ESTRO 2024 - Abstract Book

S2062

Clinical - Paediatric

ESTRO 2024

intervention for hydrocephalus–ommaya reservoir insertion (1), ventriculostomy (1), and ventriculoperitoneal shunt (2). Patients received a variety of interventions, including systemic therapies and surgical procedures, as described in Table 1, to treat clinically significant pseudoprogression.

Intervention

Number of patients (%)

Steroids

5 (11.1%)

Bevacizumab

1 (2.22%)

Pentoxifylline and Vitamin E

1 (2.22%)

Cyst fenestration

1 (2.22%)

Cyst aspiration

1 (2.22%)

Table 1 : Interventions for pseudoprogression

There was a trend towards a higher probability of developing pseudoprogression in patients receiving lower doses (<54Gy) although this was not statistically significant (p=0.064) (Figure 1).

Figure 1 : Freedom from pseudoprogression by total dose

Univariate logistic regression modelling did not show any statistical significance between pseudoprogression outcome and volume of the CTV (Clinical Target Volume) (p=0.92), prior chemotherapy (p=0.60), prior surgery(p=0.70) or age at treatment (p=0.45).

Conclusion:

We describe rates of pseudoprogression as well as local control and survival outcomes in our cohort of patients with a diagnosis of LGG treated with PBT. Our early data shows low rates of progression and only one recorded death. The rate of pseudoprogression in our cohort is similar to results in published series and is a relatively common phenomenon after radiotherapy treatment of paediatric type low grade glioma (2,4).

Keywords: Pseudoprogression, Low Grade Glioma, Radiotherapy