Search

T Kumar,1–3 A Schernberg,1,2F Busato,1,2M Laurans,1,2I Fumagalli,1,2I Dumas,1,2E Deutsch,1,2C Haie-Meder,1,2C Chargari1–2,4–51Brachytherapy Unit, Gustave Roussy, Cancer Campus, Villejuif, France; 2Radiotherapy Department, Gustave Roussy, Villejuif, France; 3Radiotherapy Department, University Hospital of Grenoble, Grenoble, France; 4Departement ’Effets Biologiques des Radiations’, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France; 5French Military Health Academy, Ecole du Val-de-Grâce, Paris, FrancePurpose: To evaluate theassociation between pelvic bone marrow (BM) dose volume parameters and probability of acute hematological toxicity (HT), a cohort of cervical cancer patients receiving definitive chemoradiation (CRT) was assessed.Materials and methods: Medical records of patients treated by CRT (45 Gy in 25 fractions, without dose constraints applied to the BM) were reviewed. Baseline and weekly hematological parameters were collected. BM was retrospectively delineated and divided into sub-sites: iliac crests, lower pelvis, lumbosacral region. BM volumes (V) receiving 5, 10, 20, 30, 40 Gy (V5, V10, V20, V30, V40, respectively) and mean dose (Dm) were calculated. Logistic regression was used to analyze associations between HT and dose-volume histograms parameters.Results: 114 patients were included. 75.4% were treated with 3D radiation therapy and 24.6% were receiving intensity modulated radiation therapy (IMRT). Neither age, chemotherapy regimen (cisplatin vs carboplatin), number of chemotherapy cycles, performance status, body mass index, or para-aortic irradiation were associated with HT. In univariate analysis, more frequent grade 3+ leukopenia was found in the IMRT group (odds ratio [OR]: 3.5; 95% CI, 1.4–9.1; p=0.007). In multivariate analysis, grade 4 HT was associated with lower pelvis V5>95% (OR 4.1; 95% CI, 1.6–14. p=0.02), lower pelvis V20>45% (OR 3.5; 95% CI, 1.1–13.4; p=0.05), total pelvic bone V20>65%, and iliac crests Dm >31 Gy (OR 4.5; 95% CI, 1.4–14.7; p=0.02).Conclusion: The following dose constraints could be proposed to decrease acute HT risk: lower pelvis V5

Background: Embryonal tumors represent a heterogeneous entity of brain tumors that need a multidisciplinary treatment including cranio-spinal irradiation (CSI), with a known impact on the acute toxicity. Proton therapy (PT) boasts a reduction in acute hematological toxicity. Methods: We retrospectively examined 20 pediatric patients affected by high-risk medulloblastoma and other rare embryonal brain tumors subjected to CSI with PT from September 2016 to April 2020. Before CSI, all patients received induction chemotherapy, and three patients additionally received two high-dose courses with thiotepa, followed by an autologous haemopoietic stem cell transplantation. We recorded the total white blood cell count, absolute neutrophil count, platelets, and hemoglobin levels for all patients during PT. Results: Leucocytes and neutrophils decreased directly after the beginning of treatment, reaching a complete recovery at the end of treatment. Hemoglobin values remained constant over the treatment course. The median platelet value decreased until reaching a plateau around halfway through therapy, followed by a slow increase. No cases of febrile neutropenia or severe infections were reported. No treatment discontinuation due to hematological toxicity was necessary. Conclusions: CSI with PT was proven to be safe in this setting of pediatric patients. Our study showed that despite all patients having undergone chemotherapy prior to irradiation, no serious hematological toxicity was reported at the end of the treatment with PT, and, therefore, no treatment was discontinued or delayed.