H,Oyieldfragilitywashes. Spleen scanning .... Scanning, Freeman LM and Johnson PM, eds, New York, ... FISCHERJ, WOLF R, LEON A : Technetium-99m as a.
11111/CONCISE
COMMUNICATION
VISUALIZATION OF THE HUMAN SPLEENWITH OOmTC.LABELED RED BLOOD CELLS
w. Eckelman, P.Richards, H.1.Atkins, W.Hauser, andJ.F.Klopper Brookhaven National Laboratory, Upton, New York
of alternation of the cells by stannous ion. We corn pared the osmotic fragility of the normal and altered canine cells with human cells altered to various extents by using 1, 2, and 5 ml of stannous chloride solution in the procedure previously described (2). The results of this study are summarized in Table 1. Addition of 1 ml of stannous chloride to the human red cells did not produce a change in the osmotic fragility compared with that of normal human red cells. However, both 2 and 5 ml of stannous solu alteration of the red blood cells by stannous ion tion produced changes in the osmotic fragility simi would permit a shorter and more sterile labeling lar to that produced in canine cells by 1 ml of stan procedure than the heat treatment of °°“Tc-RBC as nous chloride solution. Also shown in Table 1 are the labeling yields. The proposed by Fischer et al (3). The resuspension of the cells in plasma and the careful heating at 49°C labeling efficiency was found to be independent of with Fischer's method present problems of time, the volume of stannous chloride solution used. With sterility, and reproducibility that can be avoided with the usual small volume of pertechnetate (0. 1 ml) our new procedure. we obtained yields in the range 50—75%, indicating The first clinical trial using amounts of stannous that the yield is related to the intra- and extra-cellular ion sufficient to alter canine cells and produce spleen distribution ratio of pertechnetate and not to the scans produced only slight splenic accumulation. volume of stannous chloride reducing agent. The activity did, however, remain in the blood pool Tin-i 13 recovery studies showed that the use of indicating good labeling stability. After this result 5 mg (5 ml) of stannous chloride left 36% of the we used an in vitro method to determine the degree stannous ion associated with the cells after two Spleen scanning
has supplied
useful information
in many clinical situations. Enlarged or atrophied spleens, accessory or ectopic spleens, space-occupy ing lesions and infarcts are among the abnormalities identified by this procedure (1). A recent paper from this laboratory (2) mdi cated that with the use of stannous chloride, rabbit, dog, and human cells could be labeled with oomTc. Dog cells could be made to be sequestered by the spleen if excess stannous ion was used. We felt that
saline TABLE1. EFFECTOF STANNOUS CONCENTRATiONON HUMAN AND CANINE
RED BLOOD CELLS
ml of‘°@‘TcRecovery in1mg/mIlabelingOsmotictwo salineSnCI,2 . H,Oyieldfragilitywashes Dog cells 0 1.0
of
@Sn
did not increase of radioactivity
—
0.45
42% (2)'f
0.52 0.46
51•/. (1)1' 0.46 0.51
56% (8)j' 73% (2)'f
>99°!. 97°f. 82°!. 64°!.
51•/. (1)t 0.53
68°!.(1)f
Since
the 2 mg (2 ml)
stannous
appreciably
within the next 2 hr.
Serial scintiphotos up to 2 hr showed no localization
Human cells 0.1 1.0 2.0 3.0 5.0
washes.
chloride left only 3% of the stannous ion associated with the cells, it was chosen as the procedure for the next clinical trial. As seen in Fig. 1, this procedure produced splenic uptake. Within 10 mm approximately 15 % of the administered activity accumulated in the spleen and
in the stomach,
thyroid
gland,
liver,
intestine, lungs, or kidneys. A small amount of ac tivity was found in the bladder at 2 hr. The distribution studies shown in Table 2 point out the species difference observed in labeling red blood cells. The labeling procedure takes about 1½ hr to complete. The entire time from the withdrawal Received Jan. 11, 1971; original accepted Feb. 17, 1971.
.
°1. saline
concentration
for
50%
hemolysis
t Numberof experiments performed.
310
of
RBC.
For reprints contact: William C. Eckelman, Medical Ra
dionuclide Group, Dept. of Applied Science, Brookhaven National Laboratory, Upton, N.Y. 11973. JOURNAL OF NUCLEAR MEDICINE
,z,-@ @
..
@
‘@ .-
‘*
FIG. 1. Spleenscan1@/2 hr after1.8 mCi i.v. injection using °°mTc-RBC labeled by method using 2 ml of 1 mg/mI SnCI, 2H,O.
of blood to the completion of the scan is about 2½ hr.
TABLE 2. DISTRIBUTiON OF RED BLOOD CELLSIN DIFFERENTSPECIES
The labeling was performed under sterile condi tions using capped sterile centrifuge tubes. The com plete procedure for human splenic scanning is as
follows: 1. Draw 16 ml of blood from the patient into a syringe
containing
2. Transfer
4 ml of ACD
to a centrifuge
solution.
tube and centrifuge
for 10 mm at 1,500 rpm. Draw 4 ml RBC from the lower layer and add to a centrifuge tube. 3. Add 0. 1 ml O9mTcO—saline solution4. 4. Incubate
Rabbit
blood poo1
Dog Man
blood pool blood pool
. ml
of
1 mg/mI
for 30 mm at 37°C.
solution. (The solution should be prepared imme diately before use and filtered directly
into the red
cell suspension through a 0.22-micron filter.) 6. Shake gently at room temperature for 15 mm. 7. Wash twice with 20 ml isotonic saline.
8. Resuspend cells in 10 ml saline to prevent ag glutination.
Following the guidelines published in the MIRD pamphlets (4—6), we have calculated the radiation dose absorbed
by the spleen based on a 15 % up
take as 0.43 rad/mCi. The splenic radiation dose for 51Cr-altered red cells based on the same assump tions is 4.2 rad/mCi.
Stannous chloride is the only compound used in the labeling procedure that could cause any form toxicity.
The
amount
used
(2 mg)
is,
however, well below an amount known to cause no adverse reaction
( 350 mg/kg)
SnCI,2H5O
(7).
This procedure appears to be simple, safe, and useful for clinical studies of the spleen. See
Ref.
2
for
further
information
concerning
of pertechnetate volume on labeling yield.
Volume 12, Number 6
2 ml Sn@
blood pool bladder spleen blood pool solution
— — spleen
in ACD.
The authors wish to acknowledge the technical assistance of A. Macaulay. This work was performed under the aus pices of the USAEC. REFERENCES 1. JOHNSON PM: The spleen. In Clinical Scintillation Scanning, Freeman LM and Johnson PM, eds, New York, Harper and Row, 1969, pp 414-445 2. ECKELMAN W, RICHARDSP, HAUSER W, et al: Tech
netium-labeled red blood cells. I Nucl Med 12: 22—24,1971 3. FISCHER J, WOLF R, LEON A : Technetium-99m
the
effect
as a
label for erythrocytes. I NucI Med 8: 229—232,1967 4. LOEVINGERR, BERMANM : A schema for adsorbed
dose calculations for biologically distributed radionuclides. MIRD Pamphlet
No 1, I NucI Med 9: Supplement
No 1,
7—14, 1968
5. DILLMAN LT: Radionuclide decay schemes and nu clear parameters for use in radiation-dose estimation. MIRD Pamphlet No. 4, 1 NucI Med 10: Supplement No 2, 5—32, 1969 6. SNYDERWS, FoRD MR, WARNER0G. Ct al: Estimates
of adsorbed fractions for monoenergetic photon sources uni formly distributed in various organs of a heterogeneous phantom. MIRD Pamphlet No 5, 1 NucI Med 10: Supple ment No 3, 5—52,1969 7. FISCHER HW : Colloidal
C
1 ml Sn@
ACKNOWLEDGMENT
5. Add 2 ml of 1 mg/mi SnC122H2Oin ACD
of chemical
0.1 ml Sn@°
on a new hepatolienographic
stannic
oxide
animal
agent. Radiology
studies
68 : 488—
498, 1957
311
