Table 1 Clinical characteristics of patients

Age [median (range)]

16.5 (12–24) years

Sex [n (%)]

 Male

18 (75%)

 Female

6 (25%)

Location of primary tumour [n (%)]

 Femur

17 (64%)

 Tibia

15 (43%)

 Shoulder

3 (1%)

Tumour-volume [median (range)]

412.84 (87.01–3559.46) cc

Metastasis at diagnosis [n (%)]

 Metastatic

11 (31%)

 Localized

24 (69%)

Alkaline phosphatase [median (range)]

412 (134–7980) IU/L

Lactate dehydrogenase [median (range)]

303 (173–665) U/L

Histopathological response evaluation

 Percentage of necrosis [median (range)]

30 (0–99) %

 Good response [n (%)]

13 (37%)

 Poor response [n (%)]

22 (63%)

Survival outcome evaluation

 Follow-up time [median(range)]

25.93 (7.6–54.4) months

 Event free survival [n (%), median (range) time]

11 (31%), 16.27 (5.5–54.4) months

 Overall survival [n (%), median (range) time]

24 (69%), 25.9 (7.6–54.4) months