67

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~ARISOUOFAMBER ANDHIGHKVCHEST FILJLS IN THE DFIWXION OF LUNG CARCINOHA. Allen CM.Carr DH Royal B-ton ~os~itaI.~DON.UK.

Advanced multiple beam equalisation radiographycAMBER) has been shown to improve nodule detection and media- stinal detail in experimental and clinical studies.This is the first prospective study comparing AMBER and high KV radiography in patients with suspected lung carcin- oma.52 patients were examined using both radiographic techniques.These were interpreted by 2 radiologists independently,without knowledge of the clinical details and results compared with CT scan and oper- ative findings. LESIONS CORIWTLY AMFJER+HKV AUBKR ONLY HKV ONLY IDENTIFIED Parenchymal 56 3 1 Hilar 28 3 1 Mediastinal 18 2 1 There was no statistical difference between the-groups There was also no difference in the false+ve or -ve rate between the 2 techniques.Mediastinal detail was assessed by the detection of the azygooesophegeal line (A0 line).This was significantly improved in the AMBER groupt76% of AMBER films had a complete A0 line comp- ared with 22% of highKV films).Subjectively left lower lobe collapse and lesions below the diaphragm were easier to identify on AMBER films.Although we have not shown any difference in the detection of lung and med- iastinal pathology between the 2 techniques,the AMBER films were subjectively superior.Tgis may result in interpret&on differences in less experienced ob- sdrvers.This will be examined in further studies.

244

coypuTIIR1zm romrouaPw(n) F-ox BVALUATION OF RBSPGNSB To TEBRAPY I.IBnALLCALLLUnGCAwCBll (Q‘=.=)H.I(rQw _‘

Lisbona.- Jewish General Iioapital,McGill A. University,Montteal,Canada a Cancer and Leukemia Group B, Lebanon,NH,USA

The % of pts achieving complete response(CR) is often used as a measure of treatment efficacy in SCLC.Chest x-rays(CXR) are difficult to evaluate following therapy and differences in reported response rates may be due to intQrObSQrVer variation.CT scans may permit more precise tumor measurement than do& -CXR,and may reduce the variability seen with evaluation of CXR.14 radia- logiets with expertise in CT imaging of the thorax reviewed 15 cases of SCLC pre 6 post chemotherapy (210 observations).In the first session reviewers were required to measure or evaluate all possible lesions on CXR done pre & post treatment. In the 2"1 session,accompanying CT scans were provided in order to make the- same- assessments.T~e number(%) of instances in which tumor was measurable in 2 cross sectional diameters on pretreatment films was 164(79%) on CXR and 202(97%) on CT scans. Inter- observer agreement was assessed by comparing tumour measurements as well as reports of complete response (CR)among the 15 observers.This ranged from 0% - 86% with CXR,and 0% - 95% using CT scan.Usually after viewing the CT scan,readers changed their opinion as to whether CR had actually occurred. Overall,in the 210 observations the CR rate was 29% when reading CXR and 19% with CT scans on the same patients (PsO.016). Therefore CR rate may differ depending on the type of image used to assess response.Since tumor is more often measurable and the interobserver variation re:rasponse superior with CT scan we suggQst that it be used for staging of disease and assessment post therapy.

243

Secondary pulmonary lobule and small peripheral pulmonary carcinoma Rentgenologic-pathologic correlative study

E. Matsui, M.Seki, R. Mochiduki, M, Kanematsu* M. Shibayama, H. Doi, K. shimokawa , Y. Ikeda , Department of Radiology, Department of Pathology, Gifu University Shool of Medicine, 40 Tsukasa-machi, Gifu, JAPAN.

The progression or regression of the pulmonary lesion brings changes in surrounding structures(the brocni, the blood vessels and the secondary pulmonary lobules etc.). CT, paticularly the high resolution CT(HRCT) is helpful in analyzing the changes. In order to get a better understanding of the growth patterns of small peripheral pulmonary carcinoma, we carried out a radiologic-pathologic correlative study. Surgically resected, 11 peripheral pulmonary carcinomas, 2.0cm or less in diameter (7 Adenocar- cinomas(Ad), 2 Squamous cell carcinomas(Sq), 2 Small cell carcinomas(Sm)) were examined. The lungs were distended with a fixative fluid and air dried by Heitzman-s method. HRCT scans of the lungs were per- formed by obtaining l.Omm thich slices and the speci- mens were cut into 0.5-l.Omm thick sections and radiographed using fine-grain films. Then, pulmonary pathology with ragiologic findings was correlated. The histologic types of the carcinomas showed differ- ent growth patterns. Ad tended to extend over more than 2 adjacent segments and to involve more second- ary pulmonary lobules. Sq and Sm tended to localize within one segment and to involve less lobules.

245

USEFULNESS OF THE ESOPHAGEAL ULTRASONOGRAPHY FOR DETECTION AND CHARACTERIZATION OF HILAR AND MEDIASTINAL LYMPH NODES INVASION BY PRIMARY LUNG CANCER

J. Nakajima M.D., G. Shindo M.D., H. Kubota M.D., M. Takeshita M.D., and A. Fur-use M.D. Department of Thoracic Surgery, University of Tokyo, JAPAN.

We had established the method of Esophageal Ultrasonography (EUS) to identify the region of lymph nodes (LN) by depicting surrounding organs, i.e., the heart and the great vessels which were easily detected by their unique morphologic shapes. And then we examined the EUS compared with the chest CT (CT) as the new method for detecting LN invaded by the lung cancer.

Fifty patients with primary lung cancer were evaluated in point of N factor of TNM classification. Esophageal endoscope with Z-dimensional echography (EPE-703FL, TOSHIBA Co.) was inserted orally in each patient without any complications. The smallest detectable LN were 4mm in diameter by EUS, and 5mm by CT. Seventy-two percent of regional LNs were detectable by EUS, and 61X by CT. Fifty-two percent of invaded LN were detectable by EUS as low echoic masses larger than lcm in diameter and 50% by CT. EUS detected LN more clearly than CT esp. in hilar, subcarinal, and AP window regions. EUS and CT will be reciprocal diagnostic apparatus to improve the detectability of the N factor in primary lung cancer.