Treatment outcomes and target delineation utilizing CT and MRI in 13 dogs treated with a uniform stereotactic radiation therapy protocol (16 Gy single fraction) for pituitary masses : (2014-2017)

© 2020 John Wiley & Sons Ltd..

Canine pituitary tumours are increasingly treated with stereotactic radiotherapy (SRT). Here, we report clinical outcomes in dogs treated with single-fraction SRT; we also explore technical aspects of SRT treatment planning. A single-institution retrospective study was performed, including any dog with a pituitary mass (PM) that was treated using a standardized single-fraction (16 Gy) SRT protocol between 2014 and 2017. Via medical records review, 13 cases were identified. Nine dogs neurologically improved after SRT. Four dogs experienced MRI-documented tumour volume reduction. Nine dogs experienced neurologic decline in 1.5 to 18 months after SRT and were euthanized. The median overall survival time was 357 days, with 15% alive 18 months after SRT. To better understand whether SRT target delineation is predictably altered by use of magnetic resonance imaging (MRI) in addition to computed tomography (CT), two radiation oncologists (RO) retrospectively re-evaluated all imaging studies used for SRT planning in these 13 cases. Gross tumour volume (GTV) was contoured on co-registered CT and MRIs for each case. In seven cases, CT alone was deemed inadequate for GTV contouring by at least one RO. T1 post-contrast MRI was considered the ideal image for GTV contouring in 11 cases. Contouring on MRI yielded larger GTV than CT for 11 cases. Inter-observer variability existed in each case and was greater for MRI. In summary, use of co-registered CT and MRI images is generally considered advantageous for PM delineation when using SRT. Notably, survival times reported herein are shorter than what has previously been reported for PM treated with finely fractionated full-course RT protocols.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:19

Enthalten in:

Veterinary and comparative oncology - 19(2021), 1 vom: 30. März, Seite 17-24

Sprache:

Englisch

Beteiligte Personen:

Gieger, Tracy L [VerfasserIn]
Nolan, Michael W [VerfasserIn]

Links:

Volltext

Themen:

Brain tumour
Intracalvarial
Journal Article
Radiosurgery
Radiotherapy
SRS

Anmerkungen:

Date Completed 22.09.2021

Date Revised 22.09.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/vco.12627

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311277292