Một phản ứng kém với điều trị. Osteogenic sarcoma xương cánh tay trái gần một cô gái 14 tuổi. Top hàng cho thấy pretherapy MRI (T1 postgadolinium) và nghiên cứu 18F-FDG. MRI cho thấy phá hủy được đánh dấu của xương cánh tay gần với khối u qua các tấm tăng trưởng, hoại tử xương trung tâm, và các mô mềm mở rộng khối u đại chúng. | 278 Chapter 15 Primary Bone Tumors Figure . A poor response to treatment. Osteogenic sarcoma of the proximal left humerus in a 14-year-old girl. Top row shows pretherapy MRI T1 postgadolinium and 18F-FDG study. The MRI shows marked destruction of the proximal humerus with tumor crossing the growth plate central bone necrosis and extensive soft tissue tumor mass. The PET study shows marked heterogeneous distribution of FDG in the proximal humerus with focal increased metabolism seen peripherally and central necrosis. This scan indicates more specific biopsy sites in the most metabolic areas. This patient was a poor responder to neoadjuvant therapy bottom row with the MRI showing significant enhancement and the PET study persisting increased uptake. The post-surgical resection specimen showed 5 necrosis confirming poor response. Subsequently this patient developed pulmonary metastases. correlation with tumor grade in a series of 42 patients with soft tissue and bone sarcoma. Specific types of bone tumor were not detailed. The same group reported that the median SUVmax was significantly different for each histologic grade of tumor when divided into high- intermediate- and low-grade tumors. Looking at other markers of tumor aggressiveness such as increased tumor cellularity mitosis and level of Ki-67 proliferation of a specific nuclear antigen detected by immunohistochemical staining which correlates with growth fraction of tumors proliferative index there was also a significant correlation found with SUVmax. These researchers and others have also found moderate correlation with tissue levels of the cell growth regulation product p53 31 32 . These parameters have been correlated with a poorer outcome for higher tumor grades shorter survival and development of distant metastatic disease. Table . Summary of studies of histologic grading or tumor aggressiveness and measures of fluorodeoxyglucose uptake Study No. of patients and tumor type Histologic grade good .
