Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 8 1 2014 03 15 5 8 Mozhgan Aalam Samimi Assistant Professor, Minimally Invasive Surgery Research Center, Iran University Of Medical Science, Tehran, Iran. Nooshin Mirkheshti Medical Doctor, East Sage Research Corporation, Isfahan Science and Technology Town, Isfahan, Iran. Abdolreza Pazouki Assistant Professor, Minimally Invasive Surgery Research Center, Iran University Of Medical Science, Tehran, Iran. 2015 10 14 Introduction: Osteosarcoma is the most common primary bone tumor in children and young adults and appropriate chemotherapy can increase limb sparing and overall survival. Yet, the toxicity of chemotherapy regimens including MTX can be life threatening. Therefore; we tried another chemotherapy regimen for these patients. Method and materials: We investigated 15 patients aged 15 to 40 years old and used continuous infusion of cisplatin, doxorubicin intermittently with ifosfamide, doxorubicin as neoadjuvant chemotherapy. Percent of necrosis and toxicities was recorded for each patient. Results: Out of 15 patients investigated, 13 were males and 2 females. Tumor necrosis≥ 90% (defined as good necrosis) was observed in 60% of patients. 26.7% of the patients showed leucopenia grade three or four, 26.7% had anemia grade three or four, and 20% showed thrombocytopenia grade three or four. Conclusion: The above chemotherapy regimen can cause as good necrosis as the chemotherapy regimens including high dose of MTX with reduced toxicity and less nursing cares and laboratory tests. Of course small sample size limits extension of our result to all patients but trying this regimen is recommended in more patients to see more reliable results. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/434 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/434/363