TABLE 1.

Clinicopathologic features at diagnosis and radiotherapy characteristics.

Characteristic		N	% or Median (Range)
Age		28	13.4 (7–19) years
Gender	Male	17	61%
	Female	11	39%
Site of primary tumor	Head/neck	6	21%
	Spine/trunk	4	14%
	Extremity	12	43%
	Pelvis	6	22%
Primary tumor size		28	5.2 (1.1–24.0) cm
AJCC stage	IA	1	4%
	IIA	10	36%
	IIB	7	25%
	IVA	10	35%
Surgery for primary tumor	Yes	22	79%
	No	6	21%
Primary surgical margins	Positive	2	9%
	Negative	20	91%
Histologic response	<90%	8	36%
	≥90%	11	50%
	N/A	3	14%
Disease course @ RT	Primary	16	57%
	Recurrent	12	43%
Indications for RT*	Unresectable primary	6	21%
	Positive/close margins	12	43%
	Poor histologic response	5	14%
	Metastatic consolidation	9	32%
Irradiated site	Head/neck	5	18%
	Spine/trunk	6	21%
	Extremity	7	25%
	Pelvis	8	29%
	Lung	2	7%
Radiotherapy	Dose/fraction	28	2.7 (1.1–8.0) Gy
	Total EBRT dose	25	59.4 (40.0–76.0) Gy
	Total brachy dose	3	34.0 (32.0–40.5) Gy
RT technique	3D CRT	14	50%
	IMRT (SBRT)	10 (4)	36% (14%)
	Brachy	3	11%
	IMPT	1	3%

RT, radiation therapy; EBRT, external beam radiation therapy; 3D CRT, 3D conformal radiotherapy; Brachy, brachytherapy; IMRT, intensity-modulated radiotherapy; IMPT, intensity-modulated proton therapy; N/A, not available;

^*Indications for RT for 5 patients included both poor histologic response and positive/close margins.