With CT-based Monte Carlo (MC) dose calculations, material composition is often assigned based on the standard Hounsfield unit ranges. This is known as the density threshold method. In bolus electron conformal therapy (BolusECT), the bolus material, machineable wax, would be assigned as soft tissue and the electron density is assumed equivalent to soft tissue based on its Hounsfield unit. This ...

Simple and easy methods to evaluate swallowing are required because of the recently increased need of rehabilitation for dysphagia. "Artificial food bolus", but not "artificial food", would be a valuable tool for swallowing evaluation without considering the mastication effect which is altered according to the individual's oral condition. Thus, this study was carried out to fabricate artificial...

A product available commercially for making dental impressions, Jeltrate Plus, was evaluated as a tissue equivalent bolus material. Jeltrate Plus was found to be tissue equivalent in 6 and 15 MV photon energy beams and 6, 12, and 20 MeV electron energy beams. As a first step, different preparations for making the bolus material were investigated and an optimal mixture was determined to be two p...

In electron and proton radiotherapy, applications of patient-specific electron bolus or proton compensators during radiation treatments are often necessary to accommodate patient body surface irregularities, tissue inhomogeneity, and variations in PTV depths to achieve desired dose distributions. Emerging 3D printing technologies provide alternative fabrication methods for these bolus and compe...

BACKGROUND The classic Kaposi's sarcoma (KS) patients usually present with progressive skin lesions over the lower extremities, following an indolent course. Although radiotherapy is an effective treatment for KS, radiation over these lesions is not without difficulty. The intrinsic difficulty resides in how a homogenous radiation dose over superficial lesions involving large areas and irregula...

Bolus materials are occasionally used during the high energy photon and electron radiation treatments of head, neck, breast, and chest wall areas in order to deliver the full prescribed dose to the skin surface and underlining tissue. Where skin surface curvatures make uniform contact between the bolus material and skin surface difficult, we have studied a new bolus material called Elasto-gel. ...

Several vascular abnormalities related with urinary system such as crossing accessory renal vessels, retroiliac ureters, retrocaval ureters, posterior nutcracker syndrome, and ovarian vein syndrome may be responsible for urinary collecting system obstruction. Split-bolus magnetic resonance urography (MRU) using contrast material as two separate bolus injections provides superior demonstration o...

A three-dimensional (3D)-printed customized bolus (3D bolus) can be used for radiotherapy application to irregular surfaces. However, bolus fabrication based on computed tomography (CT) scans is complicated and also delivers unwanted irradiation. Consequently, we fabricated a bolus using a 3D scanner and evaluated its efficacy. The head of an Alderson Rando phantom was scanned with a 3D scanner...