What is the conformity index?

Conformity index is introduced as an extension of section-by-section dosimetric analysis and dose-volume histograms and can be defined as an absolute value resulting from the ratio between a fraction of the tumour volume and the volume covered with the certain isodose line.

What is gradient index in radiotherapy?

Dose gradient index (DGI) quantifies the dose drop off. Tables of DGIs versus target volumes have been published for body sites, but none is available for brain. This study recommends guidelines for DGIs for brain SRS/SRT treatments based on clinical CyberKnife (CK) cases.

What is heterogeneity index?

Purpose/Objectives: Heterogeneity index (HI) has been described in the literature as a tool for evaluating dose gradients within a planning target volume (PTV). HI may be expressed as D1/D95 where D1 and D95 equal the dose encompassing 1% and 95% of the target volume.

How do you measure radiotherapy?

The radiation dose absorbed by a person (that is, the amount of energy deposited in human tissue by radiation) is measured using the conventional unit rad or the SI unit gray (Gy). The biological risk of exposure to radiation is measured using the conventional unit rem or the SI unit sievert (Sv).

What is conformal radiotherapy?

3D conformal radiation therapy is a cancer treatment that shapes the radiation beams to match the shape of the tumor. In the past, radiation beams only matched the height and width of the tumor — exposing healthy tissue to radiation.

What Icru 62?

ICRU Report 62 provides recommendations on the volumes and absorbed doses that are important in prescribing, recording and reporting photon beam therapy, utilizing the new and improved irradiation techniques that have become available since the publication of ICRU Report 50 in 1993.

How do you calculate gradient index?

Gradient Index: GI = PIVhalfPIV where PIVhalf is the prescription isodose volume, at half the prescription isodose and PIV is the prescription isodose volume.

What is paddick conformity?

IAN PADDICK, M.SC. ✔ A conformity index is a measure of how well the volume of a radiosurgical dose distribution conforms to the size and shape of a target volume.

What is i2 heterogeneity?

Heterogeneity in meta-analysis refers to the variation in study outcomes between studies. The I² statistic describes the percentage of variation across studies that is due to heterogeneity rather than chance (Higgins and Thompson, 2002; Higgins et al., 2003).

What homogeneity means?

1 : the quality or state of being of a similar kind or of having a uniform structure or composition throughout : the quality or state of being homogeneous.

What is the normal amount of radiotherapy?

Most people have 5 treatments each week (1 treatment a day from Monday to Friday, with a break at the weekend). But sometimes treatment may be given more than once a day or over the weekend.

What is the conformity index for radiation therapy?

Radiation Therapy Oncology Group criteria. If the conformity index is situated between 1 and 2, treatment is considered to comply with the treatment plan; an index between 2 and 2.5, or 0.9 and 1, is considered to be a minor violation, and an index less than 0.9 or more than 2.5 is considered to be a major violation.

How many teletherapy isodose plans are needed for radiation therapy?

Teletherapy isodose plan is considered medically necessary for a given course of radiation therapy to a specific volume of interest. The typical course of radiation therapy will require from one to three isodose plans. Usually only one plan per volume of interest will be sufficient, though some patients

Is the freestanding radiation therapy center covered by Medicare?

Freestanding Radiation Therapy Center Services and supplies furnished by auxiliary personnel in the care of a patient and “Incident To” a physician’s professional services are a covered Medicare benefit under Section 1861(s)(2)(A) of the Social Security Act.

How is radiation therapy covered under Social Security?

Radiation therapy services furnished in a freestanding radiation therapy center are covered under a separate benefit category from therapeutic services provided in a hospital outpatient department. Freestanding center radiation therapy services are specifically covered under Section 1861(s)(4) of the Social Security Act.