Purpose To analyze dose uncertainty using a previously published dose-uncertainty model, and to assess potential dosimetric risks existing in prostate intensity-modulated radiotherapy (IMRT). Methods and Materials The dose-uncertainty model provides a three-dimensional (3D) dose-uncertainty distribution in a given confidence level. For 8 retrospectively selected patients, dose-uncertainty maps were constructed using the dose-uncertainty model at the 95% CL. In addition to uncertainties inherent to the radiation treatment planning system, four scenarios of spatial errors were considered: machine only (S1), S1 + intrafraction, S1 + interfraction, and S1 + both intrafraction and interfraction errors. To evaluate the potential risks of the IMRT plans, three dose-uncertainty–based plan evaluation tools were introduced: confidence-weighted dose–volume histogram, confidence-weighted dose distribution, and dose-uncertainty–volume histogram. Results Dose uncertainty caused by interfraction setup error was more significant than that of intrafraction motion error. The maximum dose uncertainty (95% confidence) of the clinical target volume (CTV) was smaller than 5% of the prescribed dose in all but two cases (13.9% and 10.2%). The dose uncertainty for 95% of the CTV volume ranged from 1.3% to 2.9% of the prescribed dose. Conclusions The dose uncertainty in prostate IMRT could be evaluated using the dose-uncertainty model. Prostate IMRT plans satisfying the same plan objectives could generate a significantly different dose uncertainty because a complex interplay of many uncertainty sources. The uncertainty-based plan evaluation contributes to generating reliable and error-resistant treatment plans.

Application of a novel dose-uncertainty model for dose-uncertainty analysis in prostate intensity-modulated radiotherapy.

Objective To illustrate the wider potential scope of image-guided intensity-modulated radiotherapy (IG-IMRT), outside of the “standard” indications for IMRT. Methods Nine challenging clinical cases were selected. All were treated with radical intent, although it was accepted that in several of the cases the probability of cure was low. IMRT alone was not adequate owing to the close proximity of the target to organs at risk, the risk of geographical miss, or the need to tighten planning margins, making image-guided radiotherapy an essential integral part of the treatment. Discrepancies between the initial planning scan and the daily on-treatment megavoltage CT were recorded for each case. The three-dimensional displacement was compared with the margin used to create the planning target volume (PTV). Results All but one patient achieved local control. Three patients developed metastatic disease but benefited from good local palliation; two have since died. A further patient died of an unrelated condition. F...

/pdf/the-value-of-image-guided-intensity-modulated-radiotherapy-dt283h8e1e.pdf

The value of image-guided intensity-modulated radiotherapy in challenging clinical settings

Objective To estimate the benefit of introduction of image-guided radiotherapy (IGRT) to prostate radiotherapy practice with current clinical target volume–planning target volume (PTV) margins of 5–10 mm. Methods Systematic error data collected from 50 patients were used together with a random error of σ=3.0 mm to model non-IGRT treatment. IGRT was modelled with residual errors of Σ=σ=1.5 mm. Population tumour control probability (TCPpop) was calculated for two three-dimensional conformal radiotherapy techniques: two-phase and concomitant boost. Treatment volumes and dose prescriptions were ostensibly the same. The relative field sizes of the treatment techniques, distribution of systematic errors and correlations between movement axes were examined. Results The differences in TCPpop between the IGRT and non-IGRT regimes were 0.3% for the two-phase and 1.5% for the concomitant boost techniques. A 2-phase plan, in each phase of which the 95% isodose conformed to its respective PTV, required fields that wer...

/pdf/consideration-of-the-likely-benefit-from-implementation-of-2ifvsrdcgk.pdf

Consideration of the likely benefit from implementation of prostate image-guided radiotherapy using current margin sizes: a radiobiological analysis

https://www.radiographyonline.com/article/S1078-8174(18)30085-3/pdf

National survey of fiducial marker insertion for prostate image guided radiotherapy.

Background: To correct pa ent posi oning errors (setup errors) during prostate cancer treatment using EPID and fiducial gold markers, to improve the accuracy of the dose delivery in these pa ents. Materials and Methods: Fi\"een pa ents with localized prostate carcinoma a\"er implanta on of fiducial gold markers in their prostate gland underwent the five-field IMRT planning technique. The plan was prepared in accordance with ICRU 50 guidance (PTV to receive 95-107% dose). The so\"ware program reconstructed the three-dimensional posi on of the markers from the different Beams Eye Views (BEV). The discrepancies of the seeds’ posi ons (prostate surrogate) between plan and daily images were calculated three dimensionally. Then, necessary correc ons were applied to match the prostate fiducial markers in the portal image with the BEV image in the planned one by moving the couch in the X, Y and Z direc ons. Results: Data from 15 pa ents and 469 frac ons of radiotherapy were analyzed in this study. Two sets of data were available from EPID so\"ware before and a\"er 3D set-up correc ons. The mean of the popula on displacement in Le\" /Right (L/R), Anterior/Posterior (A/P) and Crania/Caudal (C/C) direc ons were 0.5, -1.0 and 2.4mm before, and -0.1, -0.5 and 0.9mm a\"er correc ons, respec vely. The systema c and random errors for the measured popula ons in the three men oned direc ons were 2.4, 2.7 and 2mm and 6.4, 5.9 and 6.1mm before correc ons, and 1.1, 2.4 and 1.4mm and 3.8, 3.9 and 3.6mm a\"er correc ons, correspondingly. Conclusion: This study provides further evidence that using gold markers in the prostate improves dose delivery to the prostate. Also, it has been demonstrated that the EPID can be a powerful tool in the reduc on of treatment setup errors and the quality assurance and verifica on of complex treatments.

Accuracy of the dose delivery in prostate cancer patients-using an electronic portal imaging device (EPID)

Practical issues in the implementation of image-guided radiotherapy for the treatment of prostate cancer within a UK department.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

S.L. Vowler

Author Tools

Chat about Author

Papers

Practical issues in the implementation of image-guided radiotherapy for the treatment of prostate cancer within a UK department.