<prompt> Which of the following investigations is not required in Osteosarcoma?MRIBone marrow biopsyCT chestBone scan  <response>: A biopsy from the lesion is essential for grading of the tumour but a biopsy from bone marrow is not indicated. Bone scan, CT chest and MR1 femur are impoant staging investigations for osteosarcoma. Ref: Apleys system of ohopaedics and fractures 8th185; Pediatric and Adolescent Osteosarcoma By Norman Jaffe, Oyvind S. Bruland, 2009, Page 209; Final FRCR 2B Long Cases: A Survival Guide By Jessie Aw, John Cuis, 2010, Page 165. 