The dosimetric advantages of perirectal hydrogel spacer in men with localized prostate cancer undergoing stereotactic ablative radiotherapy (SABR).
Med Dosim
; 47(2): 173-176, 2022.
Article
in English
| MEDLINE | ID: covidwho-1983651
ABSTRACT
To evaluate the dosimetric differences for patients receiving a perirectal hydrogel spacer (PR-HS) using SpaceOAR undergoing stereotactic ablative radiotherapy (SABR) for localized prostate cancer with the CyberKnife VSI system. Gold fiducial markers and a PR-HS was inserted in 22 consecutive patients with histologically confirmed localized prostate cancer. For planning comparison, dosimetry from the clinical plans was compared against replans based on a simulated rectum volume designed to recreate a clinically appropriate spacer-less anatomy for each patient. Both sets were planned to 36.25 Gy in 5 fractions using the treatment planning system associated with the CyberKnife VSI system. The aim was to ensure equivalent target coverage for both plans and to evaluate doses to the organs-at-risk (OARs) rectum, bladder and penile bulb. The median PR-HS implant volume was 11.2 cc (range 8.8 to 14.9 cc). The maximal median perirectal separation was 15.5 mm (10.5 to 20.7 mm). Statistically significant reductions were noted for the 3 OARs, with no statistically significant difference in planning target volumes or clinical target volume coverage. All rectal dose constraints were significantly improved in the PR-HS plans with a percentage dose difference of at least 24% (rectum V18.1Gy (%)) to 60.5% (rectum V36Gy (cc)). The bladder and penile bulb dose constraints parameters were also significantly improved the bladder V37Gy was reduced by 17.1%, V18.1Gy was reduced by 4.2%; the penile bulb D50% was reduced by 7.7%. The use of PR-HS was able to significantly reduce planned dose to the rectum, bladder and penile bulb with SABR techniques associated with the CyberKnife VSI system.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Prostatic Neoplasms
/
Radiosurgery
/
Radiotherapy, Intensity-Modulated
Type of study:
Experimental Studies
/
Prognostic study
Limits:
Humans
/
Male
Language:
English
Journal:
Med Dosim
Journal subject:
Radiotherapy
Year:
2022
Document Type:
Article
Affiliation country:
J.meddos.2022.02.003
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