Radiation therapy is used in a variety of settings for patients diagnosed with melanoma, including the adjuvant/postoperative setting and for palliation. Although not often used for the primary treatment of a melanoma, radiotherapy is often used postoperatively (after surgery) for patients with nodal involvement. In this setting, various trials have demonstrated improved locoregional control in the involved nodal basin. In certain circumstances (desmoplastic neurotropic melanoma with close margins), radiation may improve local control as well.
For patients with advanced metastatic disease, short course radiation can be used for palliation of pain, obstructive symptoms or bleeding due to bone, brain, lung or nodal involvement.
At St. Joseph Hospital, melanoma patients have access to the latest technology to deliver radiation therapy with precision. The department has three Varian Linear accelerators which have the ability to deliver 3D conformal radiation, IMRT, IGRT, SBRT and SRS:
Three-Dimensional (3D) Conformal Radiation Therapy
3D conformal radiation therapy is a technique where the beams of radiation used in treatment are shaped to match the tumor. Previously, radiation treatment matched the height and width of the tumor, meaning that healthy tissue was exposed to the beams. Advances in imaging technology have made it possible to locate and treat the tumor more precisely.
Intensity Modulated Radiation Therapy (IMRT)
A type of conformal radiotherapy that focuses multiple radiation beams directly on the tumor itself. Variable beam intensities are utilized to treat the cancer with the highest possible doses while reducing radiation dose to surrounding normal structures. Radiation oncologists use special planning software to determine the most accurate treatment.
Stereotactic Body Radiation Therapy (SBRT)
SBRT combines elements of three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), which links CT scans of the tumor site with treatment-planning software to determine optimum photon radiation beam direction and intensity. Specialized treatment techniques account and adjust for tumor motion and anatomy changes during the course of radiotherapy. SBRT allows the delivery of ablative doses of radiation to the target in significantly shorter treatment time of 5 or fewer fractions. This approach may be used in patients with isolated melanoma metastasis in the lung, liver and other sites.
Stereotactic Radiosurgery (SRS)
SRS is a form of radiation therapy that focuses multiple radiation beams to precisely target the brain. It delivers high doses of radiation to the target area with minimal exposure to the healthy tissue that surrounds it. Despite its name, radiosurgery is not a surgical procedure and there are no incisions. It is a one-day, outpatient treatment that is associated with minimal discomfort and side effects. Patients with limited melanoma lesions in the brain can be treated with this technique.