Improving 3D ultrasound prostate localisation in radiotherapy through increased automation of interfraction matching

Grimwood, Alexander; Rivaz, Hassan; Zhou, Hang; McNair, Helen; Jakubowski, Klaudiusz; Bamber, Jeffrey C.; Tree, A.; Harris, Emma

doi:10.1016/j.radonc.2020.04.044

Cited by 2 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the probe has an integrated sensor which triggers when it passes through the center. Every sweep is checked for geometrical accuracy [ 21 ]. Therefore, such a probe allows a more efficient verification of the position of the tumor and critical structures; indeed, the employment of this technique shows a significant reduction in matching errors compared to standard treatments [ 20 , 21 ].…”

Section: Methodsmentioning

confidence: 99%

“…Every sweep is checked for geometrical accuracy [ 21 ]. Therefore, such a probe allows a more efficient verification of the position of the tumor and critical structures; indeed, the employment of this technique shows a significant reduction in matching errors compared to standard treatments [ 20 , 21 ]. We want to highlight that this continuous monitoring does not imply a higher dose administration to the patient, since we are dealing with ultrasound images and no additional device needs to be implanted in the patient’s prostate [ 22 ].…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

SBRT for Localized Prostate Cancer: CyberKnife vs. VMAT-FFF, a Dosimetric Study

Serra

Quarto

Loffredo

et al. 2022

Life

View full text Add to dashboard Cite

In recent years, stereotactic body radiation therapy (SBRT) has gained popularity among clinical methods for the treatment of medium and low risk prostate cancer (PCa), mainly as an alternative to surgery. The hypo-fractionated regimen allows the administration of high doses of radiation in a small number of fractions; such a fractionation is possible by exploiting the different intrinsic prostate radiosensitivity compared with the surrounding healthy tissues. In addition, SBRT treatment guaranteed a better quality of life compared with surgery, avoiding risks, aftermaths, and possible complications. At present, most stereotactic prostate treatments are performed with the CyberKnife (CK) system, which is an accelerator exclusively dedicated for stereotaxis and it is not widely spread in every radiotherapy centre like a classic linear accelerator (LINAC). To be fair, a stereotactic treatment is achievable also by using a LINAC through Volumetric Modulated Arc Therapy (VMAT), but some precautions must be taken. The aim of this work is to carry out a dosimetric comparison between these two methodologies. In order to pursue such a goal, two groups of patients were selected at Instituto Nazionale Tumori—IRCCS Fondazione G. Pascale: the first group consisting of ten patients previously treated with a SBRT performed with CK; the second one was composed of ten patients who received a hypo-fractionated VMAT treatment and replanned in VMAT-SBRT flattening filter free mode (FFF). The two SBRT techniques were rescaled at the same target coverage and compared by normal tissue sparing, dose distribution parameters and delivery time. All organs at risk (OAR) constraints were achieved by both platforms. CK exhibits higher performances in terms of dose delivery; nevertheless, the general satisfying dosimetric results and the significantly shorter delivery time make VMAT-FFF an attractive and reasonable alternative SBRT technique for the treatment of localized prostate cancer.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

SBRT for Localized Prostate Cancer: CyberKnife vs. VMAT-FFF, a Dosimetric Study

Serra

Quarto

Loffredo

et al. 2022

Life

View full text Add to dashboard Cite

show abstract

“…Recommendation 5 : Image registration algorithms should be integrated into the matching workflow . Online observer errors could be significantly reduced, even among inexperienced users, and matching times reduced [27] . Further error reductions may be possible through contouring and registration of additional anatomical structures, such as the penile bulb, calcifications and inferior bladder wall.…”

Section: Discussionmentioning

confidence: 99%

“…Reported interobserver variability (IOV) was reported as comparable to soft tissue localisation using CBCT [26] , with differences between experienced observers varying by up to 19 mm [27] . A study involving seven radiation therapists also reported significant IOV improvements with observer experience [28] .…”

Section: Introductionmentioning

confidence: 99%

Factors affecting accuracy and precision in ultrasound guided radiotherapy

Grimwood

Thomas

Kember

et al. 2021

Physics and Imaging in Radiation Oncology

Self Cite

View full text Add to dashboard Cite

Background and purpose Transperineal ultrasound (TPUS) is used clinically for directly assessing prostate motion. Factors affecting accuracy and precision in TPUS motion estimation must be assessed to realise its full potential. Methods and materials Patients were imaged using volumetric TPUS during the Clarity-Pro trial (NCT02388308). Prostate motion was measured online at patient set-up and offline by experienced observers. Cone beam CT with markers was used as a comparator and observer performance was also quantified. The influence of different clinical factors was examined to establish specific recommendations towards efficacious ultrasound guided radiotherapy. Results From 330 fractions in 22 patients, offline observer random errors were 1.5 mm, 1.3 mm, 1.9 mm (left–right, superior-inferior, anteroposterior respectively). Errors increased in fractions exhibiting poor image quality to 3.3 mm, 3.3 mm and 6.8 mm. Poor image quality was associated with inconsistent probe placement, large anatomical changes and unfavourable imaging conditions within the patient. Online matching exhibited increased observer errors of: 3.2 mm, 2.9 mm and 4.7 mm. Four patients exhibited large systematic residual errors, of which three had poor quality images. Patient habitus showed no correlation with observer error, residual error, or image quality. Conclusions TPUS offers the unique potential to directly assess inter- and intra-fraction motion on conventional linacs. Inconsistent image quality, inexperienced operators and the pressures of the clinical environment may degrade precision and accuracy. Experienced operators are essential and cross-centre standards for training and QA should be established that build upon current guidance. Greater use of automation technologies may further minimise uncertainties.

show abstract

Improving 3D ultrasound prostate localisation in radiotherapy through increased automation of interfraction matching

Abstract: Highlights Automated matching improves accuracy and precision of ultrasound guided radiotherapy. Image registration software lowers setup errors and sonography training requirements. Spatial regularisation improves registration algorithm performance.

Cited by 2 publications

References 18 publications

SBRT for Localized Prostate Cancer: CyberKnife vs. VMAT-FFF, a Dosimetric Study

SBRT for Localized Prostate Cancer: CyberKnife vs. VMAT-FFF, a Dosimetric Study

Factors affecting accuracy and precision in ultrasound guided radiotherapy

Contact Info

Product

Resources

About