ESTRO 2024 - Abstract Book

S829

Clinical - CNS

ESTRO 2024

Results:

36 patients were recruited between April 2017 and December 2018. Mean age was 64 years and median WHO performance status was 1 (range 0-2). At baseline, 65% of patients displayed NCF impairment in at least 1 NCF domain and 67% of patients demonstrated other neurological symptoms different from NCF. Higher dose to 0.1cc (D0.1cc) of the hippocampus ipsilateral to the brain metastasis was associated with reduced NCF test scores observed at each time point but this was most apparent at 1 month. Patients who received < 5Gy to 0.1 cc of the hippocampus demonstrated significantly lower change in mean HVLT-TR T-score at 1 month, compared to those who received ≥5 Gy, mean HVLT -TR T-score -1.6 (95%CI -4.3 - 1.1), vs -10.20 (95% CI -14.1-7.7) respectively, (p = 0.04). This difference was not detected at the 3-or 6-months timepoint. Between the two groups divided according to having greater or less than 5Gy to the ipsilateral hippocampus, there was no significant difference between the other brain dose parameters of D10cc, V12 Gy or V5 Gy. Participants who demonstrated a decline in HVLT-TR tests score at 1 month had a mean dose to 0.1cc of the hippocampus of 5.39 Gy compared to 2.28 Gy in participants who had maintained HVLT-TR T-score, (p-value with univariate analysis was 0.026). Multivariate analysis demonstrated that D0.1cc of >5Gy of the ipsilateral hippocampus was associated with decline in HVLT-TR at 1 month (p-value < 0.001) irrespective of whole brain V12Gy, V5Gy and D10cc. Hippocampus mean dose and D40 did not demonstrate the same relationship as dose to 0.1cc. Decline in NCF correlated with reduction in QoL measure at 1 month on the EORTC QLQ-C30 score. Mean global QoL scores at baseline, 1-, 3-, and 6-months were 66.39, 59.96, 62.75, and 66.67 respectively. Patients with reduced HVLT TR T-score at 1 month exhibited reduced global QoL scores compared to the group with retained T-score: mean scaled score of 67.36 (95% CI 61.99 – 72.73) vs 57.41, (95% CI 54.17 – 60.65) respectively.

Conclusion:

A significant proportion of patients in this study exhibited impaired NCF at baseline with greatest NCF decline seen at 1 month and recovery of NCF evident at 6 months. In this study, higher hippocampal D0.1cc doses were associated with acute reduction in NCF. NCF impairment has a significant impact on QoL in these patients who already have a limited prognosis. By reducing the dose to the hippocampus during treatment planning, it may be possible to prevent acute deterioration in NCF and improve patient’s QoL. Contouring the hippocampus as an organ at risk during SRS treatment planning and prioritising it as an optimal but not a mandatory constraint should be considered. Long term NCF impairment following SRS was not measured due to the constraints of this study.

Keywords:

cognitive

impairment,

hippocampus,

stereotactic

References:

1. BROWN, P. D., JAECKLE, K., BALLMAN, K. V., FARACE, E., CERHAN, J. H., ANDERSON, S. K., CARRERO, X. W., BARKER, F. G., 2ND, DEMING, R., BURRI, S. H., MENARD, C., CHUNG, C., STIEBER, V. W., POLLOCK, B. E., GALANIS, E., BUCKNER, J. C. & ASHER, A. L. 2016b. Effect of Radiosurgery Alone vs Radiosurgery With Whole Brain Radiation Therapy on Cognitive Function in Patients With 1 to 3 Brain Metastases: A Randomized Clinical Trial. JAMA, 316, 401-9.