- Soft tissue disease that has been radiated within two months prior to registration is not assessable as measurable disease; soft tissue disease that has been radiated two or more months prior to registration is assessable as measurable disease provided that the lesion has progressed following radiation; as the biology of previously irradiated tumors may be different from non-irradiated tumors, patients must have at least one measurable lesion outside the previously irradiated region in order to be considered to have measurable disease