Residual Masses After Chemotherapy in Men With Seminomas

Residual radiological abnormalities are common at the completion of chemotherapy. Such masses are not treated unless they grow or are histopathologically shown to contain viable cancer. In a combined retrospective consecutive series of 174 seminoma patients with postchemotherapy residual disease seen at ten treatment centers, empiric radiation was not associated with any medically significant improvement in PFS after completion of platinum-based combination chemotherapy.[23][Level of evidence C2] In some series, surgical resection of specific masses has yielded a significant number of patients with residual seminoma that require additional therapy.[24] Larger masses are more likely to harbor viable cancer, but there is no size criteria with high sensitivity and specificity. Fluorine F 18-fludeoxyglucose-positron emission tomography (18F-FDG PET) scans have been shown to be helpful in identifying patients who harbor viable cancers, but the false-positive rate is substantial in some series.[25-27] The strength of positron emission tomography (PET) scans in residual seminoma masses is that they have a very high sensitivity and a low false-negative rate. Thus, for men with residual masses for whom resection is being planned, a negative PET scan provides evidence that surgery is not necessary.

Although larger residual masses are more likely to harbor viable seminoma, the size of the residual mass is of limited prognostic value.[24-26] Most residual masses do not grow, and regular marker and computed tomography (CT) scan evaluation is a viable management option for large or small masses.[28] An alternative approach is to operate on larger masses, to resect them when possible, and to perform biopsies of unresectable masses. Postchemotherapy masses are often difficult or impossible to resect because of a dense desmoplastic reaction. Historically, such surgery has been characterized by a high rate of complications or additional procedures such as nephrectomy or arterial or venous grafting.[29]