ESTRO 2022

Session Item

Monday

May 09

16:45 - 17:45

Room D1

CNS

Chair: Danielle Eekers, The Netherlands;

Co-Chair: Maarten Lambrecht, Belgium

Session Code: 3460

Session Type: Proffered Papers

Track: Clinical

17:35 - 17:45

How to manage consolidative radiotherapy after HD methotrexate in PCNSL patients: a phase II study

Silvia Chiesa, Italy

Presentation Number: OC-0929

Abstract

Abstract Title:

How to manage consolidative radiotherapy after HD methotrexate in PCNSL patients: a phase II study

Authors:

Silvia Chiesa¹, Francesco Beghella Bartoli¹, Ciro Mazzarella¹, Stefan Hohaus², Maria Chiara Cannatà¹, Francesco Catucci³, Francesco D'Alò⁴, Serena Bracci⁵, Alessia Nardangeli⁵, Antonella Martino⁶, Nicola Dinapoli⁵, Fabio Marazzi⁵, Stefania Manfrida⁵, Maria Antonietta Gambacorta^5,7, Cynthia Aristei⁸, Vincenzo Valentini^1,7, Mario Balducci^1,7

¹Fondazione Policlinico Universitario A. Gemelli IRCCS, UOC di Radioterapia Oncologica, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; ²Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy., UOC di Ematologia, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, , Rome, Italy; ³Mater Olbia Hospital, Radiation Oncology, Olbia, Italy; ⁴Fondazione Policlinico Universitario A. Gemelli IRCCS , UOC di Ematologia, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; ⁵ Fondazione Policlinico Universitario A. Gemelli IRCCS, UOC di Radioterapia Oncologica, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; ⁶ Fondazione Policlinico Universitario A. Gemelli IRCCS, UOC di Radioterapia Oncologica, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; ⁷Istituto di Radiologia, Università Cattolica del Sacro Cuore, Rome, Italy; ⁸Università degli studi di Perugia, Azienda Ospedaliera di Perugia, Sezione di Radioterapia Oncologica, Dipartimento di Chirurgia e Scienze Biomedicali, Perugia, Italy

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Purpose or Objective

The purpose of this study is to evaluate the addition of temozolomide (TMZ) to consolidation radiotherapy in a subset of patients with primary cerebral lymphoma (PCNSL) previously treated with high-dose methotrexate (MTX-HD) in terms of overall survival (OS).

Material and Methods

This study considered patients with histologically proven diagnosis of PCNSL treated in induction therapy with HD-MTX based chemotherapy who were not candidates for autologous stem-cell transplantation or other consolidation chemotherapy who were subsequently subjected to radiation therapy plus Temozolomide. Two clinical Target Volumes (CTVs) were defined: CTV2 was represented by Whole Brain plus leptomeninges until C2, reaching a dosage of 30 Gy in 15 daily fractions, while CTV1 comprising the initial disease location and residual mass if present. The total dose delivered on CTV1 was related to the type of response had to treatment with HD-MTX (complete response = 6 Gy, partial response = 10 Gy, progression disease = 16 Gy). Temozolomide was administered concomitantly at the dose of 75 mg/mq/die according to our previous phase I escalation study¹

Results

Thirty-eight patients were enrolled from March 2004 to December 2019: 21 male and 17 female. Median age was 66 yrs (range 23-82). Twenty-five out of 38 patients received two cycle of MTX-HD, 9 patients received only one cycle of HD-MTX because of hematological toxicity and 4 patients did not received any cycle due to poor performance status. Ten patients underwent macroscopic surgical excision, while 28 patients received biopsy. In 28 patients TMZ was associated to radiotherapy. At a median follow up of 113 months (range 21-207), 4 of 38 patients (10,5%) are alive and without disease, 32 patients died because of disease and two patients died because of other causes. Median OS for all patients was 18.3 months with at 1 yrs OS of 60% and at 3 yrs OS of 36% of patients (Fig.1). The use of concomitant TMZ significantly impact the OS (p=0.002) (Fig.2).

Conclusion

This analysis shows that the addition of TMZ at the dose of 75 mg/mq, in a selected patients population, could be a reasonable option as consolidation therapy after HD-MTX , due to the better outcome compared to RT alone and to the clinical outcomes of the entire study population aligned with literature data².

1. Chiesa S, Hohaus S, Falcinelli L et al. Chemoradiotherapy with temozolomide after high-dose methotrexate for primary CNS lymphoma: a multicenter phase I study of a response-adapted strategy. Ann Hematol. 2020 Oct;99(10):2367-2375. doi: 10.1007/s00277-020-04220-1.

2. Houillier C, et al Management and outcome of primary CNS lymphoma in the modern era: An LOC network study. Neurology. 2020 Mar10;94(10):e1027-e1039. doi: 10.1212/WNL.0000000000008900. Epub 2020 Jan 6. PMID: 31907289; PMCID: PMC7238921.