A Clinical Study On The Relationship Between The Size And Long-term Prognosis Of Osteosarcoma Of Extremities

BACKGROUNDOsteosarcoma(osteosarcoma,os)is the most common primary malignant bone tumor in children and adolescents.Even if patients with osteosarcoma who did not undergo chemotherapy were treated with radical amputation,about 80% of patients died of distant metastasis within 2years.The 5-year overall survival rate is less than 20%.The emergence of chemotherapeutic drugs,especially the widespread popularity of neoadjuvant therapy concepts,has increased the 5-year overall survival rate of patients to 70%,but the treatment of osteosarcoma has not made substantial progress in the past 30 years,and the overall survival rate of patients has not improved significantly.At present,the unified standard treatment plan is used,and the prognosis of patients is still large.About 30% of patients still die of lung metastasis within 5 years.Therefore,it is urgent to explore the factors that affect the prognosis of osteosarcoma patients and develop individualized treatment plans for different patients.Previous studies have shown that tumor size,sensitivity to chemotherapy,and presence or absence of distant metastasis are the main factors affecting the prognosis of patients with osteosarcoma.The size of the tumor at the time of osteosarcoma of the extremities has a significant impact on the prognosis.In most previous studies,the size of the tumor is usually measured directly using a tape measure to measure the maximum circumference of the soft tissue mass of the affected limb to determine the relationship between tumor size and prognosis.People’s health awareness is gradually increasing.Some patients have come to the hospital early in the onset of the disease,and no obvious soft tissue mass has formed in the affected limb;some scholars have used X-ray film or CT scan measurement to assess the relationship between tumor size and prognosis,but X-ray or CT scanning to delineate the extent of the tumor is limited,especially the tumor boundary cannot be accurately measured.With the development of medical imaging technology,especially the great progress of magnetic resonance imaging technology,the use of magnetic resonance three-dimensional imaging technology can accurately measure the size of tumor volume.The improvement of the survival rate of osteosarcoma patients,adjuvantchemotherapy plays a cornerstone role in the comprehensive treatment of osteosarcoma,but lung metastasis is currently the main cause of treatment failure and death in osteosarcoma patients.This study aims to measure the new Tumor volume before and after adjuvant chemotherapy to assess the relationship between initial tumor size and long-term prognosis and lung metastasis.The change in tumor volume before and after neoadjuvant chemotherapy is used to assess the sensitivity of osteosarcoma patients to neoadjuvant chemotherapy.Objective:MRI was used to measure the tumor volume before and after neoadjuvant chemotherapy,to evaluate the relationship between the initial tumor volume and long-term prognosis and lung metastasis,and to measure the change in tumor volume before and after neoadjuvant chemotherapy to evaluate the sensitivity of OS patients to neoadjuvant chemotherapy.Method:A retrospective analysis of osteosarcoma patients retrieved from our hospital’s medical record system from January 2010 to December 2015 was performed on all 3.0-T scanners(GE Medical system,Milwaukee,MR imaging on USA)to obtain magnetic resonance images that can be measured,measure the length of the tumor in the coronal section,and measure the width and depth of the tumor in the axial section.When measuring the tumor size of the magnetic resonance image,the two radiologists independently reviewed the results,and the average value of the two was taken.When the size difference exceeded 10%,the two authors jointly reviewed these images and based on the consensus of the two Make the final decision.The calculation of tumor volume is based on the calculation formula of ellipsoidal volume V = length × width × depth × π / 6,and the change of tumor volume =(tumor volume before chemotherapy V1-tumor volume after chemotherapy V2).SPSS 22.0 software package was used for statistical analysis of the data.P<0.05 indicated statistical significance.Result:The enrolled 57 patients had a 5-year overall survival rate of 59.2%.The statistical results of Pearson correlation analysis showed that the initial tumor volume was negatively correlated with the 5-year survival rate of patients.The larger the initial tumor volume,the worse the prognosis of patients(Pearson r =-0.784,P <O.O5).Forty-eight(84.2%)OS patients completed 2 cycles of neoadjuvant tumor volume shrinkage to varying degrees.The amount of tumor volume changebefore and after neoadjuvant chemotherapy was positively correlated with the patient ’s 5-year survival rate.Long,indicating that OS patients are more sensitive to neoadjuvant chemotherapy(Pearson r = 0.727,P <O.O5).The results of point-biserial correlation statistical analysis prove that the larger the initial tumor volume,the greater the possibility of lung metastasis(point-biserial correlation coefficient = 0.674,P <O.O5).Conclusion:1.The initial tumor volume is negatively correlated with the patient’s long-term prognosis.The larger the initial tumor volume,the worse the patient’s long-term prognosis.2.The greater the initial tumor volume,the greater the chance of lung metastasis.3.The change of tumor volume before and after neoadjuvant chemotherapy can objectively reflect the sensitivity of osteosarcoma patients to neoadjuvant chemotherapy.