Efficacy of residual site RT in patients with primary mediastinal lymphoma with DS 4 following R-CHT
PO-1165
Abstract
Efficacy of residual site RT in patients with primary mediastinal lymphoma with DS 4 following R-CHT
Authors: Giuseppe Facondo1, Mattia Serio1, Giancluca Vullo1, Maria Paola Bianchi2, Sabrina Pelliccia2, Alice Di Rocco3, Tiziana Lanzolla4, Maurizio Valeriani1, Vitaliana De Sanctis1, Mattia Falchetto Osti1
1Università degli Studi di Roma "La Sapienza", A.O.U Sant'Andrea M-P, Radiation Oncology, Rome, Italy; 2Università degli Studi di Roma "La Sapienza", A.O.U Sant'Andrea M-P, Hematology, Rome, Italy; 3Università degli Studi di Roma "La Sapienza", Policlinico Umberto I, Hematology, Rome, Italy; 4Università degli Studi di Roma "La Sapienza", A.O.U Sant'Andrea M-P, Nuclear Medicine, Rome, Italy
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Purpose or Objective
To evaluate the efficacy of residual site radiation therapy (RSRT) in term of progression free (PFS) and overall survival (OS) in patients with primary mediastinal lymphoma (PMBCL) with Deauville Score 4 (DS 4) following rituximab and chemotherapy treatment (R-CHT) in a monoinstitutional retrospective study.
Material and Methods
Between 2010 and 2022 we analysed 31 patients with PMBCL with median age of 34 years (range 16-52years). Thirteen patients were females and 18 were males. At the end of R-CHT, patients were evaluated by 18F-fluorodeoxyglucose positron-emission tomography, showing DS4, and were treated with adjuvant RSRT. RT was delivered by Intensity-modulated radiation therapy (IMRT) and three-dimensional conformal RT (3D-CRT). The gross tumor volume (GTV) included morphological mediastinal residual disease after R-CHT. Most patients underwent image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) system as daily pre-treatment imaging. All patients were evaluated every 3 months for the first 2 years and every 6 months afterwards for a period of at least 5 years with clinical and radiological procedures as required. The Kaplan-Meier method was used to calculate survival curve estimates.
Results
All patients received RSRT with a dose of 30 Gy in 15 fractions. Median follow-up was 43 months (range 1-148 months). The median survival was 49 months (range 8-155 months) and 10-years OS was 100%. 1 year and 5 years PFS was 96.6% and 91.5% respectively. Patients with progressive disease have been treated with high-dose chemotherapy (HDC) and/or autologous stem cell transplant (auto-SCT.)
Conclusion
RSRT in patients with PMBCL treated with ICHT and DS 4 did not impact unfavourably on patient survival.