MEDRADSC 2AA3 - Lecture 7.4 - The Application of Nuclear Medicine in Radiation Therapy

what is the most common use of nuclear medicine in radiation therapy?

PET

PET is effective in RT in that:

it is accurate in detecting and staging diseases and assessing treatment response

what are the 5 most common types of cancer?

lung, breast, prostate, colorectal and lymphoma

F-18 FDG is the radiotracer ________ of PET/CT oncology.

workhorse

F-18 FDG is a ___ analog.

glucose

what is the half-life of Ff-18 FDG?

<2 hours

PET adds a metabolic dimension allow for?

identification of non-malignant areas, identifying targets not visualized with other imaging modalities and shows areas of hypoxia, necrosis, etc.

use of PET in non small cell lung cancer

distinguishes between active tumour and atelectasis, adjustment of tumour volumes and increases dose precision

use of PET in RT in the esophagus

PET can show the lower extent of the tumour volume when US guidance is obstructed

use of PET in colorectal cancer treatment

refines staging of patients who are thought to have a recurrence or oligometastatic disease

Recurrence of colorectal cancer occurs in ______% of patients who have had surgery.

30-40

use of PET in prostate cancer treatment

determines area of spread so appropriate treatment can be planned, usually used for high risk patients or patients with recurrent disease

what radiotracer is used in PET for prostate cancer? why?

Ga-68-PSMA, it links to prostate-specific antigens and localizes cancer cells

what are other ways PET can be used in RT?

differentiation of benign and malignant diseases, staging, selecting region of tumour to biopsy and evaluating effectiveness of treatment

use of PET to detect SPN in RT

F-18 FDG PET is found to be equivalent to contrast CT in differentiating between benign and malignancies

SPN

solitary pulmonary nodule, 50% will be malignant

PET/CT can improve the staging of ___ disease and _______/_____ disease

local, regional, distant

PET/CT can be used for selecting region of tumour to be ______.

biopsied

F-18 FDG can indicate optimal site for biopsy in _______ _____, and can direct biopsies in ____ _____.

brain lesions, bone lesions

Ga-68 PSMA can show neoplastic active areas of the ________.

prostate

Lugano classification

uses 5-point Deauville scale

5-point Deauville scale

compares FDG uptake in lymphoma tissue to mediastinum and liver uptake

Deauville scale values

1&2 - complete metabolic response

3 - grey area

4 - partial metabolic response

5 - partial response, progressive disease