Patients in the control group were treated with neoadjuvant androgen suppression with leuprorelin ( 225 mg every 3 months , intramuscularly ) for 6 months ( short-term ) and radiotherapy alone ( designated STAS ) ; this procedure was either followed by another 12 months of androgen suppression with leuprorelin ( intermediate-term ; ITAS ) or accompanied by 18 months of zoledronic acid ( 4 mg every 3 months for 18 months , intravenously ; STAS plus zoledronic acid ) or by both ( ITAS plus zoledronic acid ) .