Abstract. A radioisotopic method was used to evaluate the state and dynamics of the lymphatic system in 92 patients affected by chronic oedema of the limbs and ...
I~k::~,'Jr
European I~11 Journal of I ~lll.,11~.Pl~3,1F...4./
Eur J Nucl Med (1988) 14:88-92
Medicine
© Springer-Verlag 1988
Quantitative lymphoscintigraphy M. Carena 1, R. Campini i, G. Zelaschi i, G. Rossi 2, C. Aprile l, and G. Paroni z 1 Department of Nuclear Medicine, Fondazione Clinica del Lavoro, 1-27100 Pavia, Italy z Department of Vascular Surgery, Istituto di Ricovero e Cura a Carattere Scientifico, Policlinico Ospedale S. Matteo, 1-27100 Pavia, Italy Abstract. A radioisotopic method was used to evaluate the state and dynamics of the lymphatic system in 92 patients affected by chronic oedema of the limbs and in 12 control subjects. After interstitial injections of 99roTe-sulphur microcolloid, scans were obtained using a LFOV camera linked to a data processor. The quantitative indices of clearance and lymph node uptake obtained showed good correlation with lymphoedema etiology, controls and ostensibly healthy limbs of patients affected by monolateral disease. In conclusion, quantitative lymphoscintigraphy appears to be a feasible indicator of early changes in the lymph pathophysiology and supports the hypothesis that lymphoedema generally arises from a predisposing congenital pathology. Key words: Lymphoscintigraphy- 99mTc-sulphur microcolloid - Limb oedema
Although the commonly accepted test for the evaluation fo the lymphatic system is the Kinmonth (1954) traditional radiological lymphoangiography, there exists a need for a non invasive method which could be easily repeated, free of any complications, suitable for the investigation of lymph formation and drainage dynamics and of lymphonodal morphology. As a consequence, we intend to evaluate the clinical benefit of a quantitative radioisotopic technique through the study of: A) cronical oedemas of limbs B) lymphoedema pathogenesis Colloids, when injected intradermically, are removed and conveyed with the lymph along the lymphatic vessels which drain the injection site (I.S.) and are partially held in the intercalary lymph nodes. It is likely that the clearance and distribution of a radioactive colloid, subcutaneously injected, reflect the physiological state of the lymphatic system (Anghileri 1967; Croll et al. 1983).
Materials and methods Patients Lower limbs. The subjects undergoing testing are divided
into three groups: 1) Fifty one patients (64 limbs, 6 males Offprint requests to: M. Carena
and 45 females of average age 39 years, range 11-78 years) affected by prevalent lymphatic pathology, with sure exclusion of infections etiology in progress, neoplastic, traumatic or iatrogenic. 2) Twenty six patients (35 limbs, I male and 25 females of average age 43.8 years, range 18 75 years) affected by prevalent venous pathology (previous thrombophlebitis and/or positive doppler examination for venous insufficiences). 3) Eight healthy volunteers (16 limbs) definitely free from lymphatic and/or venous pathology (3 males and 5 females of average age 40 years, range 2z1~59 years). Upper limbs. These subjects are divided into two groups. 1) Fifteen patients (1 male and 14 females of average age 58.2 years, range 46-76 years) with monolateral lymphoedema, of which 13 were diagnosed after homolateral mastectomy and 2 were of unknown origin. 2) Four healthy volunteers (2 males and 2 females of average age 30.2 years, range 22-57 years). Using an insuline syringe, 0.1 0.2 ml of tracer, corresponding to 18-20 MBq 99mTC microcolloidal sulphide (Lymphoscint Solco) with a particle diameter less than 50 nm (Pedersen and Kristensen 1981) was injected into the interstitial space of the interdigital plicae (1st and 3rd). The radiopharmaceutical preparation was checked for free pertechnetate by thin layer chromatography and the labeling yield was always greater than 95%. Scintigraphic scans employing a LFOV gamma camera (Gammatone T 9000 CGR) equipped with a high resolution collimator, were taken at time zero at the injection site and after 1 and 6 h at the injection site and draining lymph nodes. The images, stored on the computer fixed disk (IMAC 7310 Adac) in a 128 x 128 matrix were retrieved afterwards for data analysis involving selection of ROls (regions of interest) defining the draining regional lymph nodes (RL) and delimiting the full field of view, as far as the injection site (IS). For each area, the activity corrected for physical decay and expressed as a percentage of the activity found on IS at time zero was determined. The weekly examinations were preceeded by general quality control procedures on the gamma camera. Besides checking the precision of our instruments, we carried out repeated measurements with a cotton phantom soaked in
89 %
Q
16 30
i m m i l
15 m
i
125 U I
I
e l m
B i
I
u m l
m I
n i
10 %
75 i
I
I
I
Fig. 1. Lower limb; distribution of percentage of microcolloid drained from IS after 1 h with patients at rest in the three groups of limbs considered. C: control; L: lymphoedema; V: venous oedema, P=ns
eel
5 CL
i l l
i i B i l l m m m m m i i l l R i • m
i g l l m
25 i m l ~ i i N
n N i m l m m m m l i m l i g n l m m m i l m i n • u • m •
i n i n m l B i i m
0 V
cases
%
50 i
£1_
32.5 30 27.5 o u r 25 , . . 22.5 2O 17.5 15 12.5 10 7.5 "
u • .
i n n
m w m u n n n n n l o m m a i m m o | u l n n | u
iiiiiiii221...
5 2"50
ii
. . . . . .
cases
C
radiocolloid, at different distances from the collimator surface and at different places in the field o f view. W e usually obtained a count rate of 2000 cps from the patient and the s t a n d a r d deviation of the measurements was always within the statistical fluctuation, which, for a preset count of 100 K counts, was less than 0.4%. The measurements were always carried out at a distance o f 40 cm from the collimator, along the perpendicular line passing through its center. In order to check the counting stability o f the g a m m a camera at 0,1 and 6 h after injection, every measurement was immediately preceeded by counting a reference source with the same activity given to the patient, these never showed variations greater than 3 %. N o corrections were m a d e regarding the different counting geometry and depth o f l y m p h nodes. The following p a r a m e t e r s were calculated: 1) T1 and T6: percentage o f tracer removed by IS after 1 and 6 h respectively. Passive drainage is indicated by T1 as the subjects under study were kept at complete rest during the first hour. Afterwards the patient was invited to follow n o r m a l activity until 6 h, thus T6 includes a muscular skeletal contribution. 2) M T 6 is the tracer percentage removed every h o u r from IS between I a n d 6 h, this d a t u m was considered as a clearance index.
Fig. 2. Lower limb, distribution of percentage of the tracer removed from IS after 6 h (patients were invited to walk freely between 1 and 6 h. C: control; L: lymphoedema; V: venous oedema; P 2 0 % in 87% o f control subjects (Fig. 2, Table 1), it is also < 2 0 % in 90% o f the limbs classified under prevalent lymphatic p a t h o l o g y ( P < 0 . 0 0 1 ) . It shows a various course in venous oedema, n o t significantly different to those o f the controls. - The drainage percentage per h (MT6) (Table 1) is > 2.5 in 94% o f the control subjects and < 2 5 % in 83% o f the l y m p h o e d e m a s (P < 0.001). In p h l e b o e d e m a it shows a varied course, but the difference is significant in c o m p a r i s o n to the controls (0.001 < P < 0 . 0 1 ) - The l y m p h o n o d a l u p t a k e (EU) (Fig. 3, Table 1) at 6 h was always > 10% in all control subjects; < 10% in 98% o f l y m p h o e d e m a s a n d 91% o f oedema with a venous corn-
90 % lO
8 75 7 65
6 5 45 4 g ,j
35 3 25 2
I= I
I
n i
I
Fig. 3. Lower limb; distribution of percentage values of the tracer retained by the lymph nodes after I h in the three groups of limbs considered. C : control; L: lymphoedema; V: venous oedema; P
