[Potential role of gravity in computerized tomography in neoplasms]

The possible evolution of the usual CT signs in oncology makes the logical premise of our experience. Our goal was to transform instrumental findings in information richer in clinical yield, in compliance with the guidelines of the National Cancer Institute (Bethesda, Md, USA).

Our study was developed over a 3-year period and involved 432 selected patients with primary neoplasms. The lesions were in pulmonary, gastroenteric and genitourinary sites and stages differed (T2/T3, N0/N3, M0/M1); the Karnofsky score ranged 60-90. We integrated the tumor staging obtained with CT with gravitational tests by means of simple changes in the position of forced decubitus resulting in procubitus and triclinium-like positions (right and left lateral decubitus). We restudied only the cT class of each lesion, looking for a better depiction of the lesion-adjacent, fat, and compared the results the examinations in the standard versus the modified decubitus. Judgements were relative to the technical quality of the modified examination and to the potential impact of these findings on the following pTNM staging.

In our 432 patients and only relative to the cT parameter, CT with standard decubitus correctly staged 312 lesions (mean accuracy: 72.2%) versus 352 for CT with modified decubitus (mean accuracy: 81.5%). Improvements were more marked in gastric (22.9% of 48 cases), vesical (23% of 26 cases) and colic (22.3% of 76 cases) lesions, and less marked in pulmonary (10.6% of 132 cases), ovarian (14% of 71 cases) and endometrial (17.1% of 70 cases) lesions. The routine application of pTNM verifications to CT staging helped show the most frequent causes of cTNM mistaging in solid lesions which, in most of the T2/T3 classes, involve the direct spread to an adjacent organ and the depth of invasion of adjacent structures.

The combination and comparison of cTNM with pTNM are useful not only for final tumor staging but also to assess the pretreatment diagnostic accuracy of CT studies. Introducing gravitational tests and reading examinations in pairs improved lesion location, which is the most important technical information for subsequent prognosis and treatment and can help decrease pre-/post-treatment management costs.