Clinical relevance of the radiation dose bath in lower grade glioma, a cross-sectional pilot study on neurocognitive and radiological outcome

Hiska L Van Der Weide,Justyna Kłos,Johannes A Langendijk,Charlotte L Brouwer,Peter F Sinnige,Ronald J.H Borra,Rudi A.J.O Dierckx,Rients B Huitema,Sandra E Rakers,Anne M Buunk,Jacoba M Spikman,Ingeborg B Bosma,Roelien H Enting,Merethe Blandhol,Roland K Chiu,Anouk Van Der Hoorn,Miranda C.A Kramer

doi:10.1016/j.ctro.2022.02.001

Hiska L Van Der Weide, Justyna Kłos + Show 15 more

Open Access

https://doi.org/10.1016/j.ctro.2022.02.001

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Abstract

AimTo investigate the clinical relevance of the radiotherapy (RT) dose bath in patients treated for lower grade glioma (LGG). MethodsPatients (n = 17) treated with RT for LGG were assessed with neurocognitive function (NCF) tests and structural Magnetic Resonance Imaging (MRI) and categorized in subgroups based on tumour lateralisation. RT dose, volumetric results and cerebral microbleed (CMB) number were extracted for contralateral cerebrum, contralateral hippocampus, and cerebellum. The RT clinical target volume (CTV) was included in the analysis as a surrogate for focal tumour and other treatment effects. The relationships between RT dose, CTV, NCF and radiological outcome were analysed per subgroup. ResultsThe subgroup with left-sided tumours (n = 10) performed significantly lower on verbal tests. The RT dose to the right cerebrum, as well as CTV, were related to poorer performance on tests for processing speed, attention, and visuospatial abilities, and more CMB.In the subgroup with right-sided tumours (n = 7), RT dose in the left cerebrum was related to lower verbal memory performance, (immediate and delayed recall, r = −0.821, p = 0.023 and r = −0.937, p = 0.002, respectively), and RT dose to the left hippocampus was related to hippocampal volume (r = −0.857, p = 0.014), without correlation between CTV and NCF. ConclusionBy using a novel approach, we were able to investigate the clinical relevance of the RT dose bath in patients with LGG more specifically. We used combined MRI-derived and NCF outcome measures to assess radiation-induced brain damage, and observed potential RT effects on the left-sided brain resulting in lower verbal memory performance and hippocampus volume.

Highlights

Radiotherapy (RT) is an important treatment modality in the man agement of patients with lower grade glioma (LGG), for whom a long survival can be expected after treatment [1]
We divided the patient cohort in more homogeneous subgroups based on tumour location, evaluated RT dose and Magnetic Resonance Imaging (MRI) based endpoints in brain structures contralateral to the tumour, and included the RT clinical target volume (CTV) as a surrogate for focal tumour and treatment effects
Studying radiation-induced brain damage (RIBD), clinically manifesting as neuroanatomical changes and neurocognitive function (NCF) decline, in patients with LGG is challenging, since there are multiple factors that can have a profound influence on the outcome, including tumour progression and specifications of multi-modality treatment

Summary

Introduction

Radiotherapy (RT) is an important treatment modality in the man agement of patients with lower grade glioma (LGG), for whom a long survival can be expected after treatment [1]. Limiting radiation-induced brain damage (RIBD) is an important goal within the treatment strategy. Little is known about RT dose, volume, and timing effect relationships on non-tumour clinical outcomes in LGG patients. The NCF of patients with LGG is affected by multiple tumour and treatment related factors, identifying the RT contribution is complicated. After tumour progression and multi-modality therapy, the overall NCF function of patients seems most profoundly affected in processing speed, attention and executive function domains [7]. It is important to recognise that a cohort of patients with LGG can, from a functional point of view, be very heterogeneous regarding the vari ability in tumour location and size [8]

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