zDVH-class: Class '"zDVH"'

In RadOnc: Analytical Tools for Radiation Oncology

Class "zDVH"

Description

A data structure containing axially-segmented Dose-Volume Histogram (zDVH) data and associated parameters for a single structure

Objects from the Class

Objects can be created by calls of the form new("zDVH", patient, structure.name, structure.volume, type, dose.max, dose.min, dose.mean, dose.median, dose.mode, dose.STD, conf.index, equiv.sphere, gradient, dose.rx, dose.fx, doses, dose.type, dose.units, volumes, volume.type, ...).

Slots

patient:

Name of the patient (e.g. "Jane Doe")

ID:

Additional patient identifier or medical record number (e.g. "123456789")

structure.name:

Name of the structure (e.g. "Stomach")

structure.volume:

Volume of the structure (in cubic centimeters)

type:

A character string specifying the DVH type (must be one of "cumulative" or "differential")

dose.max:

Maximum (point) dose contained within the structure

dose.min:

Minimum dose contained within the structure

dose.mean:

Mean dose to the structure

dose.median:

Median dose to the structure

dose.mode:

Modal dose to the structure

dose.STD:

Standard deviation of dose to the structure

conf.index:

Conformality index

equiv.sphere:

Equivalent sphere (diameter in centimeters)

gradient:

Dose gradient (in centimeters)

dose.rx:

Prescription dose (in units specified by dose.units)

dose.fx:

Fractional dose (in units specified by dose.units)

rx.isodose:

Isodose line (%) receiving prescription dose (default is 100%)

doses:

List of doses corresponding to "volumes"

dose.type:

A character string specifying the dose type (must be one of "relative" or "absolute")

dose.units:

A character string specifying the dose units (must be one of "cGy" or "Gy")

volumes:

Matrix containing NxM dimensions, with N=length(doses) and M representing the number of axial segments for which of each a DVH was obtained

volume.type:

A character string specifying the volume type (must be one of "relative" or "absolute")

Methods

[

Extract dose or volume parameter(s) from zDVH object. Only one parameter may be specified at a time. Parameter specification should be of the form ["<A><B><C>"]: <A> is equivalent to "V" or "D", representing a volume or dose, respectively; <B> usually denotes a numerical value specifying the dose or volume; and <C> represents the dose or volume units ("cGy", "Gy", "%", or "cc"). An example would be ["V20Gy"] which represents the volume of the structure receiving at least 20Gy dose. Specialized dosimetric keywords may also be used: "Dmax" (maximum dose), "Dmin" (minimum dose), "Dmean" (mean dose), "Dintegral" (estimated integral dose), "DRx" (prescription dose), and "volume" (total structure volume). If an improper parameter is specified however, NA results will be returned. See package documentation (vignette) for more details.

$

Extract a given parameter from a zDVH object

$<-

Assign a value to a given parameter within a zDVH object

c

Combine multiple zDVH objects into a single list

max

Extract maximum dose from zDVH object

mean

Extract mean dose from zDVH object

min

Extract minimum dose from zDVH object

names

Extract structure name from zDVH object

names<-

Assign structure name to zDVH object

print

Display summary of zDVH object

range

Extract dose range from zDVH object

show

Display summary of zDVH object

sum

Compute the total (summed) DVH from two or more zDVH and/or DVH objects. Note that structures are assumed to be non-overlapping; any overlaps in structure volumes may generate inaccurate dose summation.

Author(s)

Reid F. Thompson ([e-mail])

See Also

DVH, DVH.list, read.DVH

Examples

# Description of structure/slots in class
showClass("zDVH")

RadOnc documentation built on April 3, 2025, 7:23 p.m.