Clinical comparison of computed tomography and lymphangiography for detection of retroperitoneal lymphadenopathy.

The advantages of CT scan over lymphangiography are numerous and significant. The accuracy of CT scan was virtually identical to lymphogram for the detection of para-aortic lymph node involvement; however, CT provides a better means of assessing the true extent of disease. In such cases it is possible to determine whether the neoplastic process involves retroperitoneal structures such as the kidneys, ureters, pancreatic region, hilum of the liver, or the major vessels. Moreover, this excellent definition permits accurate follow-up assessment of therapy. Finally, CT is a noninvasive examination and does not require significant technical expertise, and the examination is easily reproducible following any time period from the initial examination. Finally, although we have not specifically discussed biopsy procedures, the CT scan is an excellent means for guiding biopsy procedures even for retroperitoneal abnormalities, perhaps precluding the necessity for laparotomy in order to provide histologic diagnosis of disease (Fig. 11). The disadvantages of CT are several. Of course, the acquisition of CT equipment is expensive and the cost effectiveness has not yet been proven. The most significant disadvantage is its inability to resolve or detect neoplastic disease within normal-sized lymph nodes. This was not a significant problem in our series, because our series contained only a few cases of suspected metastatic disease as opposed to lymph node neoplasms. The advantages of lymphography have been discussed by other authors. Because of the better spatial resolution of lymphograms, it is possible by proper interpretation to distinguish between neoplastic disease and lipogranulomatous changes. In a few cases in our series, this did not prove to be true; however, this may have been due to deficiencies in our interpretations (two cases of lymphoma were called positive for neoplasm, but proved to be lipogranulomatous changes by biopsy). Secondly, surveillance films may be easily and cheaply obtained to detect recurrences of disease. In addition, lymphography also provides the opportunity for biopsy of lymphoma masses, but to date this has only been accomplished by skinny-needle biopsy aspirations and not by large core biopsy techniques. After reviewing the literature and evaluating our data, we believe that several recommendations are appropriate with respect to the roles of computed tomography and lymphography. We agree with the previously stated concept that CT should be used for screening for lymphoma; however, we disagree that lymphograms have a greater advantage over CT in the biopsy-proven cases of lymphoma. Rather we believe that CT is better suited than lymphography for those cases with biopsy proven lymphoma. CT is better able to accurately localize the lymph node masses for surgeons if the surgical approach is desired and better able to define the extent of the disease throughout the abdomen. As a result of this it is capable of providing a better follow-up for therapy...