PURPOSE: To assess the technical feasibility and safety of weekly outpatient percutaneous computed tomographic (CT)-guided intratumoral injections of interleukin-2 (IL-2) plasmid DNA in a wide variety of superficial and deep tumor sites.
MATERIALS AND METHODS: Twenty-nine patients with metastatic renal cell carcinoma and a total of 30 lesions measuring 1.0 cm2 or greater in accessible thoracic (n = 15) or abdominal (n = 15) locations underwent up to three cycles of six weekly intratumoral IL-2 plasmid DNA injections. CT was used to guide needle placement and injection. After injection cycle 1, patients whose tumors demonstrated stable (<25% increase and <50% decrease in product of lesion diameters) or decreased size (>50% decrease in product of lesion diameters) advanced to injection cycle 2. Patients whose lesions decreased in size by more than 50% over the course of injection cycle 2 were eligible to begin injection cycle 3. An acceptable safety and technical feasibility profile for this technique was deemed to be (a) a safety and feasibility profile similar to that of single-needle biopsy and (b) an absence of serious adverse events (as defined in Title 21 of the Code of Federal Regulations) and/or unacceptable toxicities (as graded according to the National Cancer Institute Common Toxicity Criteria).
RESULTS: A total of 284 intratumoral injections were performed, with a mean of 9.8 injections (range, 6-18 injections) received by each patient. Technical success (needle placement and injection of gene therapy agent) was achieved in all cases. Complications were experienced after 42 (14.8%) of the 284 injections. The most common complication was pneumothorax (at 32 [28.6%] of 112 intrathoracic injections), for which only one patient required catheter drainage. Complications occurred randomly throughout injection cycles and did not appear to increase as patients received more injections (P = .532). No patient experienced serious adverse events or unacceptable toxicities.
CONCLUSION: Percutaneous CT-guided intratumoral immunotherapy injections are technically feasible and can be safely performed.