Scalp and Cranium Radiation Therapy Using Modulation (SCRUM) and Bolus

Abstract

Purpose A bolus is usually required to ensure radiation dose coverage of extensive superficial tumors of the scalp or skull. Oftentimes, these boluses are challenging to make and are nonreproducible, so an easier method was sought. Methods and Materials Thermoplastic sheets are widely available in radiation oncology clinics and can serve as bolus. Two template cutouts were designed for anterior and posterior halves to encompass the cranium of children and adults. Results The created bolus was imaged using computed tomography, which demonstrated good conformity and minimal air gaps. Conclusions Although making a bolus for treating superficial tumors of the scalp or head and neck is challenging, the presented technique enables thermoplastic to be used as a bolus and is quick, easy, and reproducible.

Modulating Synchrotron Microbeam Radiation Therapy Doses for Preclinical Brain Cancer

“…This is promising for the use of a bolus in MRT. Radiotherapy with a bolus increases skin dose [30,31], and we can confirm that this is also the case with the MRT valley dose, and not so with the peak dose, which is 20% less without the bolus. It should be noted that the high dose rates used for MRT (280-6000 Gy/s in-beam) may further facilitate skin-tissue sparing due to the FLASH effect above 40 Gy/s [12].…”

“…Dose modulation in radiotherapy is achieved with a bolus material. Bolus use in brain radiotherapy with megavoltage or electron beams is often implemented to reduce hotspots and improve the dose coverage of superficial tumors [30,31]. For the first time, we will use a dose-modulating bolus for MRT tumor dose conformity and investigate the effect of a bolus on critical structures.…”

Total scalp irradiation: A study comparing multiple types of bolus and VMAT optimization techniques

“…Numerous radiotherapy clinics have investigated various bolus designs for TSI over the past several years to help obtain a more homogeneous dose to the total scalp 11,12 . While Superflab is commonly cut and pieced together to form a helmet, it can be cumbersome to craft and may not be reproducible for daily treatments 13 . Thermoplastic sheets are another commercial option that when heated, soften and easily conform to the scalp, helping to reduce air gaps.…”

“… 11 , 12 While Superflab is commonly cut and pieced together to form a helmet, it can be cumbersome to craft and may not be reproducible for daily treatments. 13 Thermoplastic sheets are another commercial option that when heated, soften and easily conform to the scalp, helping to reduce air gaps. However, once the plastic bolus dries, it will harden and can become uncomfortable, even painful, increasing the chance of setup error.…”