ESTRO 2022

Session Item

CNS

Session Code: 6002

Session Type: Poster (digital)

Track: Clinical

Unconventional treatment in GBM with pseudoprogression: low-dose radiotherapy could be an option?

Francesco Beghella Bartoli, Italy

Presentation Number: PO-1123

Abstract

Abstract Title:

Unconventional treatment in GBM with pseudoprogression: low-dose radiotherapy could be an option?

Authors:

Francesco Beghella Bartoli¹, Alessia Nardangeli¹, Silvia Chiesa¹, Ciro Mazzarella¹, Filippo Maria Topa¹, Elisabetta Lepre¹, Antonella Martino¹, Serena Bracci², Maria Chiara Cannatà², Giuseppe Maria Della Pepa³, Loredana Dinapoli⁴, Giuseppe Ferdinando Colloca¹, Silvia Longo¹, Mariangela Massaccesi¹, Alessandro Olivi^3,5, Maria Antonietta Gambacorta^1,6, Vincenzo Valentini^7,1, 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,, UOC di Radioterapia Oncologica, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; ³Fondazione Policlinico Universitario A. Gemelli IRCCS, Istituto di Neurochirurgia, Rome, Italy; ⁴Fondazione Policlinico Universitario A. Gemelli IRCCS, UOS Psicologia Clinica, Rome, Italy; ⁵Università Cattolica del Sacro Cuore, Istituto di Neurochirurgia, Rome, Italy; ⁶Università Cattolica del Sacro Cuore,, Istituto di Radiologia, Rome, Italy; ⁷Università Cattolica del Sacro Cuore, Istituto di Radiologia, Rome, Italy

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Purpose or Objective

Pseudoprogression is still a challenging issue in clinical practice, occurring in about 20% of high-grade glioma patients treated with adjuvant radiation plus temozolomide (TMZ).¹ Pathological confirmation is the gold standard for the diagnosis of pseudoprogression but it is not often applicable, and it may take several months before pseudoprogression can be clearly distinguished from early tumor progression on follow-up imaging. The therapeutic approach is usually to continue with the adjuvant TMZ. According to our institutional experience in taking advantage of chemosensitive effect of low dose fractionated radiotherapy in Glioblastoma Multiforme (GBM)^2-3-4 at recurrence or at diagnosis with poor prognosis, we explored the safety and efficacy of low-dose radiotherapy plus temozolomide in patients with GBM with evidence of pseudoprogression after radiochemotherapy .

Material and Methods

Patients affected by GBM previously treated by primary standard radiochemotherapy with evidence of pseudoprogression during adiuvant chemotherapy with temozolomide were enrolled. Radiologically, pseudoprogression was defined as a new or enlarging area(s) of contrast agent enhancement, in the absence of true tumor growth. Low dose radiotherapy (0.60 Gy twice daily over 5 days, every 28 days) with concurrent temozolomide for two cycles was administered. Primary endpoints were toxicity, progression free survival (PFS) and overall survival (OS).

Results

A total of twenty-seven patients were enrolled from January 2018 to August 2020. Acute hematologic toxicity G1-G2 was observed in 6 patients (22.2%) and G3 in 1 patient (3.7%). No acute neurological toxicity was detected. Two patients (7.4%) had partial response after low-dose radiotherapy while stable disease was registered in 10 patients (37%) for at least 8 weeks. Fifteen patients experienced progressive disease (55.6%). With a median FUP of 20 (range 4-35 months), the median OS was 15 months with a 1-year OS of 61.3%, while the median PFS was 9 months with a 1-year PFS rate of 36%.

Conclusion

Low-dose radiotherapy with concomitant temozolomide was well tolerated and could be useful in continuing the use of the first-line chemotherapy in patients with pseudoprogression, reserving the shift to a second line of chemotherapy only for those patients with a progression disease.

1. Kruser TJ, et al. Pseudoprogression after glioma therapy: a comprehensive review. Expert Rev Neurother. 2013;13(4):389–403.

2. Balducci M, et al. Low-dose fractionated radiotherapy and concomitant chemotherapy in glioblastoma multiforme with poor prognosis: a feasibility study. Neuro Oncol. 2012;14(1):79-86.

3. Balducci M, et al. Low-dose fractionated radiotherapy and concomitant chemotherapy for recurrent or progressive glioblastoma: final report of a pilot study. Strahlenther Onkol. 2014;190(4):370-376.

4. Chiesa S. et al. Hypofractionated and Low dose radiotherapty combined with Temozolamide in naïve unresectable glioblastoma: a pilot Study.