Definition and visualisation of regions of interest in post-prostatectomy image-guided intensity modulated radiotherapy
نویسندگان
چکیده
INTRODUCTION Standard post-prostatectomy radiotherapy (PPRT) image verification uses bony anatomy alignment. However, the prostate bed (PB) moves independently of bony anatomy. Cone beam computed tomography (CBCT) can be used to soft tissue match, so radiation therapists (RTs) must understand pelvic anatomy and PPRT clinical target volumes (CTV). The aims of this study are to define regions of interest (ROI) to be used in soft tissue matching image guidance and determine their visibility on planning CT (PCT) and CBCT. METHODS Published CTV guidelines were used to select ROIs. The PCT scans (n = 23) and CBCT scans (n = 105) of 23 post-prostatectomy patients were reviewed. Details on ROI identification were recorded. RESULTS Eighteen patients had surgical clips. All ROIs were identified on PCTs at least 90% of the time apart from mesorectal fascia (MF) (87%) due to superior image quality. When surgical clips are present, the seminal vesicle bed (SVB) was only seen in 2.3% of CBCTs and MF was unidentifiable. Most other structures were well identified on CBCT. The anterior rectal wall (ARW) was identified in 81.4% of images and penile bulb (PB) in 68.6%. In the absence of surgical clips, the MF and SVB were always identified; the ARW was identified in 89.5% of CBCTs and PB in 73.7%. CONCLUSIONS Surgical clips should be used as ROIs when present to define SVB and MF. In the absence of clips, SVB, MF and ARW can be used. RTs must have a strong knowledge of soft tissue anatomy and PPRT CTV to ensure coverage and enable soft tissue matching.
منابع مشابه
Rationale and development of image-guided intensity-modulated radiotherapy post-prostatectomy: the present standard of care?
The indications for post-prostatectomy radiotherapy have evolved over the last decade, although the optimal timing, dose, and target volume remain to be well defined. The target volume is susceptible to anatomical variations with its borders interfacing with the rectum and bladder. Image-guided intensity-modulated radiotherapy has become the gold standard for radical prostate radiotherapy. Here...
متن کاملPost-Prostatectomy Image-Guided Radiotherapy: The Invisible Target Concept
In the era of intensity-modulated radiation therapy, image-guided radiotherapy (IGRT) appears crucial to control dose delivery and to promote dose escalation while allowing healthy tissue sparing. The place of IGRT following radical prostatectomy is poorly described in the literature. This review aims to highlight some key points on the different IGRT techniques applicable to prostatic bed radi...
متن کاملLong-term decision regret after post-prostatectomy image-guided intensity-modulated radiotherapy.
INTRODUCTION Decision regret (DR) may occur when a patient believes their outcome would have been better if they had decided differently about their management. Although some studies investigate DR after treatment for localised prostate cancer, none report DR in patients undergoing surgery and post-prostatectomy radiotherapy. We evaluated DR in this group of patients overall, and for specific c...
متن کاملToxicity after post-prostatectomy image-guided intensity-modulated radiotherapy using Australian guidelines.
INTRODUCTION We evaluated single institution toxicity outcomes after post-prostatectomy radiotherapy (PPRT) via image-guided intensity-modulated radiation therapy (IG-IMRT) with implanted fiducial markers following national eviQ guidelines, for which late toxicity outcomes have not been published. METHODS Prospectively collected toxicity data were retrospectively reviewed for 293 men who unde...
متن کاملThe Use of Sectional Imaging with CT and MRI for Image-Guided Therapy
Sectional imaging is integrated in each link of the modern radiotherapy chain, from diagnostic procedures to target volume definition to treatment planning, dose delivery, and verification. While CT is widely used for modern EBRT, including intensity modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT), MRI represents the gold standard for IGBT for gynecological malignancies (see ...
متن کامل