Fig. 1.
a The skin of the tumor appeared red and black in some places and showed signs of necrosis before the first procedure. b A stony hard mass (6 × 7 × 8 cm3) appeared in the left neck before the first procedure. c At the 8-month follow-up after the first procedure, it was observed that the tumor under the skin surface of the left neck shrank obviously and showed signs of slight radiation-induced skin reaction. d The skin surface showed complete recovery, and the skin on the treatment side had completely healed in the 12th month after the first procedure.