dc.description.abstract |
The present study was carried out with forty patients, twenty each, for
kidney and liver and were categorized in three different age groups of21-30 years,
31-40 years and 41-50 years. The radiopharmaceuticals, 99mTc_DTPAfor target
organ kidney and 99mTc_Tin Colloid for target organ liver were used as the
injected radiopharmaceuticals. Besides the target organs kidney and liver, other
surrounding organs' distribution was also measured.
99mTc_DTPA (Diethylene-Triamine-Pentaacetic Acid) was introduced in
individual human bodies to study the renal function and 99mTc_TinColloid was
introduced to study the liver function in-terms ofbiodistribution and also in-terms
of measuring the cumulative activity, the dose absorbed by different organs of the
body and also by the radiation absorbed dose in the whole body. For interpretation
of the clinical findings pharmacokinetic studies were also performed in kidneys of
twenty patients of different age group. Data of pharmacokinetic distribution of
radiation dose from Tc-99m DTPA were measured in twenty individuals who had
undergone diagnostic process.
The biodistribution of Tc-99m DTPAwas found highest in lungs followed
by kidneys. In lungs it varied from 9.31% to 13.26% and in kidney biodistribution
ranged from 5.68% to 10.28. The lowest biodistribution was recorded in bones of
the body which indicated that the radiopharmaceutical did not move sufficiently
through the more solid part of the body. The biodistribution of 99mTc_Tin Colloid
was highest in liver which ranged between 46.06% and 70.22%, the average value
being 62.58%. It is observed that, most of the radiopharmaceutical remained
concentrated in the liver, which indicates the high affinity of the
radiopharmaceutical to the organ. The lowest biodistribution was recorded in the
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small intestine (SI) which shows a lower affinity of the radiopharmaceutical to the
small intestine.
In case of kidney, the highest amount of 99mTc -DTPA was absorbed in the
target organ kidney which ranged from 0.132 to 0.293rads, the average value
being 0.182 rad. Lowest absorption was recorded in thyroid. This indicated that,
the movement of the radiopharmaceutical varied according to the position of the
organ from the source organ. In case of liver, The highest amount of
radiopharmaceutical was absorbed in the target organ liver, the average value was'
1.2445 rads. Lowest absorption was recorded in bladder.
The radiation absorbed dose in the kidney ranged from 0.0383 to 0.06952
rad per mCi. The mean value was 0.048 rad/mCi. Some variations were observed
in radiation absorbed dose of twenty patients but these variation is not very
significant .The variation may be due to the difference in age group of patients.
The 20 patients were grouped into three categories, 5 being in the 21-30 years age
group, 8 in the 31-40 years age group and 7 in the 41-50 years age group. The
radiation absorbed dose is higher in patients of lower age group of 21-30 years,
followed by middle age group of 31-40 years. The lowest absorbed dose was
observed in older age group of 41-50 years.
The radiation absorbed dose in the liver of the twenty patients ranged
between 0.1909 rads/ mCi to 0.2816 rads/mCi, the mean value being
0.2482 rads/mCi. A little variations were observed in radiation absorbed dose in
twenty patients due to the difference in age group of patients. Among all of them,
37% of patients showed highest radiation absorption who are in the younger
group. This was followed by middle aged patient group which is 33% and the
older group include only 30%. This study indicates that the radiation absorption
was higher in young age patients who are normally much healthier and stronger.
The radiation absorbed dose in adults for Tc-99m DTPA and also for
Tc-99m Tin Colloid was very much within the limit as reported in world
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literature. Dose estimates for the patients, studied at different times included in
this study are in reasonable accord for individual organ doses between different
patients.
The biodistribution of 99mTc_DTPAand dose absorbed in kidney alone/5mci
of the injected dose was also compared. It is obtained that there is similarity in the
trend of biodistribution and dose absorbed by kidney. The patient who showed
higher biodistribution, had higher dose absorption in kidney and vice-versa. This
was same for the comparison between biodistribution of the radiopharmaceutical
and the dose absorption in liver alone due to the injected dose of 5mCi.
A study was undertaken to observe the radioactivity remaining in the body
and its clearance with time. It is found that the three half-lives of the
radiopharmaceutical was observed at 9,90 and 600 min in case of all the samples
taken after 3,5,7 and 11th min of infusion. This indicates that the remaining
activity of the radiopharmaceutical becomes negligible after 10 hrs of infusion and
thereafter the activity becomes gradually cle¥ed. So the patients are free of any
hazardous effect of the radiopharmaceuticals. The obtained result for both the
readiopparmaceutical was very much within the limit as reported before. They are
obviously in agreement with the result obtained by other investigators. |
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