The role of routine imaging in pediatric cutaneous melanoma

Background: Optimal imaging for children with pediatric malignant melanoma (MM) is unknown.

Methods: We reviewed clinical and imaging findings of patients with American Joint Commission on Cancer (AJCC) stage IIC-IV MM treated on our institutional MEL06 trial. All patients had baseline brain magnetic resonance imaging/computed tomography (MRI/CT), positron emission tomography/computed tomography (PET/CT), CT chest, abdomen, and pelvis (CTCAP). Patients on stratum A (PEG-interferon, where PEG is pegylated; AJCC IIC, IIIA, IIIB; n = 16) had imaging every 6 months; stratum B1 (PEG-interferon and temozolomide; unresectable measurable disease, metastatic, or recurrent; n = 2) had PET/CT scans every 2 months and brain imaging studies every 4 months; stratum B2 patients (PEG-interferon and temozolomide; unresectable nonmeasurable, metastatic, or recurrent, n = 3) had imaging every 4 months. Off-therapy imaging was done every 6 months for 3 years.

Results: There were 21 patients (11 females, 11 spitzoid, median age 14 years, head/neck [6], trunk [7], extremities [8]). Patients with spitzoid melanoma underwent 236 imaging studies in total (86 PET/CT, 81 CTCAP, 11 CT chest, 10 CT brain, 48 MRI brain) at a median cost per patient of $32,718. Thirteen studies (5.8%) had findings that led to two biopsies (one positive). For conventional MM, 162 studies (61 PET/CT, 57 CTCAP, 8 CT chest, 7 CT brain, and 29 MRI brain) were performed with a median cost per patient of $23,420. Twenty (14%) had findings leading to six biopsies (four positive). At 6.3 years (range 0.4-9.2), 17 patients remain disease-free.

Conclusion: Children with spitzoid melanoma require minimal imaging at diagnosis and follow-up. Patients with conventional MM should be imaged according to adult guidelines.