{Reference Type}: Journal Article
{Title}: The dosimetric parameters impact on local recurrence in stereotactic radiotherapy for brain metastases.
{Author}: Berthet C;Lucia F;Bourbonne V;Schick U;Lecouillard I;Le Deroff C;Barateau A;de Crevoisier R;Castelli J;
{Journal}: Br J Radiol
{Volume}: 97
{Issue}: 1156
{Year}: 2024 Mar 28
{Factor}: 3.629
{DOI}: 10.1093/bjr/tqae029
{Abstract}: <B>OBJECTIVE: </B>Stereotactic radiotherapy (SRT) for brain metastases (BM) allows very good local control (LC). However, approximately 20%-30% of these lesions will recur. The objective of this retrospective study was to evaluate the impact of dosimetric parameters on LC in cerebral SRT.<BR><B>METHODS: </B>Patients treated with SRT for 1-3 BM between January 2015 and December 2018 were retrospectively included. A total of 349 patients with 538 lesions were included. The median gross tumour volume (GTV) was 2 cm3 (IQR, 0-7). The median biological effective dose with α/β = 10 (BED10) was 60 Gy (IQR, 32-82). The median prescription isodose was 71% (IQR, 70-80). Correlations with LC were examined using the Cox regression model.<BR><B>RESULTS: </B>The median follow-up period was 55 months (min-max, 7-85). Median overall survival was 17.8 months (IQR, 15.2-21.9). There were 95 recurrences and LC at 1 and 2 years was 87.1% (95% CI, 84-90) and 78.1% (95% CI, 73.9-82.4), respectively. Univariate analysis showed that systemic treatment, dose to 2% and 50% of the planning target volume (PTV), BED10 > 50 Gy, and low PTV and GTV volume were significantly correlated with better LC. In the multivariate analysis, GTV volume, isodose, and BED10 were significantly associated with LC.<BR><B>CONCLUSIONS: </B>These results show the importance of a BED10 > 50 Gy associated with a prescription isodose <80% to optimize LC during SRT for BM.<BR><B>CONCLUSIONS: </B>Isodose, BED, and GTV volume were significantly associated with LC. A low isodose improves LC without increasing the risk of radionecrosis.