VALUE OF CHEST COMPUTED TOMOGRAPHY

IN GENITOURINARY MALIGNANCIES

STEVEN SUTTON, M.D.

ALAN M. COHEN, M.D.

MARTIN I. RESNICK. M.D.

From the Division of Urology and Department of Radiology, Case Western Reserve University, School of Medicine, Cleveland, Ohio

ABSTRACT-Fifty-one patients with genitourinary malignancies with normal chest x-ray films all had chest computerized tomography in an attempt to detect metastatic disease. One patient with a hypernephroma and another with a bladder carcinoma had metastatic nodules detected. One pa- tient with a testicular tumor had a histologically confirmed benign nodule. Chest computerized tomography should be performed on patients with tumors that have a high likelihood of metastasix- ing to the lung.

All genitourinary (GU) tumors can metastasize to the pulmonary parenchyma. Some, such as hypernephroma, Wilms tumor, and testicular tumors, have a greater predilection to spread to this organ.’ Chest roentgenography (PCR) has been the standard method to evaluate all GU tumors for pulmonary metastasis, and recently whole lung tomography (WLT) and chest com- puted tomography (CT) have become available.

Chest CT is the most sensitive method to de- tect pulmonary nodules.2-” Though it detects more and smaller nodules than PCR or WLT, small nodules are statistically more often benign. Most authors make few conclusions concerning criteria for use of chest CT as a means of detecting metastatic disease. In addi- tion, previous studies have grouped all classes of neoplasms, therefore, few conclusions can be made about the specific use of chest CT in eval- uating patients with GU neoplasms. The role of chest CT in tumor staging in this patient popu- lation is evaluated by this study.

Material and Methods

Between the years 1978 to 1982, 166 patients who had a newly diagnosed malignancy and a

normal PCR were identified by a retrospective chart review. The patients included in this study also obtained a chest CT as part of the initial tumor staging. Three hospitals, Univer- sity Hospitals of Cleveland, Mount Sinai Medi- cal Center, and St. Luke’s Methodist Hospital, provided the patient material. Of the 166 pa- tients identified 51 had GU malignancies. These 51 patients comprise the study group. The patients were evaluated for the effect of chest CT on tumor staging and the implications of this information for therapy.

Results

Fifty-one patients with a variety of newly diagnosed malignant GU neoplasms were found who had a normal PCR. Three of these had nodules discovered on chest CT performed for tumor staging (6 %) (Table I). Biopsy was done of the nodules, and 2 represented malig- nant disease: 1 from a hypernephroma and the other from a bladder carcinoma. The nodule in the third case was comprised of fibrosis. This was caused by bleomycin in a patient with tes- ticular carcinoma who had received the cyto- toxic drug for treatment of a prior malignancy.

UROLOGY i DECEMBER 1983 / VOLUME XXII, NUMBER 6 667

TABLE I. Genitourinary cancers*

Location -CT +CT Total

Penis 2 . . 2 Bladder 14 1 15 Prostate 9 * . 9 Testes 10 1 11 Renal 19 1 20 Ureter 1 . . 1

TOTALS 55 3 58 *All patients had normal chest x-ray film.

Comment While all tumors metastasize, the true fre-

quency of spread is difficult to evaluate. The frequency found depends on the tumor cell type and the stage at time of evaluation. Gilbert and Kagan12 document the difference that the time of evaluation of GU tumors can make by show- ing an increased number of pulmonary metas- tases found at autopsy when compared with the number found at initial presentation (Table II). Even this cannot represent an accurate com- parison since the methods of evaluation are not equivalent. Autopsy evaluation is performed on all available tissue; thus, fewer lesions are missed and smaller lesions are histologically identifiable.

Some tumors such as hypernephromas have a well-known high rate of pulmonary metasta- sis.‘O Others, such as bladder and testicular tu- mors, also have a surprisingly high incidence of pulmonary spread. l2 Our series support these data with metastases found at initial presenta- tion in 1 of 20 (5%) hypernephromas and 1 of 15 (7%) bladder carcinomas.

CT also presents problems. CT will detect up to 60 per cent more and smaller nodules than PCR. More small nodules are benign;” thus, every nodule found on CT is not malignant. Nodule biopsy for proof is required for diagnos- tic confirmation even in seemingly obvious cases, Our patient with testicular carcinoma who had a benign nodule on biopsy, emphasizes this point.

The role of CT in detection of metastatic dis- ease is not totally defined. Muhm, Brown, and Crowe3 believe all patients with malignant dis- ease should receive CT staging. Accurate stag- ing is required for optimal and appropriate therapy; however, there is also a current mone- tary crisis to stabilize medical costs.

Our data suggest that GU tumors with a high risk of pulmonary metastasis include renal and bladder tumors. Testicular tumors have been

TABLE II. Incidence of metastases*

Presentation Autopsy Location (%) (%) Bladder 5-10 25-30 Kidney 5-30 50-75 Penis 1 10 Prostate 5 13-53 Testes 2-12 70-80

*Modified from Gilbert and Kagan.‘*

implicated by others. r.12 These tumor types should be primarily staged using chest CT. Even patients with solitary, unilateral, resect- able nodules might benefit if nodule resection is possible. If other nodules are not found, this would alter the therapy.

In other GU tumors, the situation appears to be different. Chest CT yields less information, and may need to be reserved for problem pa- tients with unsolved pulmonary questions or when a high suspicion of pulmonary metastases exists.

Division of Urology University Hospitals of Cleveland

Cleveland, Ohio 44106 (DR. RESNICK)

References

1. Skinner DG, and DeKernion JB: Genitourinary Cancer, Philadelphia, WB Saunders Co, 1978.

2. Muhm JR, et al: Comparison of whole lung tomography and computed tomography for detecting pulmonary nodules, AJR 131: 981 (1978).

3. Muhm JR, Brown LR, and Crowe JK: Use of computed tomography in the detection of pulmonary nodules, Mayo Clin Proc 52: 345 (1977).

4. Kollins SA: Computed tomography of the pulmonary parenchyma and chest wall, Radio1 Clin North Am 15: 297 (1977).

5. Kreel L: Computed tomography of the lung and pleura, Semin Roentgen01 13: 213 (1978).

6. Change AE, et al: Evaluation of computed tomography in the detection of pulmonary metastases. A prospective study, Can- cer 43: 931 (1979).

7. Chang CHJ, et al: Specific value of computed tomographic breast scanner (CT/M) in diagnosis of breast diseases, Radiology 132: 647 (1979).

8. Schaner EG, et al: Comparison of computed and conven- tional whole lung tomography in detecting pulmonary nodules: a prospective radiologic-pathologic study, AJR 131: 51 (1978).

9. McCloud TL, Wittenberg J, and Ferrucci JT, Jr: Computed tomography of the thorax and standard radiographic evaluation of the chest: a comparative study, J Comput Assist Tomogr 3: 170 (1979).

10. Libshitz HI, and North LB: Pulmonary metastases, Radio1 Clin North Am 20: 437 (1982).

11. Cohen AM, Haaga JR, and Alfidi RJ: The lungs and chest wall, in Haaga JR, and Afidi RJ (Eds): Computed Tomography of the Whole Body, St. Louis, CV Mosby Co, 1983.

12. Gilbert HA, and Kagan AR: Metastases: incidence, detec- tion, and evaluation without histologic confirmation, in Weiss L (Ed): Fundamental Aspects of Metastasis, Amsterdam-Oxford, North-Holland Publishing Co, 1976.

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