3.2. Treatment
Systemic and local treatment given to patients in both protocols are detailed in Table 2 . One hundred and forty-five (145) patients who were enrolled in RMS2005 (94%) received chemotherapy according to protocol, 8 patients received IVA without doxorubicin, and 1 patient received IVA followed by VA. All patients included in ARST0531 received chemotherapy according to protocol: 44 received VAC and 41 VAC/VI.
Radiotherapy to the site of primary tumor and nodes was administered in 132 (86%) and 82 (97%) patients enrolled in RMS2005 and ARST0531, respectively (Table 2). A significantly higher proportion of patients in EpSSG did not receive RT for the following reasons: parent refusal (2), early progression (6), amputation (2), very young age (1) and treatment center decision (7). Four patients received nodal RT only. The most common type of radiotherapy in both series was photon external beam, and a minority of patients in both protocols received proton beam radiotherapy.
In the EpSSG cohort, 75 out of 154 patients (49%) underwent surgical resection of the primary tumor: up-front primary resection in 10/75 (13%) and delayed primary resection in 65/75 (87%). Results of surgery included complete local resection (R0) in 55 (73%), microscopic residual disease (R1) in 14 (19%), and macroscopic residual (R2) in 6 (8%). In the COG cohort, 22 out of 85 patients (26%) underwent surgical resection of the primary tumor: up-front primary resection in 17/22 (77%) and delayed primary resection in 5/22 (23%). R0 was achieved in 20 (91%) and R1 in 2 (9%).