 99mTc-NO moiety and a ligand which confers biological target-seeking properties on the complex. Preferred are mono-cationic complexes, particularly having the formula [99mTc(NO)L2X]? where X is halide or pseudohalide and L is a bidentate ligand for Technetium, which have interesting properties for use as heart visualizing agents. Examples of ligands include di-(dialkyl and diphenyl)-­phosphino ethanes and o-phenylenebis dimethyl arsine. The complexes may be made by reacting generator eluate pertechnetate with a hydroxylamine salt and with the ligands, preferably in a single step by providing a reaction mixture containing the three reagents optionally in the presence of a reducing agent.
[004] By reference to US application no. US4431626A by REGENTS OF THE UNIVERSITY OF CALIFORNIA THE, dated 981-09-28, titled” Tc-99m Labeled carrier for imaging” discloses Novel radionuclide imaging agents, having particular application for lymphangiography are provided by non-covalently binding Tc-99m to a pharmaceutically acceptable cross-linked polysaccharide. Upon injection of the Tc-99m labeled polysaccharide into the bloodstream, optimum contrast can be obtained within one hour.
[005] By reference to US application no. US6056941A by Bracco Research USA Inc dated 1999-07-28, titled” Kit for the preparation of technetium TC 99m teboroxime myocardial perfusion agent” discloses a kit containing a solution of boronic acid adducts of technetium-99 m dioxime complexes; and hydroxypropyl gamma cyclodextrin to maintain the solution free of particulate matter originating from the formulation.
[006] By reference to US application no. US4910012A by HOECHST AKTIENGESELLS CHAFT, A CORP. OF FED. REP. OF GERMANY dated 1989-03-28, titled”Products containing Tc- 99-m- ?alkylphosphinico- 1- hydroxyalkane -1 ,1- diphosphonates for bone scintigraphy and a process for the preparation of these products” discloses Tc-99m products containing at least one compound of the formula I ##STR1## in which R is a methyl, ethyl or propyl group and n represents a number from 1 to 6, or the physiologically tolerated salts thereof, are suitable for use in bone scintigraphy, especially for locating bone tumors.
[007] By reference to EP application no. EP0005638A2 by Summa Medical Corp, University Patents Inc dated 1979-05-21, titled” A composition of matter comprising a Tc-99m labeled antibody and a diagnostic kit for forming same” discloses a composition of matter comprising a Tc-99m labeled antibody and diagnostic kits for forming same are provided. The labeled antibody is anti-human chorionic gonadotropin (anti-hCG) or anit-human chorionic gonadotropin-beta subunit (anti-hCG-ß) or a mixture thereof. In diagnostic use, the labeled antibody is administered in physiologically and pharmaceutically acceptable form and its biodistribution is monitored. The labeled antibody will accumulate at cancer sites e.g. tumors that produce human chorionic gonadotropin, human chorionic gonadotropin-like material. comPounds similar or identical to the ß-chain of chorionic gonadotropin and mixtures thereof, which bind specifically to anti-hCG and/or anti-hCG-ß.
[008] By reference to US application no. US4066742A by Medi Physics Inc dated 1977-02-14, titled” Tc-99m sulfur colloid radiopharmaceuticals” discloses a Tc-99m stannous sulfur colloid radiopharmaceutical having simplicity of formulation, improved stability and desirable small particle size as well as a method of preparation therefor are described. Also provided is a reagent suitable for the preparation of such radiopharmaceutical by the addition thereto of technetium-99m pertechnetate.
[009] By reference to US application no. US2007286802A1 by Institute of Nuclear Energy Research dated 2006-06-08, titled” Method for testing radiochemical purity of Tc-99m-TRODAT-1” discloses a novel method for testing the radiochemical purity of Tc-99m-TRODAT-1 through a high performance liquid chromatography on a widely available C-18 column.
[010] By reference to US application no. US5028699A by EI Du Pont de Nemours and Co dated 1989-08-23, titled” Process for preparing Tc-99m tris(isonitrile) copper complexes” discloses Tris(isonitrile)copper(I) complex salts with anions selected from BF4, PF6, ClO4, I, Br, Cl and CF3 COO are useful in preparing radionuclide complexes rapidly at room temperature. Preferred isonitrile ligands are ether isonitriles. The tris(isonitrile)copper(I) adducts enable technetium complexes, such as those of Tc99m, to be prepared easily just prior to their use as imaging agents.
[011] However, none of the above-discussed inventions provides such a process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake. The process comprises a plurality of steps.

OBJECTS OF THE INVENTION:
[012] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
[013] The main object of the present invention is to provide a process for determining Tc-99m counts present in the thyroid to obtain the Tc-99m pertechnetate thyroid uptake using Thyroid Uptake Probe.
[014] Another object of the invention is to calculate the thyroid uptake using Tc-pertechnetate as an alternative to Radioiodine (1-131 & 1-123).
[015] Another object of the invention is to calculate the Tc-99m thyroid uptake using Gamma Camera and Thyroid Uptake Probe.
[016] Another object of the invention to calculate the mean uptake values & SD using Gamma Camera and Thyroid Uptake Probe using computer software as well as manual method.
[017] Another object of the invention to compare theTc-99m pertechnetate thyroid uptake using Gamma Camera and Thyroid Uptake Probe.

[018] Still another object of the invention is to provide the correlation (r) between probe and manual uptake, gamma camera and manual uptake, and gamma camera and probe.
[019] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY OF THE INVENTION:
[020] According to one aspect of our invention, a process for determining Tc-99m counts present in the thyroid to obtain the Tc-99m pertechnetate thyroid uptake. The thyroid Tc-99m uptake was measured using a gamma camera (GE; Millenium MPR) fitted with a (Low Energy General Purpose) LEGP collimator and thyroid uptake probe (Capintec, Inc. Captus 3000 Version1.19). Acquisition procedure for Tc-99m Thyroid uptake calculation comprising of following steps;a)Pre syringe and post syringe counts of measured dose of Tc-99m pertechnetate were taken before and after administration of dose on both gamma camera and thyroid uptake probe; b) At twenty to thirty minutes of intravenous administration of 111-158 MBq (3- to 4-mCi) Tc-99m pertechnetate, uptake was measured on gamma camera and thyroid uptake probe; c) On Gamma camera, static thyroid images were obtained in anterior view while the patient was supine with the neck extended; Image data acquisition was done in 128 x 128 computer matrix (zoom = 1);Counts for injection site were also taken using 128 x 128 computer matrix for 60 secs in order to check for subcutaneous infilteration that could invalidate the uptake calculation;d)On Thyroid Uptake Probe, patients were seated facing the detector, which was positioned 25cm from the anterior surface of the patient’s neck at the level of the cricoid;Counts were obtained in duplicate at the patient's neck for 30 seconds and the patient's background counts for 30 seconds.

[021] In another aspect of the invention, For analysis of Tc-99m pertechnetate thyroid uptake studies involves following steps. On Gamma Camera,a) a region of interest was manually placed over the thyroid on each image; b)The counts per region of interest on each image were corrected for radioactive decay; c) The Tc-99m pertechnetate thyroid uptake was calculated by using computer algorithm provided by the manufacturer for thyroid uptake applications.On Thyroid Uptake Probe , Tc-99m pertechnetate uptake was calculated using the probe inbuilt thyroid uptake software and manual calculations with the following relationship.

[022] In another aspect of the invention, the mean time taken for the uptake on gamma camera and thyroid uptake probe was 30 ± 10.02 minutes (range 20-52 minutes) and 32.1± 12.65 minutes (range 21-75 minutes).
[023] In another aspect of the invention, the mean uptake values and standard deviation calculated using thyroid uptake probe with computer software and Manual method (8.1±6.1, and 8.06±5.9) were slightly higher than uptake values calculated using Gamma camera (5.8±6.2).
[024] In another aspect of the invention, the correlation (r) between probe and manual uptake, gamma camera and manual uptake, and gamma camera and probe were 0.9947, 0.9691 and 0.9625 respectively.

BRIEF DESCRIPTION OF DRAWINGS:
[025] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[026] Figure 1: illustrates a process for determining Tc-99m counts present in the thyroid to obtain the Tc-99m pertechnetate thyroid uptake on Gamma Camera and Thyroid Uptake Probe, as per an embodiment of the present invention.
[027] Figure 2: illustrates the procedure used for determining the number of Tc-99m counts present in the thyroid in order to obtain the Tc-99m pertechnetate thyroid uptake on gamma camera. A: raw image obtained in the anterior view, B: For processing of image thyroid region of interest (roi) and background roi were drawn manually,thyroid uptake value calculated using computer algorithm is 10.1 % , as per an embodiment of the present invention.
[028] Figure 3: illustrates procedure used for determining the number of Tc-99m counts present in the thyroid in order to obtain the Tc-99m pertechnetate thyroid uptake on thyroid uptake probe. A. Background counts acquisition of the patient’s neck using lead shield on thyroid uptake probe. B. Thyroid counts acquisition of the patient’s neck using thyroid uptake probe, as per an embodiment of the present invention.

BRIEF DESCRIPTION OF INVENTION:
[029] The present invention will now be described hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. While the following description details the preferred embodiments of the present invention is not limited in its application to the details of construction and arrangement of the parts illustrated in the accompanying drawings. With reference to the figures, the enclosed description and drawings are merely illustrative of preferred embodiments and represent several different ways of configuring the present invention. Although specific components, materials, configurations and uses of the present invention are illustrated and set forth in this disclosure, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein.

[030] The present invention proposes a process for determining Tc-99m counts present in the thyroid to obtain the Tc-99m pertechnetate thyroid uptake. The thyroid Tc-99m uptake was measured using a gamma camera (GE; Millenium MPR) fitted with a (Low Energy General Purpose) LEGP collimator and thyroid uptake probe (Capintec, Inc. Captus 3000 Version1.19).Acquisition procedure for Tc-99m Thyroid uptake calculation comprising of following steps. a) Pre syringe and post syringe counts of measured dose of Tc-99m pertechnetate were taken before and after administration of dose on both gamma camera and thyroid uptake probe; b) At twenty to thirty minutes of intravenous administration of 111-158 MBq (3- to 4-mCi) Tc-99m pertechnetate, uptake was measured on gamma camera and thyroid uptake probe; c) On Gamma camera, static thyroid images were obtained in anterior view while the patient was supine with the neck extended; Image data acquisition was done in 128 x 128 computer matrix (zoom = 1); Counts for injection site were also taken using 128 x 128 computer matrix for 60 secs in order to check for subcutaneous infilteration that could invalidate the uptake calculation; d) On Thyroid Uptake Probe, patients were seated facing the detector, which was positioned 25cm from the anterior surface of the patient’s neck at the level of the cricoid; Counts were obtained in duplicate at the patient's neck for 30 seconds and the patient's background counts for 30 seconds(Figure 3).

[031] The present invention proposes a process, for analysis of Tc-99m pertechnetate thyroid uptake studies involves following steps. On Gamma Camera, a) a region of interest was manually placed over the thyroid on each image; b) The counts per region of interest on each image were corrected for radioactive decay; c) The Tc-99m pertechnetate thyroid uptake was calculated by using computer algorithm provided by the manufacturer for thyroid uptake applications(Figure 2).On Thyroid Uptake Probe, Tc-99m pertechnetate uptake was calculated using the probe inbuilt thyroid uptake software and manual calculations with the following relationship.

[032] The present invention as illustrated in Figure 1 provides another embodiment of the invention which includes a process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake on Gamma Camera and Thyroid Uptake Probe.
[033] The present invention as illustrated in Figure 2 provides another embodiment of the invention which includes a procedure used for determining the number of counts present in the thyroid in order to obtain the Tc-99m pertechnetate thyroid uptake on gamma camera. A: raw image obtained in the anterior view, B: For processing of image thyroid region of interest (roi) and background roi were drawn manually, thyroid uptake value calculated using computer algorithm is 10.1 %.
[034] The present invention as illustrated in Figure 3 provides another embodiment of the invention which includes a procedure used for determining the number of counts present in the thyroid in order to obtain the Tc-99m pertechnetate thyroid uptake on thyroid uptake probe. A. Background counts acquisition of the patient’s neck using lead shield on thyroid uptake probe. B. Thyroid counts acquisition of the patient’s neck using thyroid uptake probe.
[035] In another embodiment, ten of the twenty-seven patients were suffering from grave’s disease, ten with hyperthyroidism, four thyrotoxicosis with multinodular goiter (MNG), one euthyroid, and two thyroditis.
[036] In another embodiment, patients were injected intravenously with Tc-99m pertechnetate of mean activity ± SD; 3.32±0.34 mCi. Activity was measured using a calibrated dose calibrator, before injecting to the patients.
[037] In another embodiment, the mean time taken for the uptake on gamma camera and thyroid uptake probe was 30 ± 10.02 minutes (range 20-52 minutes) and 32.1± 12.65 minutes (range 21-75 minutes).
[038] In another embodiment, the mean uptake values and standard deviation calculated using thyroid uptake probe with computer software and Manual method (8.1±6.1, and 8.06±5.9) were slightly higher than uptake values calculated using Gamma camera (5.8±6.2).
[039] In another embodiment, the correlation (r) between probe and manual uptake, gamma camera and manual uptake, and gamma camera and probe were 0.9947, 0.9691 and 0.9625 respectively.
[040] In another embodiment, the correlation coefficient between all the three uptake methods is very high and shows a positive trend. The uptake values evaluated by the two modalities co-relate well but their mean values are different significantly. However, there is not much difference between the uptake values calculated using the probe software and the manual calculation formula.

[041] In another embodiment, the mean uptake values and standard deviation for the patients using gamma camera (GE; Millenium MPR) fitted with a (Low Energy General Purpose) collimator, calibrated thyroid probe (Capintec, Inc. Captus 3000 Version1.19), and manual methods were 5.8±6.2, 8.1±6.1, and 8.06±5.9 respectively also shown in Table 1.
[042] In another embodiment, comparison of mean (student t test) was used to calculate the significance of difference in the various uptake methods and the values are shown in Table 2. Correlation coefficient was calculated between gamma camera, uptake probe using computer software and uptake probe using manual method and the calculated values are shown in Table 3.

[043] In another embodiment, the uptake probe can be routinely used for thyroid uptake calculation using Tc-99m pertechnetate. But standardization of the thyroid uptake using pertechnetate needs to be performed before putting this for patient’s routine use.

[044] In another embodiment, uptake probe can be routinely used for thyroid uptake calculation using Tc-99m pertechnetate. This can be a simple and fast method for measurement of Tc thyroid uptake using a thyroid uptake probe with added advantages of low radiation dose, easy availability and low cost of Tc-99m pertechnetate. There is a need to establish a normal uptake range of Tc-99m thyroid uptake which could be of significant clinical relevance.
[045] The present disclosure described herein above has several technical advantages including, but not limited to,
? This is a fast process for measurement of Tc thyroid uptake using thyroid uptake probe with added advantages of low radiation dose, easy availability and low cost of Tc-99m pertechnetate.
[046] The disclosure has been described with reference to the accompanying embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.
[047] The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

We Claim:

1. On Thyroid Uptake Probe, Acquisition procedure for Tc-99m Thyroid uptake calculation comprising of following steps a) Pre syringe and post syringe counts of measured dose of Tc-99m pertechnetate were taken before and after administration of dose onthyroid uptake probe; b) At twenty to thirty minutes of intravenous administration of 111-158 MBq (3- to 4-mCi) Tc-99m pertechnetate, uptake was measured on thyroid uptake probe; c) patients were seated facing the detector, which was positioned 25cm from the anterior surface of the patient’s neck at the level of the cricoid; Counts were obtained in duplicate at the patient's neck for 30 seconds and the patient's background counts for 30 seconds; d)Tc-99m pertechnetate uptake can be calculated using the probe inbuilt thyroid uptake software.

2. The process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake using Thyroid Uptake Probe as claimed in claim 1, wherein Tc-99m pertechnetate can be used as an alternate to routinely used Radioiodine (I-131 or I-123) on thyroid uptake probe.

3. The process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake using Thyroid Uptake Probe as claimed in claim 1, wherein uptake probe can be routinely used for thyroid uptake calculation using Tc-99m pertechnetate.

4. The process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake using Thyroid Uptake Probe as claimed in claim 1, wherein this can be a simple and fast method for measurement of Tc-99m pertechnetate thyroid uptake using thyroid uptake probe with added advantage of low radiation dose, easy availability and low cost of Tc-99m pertechnetate.
5. The process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake using Thyroid Uptake Probe as claimed in claim 1, wherein this method can be used in very busy departments where the patient load is very high on Gamma Camera.
6. The process for determining counts present in the thyroid to obtain the 99m pertechnetate thyroid uptake using Thyroid Uptake Probe as claimed in claim 1, wherein this method can be utilized for very sick patients who cannot lie supine on Gamma Camera.