FIGURE 1.

Methods for T-VEC administration in patients with melanoma. (A) T-VEC can be administered by intradermal injection (left panel) at sites of cutaneous tumor or by subcutaneous injection (right panel) for tumors in the soft tissue or lymph nodes. If tumors are not clinically palpable or become undetectable after initiating treatment, portable ultrasound can be used to identify residual areas of tumor for injection. (B) The goal of injection is to distribute the virus as evenly as possible throughout areas of viable tumor cells. This can be done using a four-quadrant method (left panel), which allows re-insertion to reach all sites and may be preferred for large tumors; alternatively, a single injection site and then using a fan technique (right panel) for injection can also be used. In tumors with necrotic or liquid areas, peripheral injection at the edges where most viable tumor cells are located is also acceptable.