Biology 219

El 850 Asymptomatic brain metastases (BM) in small cell lung cancer (SCLC): Is MRI useful at initial diagnosis?

M.M.H. Hochstenbag ‘, A. Twijnstra’, E.F.M. Wouters’, G.P.M. ten Velde ’ ’ Dept. of Pulmonology; 2 Neurology University Hospital Maasfrichf, The Netherlands

Background: SCLC is a very aggressive disease, with a poor prognosis because it tends to spread rapidly to the brain, regional lymph nodes, bone marrow and liver. Most patients with BM present with neurologic symp- toms and signs, although BM are sometimes also found in asymptomatic patients.

Purpose and Methods: In this study we evaluated the usefulness of MRI in the detection of asymptomatic BM in SCLC at the initial diagnosis and studied the follow-up of these patients. 77 patients with histologically confirmed SCLC without clinical signs of BM were investigated with MRI of the brain prior to chemotherapy.

Results: In 8 (10%) of the 77 patients, MRI of the brain was positive for BM. In 2 of these 8 patients MRI changed the clinical staging from limited disease in extensive disease. After standard combination chemotherapy with CDE for 5 courses, 3 patients had a partial remission of BM. However all 8 patients developed clinical symptomatic BM combined with MRI within 6 months after finishing chemotherapy.

Conclusion: MRI is a very sensitive tool for detecting BM at initial staging of SCLC even in asymptomatic patients. In 10% of these asymp- tomatic patients MRI detected BM. However, detection of asymptomatic BM in SCLC patients has very limited clinical significance. In only a very small number of patients staging is changed. Furthermore, all asymp- tomatic patients with BM in our study group developed symptomatic BM in a short time. The question arises whether an aggressive treatment with chemotherapy combined with cranial irradiation could be of clinical value in this group of patients. This should be evaluated.

I 851 Comparison of mediastinal lymph node size criteria as lung cancer involvement

E. Jeong, S. Yang, S. Chung. Wonkwang Unive,sity Hospital, /ban, S. Korea

The original hope for the CT scan was that it would be able to predict nonin- vasively which patrents had obvious mediastinal /mph node involvement, rendering operative or other invasive staging unnecessary if its specificity and sensitivity was consistently high. When trying to evaluate nodal pathol- ogy by CT scans, largest diameter of nodes must be measured. Mediastinal nodes larger than 1.5 cm in diameter have cancer involvement in 94-97%, whereas nodes ranging from 1.0 to 1.5 cm have cancer mvolvement in 50%, and those less than 1 .O cm are usually uninvolved.

Normal mediastinal nodal diameter is influenced by location, with larger nodes in subcarinal area and smaller nodes in paraesophageal area. We regarded them as involvement if ATS mediastinal node No. 2, 6, 8, 9, 10 L were larger than 1.0 cm, and 4, 5, 7, 10 R were larger than 1.5 cm in diameter. And, we compared the accuracies between nodal involvement criteria, according to largest diameter by CT scan (1 .O cm, 1.5 cm and our method). The presence of involvement and the size of nodes removed at surgery in 57 patients with proven lung cancer were compared.

The results is as follows;

A B C

Sensitivity 097 0.76 0.86 Specificity 0.54 0.79 0.75 Positive predictive Index 0.68 0.79 0.78 Negattve predictive index 0.94 0.79 0.84 accuracy 0.75 0.78 0.81

cancer involvement criteria in nodal diameter, A: 2 1 .O cm, B: > 1.5 cm, C: > 1 .O cm (ATSnodeNo.2.6.8.9.10L),~ 1.5cm(ATSnodeNo.4.5.7.lOR)

I 852 Evaluation of lymph nodes metastasis in lung cancer by trans-esophageal endoscopic ultrasonography

S. Sasamoto, S. Shimatani, Y. Hatano, N. Katoh, K. Takagi, N. Okuyama, S. Yamazaki. Univ. of Toho., Tokyo, Jpn

Trans-esophageal endoscopic ultrasound (EUS) has only recently been a

common diagnostic procedure in the evaluation of patients with lung cancer. In this study, we describe the utility of EUS in diagnosis of lymph nodes metastasis. From 1992 through 1996, EUS examination was performed on 151 preoperative primary lung cancer patient. The lymph node areas evaluated with EUS examination were limited to left tracheobronchial, subcarinal, hilar and pulmonaly ligament, because of anatomical restrict. Results are as follows.

Lymph node area Lt. tracheobronchial Subcannal Rt. hrlar Lt. halar

Sensltlvity (%) 66.7 33.3 20.0 35.7

Speciflctty (%) 79.3 87.7 87.2 90.5

Accuracy (%) 78.7 80.1 82.8 85 4

Pulmonary ligament 100.0 94.0 94.0 Using the criteria of lymph node with diameter ? 10 mm regarded as positive. (subcari- nal lymph node with diameter > 15 mm regarded positive)

EUS is effective diagnostic procedure for limited lymp nodes, especially for pulmonary ligament lymph nodes.

I 853 Radioimmunoscintigraphy with HMFGl monoclonal antibodies, TL-201 and 99mTc-MIBI in the detection of primary lung cancer

D. Sobid-Saranovic, S. Pavlovid, D. Jovanovid, G. Radosavljevid. institute of Nuclear Medicine, lnstifute for Lung Diseases and TBC, CCS, Be/grade, Yugoslavia

During the past few years nuclear medicine methods with tumor targeting tracers have been used in primary lung cancer evaluation. The aim of this study was to evaluate diagnostic sensitivity of 99mTcHMFGl monoclonal antibody (MoAb), TI-201 and 99mTc-MIBI in 66 patients with primary lung cancer. All patients were divided in 3 groups. In Group 1 consisted of 22 patients with non-small cell lung cancer (NSCLC) 99mTc-HMFGl MoAbs were administered i.v. Twenty patients (16 with NSCLC and 4 with small cell lung cancer SCLC) in Group 2 were studied with TI-201. In the third Group 24 patients, 19 with NSCLC and 5 with SCLC, were studied with 99mTc-MIBI. Anterior and posterior chest scintigrams were performed in all patients and tumor to non-tumor (T/NT) ratio was assessed in all patients with positive findings. Results are as follows:

Grow n True DOS. Sensitrvltv (%) T/NT

Group 1 Group 2 Group 3

1 p < 0.01

22 10 45’ 1.70 i 0.36 20 18 90 1.59*0.15 24 20 83 1.60 zt 0.29

Our results indicate that TI-201 and 99mTc-MIBI showed better diag- nostic sensitivity in the detection of primary lung cancer than radioim- munoscintigraphy with 99mTcHMFGl MoAbs. The reason for this is that HMFGl is epithelial tumor associated MoAb not specific for lung cancer. T/NT ratio did not significantly differ for all three tracers.

L-l 854 Two-step immunoscintigraphy for non-small cell lung cancer staging using a bispecific anti-CEA/anti-indium-DTPA antibody and an indium-11 l-labeled DTPA dimer

D. Moro, J.Ph. Vuillez. P.Y. Brichon, E. Rouvier, E. Brambilla, J. Barbet, P. Peltier, P. Meyer, R. Sarrazin, Ch. Brambilla. Chu Grenoble, France

lmmunoscintigraphy (IS) using anti-CEA F(ab’)s monoclonal antibody (MoAb) has been proved useful for improving mediastinal staging of NSCLC but the technique was limited because of an insufficient contrast between tumor and normal tissues. The aim of the present study was to deter- mine if IS could be improved by a two-step method which uses a bis- pecific anti-CEAIanti-di-DTPA antibody (Bs-Mab) and indium Ill-labeled di-DTPA-tyrosyl-lysine bivalent hapten. Twelve patients were intravenously given a Bs-Mab infusion. Four days later, they were injected intravenously with hapten labelled with 185 MBq (5 mCi) of “‘In. Images were recorded immediately after, 6 hr and 24 hr after hapten injection. A pharmacokinetic analysis was performed. Surgery was performed three days after.

Primary tumours were visualized in 9 patients. The contrast was excel- lent, generally higher than that obtained with direct labelling of anti-CEA. In