PET/CT Response Assessment in Pediatric Hodgkin Lymphoma: Does Deauville Score 3 Reflect Negativity?

BACKGROUND: FDG PET is required for the staging and response evaluation of pediatric Hodgkin lymphoma. This study aimed to evaluate the outcomes of pediatric patients with Hodgkin's lymphoma based on interim PET CT assessments of early response following second-cycle chemotherapy using the Deauville score (DS). It also determines whether DS-3 is providing an adequate or inadequate response. METHODS: We conducted a retrospective cohort study including 504 pediatric patients with classic Hodgkin lymphoma who were treated with chemotherapy based on the Euro-Net protocol at the Children Cancer Hospital Egypt from March 2019 till the end of October 2022. RESULTS: Patients with adequate response DS 1/2 and DS 3 showed nearly the same 3-year event-free survival (EFS) of 91.9% and 91.5%, respectively, compared with those patients with inadequate response DS 4/5, who showed an EFS of 80.4% ( P =0.001). Patients with a DS 3 at interim PET evaluation were considered negative as DS 1/2. Patients of DS 3 group who did not receive radiotherapy had a much worse 3-year EFS by the existence of positive B symptoms, an ESR>30, or an advanced stage. Radiation therapy did not improve the 3-year EFS in patients with an inadequate response (DS4/5) and poor prognostic characteristics. They still need more advanced treatment. CONCLUSION: DS 1/2 and DS 3 had about the same 3-year EFS, which is better than the 3-year EFS of patients with DS 4/5. Therefore, we can classify DS 3 as having negative FDG PET CT uptake.

Plasma miRNA expression profile in pediatric pineal pure germinomas.

Background: Pure germinomas account for 40% of pineal tumors and are characterized by the lack of appreciable tumor markers, thus requiring a tumor biopsy for diagnosis. MicroRNAs (miRNA) have emerged as potential non-invasive biomarkers for germ cell tumors and may facilitate the non-invasive diagnosis of pure pineal germinomas. Material and methods: A retrospective chart review was performed on all patients treated at the Children's Cancer Hospital Egypt diagnosed with a pineal region tumor between June 2013 and March 2021 for whom a research blood sample was available. Plasma samples were profiled for miRNA expression, and DESeq2 was used to compare between pure germinoma and other tumor types. Differentially expressed miRNAs were identified. The area under the curve of the receive;r operating characteristic curve was constructed to evaluate diagnostic performance. Results: Samples from 39 pediatric patients were available consisting of 12 pure germinomas and 27 pineal region tumors of other pathologies, including pineal origin tumors [n = 17; pineoblastoma (n = 13) and pineal parenchymal tumors of intermediate differentiation (n = 4)] and others [n = 10; low-grade glioma (n = 6) and atypical teratoid rhabdoid tumor (n = 4)]. Using an adjusted p-value <0.05, three miRNAs showed differential expression (miR-143-3p, miR-320c, miR-320d; adjusted p = 0.0058, p = 0.0478, and p = 0.0366, respectively) and good discriminatory power between the two groups (AUC 90.7%, p < 0.001) with a sensitivity of 25% and a specificity of 100%. Conclusion: Our results suggest that a three-plasma miRNA signature has the potential to non-invasively identify pineal body pure germinomas which may allow selected patients to avoid the potential surgical complications.