Prognostic value of fluorodeoxyglucose positron emission tomography derived metabolic parameters and textural features in pediatric sarcoma.

PURPOSE: The aim of this study was to evaluate the prognostic value of PET-derived metabolic features and textural parameters of primary tumors in pediatric sarcoma patients. METHODS: The imaging findings of 43 patients (14 girls and 29 boys; age 11.4 ± 4.4 years) who underwent 18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography for primary staging prior to therapy between 2005 and 2020 were retrospectively evaluated. The diagnoses were osteosarcoma in 10, rhabdomyosarcoma in 10, and Ewing sarcoma in 23 patients. PET metabolic data and textural features of primary tumors were obtained. Cox proportional hazards regression models were used to identify predictors for progression-free survival and overall survival. Survival curves were estimated by using the Kaplan-Meier method. RESULTS: Distant metastases were detected in primary staging in 13 patients (30.2%). The median follow-up duration after diagnosis was 28 months (range: 10-171 months). In multivariate Cox regression analysis, the presence of distant metastasis and neighborhood grey-level difference matrix_Contrast (ngldm_Contrast) were found as independent predictors for both progression-free survival and overall survival. Grey-level zone length matrix_Zone-length nonuniformity (glzlm_ZLNU) was also found as an independent predictor for overall survival. The Kaplan-Meier survival analysis showed that higher ngldm_Contrast and glzlm_ZLNU values of primary tumors were significantly associated with shorter progression-free survival and overall survival. CONCLUSION: In addition to the presence of distant metastasis at initial diagnosis, textural features of primary tumors may be used as prognostic biomarkers to identify patients with worse prognosis in pediatric sarcoma. Higher tumor heterogeneity is significantly associated with shorter progression-free survival and OS.

Impact of peri-transplant RBC transfusion and ABO incompatibility on acute graft-versus-host disease in pediatric hematopoietic stem cell transplant patients.

It is well known that stem cell transplantation is curative for many diseases; however, graft versus host disease (GVHD), which is a common posttransplant complication, has still a substantial place among the causes of transplant-related morbidity and mortality. The association between ABO incompatibility and GVHD is controversial. There is also limited available data about the association between blood component transfusions during the peritransplant period and GVHD development in the pediatric setting. Hence, we retrospectively evaluated both the impact of ABO-mismatch and transfusions of RBC and platelets between day -7 pre-transplant and +30 post-transplant to the development of acute GVHD (aGVHD). We analyzed 139 allotransplants in 133 patients who were transplanted by myeloablative conditioning. Fifty-one patients out of 133 (36.7 %) were found to have aGVHD within +100 days post-transplantation. Of them 40 patients had grade I-II and 11 patients had grade III-IV aGVHD. Increased risk of aGVHD is associated with ABO minor mismatch (p: 0.030). Nevertheless, there was no association between ABO mismatch and severity of aGVHD. The median number of RBC transfusions in aGVHD patients was higher than the number of transfusions in patients without aGVHD; however, the difference was not statistically significant (p: 0.11). Platelet transfusion numbers were statistically similar between aGVHD patients and the patients without aGVHD (p: 0.79). In conclusion, major and bi-directional ABO-incompatibility between donors and recipients, and RBC and platelet transfusions between day -7 pretransplant and day +30 post-transplant do not contribute to aGVHD development in children undergoing HSCT by myeloablative conditioning, while ABO minor mismatch is associated with the development of aGVHD.

Thoracic Air Leak Syndrome, Pulmonary Aspergillosis, and COVID-19 Pneumonia After Allogeneic Stem Cell Transplantation in a Child With Myelodysplastic Syndrome.

Thoracic air leak syndromes (TALS) are very rare among the noninfectious pulmonary complications (PCs). They can either be idiopathic or have several risk factors such as allogeneic hematopoietic stem cell transplantation (allo-HSCT), graft versus host disease and rarely pulmonary aspergillosis. We present a 14-year-old girl with hypoplastic myelodysplastic syndrome who developed graft versus host disease on day 60, TALS on day 150, bronchiolitis obliterans syndrome on day 300, pulmonary aspergillosis on day 400 and COVID-19 pneumonia on day 575 after allo-HSCT. This is the first report of a child who developed these subsequent PCs after allo-HSCT. Therefore, the manifestations of these unfamiliar PCs like TALS and COVID-19 pneumonia, and concomitant pulmonary aspergillosis with management options are discussed.