[Opportunities of delayed densitometry of "late (fixed) contrast" as a test for tumors in residual mediastinal lesion in primary mediastinal lymphosarcoma after polychemotherapy].

AIM: To clarify the potential of delayed densitometry of late (fixed) contrast in differentiation between tumor and fibrosis in residual mediastinal lesion (RML).

MATERIAL AND

METHODS

Computed tomography (computed tomograph of the third generation COMATOM CR-3 made in Germany, SIEMENS) has examined 12 patients with mediastinal lymphosarcomas after polychemotherapy. All of them had a RML 3 to 6 cm in diameter.

RESULTS

CT has detected 8 cases of the tumor and 4 cases of fibrosis. The criteria of the tumor were the following: increased RML density shortly after the contrast medium introduction and 30 min after urographine introduction (p < 0.01); RML density 30 min after introduction of contrast medium was higher than above the aorta (p < 0.01). Fibrosis in RML was stated if RML density before, at the high of concentration and after introduction of the contrast medium was the same (p > 0.01); aortic density was significantly higher of RML density at the height of the contrast (p < 0.01).

CONCLUSION

The above method differentiates the tumor with fibrosis in RML with maximal probability. This facilitates further choice of therapeutic policy in secondary resistant form of primary mediastinal lymphosarcoma.