Although recent multimodality therapeutic protocols have led to improved survival in osteosarcoma (OS), the outcome still remains dismal. Ongoing international multicentric trials on OS aim to randomize patients for optimum management, based on histological response to NACT. The pathologic response to neoadjuvant chemotherapy (NACT) is the most important factor predicting prognosis. In this study of 23 cases of limb salvage surgery post neoadjuvant chemotherapy, mean age was 18.3 years, with male predominance. 65.5 % cases were conventional OS. Histologic assessment of chemotherapeutic effect done by Huvos grading revealed good response (Huvos lll and lV) in 15 (65.2 %) and poor response (Huvos l and ll) in eight (34.8 %). A scoring based on MRI with a scale of 1-6 was compared with histologic response. Five (62.5 %) of poor responders showed score of >3 and 73.3 % of good responders showed ≤3. Dose intensity of NACT was calculated and correlated with the histological response. 53.3 % of good responders showed ARDI > 0.9. Five (21.7 %) developed local recurrence and 10(43.4 %) had pulmonary metastasis. Adoption of more aggressive treatment modalities may ensure better histologic response and longer event free survival.
Keywords: Histological response osteosarcoma; Huvos scoring system; Limb salvage surgery; Neoadjuvant chemotherapy; Osteosarcoma; Radiological scoring osteosarcoma.