Local delivery of chemotherapy: a supplement to existing cancer treatments. A case for surgical pastes and coated stents.
Local application or direct tumor injection of chemotherapeutic drugs has been proposed as a method by which local drug concentrations can be maximized in the immediate tumor environment while systemic exposure and non-target organ toxicity is minimized. Multiple opportunities are available to combine local drug delivery with widely practised, existing medical and surgical therapies. Surgical interventions, including both open and laparoscopic procedures, allow the physician to directly visualize and manipulate pathological tissues. Intraoperative placement of implantable therapeutic compounds (barriers to prevent adhesions, sustained-release antibiotics, tissue 'glues' and hemostatic agents) at or near the disease site is increasingly common in surgical practice. Less invasive therapies assisted by diagnostic imaging (fluoroscopy, ultrasound, CT and MRI scanning) have made accurate needle or catheter placement for drainage (abscesses, cysts, obstructions), injection (contrast media, pharmacological agents, embolic agents) and therapeutic purposes (endoluminal stents, venous filters) widely practised interventional medical procedures. This article describes a chemotherapeutic polymer-based paste we have developed for application at the time of surgery to reduce local recurrence of disease at tumor resection sites and a chemotherapeutic polymer-coated stent for use in the palliative management of malignant obstruction to improve the effective lifespan of the device (e.g., esophageal, biliary, prostate, and pulmonary disease). Despite the growth of local therapy in other disease states, regional cytotoxic drug therapy has not been widely deployed in the management of malignancy due to a clinical bias that local therapy will have limited utility in what is considered to be a systemic disease. In the above manner, local drug delivery could be incorporated into therapeutic protocols designed to enhance, not replace, the efficacy of existing treatment options.
Machan
L
Departmental Radiology, University Hospital - UBC Site, Vancouver, BC, Canada
Burt
HM
Hunter
WL