Dosimetric evaluation of parallel opposed spatially fractionated radiation therapy of deep‐seated bulky tumors

Abstract

Application of a single fraction of parallel opposed GRID beams as a means of increasing the efficiency of radiation delivery to deep-seated tumors has been investigated. This evaluation was performed by measurement of dosimetric characteristics of the GRID radiation field in parallel opposed and single beam geometry. The limitations of the parallel opposed technique in terms of field size and tumor thickness have been evaluated for the conditions of acceptable spatial modulation. The results of this investigation have demonstrated an increase in therapeutic advantage for the parallel opposed technique over the single beam method when treating a deep seated tumor.

Technical Note: Fabricating Cerrobend grids with 3D printing for spatially modulated radiation therapy: A feasibility study

“…Megavoltage grid therapy itself has over six decades of history, spanning multiple tumor types and sites. [3][4][5][6][7][8][9][10][11] With either a curative or palliative intent, grid therapy is often delivered in a single fraction with 15-20 Gy at the depth of maximum dose (d max ). Skin is the organ at risk during grid therapy, and the clinical benefit of skin sparing is achieved by delivering a beam of a grid pattern.…”

Evaluation of a commercially‐available block for spatially fractionated radiation therapy

“…( 1 – 3 ) The technique has shown high efficacy for bulky tumors receiving doses of 10 to 20 Gy in a single fraction. ( 2 ) The biological mechanisms of this technique are not fully understood, although several theories have been proposed.…”

“…( 1 – 6 ) Although the results have been promising, the number of institutions practicing GRID therapy are very few. Many of the reasons for this hesitance have to do with the construction of the GRID itself.…”

Dose evaluation of Grid Therapy using a 6 MV flattening filter‐free (FFF) photon beam: A Monte Carlo study

“…If needed, higher PVDR in normal tissues can be obtained by increasing ctc, while low PVDR values or a quasi‐homogenous dose distribution could be obtained at the tumor by using an interlaced irradiation. For instance, the use of two orthogonal beams would produce more homogeneous dose distributions . Several arrays could also be used by interlacing several beams from several directions.…”