ESTRO 2024 - Abstract Book

S2066

Clinical - Paediatric

ESTRO 2024

Considering all 7 cases, the average dose covering 95% of PTV (D95%) was greater than 96% of the prescription dose while the D98% was greater than 91%. The D90% of the Chestwall including the ribs had a mean value of 95.5% of the prescription dose. With the optimization strategy of assigning a dose greater than the prescription to the bones, there was a 4% increase in the mean D95% of Bones except ribs and a 3% increase to all bones. The total lung volume for this cohort ranged from 245cc to 776cc with a mean volume of 451.5cc, which is around 1/10 of an adult’s total lung volume. An average mean lung dose of 7.6 Gy was achieved. The average BOT was 20 minutes. Patient 4 was 135cm tall, and since the treatment length was beyond the travel range of the Radixact couch, the patient had to be treated with two plans with the region of overlap at the thigh. This patient was treated without anesthesia.

Conclusion:

Vaclok well conformed to the patient's contours ensures good immobilization, which is crucial for this treatment. A virtual bolus was employed to guarantee sufficient dose coverage of the fingers and toes, accounting for potential deviations from their scanned locations. Elevating the dose to the bones enhanced the dose distribution, crucial for an improved therapeutic result, thereby facilitating a hybrid Total Marrow Irradiation-Total Body Irradiation (TMI-TBI) treatment approach. Optimal pitch and modulation factor were chosen to achieve a more homogenous plan and minimize the treatment duration.

Keywords: TBI, Tomotherapy, dosimetric

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Association of brain metastases with classification, treatment, and outcomes of extracranial OMD

Sebastian M Christ 1 , Gabriel W. Thiel 2 , Philip Heesen 2 , Michael Mayinger 1 , Jonas Willmann 1 , Maiwand Ahmadsei 1 , Urs J. Muehlematter 3 , Alexander Maurer 3 , Josef A. Buchner 4 , Jan C Peeken 4 , Rifaquat Rahman 5 , Ayal Aizer 5 , Emilie Le Rhun 6,7 , Nicolaus Andratschke 1 , Michael Weller 6 , Martin Huellner 3 , Matthias Guckenberger 1