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Delineation radiotherapy

Oliver J Gurney-Champion, Thijs Bruins Slot, Eelco Lens, Astrid van der Horst, Remy Klaassen, Hanneke W M van Laarhoven, Geertjan van Tienhoven, Jeanin E van Hooft, Aart J Nederveen, Arjan Bel
PURPOSE: Biliary stents may cause susceptibility artifacts, gradient-induced artifacts, and radio frequency (RF) induced artifacts on magnetic resonance images, which can hinder accurate target volume delineation in radiotherapy. In this study, the authors investigated and quantified the magnitude of these artifacts for stents of different materials. METHODS: Eight biliary stents made of nitinol, platinum-cored nitinol, stainless steel, or polyethylene from seven vendors, with different lengths (57-98 mm) and diameters (3...
October 2016: Medical Physics
Wookjin Choi, Ming Xue, Barton F Lane, Min Kyu Kang, Kruti Patel, William F Regine, Paul Klahr, Jiahui Wang, Shifeng Chen, Warren D'Souza, Wei Lu
PURPOSE: To develop an individually optimized contrast-enhanced (CE) 4D-computed tomography (CT) for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). METHODS: Ten PDA patients were enrolled. Each underwent three CT scans: a 4D-CT immediately following a CE 3D-CT and an individually optimized CE 4D-CT using test injection. Three physicians contoured the tumor and pancreatic tissues. Image quality scores, tumor volume, motion, tumor-to-pancreas contrast, and contrast-to-noise ratio (CNR) were compared in the three CTs...
October 2016: Medical Physics
T Doshi, C Wilson, C Paterson, C Lamb, A James, K MacKenzie, J Soraghan, L Petropoulakis, G Di Caterina, D Grose
AIMS: To carry out statistical validation of a newly developed magnetic resonance imaging (MRI) auto-contouring software tool for gross tumour volume (GTV) delineation in head and neck tumours to assist in radiotherapy planning. MATERIALS AND METHODS: Axial MRI baseline scans were obtained for 10 oropharyngeal and laryngeal cancer patients. GTV was present on 102 axial slices and auto-contoured using the modified fuzzy c-means clustering integrated with the level set method (FCLSM)...
October 22, 2016: Clinical Oncology: a Journal of the Royal College of Radiologists
Tejinder Kataria, Deepak Gupta, Shikha Goyal, Shyam Singh Bisht, Ravi Chaudhary, Kushal Narang, Susovan Banerjee, Trinanjan Basu, Ashu Abhishek, Sasikumar Sambasivam, Nisha T Vishnu
Stereotactic body radiotherapy (SBRT) is being increasingly utilized in the treatment of prostate cancer. With the advent of high precision radiosurgery systems, it is possible to obtain dose distributions akin to High Dose Rate (HDR) brachytherapy with SBRT. However, urethral toxicity has a significant impact on the quality of life in prostate cancer patients. Contouring the male urethra on a computed tomography scan is difficult in the absence of an indwelling catheter. In this pictorial essay, we have used the magnetic resonance imaging obtained for radiotherapy planning to aid in delineation of the male urethra and have attempted to define guidelines for the same...
October 17, 2016: British Journal of Radiology
R J Cassidy, X Yang, T Liu, M Thomas, S G Nour, A B Jani
PURPOSE: Sexual dysfunction after radiotherapy for prostate cancer remains an important late adverse toxicity. The neurovascular bundles (NVB) that lie posterolaterally to the prostate are typically spared during prostatectomy, but in traditional radiotherapy planning they are not contoured as an organ-at-risk with dose constraints. Our goal was to determine the dosimetric feasibility of "NVB-sparing" prostate radiotherapy while still delivering adequate dose to the prostate. METHODS: Twenty-five consecutive patients with prostate cancer (with no extraprostatic disease on pelvic magnetic resonance imaging [MRI]) who that were treated with external beam radiotherapy, with the same primary planning target volume margins, to a dose of 79...
October 13, 2016: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
C M van Leeuwen, J Crezee, A L Oei, N A P Franken, L J A Stalpers, A Bel, H P Kok
PURPOSE: Currently, clinical decisions regarding thermoradiotherapy treatments are based on clinical experience. Quantification of the radiosensitising effect of hyperthermia allows comparison of different treatment strategies, and can support clinical decision-making regarding the optimal treatment. The software presented here enables biological evaluation of thermoradiotherapy plans through calculation of equivalent 3D dose distributions. METHODS: Our in-house developed software (X-Term) uses an extended version of the linear-quadratic model to calculate equivalent radiation dose, i...
October 17, 2016: International Journal of Hyperthermia
Shalini K Vinod, Michael G Jameson, Myo Min, Lois C Holloway
BACKGROUND AND PURPOSE: Volume delineation is a well-recognised potential source of error in radiotherapy. Whilst it is important to quantify the degree of interobserver variability (IOV) in volume delineation, the resulting impact on dosimetry and clinical outcomes is a more relevant endpoint. We performed a literature review of studies evaluating IOV in target volume and organ-at-risk (OAR) delineation in order to analyse these with respect to the metrics used, reporting of dosimetric consequences, and use of statistical tests...
October 8, 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Giuseppe Minniti, Mattia Falchetto Osti, Maximillian Niyazi
Stereotactic radiosurgery (SRS) delivered as either single-fraction or multi-fraction SRS (2-5 fractions) is frequently employed in patients with residual or recurrent pituitary adenoma. The most common delivery systems used for SRS include the cobalt-60 system Gamma Knife, the CyberKnife (CK) robotic radiosurgery system, or a modified conventional radiotherapy machine (linear accelerator, LINAC). Tumor control and normalization of hormone hypersecretion have been reported in 75-100 % and 25-80 % of patients, respectively...
October 11, 2016: Radiation Oncology
Stephanie Casey, Lara Best, Olga Vujovic, Kevin Jordan, Barbara Fisher, Deborah Carey, Deborah Bourdeau, Edward Yu
PURPOSE : Non-melanotic skin cancers remain the most commonly diagnosed cancers. Radiotherapy and surgery are the most common treatment options. Radiotherapy has a recurrence rate of up to 20% for basal or squamous cell cancers. One of the difficulties is to determine the extent of disease for poorly demarcated tumors. This study utilizes protoporphyrin (PpIX) fluorescence to provide information on the extent of subclinical disease for poorly demarcated tumors treated with radiotherapy...
September 4, 2016: Curēus
Hoibin Jeong, Seoyeon Bok, Beom-Ju Hong, Hyung-Seok Choi, G-One Ahn
Recent advancement in the radiotherapy technology has allowed conformal delivery of high doses of ionizing radiation precisely to the tumors while sparing large volume of the normal tissues, which have led to better clinical responses. Despite this technological advancement many advanced tumors often recur and they do so within the previously irradiated regions. How could tumors recur after receiving such high ablative doses of radiation? In this review, we outlined how radiation can elicit anti-tumor responses by introducing some of the cytokines that can be induced by ionizing radiation...
September 2016: Blood Research
Oliver Oehlke, Michael Mix, Erika Graf, Tanja Schimek-Jasch, Ursula Nestle, Irina Götz, Sabine Schneider-Fuchs, Astrid Weyerbrock, Irina Mader, Brigitta G Baumert, Susan C Short, Philipp T Meyer, Wolfgang A Weber, Anca-Ligia Grosu
BACKGROUND: The higher specificity of amino-acid positron emission tomography (AA-PET) in the diagnosis of gliomas, as well as in the differentiation between recurrence and treatment-related alterations, in comparison to contrast enhancement in T1-weighted MRI was demonstrated in many studies and is the rationale for their implementation into radiation oncology treatment planning. Several clinical trials have demonstrated the significant differences between AA-PET and standard MRI concerning the definition of the gross tumor volume (GTV)...
October 5, 2016: BMC Cancer
E Metcalfe, L Aspin, R Speight, E Ermiş, S Ramasamy, K Cardale, K E Dyker, M Sen, R J D Prestwich
AIMS: To determine outcomes after adjuvant radiotherapy for squamous cell carcinoma of the oral cavity and to correlate locoregional recurrence patterns with radiotherapy target volumes. MATERIALS AND METHODS: All patients receiving adjuvant radiotherapy±chemotherapy after surgery with curative intent for oral cavity squamous cell carcinoma between 2007 and 2012 were retrospectively analysed. Locoregional recurrences were reconstructed on the planning computed tomography scan by both deformable image co-registration and by visual assessment...
October 3, 2016: Clinical Oncology: a Journal of the Royal College of Radiologists
W V Vogel, M G E H Lam, F A Pameijer, U A van der Heide, J B van de Kamer, M E Philippens, M van Vulpen, M Verheij
AIMS: Functional imaging with positron emission tomography/computed tomography (PET/CT) and multiparametric magnetic resonance (mpMR) is increasingly applied for radiotherapy purposes. However, evidence and experience are still limited, and this may lead to clinically relevant differences in accessibility, interpretation and decision making. We investigated the current patterns of care in functional imaging for radiotherapy in the Netherlands in a care evaluation study. MATERIALS AND METHODS: The availability of functional imaging in radiotherapy centres in the Netherlands was evaluated; features available in >80% of academic and >80% of non-academic centres were considered standard of care...
September 27, 2016: Clinical Oncology: a Journal of the Royal College of Radiologists
Amy Walker, Peter Metcalfe, Gary Liney, Vikneswary Batumalai, Kylie Dundas, Carri Glide-Hurst, Geoff P Delaney, Miriam Boxer, Mei Ling Yap, Jason Dowling, David Rivest-Henault, Elise Pogson, Lois Holloway
The purpose of this study was to determine the impact of magnetic resonance imaging (MRI) geometric distortions when using MRI for target delineation and planning for whole-breast, intensity-modulated radiotherapy (IMRT). Residual system distortions and combined systematic and patient-induced distortions are considered. This retrospective study investigated 18 patients who underwent whole-breast external beam radiotherapy, where both CT and MRIs were acquired for treatment planning. Distortion phantoms were imaged on two MRI systems, dedicated to radiotherapy planning (a wide, closed-bore 3T and an open-bore 1T)...
2016: Journal of Applied Clinical Medical Physics
Barbara Segedin, Primoz Petric
BACKGROUND: Modern radiotherapy techniques enable delivery of high doses to the target volume without escalating dose to organs at risk, offering the possibility of better local control while preserving good quality of life. Uncertainties in target volume delineation have been demonstrated for most tumour sites, and various studies indicate that inconsistencies in target volume delineation may be larger than errors in all other steps of the treatment planning and delivery process. The aim of this paper is to summarize the degree of delineation uncertainties for different tumour sites reported in the literature and review the effect of strategies to minimize them...
September 1, 2016: Radiology and Oncology
Tom Konert, Wouter V Vogel, Sarah Everitt, Michael P MacManus, Daniela Thorwarth, Elena Fidarova, Diana Paez, Jan-Jakob Sonke, Gerard G Hanna
BACKGROUND AND PURPOSE: To assess the impact of a standardized delineation protocol and training interventions on PET/CT-based target volume delineation (TVD) in NSCLC in a multicenter setting. MATERIAL AND METHODS: Over a one-year period, 11 pairs, comprised each of a radiation oncologist and nuclear medicine physician with limited experience in PET/CT-based TVD for NSCLC from nine different countries took part in a training program through an International Atomic Energy Agency (IAEA) study (NCT02247713)...
September 20, 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Rodolfo Chicas-Sett, Francisco Celada-Alvarez, Susana Roldán, Asunción Torregrosa, Jesus Betancourt, Juan Bautista-Ballesteros, Dolores Farga, Blanca Ibañez, Alejandro Tormo, Jose Perez-Calatayud
PURPOSE: Groupe Européen de Curiethérapie (GEC) and European Society for Radiotherapy & Oncology (ESTRO) has proposed a rectal dose constraint of the most exposed 2-cc volume (D2cc of ≤ 75 Gy EQD2α/β = 3) during external-beam plus high-dose-rate brachytherapy (HDR-BT) in localized prostate cancer patients. This study aimed to evaluate D2cc for rectal contouring via interobserver variability. MATERIAL AND METHODS: Four blinded observers contoured rectums of 5 patients...
August 2016: Journal of Contemporary Brachytherapy
Martje Marie Terheyden, Corinna Melchert, György Kovács
PURPOSE: This study aims to compare the dosimetric data of local tumor's bed dose escalation (boost) with photon beams (external beam radiation therapy - EBRT) versus high-dose-rate interstitial brachytherapy (HDR-BT) after breast-conserving treatment in women with early-stage breast cancer. MATERIAL AND METHODS: We analyzed the treatment planning data of 136 irradiated patients, treated between 2006 and 2013, who underwent breast-conserving surgery and adjuvant whole breast irradiation (WBI; 50...
August 2016: Journal of Contemporary Brachytherapy
Ditte Sloth Møller, Marianne Ingerslev Holt, Markus Alber, Marie Tvilum, Azza Ahmed Khalil, Marianne Marquard Knap, Lone Hoffmann
BACKGROUND AND PURPOSE: Advanced lung cancer patients experience anatomical changes during radiotherapy. Uncorrected, these may lead to lower tumor dose, but can be corrected for by adaptive radiotherapy (ART). MATERIAL AND METHODS: Anatomical changes in 233 patients were monitored online on cone-beam CT-scans used for daily soft-tissue matching. If systematic changes above the pre-defined trigger criteria were observed, a new CT-scan, delineations, and treatment plan were made, restoring the intended dose distribution...
September 16, 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Lars König, Alexander Derksen, Nils Papenberg, Benjamin Haas
BACKGROUND: Deformable image registration (DIR) is a key component in many radiotherapy applications. However, often resulting deformations are not satisfying, since varying deformation properties of different anatomical regions are not considered. To improve the plausibility of DIR in adaptive radiotherapy in the male pelvic area, this work integrates a local rigidity deformation model into a DIR algorithm. METHODS: A DIR framework is extended by constraints, enforcing locally rigid deformation behavior for arbitrary delineated structures...
September 20, 2016: Radiation Oncology
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