Regional intra-vascular and intra-lymphatic therapy of neoplastic diseases: a review

The aims of regional therapy are to increase the exposure of regional confined cancers to drugs and to decrease their systemic levels. Two main approaches are available: intra-vascular and intra-lymphatic (I.L.) therapy. The former is comprised of different methods of delivering chemo-radio therapeutic agents directly to the tumor, i.e. intra-arterial infusion (I.A.I.), isolation perfusion (I.P.), tourniquet infusion (T.I.), trans-catheter embolization (T.C.E.) and intra-portal infusion (I.P.I.). The main aim of the latter is the prevention or cure of lymphatic metastases. So far none of the reported methods have been universally accepted. Pharmacokinetic studies have recently made I.A.I. a more rational method: the increase in regional exposure achieved is a direct function of the total body clearance of a drug and an inverse function of the regional arterial blood flow. I.A.I. is most effective in the treatment of hepatic metastases from carcinoid and colo-rectal cancer. I.P. gives objective response in 50% of recurrent melanomas. T.I., T.C.E., I.P.I. and I.L. therapy are still experimental methods. However, the future for regional therapy appears exciting, since pharmacological and technological developments seem to have greatly improved its potential effectiveness as a cancer treatment.