- The role of radiation therapy in melanoma care continues to evolve:
- Particularly in this emerging era of more effective systemic therapy
- Overall, it is not as commonly utilized in contemporary practice:
- Compared to the era preceding the implementation of checkpoint blockade and targeted therapy
- Radiation therapy is sometimes deployed:
- In effort to enhance outcomes for melanoma patients
- While local control is routinely achieved by primary tumor wide excision:
- Adjuvant radiation therapy is sometimes used in the uncommon presentation of:
- The potentially locally aggressive desmoplastic neurotropic melanoma subtype:
- The use of radiation in this setting is supported by various retrospective studies and the current national consensus guidelines
- The potentially locally aggressive desmoplastic neurotropic melanoma subtype:
- Radiation therapy is also sometimes used when surgery is not possible or feasible
- Adjuvant radiation therapy is sometimes used in the uncommon presentation of:
- Although adjuvant radiation therapy has historically been offered:
- To patients with multiple involved or matted regional nodes or with extracapsular extension of regional lymphatic metastases:
- Its role in this context continues to rapidly evolve, and if considered, treatment plans should be developed in the context of the multidisciplinary care of the patient
- Indeed, adjuvant radiation in the prevention of nodal relapse in high-risk populations was recently studied in the ANZMTG trial:
- That randomized 250 patients with palpable regional nodal disease and high risk of nodal recurrence after lymphadenectomy to either adjuvant radiation therapy or observation:
- Although radiation therapy decreased nodal recurrence in the radiation arm:
- 21% vs. 36%, P = .02
- The additional therapy did not result in a significant difference in either overall or relapse-free survival
- Although radiation therapy decreased nodal recurrence in the radiation arm:
- That randomized 250 patients with palpable regional nodal disease and high risk of nodal recurrence after lymphadenectomy to either adjuvant radiation therapy or observation:
- The role of radiation therapy in the setting of progressively improving systemic treatment options remains an area of active clinical investigation
- At MD Anderson, radiation therapy is sometimes used in the adjuvant setting:
- To reduce in-basin failure in high-risk patients following lymphadenectomy
- It is also used for the palliation of local symptoms and to reduce risk of local recurrence after failure of first-line therapy
- More recently, radiation therapy has also been deployed in a clinical trial of nodal radiation therapy after SLN biopsy:
- For patients with high-risk SLN-positive melanoma who are scheduled to have immunotherapy without completion lymph node dissection (i.e., undergoing nodal observation with active surveillance) (NCT04594187)
- To patients with multiple involved or matted regional nodes or with extracapsular extension of regional lymphatic metastases:
- Future research goals include clinical trials to further define the role of adjuvant radiation therapy alone or in combination with systemic therapies
- Patients with multiple involved or matted regional nodes or with extracapsular extension of regional lymphatic metastases may be considered for adjuvant radiation therapy in the context of the multidisciplinary care of the patient with metastatic melanoma
- Summary:
- Radiation therapy (RT) is not a first-line treatment for primary cutaneous melanoma:
- Which is optimally managed with surgical excision
- However, RT has a defined role in select clinical scenarios:
- Adjuvant RT is most clearly indicated for desmoplastic melanoma with high-risk features, such as:
- Breslow thickness > 4 mm
- Clark level V
- Extensive neurotropism / perineural invasion
- Head and neck location
- Narrow deep margin resection
- Adjuvant RT is most clearly indicated for desmoplastic melanoma with high-risk features, such as:
- The American Academy of Dermatology recommends considering adjuvant RT in these cases to improve local control:
- Though it does not impact distant metastasis or overall survival
- Multidisciplinary consultation:
- Including a radiation oncologist, is advised to weigh risks and benefits
- Primary RT may be considered for:
- Melanoma in situ
- Llentigo maligna type (MIS, LM):
- When complete surgical excision is not feasible:
- This is more common outside the United States, and recurrence rates in retrospective series range from 0% to 17%:
- The depth of penetration with superficial RT is a concern, and its use is uncommon in the US
- This is more common outside the United States, and recurrence rates in retrospective series range from 0% to 17%:
- When complete surgical excision is not feasible:
- Palliative RT:
- Is used for symptomatic control of unresectable locoregional or metastatic disease, including cutaneous, subcutaneous, or brain metastases:
- To reduce morbidity and improve quality of life
- Is used for symptomatic control of unresectable locoregional or metastatic disease, including cutaneous, subcutaneous, or brain metastases:
- The role of RT in the adjuvant setting for high-risk, resected melanoma is less well defined in the era of effective systemic therapies:
- Ongoing studies are evaluating its utility in combination with immunotherapy
- References:
- Guidelines of Care for the Management of Primary Cutaneous Melanoma. Swetter SM, Tsao H, Bichakjian CK, et al. Journal of the American Academy of Dermatology. 2019;80(1):208-250. doi:10.1016/j.jaad.2018.08.055.
- Radiation and Melanoma: Where Are We Now?. Bliley R, Avant A, Medina TM, Lanning RM. Current Oncology Reports. 2024;26(8):904-914. doi:10.1007/s11912-024-01557-y.
- Radiotherapy in the Treatment of Subcutaneous Melanoma. Borzillo V, Muto P. Cancers. 2021;13(22):5859. doi:10.3390/cancers13225859.
- The Evolving Role of Radiation Therapy in the Management of Malignant Melanoma. Khan N, Khan MK, Almasan A, Singh AD, Macklis R. International Journal of Radiation Oncology, Biology, Physics. 2011;80(3):645-54. doi:10.1016/j.ijrobp.2010.12.071.
- Radiation Therapy in the Management of Malignant Melanoma. Mahadevan A, Patel VL, Dagoglu N. Oncology (Williston Park, N.Y.). 2015;29(10):743-51.
Rodrigo Arrangoiz MS, MD, FACS, FSSO 