MEDRADSC 2AA3 - Lecture 7.3 - The Application of Ultrasound in Radiation Therapy

ultrasound usage in RT

used for soft-tissue visualization and plays a role in staging, prognosis and optimizing therapeutic decisions

ultrasound is most commonly integral in __________.

brachytherapy

ultrasound can be used in the investigative workup involving:

A. Local tumour invasion (T)

B. Lymph node involvement (N)

C. Distant metastases (M)

D. A and B

E. All of the above

D

benefits of ultrasound-guided biopsies/FNAs for breast

reduced surgical need and risk

limitations of ultrasound-guided biopsies/FNAs for breast

inaccessible locations in breast and small, thin breasts pose a challenge

benefits of ultrasound-guided biopsies/FNAs for prostate

no need for sedation

limitations of ultrasound-guided biopsies/FNAs for prostate

risk of infection, undersampling of anterior prostate and contraindicated by inflammatory bowel disease

endoscopic ultrasound (EUS) to treat GI cancers

superior to other imaging modalities, provides accurate T and N staging, reduces number of unnecessary surgeries and local recurrences

limitations of EUS

operator-dependant, reduced accuracy in re-staging, less accurate in stage superficial tumours and contraindicated by esophageal malignancies

further advancements in EUS

elastography and contrast-enhanced ultrasounds

what imaging modalities are the standard of care for pancreatic cancers?

CT and MRI

why might EUS be advantageous for diagnosing pancreatic cancers?

accurate T staging, especially for early cancers with small lesions

what imaging modality is the standard of care for sampling mediastinal lymph nodes?

EUS

what are some other applications of EUS?

tumour ablation, direct injection chemotherapy and EUS-FNI

EUS-FNI

used to implant a fiducial marker into the tumour

US can provide guidance for both ____ and _____ radiation therapy.

internal, external

what is one of the longest standing applications of ultrasound in RT?

brachytherapy for gynaecological cancers, placement of applicators and measurement of uterine wall thickness

IGRT using US in prostate cancer patients

use of robotic ultrasound system which is integrated with linacs for intrafractional therapy guidance

areas of research and advancement with microbubbles, US and RT

microbubbles beingused to deliver oxygen to hypoxic tumours, increasing free radical formation and damage to the tumour cells