Abstract

IJNM

Indian Journal of Nuclear Medicine

0972-3919

Society of Nuclear Medicine, India

ijnm-19-4-session-008

Session VIII

122004

194153161

Role of ^99mTc-MIBI Dealayed Scintigraphy in the Characterization of Solitary Thyroid Nodules.

Sharma

Rajnish

Mondal

Anupam

Sahoo

Bhatnagar

Parul

*Sawroop

Chopra

M K

Kashyap

Ravi

¹Department of Nuclear Medicine & Medical Informatic, Lucknow Road, Delhi-110054*Department OfCytopathology, Institute of Nuclear Medicine and Allied Sciences (INMAS), Lucknow Road, Delhi-110054

Ref. No: 55RSEND2PO

AbstractObjectives

The aim of this study was to find out if thyroid nodules can be characterized on the basis of retention of MIBI and weather preoperative evaluation of malignancy is possible using this method.

Methods

Technetium- 99m -Methoxy Iso Butyl Isonitrile (MIBI) has been found to be taken up by various tumors including thyroid cancer .We prospectively evaluated 129 patients with cold thyroid solitary nodules on ^99mTc-pertechnetate scintigraphy to evaluate the diagnostic value of ^99mTc-MIBI scintigraphy. Single injection dual phase (30 and 120 min) thyroid scintigraphy using ^99mTc-MIBI was performed in all these patients. In the following days and weeks all patients underwent surgery.

Results

37 out of 45 patients of thyroid carcinoma showed uptake of ^99mTc-MIBI both at 30 and 120minutes.71 outof74 benign nodules showed a significant washout of radiotracer at 120 Mts as compared to 30 Mts. image.

Conclusions

Fine needle aspiration cytology along with delayed ^99mTc-MIBI-scintigraphy ratio appears is useful in preoperative assessment of solitary thyroid nodules.

Key wordsThyroid cancer^99mTc-MIBI scanDelayed scintigraphy.

PET-Medical Cyclotron Facility in India

Soni

P. S.

MGR

Rajan

Ghosh

J K

Medical Cyclotron Facility, BRIT/BARC, C/o TMC, Parel, Mumbai-400 088

Ref. No: 56SPPETF3PO

Abstract

Positron Emission Tomography (PET) is a diagnostic method that creates high-resolution 2D and 3D tomographic images of the distribution of positron emitting radionuclides (mainly produced from a small hospital based Medical Cyclotron) in the body. The first PET- Medical Cyclotron Facility in the Country was installed in our Center in October 2002. There are three principle functions and areas of this facility i.e. cyclotron and support equipment, radiochemistry synthesis laboratory, and quality control (QC) laboratories and support space. The cyclotron accelerates negative ions of H and D to give proton and deuteron beams of 16.5 Mev/75 ìA and 8 MeV/60 ìA respectively, and capable of producing not only the major PET radionuclides but also equally important short-lived SPECT radiotracers. The cyclotron can produce radiotracers include ¹1C (T_1/2= 20 min); ¹³N T₁/2= 10 min); ¹⁵O (T₁/2= 2 min); ¹⁸F (T₁/2= 110 min). These isotopes are used to label compounds in an automatic radiochemistry synthesis modules, which are used as PET tracers in many disease conditions. The cylindrical vertical magnet yoke consisting of 10 cm of steel acts as the primary radiation shield. Experimental measurements indicate that the cyclotron shielding, together with the 2-meter thick concrete wall of the vault, is sufficient to keep the radiation dose level outside the cyclotron vault to a safe level (<1 mR/hr). In public areas, neutron and gamma radiation dose rates are negligible.

The sub-system of cyclotron includes power supplies, water-cooling, targets, precursor chemistry, gas distribution, automated chemistry, shielding (vault), radiation interlock systems andradionuclide transport systems (pneumatic chute). The cyclotron is fitted with 6 targets remotely loaded or unloaded by pneumatic gas pressures. The radioisotopes produced are automatically transported via shielded narrow bored Tefzel tubing from the targets to the chemistry modules in the hot cells laboratory. Synthesis of ¹⁸F-fluorodeoxyglucose is done with the automated computer controlled systems therefore traditional hands-on chemistry is not required. The synthesis modules are housed in 70 mm thick lead shields and radioactive materials are transferred between the cyclotron, synthesis modules and dispensing unit for product distribution via well shielded narrow bored Tefzel. The quality control (QC) laboratory contains the equipment necessary for testing the synthesized radiotracers according to pharmaceutical Good Manufacturing Practices (GMP) and RPC specifications. To ensure this, FDG is dispensed into pre-sterile vials through a 0.22 ìm filter followed by high temperature sterilisation. The automatic dispenser is housed in a well-shielded hot cell. The cyclotron and radiochemistry laboratory area is compliant with clean airflow required by pharmaceutical manufacturing guidelines.

During synthesis, the radioactive gases from the synthesis modules are compressed in the waste gas system till it decay to background level and subsequently released to ventilation exhaust duct system. A gamma area monitor monitors the exhaust pipe and display of the same is kept in the control room. The facility is supplying FDG regularly to RMC and to various other Hospitals viz. Hinduja, Jaslok and Bombay Hospital. Soon, we will also be supplying FDG to TMH hospital.

Key wordsPositron Emission Tomography (PET)PET-Medical CyclotronSPECT Radiotracers.

Patient Hazards in Radiobioconjugate (RB) Therapy

Hazra

Gupta

Hazra

P Khanna

Gangwar

Garg

Sharma

Nuclear Medicine Unit, SN Medical College, Agra-282003

Ref. No: 57SGDMG5PO

AbstractObjectives

To highlight patient safety issues in RB therapy and suggest appropriate measures:

Methods

Safety issues in RB therapy involve consideration of both radiation hazards as well as biohazards. Radiation hazards are relevant for the administration team but not for the patient. Biohazards are important especially for the patient. RB therapy biological moieties may be antibodies, artificial antibodies constructs: so called designer antibodies, peptides, antisense nucleotides, cytokines or other receptor specific molecules, or indeed combination of the two such as peptabodies. There is also the option of using intermediate molecules such as avidin, biotin, chelates to enhance target / nontarget ratios, as well as agents to enhance tumour delivery such as the gamma globulin used by us for blocking nonspecific reticuloendothelial uptake or the various chase agents used to clear the blood of unwanted radioactive or biological moieties. In each case RB therapy is often preceded by RB administration for radiolocalisation and confirming the delivery specificity of the therapy agent, or for patient specific dosimetry. This is sometime performed with the same isotope as contemplated for therapy or a surrogate isotope. In each case the hazard to the patient from the radionuclide moiety and from the various biological molecules used need consideration, although of course basic philosophy is whether the proposed benefit in terms of tumour response or clinical wellbeing overrides patient hazard. Risks from the biological moiety per se are compounded by risk from contaminants such as murine or bacterial products; DNA or proteins or lipopolysaccharides such as endotoxins. Altered methods of producing the biological moiety can reduce the risks such as using transgenic mice/plants but do not entirely eliminate it. Methods of minimizing allergic murine molecule reactions include usage of human/ humanized antibodies; plasmapheresis and immunosuppressive therapy, and reducing the interval between scintigraphic and therapy administration and eschewing intradermal testing.

Results

Modern methods of purifying the pharmaceutical such as multiple chromatography substantially reduce the risk of contamination with the mouse DNA/RNA or mouse viruses. Terminal filters such as endotoxin filters advocated by our group also reduce the hazard from these although utmost care should be taken to avoidintroduction of hazards during radiopharmaceutical preparation. Many of the risks attributed to immmunereactionsare in fact side effects of cytokine release as when using Herceptin. The potential genetic risks from introducing DNA/RNA fragments such as anti sense nucleotides are not yet fully known, but the risks from murine RNA/DNA are infinitesmal and hopefully the former are innocuous and incapable of relication in vivo. Utilisation of universal warhead molecules such as radiolabelled biotin should reduce the logistic and financial problem of using multiple bioconstructs. Using pancarcinoma biological moieties: peptides or antibodies also reduce the risk of contamination. The existence of endogenous biotidinases or allergies to avidin/streptavidin needs to be borne in mind and avoided by appropriate bioengineering.

Conclusions

In summary while one should be aware of patient safety hazards one should not allow it to deny the availability of therapy to patients who need RB therapy.

Key wordsRadiobioconjugate (RB) TherapyPatient Hazards

Combination of Radiobioconjugate Therapy with Other Modalities: Recent Advances

Hazra

D.K.

Gupta

A. K.

Khanna-Hazra

Gupta

Gangwar

P K

Garg

Nuclear Medicine Unit, S N Medical College & Boston Medical Centre, Agra 282005

Ref. No: 58DKRTG6PO

AbstractObjective

To review recent advances in integrating radioimmunotherapy etc with bone marrow transplantation and other oncological modalities

Methods

The role of radiobioconjugate therapy is being expanded with it being deployed in combination with bone marrow/peripheral stem cell transplantation. This permits high dose (say 900 mCi Iodine 131 equivalent) use, single administration(avoiding immune reactions due to HAMA and HACA, and permitting use of murine antibodies) and is successfully being used in Seattle for lymphomas and leukaemias. Can this be extended to solid tumours and the Indian context?

Further use of radiobioconugates just after ablative surgery for preventing or mopping up micrometastases, and use of this modality in combination with small molecules blocking signal transduction in cancer cells is now attracting attention. Together with pre-targetting and universal effector molecules these suggest an expanding clinical role in not only haemopoietic malignancies but possibly solid tumours. Combination with external radiotherapy/anaerobic sensitizers/ hyperthermia to enhance tumour uptake is also being studied at various oncology centres.

Results

Combination therapy of radiolabeled antibodies and bone marrow/peripheral stem cell transplantation have been successfully used by the Seattle group in the Dept of Nuclear Medicine, Washington University Medical School (Prof Eary and colleagues) collaborating with the Fred Hutchinson Cancer Centre. Other combination therapy of radiolabeled antibody with small molecules or taxane chemotherapy/ external irradiation/ radiation sensitisers is showing encouraging results.

Conclusions

These hopefully foreshadow the routine use of this nuclear medicine radiolabelled therapy in combination with other modalities (stem cell transplantation, external irradiation, chemotherapy and surgery) leading to wide spread acceptance and use by clinical oncologists.

Key wordsRadiobioconugatesRadioimmunotherapyMicrometastases.

Estimation of Dose to Patient Joints in Radiation Synovectomy Using ¹⁶⁶Ho Radionuclide

Tandon

Pankaj

Asopa

Ramesh

Malpani

B.L.

Rohatgi

Rupali

Basu

Sandeep

Chakraborty

Sudipta

Venkatesh

Meera

Bhattand

B.C.

Nair

Radiological Physics & Advisory Division, Radiation Medicine Centre, Bhabha Atomic Research CentreRadiopharmaceutical Division, Bhabha Atomic Research Centre

Ref. No: 59TPDMG8PO

AbstractObjective

Radiation Synovectomy, which is a major example of the application of beta particles in therapy, is gaining importance in our country. With a view to calculate the radiation dose received by the joints at various depths, into which ¹⁶⁶Ho radionuclide is injected, the present study was undertaken. This procedure is a mode of radiation therapy, which has been used for more than 40 years to alleviate the pain and swelling of patients suffering from diseases such as rheumatoid arthritis, hemophilia etc. The procedure consists of the injection of a beta-emitting radionuclide into the joint capsule where it makes direct contact with the synovial membrane (synovium). Phagocytic lining cells along the synovial surface quickly absorb some of the injected radioactivity from the capsule, where it remains in contact with the synovial membrane. While the radionuclide decays, absorbed dose is imparted to the synovium, provided the amount of radioactivity injected is sufficiently large to deliver therapeutic dose to the tissue. Tissue, which regenerates over time, is expected to be asymptotic for 2-5 years, and the progression of RA in the joint is thereby arrested. Benefits to patients include increased joint movement and reduced swelling, pain and effusion.

Methods

Radiation dosimetry is an integral part of the therapeutic regimen employing radiopharmaceutical. The purpose of this study was to estimate the radiation dose received by the patient joints treated with ¹⁶⁶Ho radionuclide. The radiation dose measurements were carried out using LiF:Mg,Cu,P TL dosimeters having dimensions 3 x 3 x 0.45 mm³ and calibrated against ¹⁶⁶Ho radionuclide. This study was carried out on 20 patients treated with ¹⁶⁶Ho for knee joints. The activity administered for treating these joints varied between 74 MBq to 292 MBq depending upon the size of the joint and patient condition. After the administration of activity, a plastic sachet containing 4 TLDs was pasted on the surface of the joint before applying bandage. Further, instructions were given to patients to remove the sachet only after a week. These TLDs were measured using conventional TLD reader system and the dose in mGy was evaluated after applying the calibration factor.

Results

It was observed that in many cases the surface dose received was in the range of 0.03 - 0.06 mGy/MBq while in few cases the doses were as high as 0.16 to 0.24 mGy/MBq. The variations were due to the variations in the size of the joint. In order to estimate the dose directly to the synovial membrane, the depth of the joint capsule has to be determined by an appropriate method. Diagnostic tool such as MRI give accurate results, but would be expensive. Once the depth of the joint capsule is known, the estimated dose can be corrected for the same depth. The correction factor at various depths has already been calculated by us, using the specially designed joint phantom. The estimation of radiation dose corrected for joint depth is very important for clinician to decide the future course of action for the management of the patient with inflammatory joint diseases.

Key wordsRadiation Synovectomy¹⁶⁶Ho radionuclideRadiation Dosimetry.

Doses Received from Various Indigenously Produced Renal Agents

Tandon

Pankaj

¹Joshi

Sangeeta H.

*Bhatt

B.C.

¹Venkatesh

Meera

¹Radiological Physics & Advisory Division, BARC, Trombay - 400 085*Board of Radiation and Isotope Technology, Mumbai

Ref. No: 60TPDMG7PO

AbstractObjectives

Renal agents such as ^99mTc based DTPA, GHA and EC supplied by BRIT are being commonly used by various Nuclear medicine centres in India. In the common interest of the Nuclear Medicine Physician and the supplier, it is important to have the knowledge about the doses received by the organs of interest apart from the clinical information obtained from these radiopharmaceuticals. This study was undertaken with the view to provide such information along with the kits supplied by BRIT. The estimation of doses delivered by different renal agents to the target and non-target organs in Indian reference man have been carried out.

Methods

Doses have been estimated based on the animal studies. Biodistribution of these radiopharmaceuticals were carried out at different time points from 15 min. to 24 hours in normal adult animals. The organs of interest such as kidneys, liver, intestine, bladder, tail and the carcasses were collected and the percentage uptake was measured for each time point. Assuming that the radiopharmaceuticals undergo similar metabolism in human and the laboratory animals, the percentage uptake obtained in latter were applied to the Indian reference human and the doses were calculated theoretically. Mean dose per unit cumulative activity, the average weights of the organs in Indian reference man and all the energies of ^99mTc with their abundance were considered while calculating the doses.

Results

It was observed that the cumulative radiation dose to the kidneys in 24 hours due to DTPA, EC and GHA were 3.65E-03,1.37E-02and4.82E-01 mGy/MBq whereas the liver received 1.36E-03,5.97E-03 and 3.50E-02 mGy/MBq respectively.

Conclusion

Key wordsIndian Reference HumanCumulative Radiation Dose^99mTcDTPA^99mTcGHA^99mTcECIn-Vitro & In-Vivo Experiments on Selective Uptake of 99mTc- INH & 99mTc-EMB in Resistant Strains of Mycobacteria.SinghNamrataGulatiMohitBoseMridulaBhatnagarAseemSinghA.KRavindranathT.Institute of Nuclear Medicine and Allied Sciences, Brig. S.K.Mazumdar Marg, Delhi-54, India.

Ref. No: 61NS RP H25 PO

AbstractObjectives

Use of Nuclear Medicine technique can be helpful in diagnosing TB at an early stage very specifically. Aim of the present work is to use this technique by means of labeling INH & EMB with ^99mTc & using these radiolabelled drugs for detecting and localizing TB at an early stage in any anatomical site. Isoniazid (INH) & Ethambutol (EMB) were chosen as ligands because they are specific anti-tubercular drugs (interacts specifically with cell wall mycolic acid of Mycobacterium).

Materials and Methods

Radiocomplexation of INH & EMB with ^99mTc was worked out and standardized using stannous mediated reduction of technetium. Labeling efficiency, in-vitro and in-vivo stability, blood kinetics, biodistribution of complex were studied in balb/c mice and New Zealand White Rabbits. Post labeled biological activity of INH & EMB was studied by MIC studies, Drug uptake, Colony Forming Unit (CFU) assay of both sensitive & resistant M.tuberculosis, on solid media (Middlebrook 7H10 Agar, DIFCO). Thigh model of localized TB lesion was prepared in four rabbits by injecting 500ml of 3 x 10⁸ cells/ml of Mycobacterium tuberculosis (Clinical Human Isolate) live, resistant bacteria in growing phase. The localization kinetics of the radiolabeled complex was studied separately in the developed animal model by injecting 70-75MBq of ^99mTc-INH & ^99mTc-EMB intravenously and the images were taken with a Gamma-camera (ECIL). Human trails are being performed.

Results

Labeling efficiency of ^99mTc-INH & ^99mTc-EMB was found to be >95% & >85% respectively. Only 2-3.5% of the tracer leached out from the complex even at 24 hrs when incubated in serum at 37°C, confirming its high stability. Blood kinetics studies exhibited biphasic pattern and 50% of ^99mTc-INH & 66% of ^99mTc-EMB cleared from the blood within 5 min of the post administration. Bio-distribution studies showed the renal and hepatobiliary route of excretion of ^99mTc-INH & ^99mTc-EMB. No gastric/thyroid activity was noted suggesting a high labeling efficiency and in-vivo stability. Similar results of CFU assay of ^99mTc-INH & native INH as well as ^99mTc-EMB and native EMB suggested no loss in biological activity of INH & EMB after labeling. MIC study showed that higher concentration of drug is required to inhibit the growth of resistant forms of Mycobacterium tuberculosis. Higher drug uptake was seen in the resistant forms and the colonies increased in 48 hrs of drug treatment. Cold abscess was visible at the site of injection of bacteria in rabbit. Cytopathology, PCR, RTPCR and in-vitro culture of the aspirate further corroborated this observation. ^99mTc-INH & ^99mTc-EMB accumulated differentially in the lesion in all rabbits as early as 2 hours post administration, which increased at 4 hours and was maintained till 24.Normal biodistribution of both drugs and its localization in lesion in case of human patients is being observed.

Conclusions

The results of animal as well as human studies suggested that ^99mTc-INH & ^99mTc-EMB are viable, potential and cost effective agents for early diagnosis of resistant tuberculosis.

Key wordsAnti-tubercular drugsTc-99mInfection Imaging

Parameters Affecting the Adsorption Efficiency of Prussian Blue for Radioactive Thallium

Bhardwaj

Nidhi

Mittal

Gaurav

Bhatnagar

Aseem

Pathak

D P

^#Singh

A K

Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Mazumdar Marg, Timar Pur, Delhi-110054^#Department of Pharmaceutical Sciences, Guru Jambheshwar University, Hisar, Haryana

Ref. No: 62NBRPH26PO

AbstractObjectives

Prussian blue has been used as an effective antidote against nonradioactive thallium poisoning. Prussian blue (PB) acts by the adsorption, ion exchange and/or the mechanical trapping of monovalent ions like thallium, cesium, and potassium etc. The recommended dose of insoluble PB is 3 grams orally three times a day in case of thallium/cesium contamination. However, the efficacy of PB depends upon the different physicochemical parameters, which have not been adequately defined in the literature. In the present study, experiments were designed to study the effect of various factors such as pH, concentration of PB and Tl-201, particle size of PB on the decorporation efficacy of PB for Tl-201.

Methods

Adsorptive capacity of PB for Tl-201 was studied in the presence of potassium and sodium. Prussian blue was taken in water and 1.4 MBq of Thallium-201 was added. The system was agitated at room temperature. Radioactivity of the supernatant was measured by gamma ray spectrophotometer at different time intervals. Adsorption capacity is defined as the ration of the radioactivity in the test to the radioactivity in the control. PB has been found to be more effective at basic pH with adsorption capacity of 95.35% rather than 35.32% at pH2.

Results

These results indicate that PB would be less effective in stomach as compared to intestine. However, from duodenum to large intestine, as the pH increases, the adsorption capacity increases. Increase in temperature showed an increase in the adsorption capacity. Negligible change was observed in the adsorptive capacity of PB in the presence of potassium and sodium, suggesting that in vivo the gastrointestinal Na⁺/K⁺ content does not alter the efficacy of PB for Tl+/Cs⁺. Adsorption capacity of PB was found to be dependent on the MBq of thallium-201. 1 mg of PB adsorbed 92.67% of 1.4 MBq than 79.42% of 5.6 MBq Tl-201.

Conclusions

The observations and results indicate that the decorporation efficacy of PB can be enhanced by monitoring different parameters. Further work for the optimization of the dose of PB is in progress.

Key wordsDecorporation EfficacyThallium-201Prussian Blue

^99mTc-Alendronate: A New Generation Phosphonate for Bone Scintigraphy

Singh

Bhardwaj

Bhatnagar

Singh

A. K.

Rawat

Sahoo

INMAS, Brig. S.K. Mazumdar Marg, Delhi-110054, India

Ref. No: 63TSRPH27PO

AbstractObjective

^99mTc MDP & HEDP are the conventional bones scintigraphy agents widely used for the last 35 years. Since then, a variety of new phosphonates (e.g. Alendronate) have been synthesised which have commercially replaced the older phosphonate (MDP & HEDP) because of their higher efficacy in bone disorders by more than 500 times. We have aimed to prepare and evaluate ^99mTc -Alendronate, with a view that the new radiopharmaceutical may have better bone imaging properties compared with the conventionally available agents.

Methods

Ready to use Alendronate kits were produced using stannous chloride reductant method and characterized by ITLC-SG paper choromatography. The kit underwent extensive in-vitro and in-vivo quality control tests in animals followed by phase-I human trial.

Results

More than 97% radiolabelling was consistently achieved with stability established upto 6 h post preparation. Serum studies showed about 45% binding and stability of preparation upto 24 hrs. Animal bio-distribution and faster blood clearance data supports similar bone uptake and faster blood clearance compare to ^99mTc-MDP. Bone scintigraphy in humans suggests that adequate high bone to soft tissue ratio with ^99mTc-Alendronate occurs at 90 min. Advantages of the new pharmaceutical over conventionally used bones scintigraphy agents will be discussed.

Conclusions

The gathered data so far suggests that ^99mTc-Alendronate has the potential to become an important bone-imaging agent because of its easy availability and cost-effectiveness.

Key wordsAlendronate^99mTcBones Scintigraphy.

Four Consecutive Cases of Pagets Disease of Bone Diagnosed on ^99mTc-MDP Scan: Significance of Skeletal Scintigraphy

Narayan

Manishi L

Sudhakar

Pushpalatha

Swamy

V.K.

Gopal

Pradeep

Rao

VVS Prabhakar

Department of Nuclear Medicine, Nizam's Institute of Medical Sciences, NIMS, Punjagutta, Hyderabad: AP, INDIA.

Ref. No: 64MNSKJ4PO

Abstract

Paget's disease (PD) of the bone is characterized by excessive bone turnover by activated osteoclasts in localized parts of the skeleton. The remodeled bone is abnormal in structure & mineralization resulting in deformity, increased risk of fracture and other complications..The prevalence of the disease is around 2% in patients over 55 years of age. Although, the precise etiology of Paget's disease is unknown but there is strong evidence for viral infection, and recently a genetic disposition has also been reported. Pathologically, three phases of disease have been described; the lytic (incipient-active) phase, mixed (active) and the blastic (late-inactive) phase. For diagnosis of PD, radiography, skeletal scintigraphy and biochemical markers are necessary .Role of skeletal scintigraphy is well established in PD. Radiographically pagetoid lesions can be detected only if the 30-40% of bone is resorbed. In addition, elevated bone alkaline phosphatase level, considered as an important marker to reflect the disease activity may be normal in many of the symptomatic cases.

We describe four cases of polyostotic Pagets disease diagnosed on skeletal scintigraphy with varied lesions in different phases of evolution, not detectable on radiography and with rare sites of involvement.

Case 1

53 yr old lady after being evaluated for atypical chest pain & backache, referred for bone scan to rule out osteomyelitis involving ribs. ^99mTc-MDP whole body bone scan (BS) revealed diffusely increased tracer uptake involving right hemi pelvis and skull characteristic of Pagets. Radiographs performed later did not show any abnormality in skull, however, frontal radiograph of pelvis revealed thickening of right iliopectineal line & sclerosis of right hemi pelvis.

Case 2

Recently diagnosed case of Carcinoma breast, bone scan was performed for preoperative staging purpose. Scintigraphy showed polyostotic involvement with diffusely increased tracer uptake in skull, intense uptake in right hemi pelvis and right proximal femur. Radiographically, skull lesion was unremarkable; however, pelvis radiograph showed sclerosis.

Case 3

64 yrs. male patient presented with history of pathological fracture of tibia with Pagetic involvement. Scintigraphy revealed multiple other sites in addition to typical flame shaped pattern of uptake involving right tibia.Diffusely increased uptake of varied intensity was seen in skull, vertebrae, spine of scapula ,right hemi pelvis as well as a rare site of Pagetic involvement in periphery i.e right calcaneum.

Case 4

Also presented with pathological fracture of tibia. Scintigraphy shows polyostotic involvement with intense tracer concentration in characteristic pattern involving scapula, lumbar vertebra, left hemi pelvis and rare sites of disease i.e., fibula and ribs in addition to left tibia, known site of pagetic involvement.

Scintigraphic visualization of lytic phase is uncommon, but in our series two cases with skull lesions were detected in early stages (mixed lytic and early blastic phase) of disease with no radiographic abnormality .Most of the other lesions detected, were in sclerotic phase of disease. In literature, pagetic involvement of peripheral bones is described as rare; however here, one case showed involvement of proximal fibula and ribs and another one with calcaneum. Skull (3/4) and Pelvis involvement (4/4) was most common, pelvis was involved in all with propensity for right hemi pelvis (3 out of 4) compared to left hemi pelvis involvement (2 cases, in one b/l involvement) . 2/4 cases showed advanced involvement of tibia with pathological fracture. In two cases vertebrae were also involved. Quantitative lesion to normal bone ratio was varying between: 3:1 to 30: 1.which can be of immense use to assess the response to therapy.

Conclusions

In our series of cases skeletal scintigraphy helped in diagnosis of PD even in early stages, established the involvement of multiple sites other than known sites, reflected the disease activity and hence assisted in prognosis & treatment planning. To conclude, present study reinforces the indispensable value of skeletal scintigraphy in Pagets disease.

Quantitative Nuclear Medicine Procedure in the Evaluation of Osseous Integration Process of Endosseous Dental Implant—An Initial Experience

Mondal

Anupam

Bhatnagar

Parul

Sharma

Rajnish

Swaroop

Dutta

Meeta

*Bhandari

S.K

*Ravindranath

Division of Nuclear Medicine & Medical Informatics, Institute of Nuclear Medicine and Allied Sciences (INMAS), Lucknow Road, Delhi-110054*Department of Dental Reaserch, Institute of Nuclear Medicine and Allied Sciences (INMAS), Lucknow Road, Delhi-110054

Ref. No: 65AMSKJ5PO

AbstractObjective

To evaluate the integration process of endosseous dental implants (Titanium) by using quantitative bone SPECT.

Methods

15 patients undergoing titanium implantation procedure were evaluated by bone SPECT before loading and at a regular interval upto six months after loading. The osteoblastic activity at implant site was compared with the activity within the skull. Hence the osteoblastic activity index (AI) was derived.

Results

A time activity curve obtained by plotting AI against time over 4-6 months showed three distinct phases of osteoblastic activity- (1) A rise reflecting post operative changes, (2) Maximum activity at 4-6 months after loading (3) Gradual fall in the AI suggesting a return towards pre-implant levels

Conclusions

Nuclear Medicine/SPECT has a role in assessing the normal edentate jawbone before and subsequently after titanium dental implants. The activity index-AI (Time activity curve) derived raises few possibilities: a) A smooth healing process, b) The optimum time for loading c) An infective stage during the course of healing, d) an outright unsuccessful outcome at an early or later stage.

Key wordsEndosseous Dental Implant TitaniumActivity IndexSPECT

Diagnosis of Rare Congenital Liver Disorder by Hepatobiliary Imaging: A Case Report

Ref. No: 66MSHBJ6PO

Abstract

Caroli's disease is a congenital dilation of peripheral intrahepatic biliary ducts. Dilation usually involves the entire liver but cases limited to one lobe or segment are not uncommon.

A 12 yrs old male child presented with progressive abdominal distension, intermittent low grade fever and dull aching pain in right hypochondrium of 05 y duration.

USS, CT and MRI of liver revealed multiple dilated cystic lesions involving both the lobes of liver. However cystic dilatations were so big that none of the above mentioned modalities were able to differentiate whether the cystic lesions are due to polycystic liver disease/multiple hepatic cyst or biliary duct dilatation.

Patient was referred to Nuclear Medicine Department for confirmation of diagnosis. Hepatobiliary scintigraphy carried with 111MBqofIV^99mTc-Meberofenin. Sequential images were acquired at 15 min, 30 min, 4 h and at 24 h.

Images demonstrated multiple photon deficient defects in the early parenchymal phase, which subsequently 'fill in' in delayed images due to pooling of the trace in the dilated ducts and persisted for longer duration.

It is essential to demonstrate the communication between the cystic duct dilatation and bile duct system in order to differentiate Caroli's disease from polycystic liver disease or multiple hepatic cysts.

Hepatobiliary scintigraphy confirmed the communication of dilated cysts with the bile ducts and thus helped in clinching the diagnosis.

Comparative Evaluation of Micro Leakage with Different Types of Composite Resins: Using Radioisotope an In-Vitro Study.

Misra

Mridula

Agarwal

Chandrawati

Das

U. K.

Dr. R. Ahmad Dental College and Hospital, Kolkata*Department of Nuclear Medicine, Indian Institute of Chemical Biology, Kolkata-700 032

Ref. No: 67MMDEJ17PO

AbstractObjectives

The aspect of micro-leakage has been the constant focus of attention in assessing the success of any restorative material used in the oral environment. In this study, different types of composite resins that varied according to the size, weight, and volume in their filler patches were used. Composite resin is a restorative material that enjoys the pre-eminent position in the modern practice of dentistry. In the present study carious cervical lesions were used for restoration. These cervical lesions represent a difficult challenge to the dental progression because they are the most common, and it is likely their prevalence will increase as the nation's population ages. Therefore this study makes an effort to compare marginal micro-leakage taking different types of composites that varied according to filler content (by weight or volume) in class V cervical cavities using radioisotope solution.

Materials and Methods

60 extracted human permanent anterior teeth were taken. Class V cavities were prepared. Cavities were restored with different types of composite resins. Subjected to thermo cycling and radioisotope solution ¹²⁵I penetration for the predetermined period of time, the teeth were sectioned labiolingually. Gamma counting was performed. Further assessments were done by auto radiographs.

Results

When statistically analyzed and compared amongst the group, it was found these cavities restored with pack- able/ condensable composites i.e. Gr. A gave the least amount of leakage followed by hybrid composites i.e. Gr. B which in turn followed by micro-pilled composites i.e. Gr. C.

Conclusions

Thus both 'F' test and't' test produce similar results i.e. Gr. A has the lowest average value which is significant compared to both the Charisma (B) and Durafil (C) at 5% and 1% levels of significance respectively. However, Charisma (Gr. B) does not differ significantly (P> 0.05) with one another.

Key wordsMicro-LeakageComposite ResinsCavities.

Comparative Evaluation of Apical Micro Leakage of Different Obturation Techniques Using Gutta-Percha: An In Vitro Study Using Radioisotope

Misra

Mridula

Bera

Swarupananda

Das

U. K.

Dr. R Ahmed Dental College and Hospital, Kolkata*Department of Nuclear Medicine, Indian Institute of Chemical Biology, Kolkata-700 032

Ref. No: 68MMDEJ18PO

AbstractObjectives

The Washington study of endodontic success and failure suggests percolation of peri-apical exudates into the incompletely filled canal as the greatest cause of endodontic failure, nearly 60% of the radicular space. This study has been undertaken to compare the apical microleakage of different obturation techniques i.e. lateral condensation gutta-percha technique, vertical condensation gutta-percha technique, thermafil gutta-percha technique and injection thermoplasticized gutta-percha technique using radioisotope ¹²⁵I.

Materials and Methods

Freshly extracted human anterior teeth were used for the study. Sixty teeth were selected from the collected samples. To remove any organic debris the teeth were submerged in 5.25% NaOCl for 8 h, and then washed with tap water for one hour and subsequently stored in normal saline solution until used. Biomechanical preparation was done by crown-down technique using profile rotatory systems. All root canals were irrigated with 5.2% NaOCl and dried with paper points before obturation. The teeth so prepared were divided into 4 groups consisting of 15 samples each and were named Group I to Group IV. Group I samples were obturated by lateral condensation technique. Group II samples were obturated by thermafil gutta-percha obturation technique.

Group III samples were obturated by vertical condensation techniques.

Group IV samples were obturated by Injection thermoplasticized gutta-percha obturation technique.

The specimens were then immersed in NaI (Sodium iodide) I¹²⁵ solution for 48 hours. Strength of 2-3 micro curie/ml was used for micro-leakage study. Individual samples were then put into the dose calibrator (ATOM LAB 100^TM). The count measurements were performed in well type Gamma counter (Electronic Corporation of India Limited) for period of 10 s and an average of 3 readings were taken for each specimen.

Results & Conclusion

The average micro-leakage value was lowest (2000.4 micro curies) in Group L followedby Group II (2020.87 micro curies), Group m (2046.60 micro curies) and Group IV (2064.73 micro curies). No statistically significant difference in leakage found between the four methods of obturation when a common sealer was used.

Key wordsApical MicroleakageGutta-PerchaEndodontic Failure

^99mTc INH Human Studies: Initial Results

Datta

Mita

Singh

Namrata

Sawroop

Singh

Kashyap

Bhatnagar

Division of Nuclear Medicine & Medical Informatics, Institute of Nuclear Medicine and Allied Sciences (INMAS), Lucknow Road, Delhi-110054.

Ref. No: 69MDRPH29

AbstractAims and Objectives

We recently prepared and standardized a ready to use Isoniazide (INH) kit for Specific tubercular bacteria imaging. After confirming high radiolabel and stability of the kit and relevant animal experiments, this human study was planned after obtaining Institutional Ethical Committee clearance as a phase I study.

Materials And Methods

Eight adult patient volunteers with suspected or proven active soft tissue or bony tubercular lesion were recruited for the study. No prior fasting of the patients was done, nor were the medications (including ATT) stopped. 15 mCi Tc-99m INH was injected intravenously through a slow bolus and whole body and spot images were obtained at 1, 4 and 24 hours. In some patients, SPECT-CT imaging was done of relevant reasons. The patients were monitored clinically for the period of study. The images were analyzed for general biodistribution of the tracer, dynamic changes in the biodistribution, evidence of tracer breakdown if any, and interpersonal variability. Additionally, the radiopharmaceuticals uptake at the site of known / suspected lesions was studied.

Results

None of the 8 patients reported any of the adverse reactions passively or after active inquiry. Vital signs remained normal in the study period .The salient feature of biodistribution included hepatobiliary and renal excretion with significant lung uptake (compared to a non-specific agent like ^99mTc pertechnetate). No stomach was visualized, there was no brain uptake. A similar pattern was noted in all 8 volunteers. Lesion uptake was evident in many cases.

Conclusion

Tc-99m INH is a new potential agent for specific tubercular imaging in humans. Phase II efficacy trials are now in progress.

KeywordsInfection ImagingRadiolabeled antibiotics

Effect of Temperature, Humidity and Distance on Uniformity of Gamma Camera in Daily Routine Work

Kumar

Neeraj

Rawat

Harish

Devi

M. Memita

^#Kashyap

Ravi

Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences (INMAS), Timarpur Delhi-54^#NMR Research Center, Institute of Nuclear Medicine and Allied Sciences (INMAS), Timarpur Delhi-54

Ref. No: 70NKINF4PO

AbstractAim

Uniformity is an important tool in imaging. Temp and humidity are two important aspects, which strongly affect the uniformity. Here our aim is to find out the effects of temp and humidity on the uniformity in the routine work with Gamma Camera. We wanted also to see the effect of distance on the uniformity.

Material and Methods

Uniformity of a SPECT - Hawkeye Gamma Camera was checked daily prior to starting clinical work. Observation was made from May 2004 to Sept 2004. Working parameters in the room like the general cleanliness, room temperature, background radiation (during performance of daily Quality Control protocols) etc., were kept constant. The camera was kept on for 24 h on electricity with 24 h battery and UPS backup. Relative humidity was noted during each acquisition. Dehumidifier was used only after Quality Control acquisition during patient studies. Voltage input was kept strictly constant using UPS and standard inbuilt hardware provided by the vendor.

Acquisition Protocol

4000K count was acquired with the Co-57 flood source with count rate of approximately 14 k counts/s. We used 84 days data from May to Sept for dual headed Hawkeye Gamma Camera and 24 days data for single head Gamma Camera in the month April, May & August. Flood uniformity was calculated by software supplied by the vendor. Variability in the uniformity and the effects of ambient temp and humidity were then analyzed using standard mathematical methods. To see the effect of distance, the source was kept on one of the heads. After each experiment the heads the source was kept on the other head the experiment was repeated.

The following parameters were checked during the daily Quality Control Acquisition: Differential CFOV, Differential UFOV, Integral CFOV and Integral UFOV. The mean and standard deviations were taken for each parameter. To show the significant change, we know that the significance parameter (p-value) should be less then 0.05.

Results

In a single headed Diacam Gamma Camera there was no significant change in uniformity within the range of 22-32 °C, since the calculated p-value for this was greater than .05. However, for the data of April, May and August for humidity, the p-value was less than 0.05. The p-value shows that all 4 types of uniformity changed in different months. Similarly, for dual-headed SPECT Gamma Camera, the uniformity changed from April to September. This uniformity changes were noted in both heads. The data shows that the Head which was fixed at a distance greater than the other one gave better uniformity values, because the mean ± standard deviation of the uniformity values of this head was found to be smaller than the other.

Conclusions

the result shows that in the range from 19 - 30°C, the temp has no significant effect on the uniformity in the daily routine work, since the p value was greater than 0.05. Since the humidity was different in different months it affects the uniformity. From the results, we could say that the distance also affects the uniformity.

Key wordsGamma cameraQCuniformity