Definitions
| Term . | Definition . |
|---|---|
| Gross tumor volume (GTV) | Volume that contains the visible extent of the tumor that can be identifiable to contour and target using a CT scan |
| Clinical tumor volume (CTV) | Volume that contains a suspected microscopic disease; this could be around the gross tumor or at the original site after achieving complete remission to chemotherapy |
| Planning target volume | Volume that contains GTV and CTV; in addition, it accounts for all uncertainties like internal organ movement and daily patient’s setup errors |
| 3D planning radiation therapy | Forward planning, define anatomy on a CT scan, identify the target, and create a radiation beam arrangement to best encompass the target; generate the radiation dose that the operator judges acceptable |
| IMRT | The operator feeds the planning system the desired dose to the target and organs at risk upfront and what the end result dose distribution should look like, then the software will invert the problem and let the computer through a mathematical iteration search for the best and optimized solution; the software will keep trying until the operator judges the plan as acceptable |
| Linear energy transfer (LET) | Total amount of energy deposited per unit distance in biological materials by ionizing radiation |
| Radiobiological equivalent | Radiation relative biological effectiveness depending on LET, type of radiation particle, total dose, and dose fractionation |
| Proton active scanning | Proton beam delivery using a pencil beam that is precisely steered through the treatment volume, using a magnet in the beam line; the dose is then deposited layer by layer, allowing for a good conformation |
| Proton passive scattering | Spatially uniform dose distribution achieved by shaping the beam through a set of devices at the beam path |
| Intensity modulated proton therapy | Further shapes the active scanning to the distal tumor for irregularly shaped tumors |
| Term . | Definition . |
|---|---|
| Gross tumor volume (GTV) | Volume that contains the visible extent of the tumor that can be identifiable to contour and target using a CT scan |
| Clinical tumor volume (CTV) | Volume that contains a suspected microscopic disease; this could be around the gross tumor or at the original site after achieving complete remission to chemotherapy |
| Planning target volume | Volume that contains GTV and CTV; in addition, it accounts for all uncertainties like internal organ movement and daily patient’s setup errors |
| 3D planning radiation therapy | Forward planning, define anatomy on a CT scan, identify the target, and create a radiation beam arrangement to best encompass the target; generate the radiation dose that the operator judges acceptable |
| IMRT | The operator feeds the planning system the desired dose to the target and organs at risk upfront and what the end result dose distribution should look like, then the software will invert the problem and let the computer through a mathematical iteration search for the best and optimized solution; the software will keep trying until the operator judges the plan as acceptable |
| Linear energy transfer (LET) | Total amount of energy deposited per unit distance in biological materials by ionizing radiation |
| Radiobiological equivalent | Radiation relative biological effectiveness depending on LET, type of radiation particle, total dose, and dose fractionation |
| Proton active scanning | Proton beam delivery using a pencil beam that is precisely steered through the treatment volume, using a magnet in the beam line; the dose is then deposited layer by layer, allowing for a good conformation |
| Proton passive scattering | Spatially uniform dose distribution achieved by shaping the beam through a set of devices at the beam path |
| Intensity modulated proton therapy | Further shapes the active scanning to the distal tumor for irregularly shaped tumors |