Abstract
Targeted radiation therapy (TRT) is a strategy increasingly adopted for the treatment of different types of cancer. The urge for optimization, as stated by the European Council Directive (2013/59/EURATOM), requires the implementation of a personalized dosimetric approach, similar to what already happens in external beam radiation therapy (EBRT). The purpose of this paper is to provide a thorough introduction to the field of personalized dosimetry in TRT, explaining its rationale in the context of optimization and describing the currently available methodologies. After listing the main therapies currently employed, the clinical workflow for the absorbed dose calculation is described, based on works of the most experienced authors in the literature and recent guidelines. Moreover, the widespread software packages for internal dosimetry are presented and critical aspects discussed. Overall, a selection of the most important and recent articles about this topic is provided.
Highlights
Targeted radiation therapy (TRT) can be divided into two subgroups, depending on how the radiopharmaceutical reaches the tumoral site: molecular radiation therapy (MRT) [2] and selective intra-arterial radiation therapy (SIRT) [3]
In order to avoid possible significant errors, the European Association of Nuclear Medicine (EANM) guidelines recommend that the fractional contribution of the Time Integrated Activity (TIA) from the extrapolations should be less than 20% [62]
This paper provides an examination of methods and techniques used in TRT, with a focus on personalized dosimetry
Summary
TRTs can be divided into two subgroups, depending on how the radiopharmaceutical reaches the tumoral site: molecular radiation therapy (MRT) [2] and selective intra-arterial radiation therapy (SIRT) [3] The former uses the natural tropism of a radionuclide (e.g., 131 I for the thyroid or 223 Ra for bone tissue) or a vector molecule (e.g., PSMA or DOTATATE) selected according to biochemical properties of the disease (e.g., overexpression of specific receptors) so that the radiopharmaceutical binds preferentially to the target cells. The latter, instead, exploits the tumor vascularization: the radiopharmaceutical is directly injected, in the form of microspheres, into the tumor arterial blood circle and no active molecule is needed. The damage to the targeted cells is obtained through the emitted radiation and is expressed in terms of a physical quantity called absorbed dose, which is defined as the radiation energy absorbed per unit mass
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call