| Objective:Multiple myeloma(MM)is a heterogeneous hematologic malignancy involving the proliferation of plasma cells and characterized by abnormal monoclonal immunoglobulin,which lead to damage of target tissue and target organ.Imaging is of vital importance in the diagnosis and treatment of MM.The positron emission tomography/computerized tomography(PET/CT)was used more and more popular in MM as a new technology for combining functional metabolism and anatomic structure together.The aim of our study was to analyze the feature of18-fluorodeoxyglucose(18F-FDG)PET/CT and in order to assess the prognostic value of PET/CT in newly diagnosed MM patients.The study will provide reference for clinical diagnosis and treatments for newly diagnosed MM patients in China,to raise awareness of MM and provide some experiences for future clinical work.Methods:Sixty eight newly diagnosed MM patients of the near one decade from December 2005 to December 2015 received treatments in Tianjin medical university cancer institute and hospital were enrolled in the retrospective study and PET/CT was performed in all of them before treatments.We collected the information of epidemiological features,laboratory examinations results,clinical features,the features of PET/CT and curative effect and so on.We used the statistics software SPSS 21.0 to analysis the results through Chi-square test.Kaplan-Meier was used to analysis their survival.The univariate analysis used the method of Log-rank,while multivariate analysis used the method of the model of Cox.The level of significanceα=0.05,and P<0.05 was considered statistically significant.Results:There were sixty eight newly diagnosed MM patients in the study,and the proportion of male and female was 1.125:1.The median age was 58 years,and the range was 22~78 years.The patients who were less than 65 years old accounted formost of MM patients(N=56,82.3%)over the same period.The common type was IgG(N=37,54.4%).No matter Durie Salmon(DS)or International staging system(ISS)stage III were the most common seen.The number of patients of DS stage III was 57 cases(83.8%),and DS stage II was 8 cases(11.8%)and the least was DS stage I with 3 cases(4.4%).The number of ISS stage III was 40 cases(58.8%),and the ISS stage II was 14 cases(20.6%),and the least was ISS stage I with 14 cases(20.6%).The most common symptoms were bone ache partly or the whole body and fracture,and the common location was the back(N=20,29.4%).According to the PET/CT features of 68 MM patients,the type of bone destruction was most common seen(N=38,55.9%),and the type of diffuse bone marrow infiltration was 5 cases(7.3%)and the type of extramedullary involvements was 25 cases(36.8%).The locations of fifteen patients in the type of extramedullary involvements were next to soft tissue next to the bone and soft tissue charge into spinal canal to compress itself in 8 patients.Other extramedullary involvements included thyroid,pleura,antrum and so on.In the type of bone destruction,the parts of bone lesions were most common seen in spinal(N=24,63.1%),and in four limbs(N=8,21.1%),and other parts could seen in skull and sternum.When the bone marrow plasma > 30%,the maximum standardized uptake value(SUVmax)was higher than the other term,and the differences was statisticsly(P=0.030).When the bone marrow plasma was high and the tendency of SUVmax of bone lasions may be also high.There was no remarkable differences in SUVmax of extramedullary involvements between DS stage and ISS stage(P > 0.05)in 25 patients of extramedullary involvements.The average of SUVmax of extramedullary involvements was 5.40 ± 2.30,and the median number was 4.10.The area under the curve ROC was 0.643 and the best cutoff was 5.0 with the sensitivity 78.0% and specificity 65%.There were 17 patients(25.0%)whose effect after 4 cycles reached complete response(CR),and 18(26.5%)whose reached partial response(PR),and 8(11.8%)whose reached very good partial response(VGPR)after 4 cycles.We defined it valid when the effect was PR or more than PR,and the total was 63.2%.The time of median follow up was 25.3 months and the deadline was August,2016.15 patientswas dead because of lung infection(N=9,60.0%)and progressive disease(PD)(N=3,20.0%).The 3-year over survival(OS)rate was 81.0%,and 5-year OS rate was 62.0%.The 3-year progression free survival(PFS)rate was 78.0%,and 5-year PFS rate was 58.0%.The univariate analysis indicated β2 microglobulin(β2 MG)≥5.5 mg/l,lactic dehydrogenase(LDH)> the upper limits of normal,the extramedullary lesions on PET/CT,number of bone lesions were more than 3 and not reach complete remission(CR)(P > 0.05)when the ending of treatments were associated with shorter OS and PFS.There was no differences in OS and PFS in SUVmax with different PET/CT features(P>0.05).In multivariate analysis,β2 MG≥5.5 mg/l,LDH>the upper limits of normal,the extramedullary lesions on PET/CT,and not reach CR were the four factors leading to poor prognosis(P < 0.05).According to these factors to regroup the patients into low risk(0 score)(N=15,22.6%),medium risk(1 ~ 2 scores)(N=20,29.4%),and high risk(3 ~ 4 scores)(N=33,48.0%),and the 5-year OS rate was 78.0%,54.0%,23.0% and the significant difference existed(P<0.05).Conclusion:1.There were more old male patients with MM than female.The most common type was IgG,and the most common stage was DS III and ISS III.The most common symptoms were bone ache partly or the whole body and fracture,and the common location was the back.2.The most common PET/CT type was the type of bone destruction and the prognoise of patients with extramedullary involvements was poor.In the type of bone destruction,the results may indicate that when the percent of marrow plasma was higher,and the SUVmax of bone lesions was also higher.There was no remarkable differences in SUVmax of extramedullary involvements between DS stage and ISS stage.The best cutoff was 5.0 of bone lesions SUVmax,but there was no difference in survival(P>0.05).The univariate analysis indicated β2 microglobulin(β2 MG)≥ 5.5 mg/l,lactic dehydrogenase(LDH)> the upper limits of normal,the extramedullary lesions on PET/CT,number of bone lesions were more than 3 and not reach complete remission(CR).3.In multivariate analysis,β2 MG≥5.5 mg/l,LDH>the upper limits of normal,the extramedullary lesions on PET/CT,and not reach CR were the four factors leading to poor prognosis(P<0.05).According to these factors to regroup the patients into low risk,medium risk,and high risk,which can indicate newly MM patients prognosis to a certain extent. |
