scholarly journals Treatment Planning Optimization in Radiotherapy Using the Bolus

2017 ◽  
Vol 54 (4) ◽  
pp. 731-734
Author(s):  
Anca Munteanu ◽  
Florina Daniela Ivan ◽  
Alexandru Patrascu ◽  
Vera Balan ◽  
Catalina Ursache ◽  
...  

The present paper presents the results of the research regarding the bolus structure (Bio-Rad Win-IR instrument), the elasticity modulus, the bioadhesiveness properties (TA-XT2 Plus analyzer) and the clinical applications of the bolus in the adjuvant irradiation after radical mastectomy (Treatment Plan System Eclipse). The dose-volume histogram has made a comparative evaluation for with and without bolus treatment plans and confirmed the importance of bolus utilisation in selected patients. Conclusions: the thickness of the applied bolus is dependent on the skin dose required, on the treatment technique and must be equal to the depth of the build-up region for the removal of the skin-sparing effect of a high energy radiation.

Author(s):  
Idajet Selmani ◽  
Partizan Malkaj

One of the most important issues in the field of radiotherapy is the correct distribution of the dose around the volume of interest or planning target volume (PTV). For making this possible the exact isodose in a treatment plan has to cover the PTV, so it is used the wedge which is a part of the linear accelerator head. Wedge plays the role of a filter and usually it is called wedge filter. The wedge filter is in use almost in all treatment plans, for all the parts of the body. In this paper it is consider the use of the wedge filter for treatment of rectum tumors. The process starts with the scanning of the patient and the deliantion of the interest’s volums in the Monaco system. In the following the imagins have been sent in the treatment planning system for making the nesessary plans for treatment of the rectum. Two plans were done, one with the use of the wedge and the other without using it. The dose volume histogram helps for compering the results of the plans. The best conformity of the isodoses it was for the plan with the use of wedge through volume of interest, which is planning target volume (PTV).


2020 ◽  
Vol 93 (1110) ◽  
pp. 20190897
Author(s):  
Jennifer Cannon ◽  
Peter Bownes ◽  
Joshua Mason ◽  
Rachel Cooper

Objective: Assessment of the extent of variation in delineations and dose optimisation performed at multiple UK centres as a result of interobserver variation and protocol differences. Methods: CT/MR images of 2 cervical cancer patients previously treated with external beam radiotherapy (EBRT) and Brachytherapy were distributed to 11 UK centres. Centres delineated structures and produced treatment plans following their local protocol. Organ at risk delineations were assessed dosimetrically through application of the original treatment plan and target volume delineations were assessed in terms of variation in absolute volume and length, width and height. Treatment plan variation was assessed across all centres and across centres that followed EMBRACE II. Treatment plans were assessed using total EQD2 delivered and were compared to EMBRACE II dose aims. Variation in combined intracavitary/interstitial brachytherapy treatments was also assessed. Results: Brachytherapy target volume delineations contained variation due to differences in protocol used, window/level technique and differences in interpretations of grey zones. Planning target volume delineations were varied due to protocol differences and extended parametrial tissue inclusion. All centres met EMBRACE II plan aims for PTV V95 and high-riskclinical target volume D90 EQD2, despite variation in prescription dose, fractionation and treatment technique. Conclusion: Brachytherapy target volume delineations are varied due to differences in contouring guidelines and protocols used. Planning target volume delineations are varied due to the uncertainties surrounding the extent of parametrial involvement. Dosimetric optimisation is sufficient across all centres to satisfy EMBRACE II planning aims despite significant variation in protocols used. Advances in knowledge: Previous multi-institutional audits of cervical cancer radiotherapy practices have been performed in Europe and the USA. This study is the first of its kind to be performed in the UK.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Masayoshi Koike ◽  
Mie Yoshimura ◽  
Yasushi Mio ◽  
Shoichi Uezono

Abstract Background Surgical options for patients vary with age and comorbidities, advances in medical technology and patients’ wishes. This complexity can make it difficult for surgeons to determine appropriate treatment plans independently. At our institution, final decisions regarding treatment for patients are made at multidisciplinary meetings, termed High-Risk Conferences, led by the Patient Safety Committee. Methods In this retrospective study, we assessed the reasons for convening High-Risk Conferences, the final decisions made and treatment outcomes using conference records and patient medical records for conferences conducted at our institution from April 2010 to March 2018. Results A total of 410 High-Risk Conferences were conducted for 406 patients during the study period. The department with the most conferences was cardiovascular surgery (24%), and the reasons for convening conferences included the presence of severe comorbidities (51%), highly difficult surgeries (41%) and nonmedical/personal issues (8%). Treatment changes were made for 49 patients (12%), including surgical modifications for 20 patients and surgery cancellation for 29. The most common surgical modification was procedure reduction (16 patients); 4 deaths were reported. Follow-up was available for 21 patients for whom surgery was cancelled, with 11 deaths reported. Conclusions Given that some change to the treatment plan was made for 12% of the patients discussed at the High-Risk Conferences, we conclude that participants of these conferences did not always agree with the original surgical plan and that the multidisciplinary decision-making process of the conferences served to allow for modifications. Many of the modifications involved reductions in procedures to reflect a more conservative approach, which might have decreased perioperative mortality and the incidence of complications as well as unnecessary surgeries. High-risk patients have complex issues, and it is difficult to verify statistically whether outcomes are associated with changes in course of treatment. Nevertheless, these conferences might be useful from a patient safety perspective and minimize the potential for legal disputes.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Stefan Gerlach ◽  
Christoph Fürweger ◽  
Theresa Hofmann ◽  
Alexander Schlaefer

AbstractAlthough robotic radiosurgery offers a flexible arrangement of treatment beams, generating treatment plans is computationally challenging and a time consuming process for the planner. Furthermore, different clinical goals have to be considered during planning and generally different sets of beams correspond to different clinical goals. Typically, candidate beams sampled from a randomized heuristic form the basis for treatment planning. We propose a new approach to generate candidate beams based on deep learning using radiological features as well as the desired constraints. We demonstrate that candidate beams generated for specific clinical goals can improve treatment plan quality. Furthermore, we compare two approaches to include information about constraints in the prediction. Our results show that CNN generated beams can improve treatment plan quality for different clinical goals, increasing coverage from 91.2 to 96.8% for 3,000 candidate beams on average. When including the clinical goal in the training, coverage is improved by 1.1% points.


2006 ◽  
Vol 72 (9) ◽  
pp. 798-801
Author(s):  
Matthew Voth ◽  
Raye Budway ◽  
Angela Keleher ◽  
Philip F. Caushaj

Women undergoing breast conservation therapy (BCT) for stage 1 breast cancer have adjuvant external beam radiotherapy (EBR). In addition, the use of brachytherapy radiation is being used. We present two local tumor recurrences for review. Our first patient underwent BCT, sentinel lymph node biopsy (SLNBx) and MammoSite® brachytherapy for a T1N0M0 infiltrating ductal carcinoma (IDC) of the right breast. Pathology: 0.6 cm poorly differentiated ER, PR, and Her-2/ Neu negative IDC. At 18 months, she had palpable axillary lymph nodes. Fine needle aspiration and ultrasound-guided core biopsy of a nodule showed IDC. She underwent modified radical mastectomy (MRM) and EBR. Our second patient underwent BCT, SLNBx, and MammoSite® brachytherapy for a T1N0M0 IDC of the left breast. Pathology: 0.8 cm poorly differentiated, ER+, PR-, and Her-2/Neu negative tumor. At 18 months, a retroareolar mass was detected. Ultrasound guided core needle biopsy showed recurrent IDC. She chose a re-excision and EBR and not MRM. Pathology: 1.3 cm poorly differentiated, ER+, PR-, and Her-2/Neu negative tumor. Our 2 recurrences were >2 cm away from the lumpectomy site and therefor outside the 1 cm treatment plan of the MammoSite® catheter. Both recurrences were biologically identical to the initial tumors and are felt to be local failures rather than new primaries.


2018 ◽  
Vol 14 (12) ◽  
pp. e794-e800
Author(s):  
Dina Thompson ◽  
Kimberly Cox ◽  
James Loudon ◽  
Ivan Yeung ◽  
Woodrow Wells

Purpose: Peer review of a proposed treatment plan is increasingly recognized as an important quality activity in radiation medicine. Although peer review has been emphasized in the curative setting, applying peer review for treatment plans that have palliative intent is receiving increased attention. This study reports peer review outcomes for a regional cancer center that applied routine interprofessional peer review as a standard practice for palliative radiotherapy. Methods and Materials: Peer review outcomes for palliative radiotherapy plans were recorded prospectively for patients who began radiotherapy between October 1, 2015, and September 30, 2017. Recommended and implemented changes were recorded. The content of detailed discussions was recorded to gain insight into the complexities of palliative treatment plans considered during peer review. Results: Peer review outcomes were reviewed for 1,413 treatment plans with palliative intent. The proportions of detailed discussions and changes recommended were found to be 139 (9.8%) and 29 (2.1%), respectively. The content of detailed discussions and changes recommended was categorized. Major changes represented 75.9% of recommended changes, of which 84.2% were implemented clinically. Conclusion: Many complexities exist that are specific to palliative radiotherapy. Interprofessional peer review provides a forum for these complexities to be openly discussed and is an important activity to optimize the quality of care for patients with treatment plans that have palliative intent.


2021 ◽  
pp. OP.21.00312
Author(s):  
Zachary A. K. Frosch ◽  
Esin C. Namoglu ◽  
Nandita Mitra ◽  
Daniel J. Landsburg ◽  
Sunita D. Nasta ◽  
...  

PURPOSE Patients weigh competing priorities when deciding whether to travel to a cellular therapy center for treatment. We conducted a choice-based conjoint analysis to determine the relative value they place on clinical factors, oncologist continuity, and travel time under different post-treatment follow-up arrangements. We also evaluated for differences in preferences by sociodemographic factors. METHODS We administered a survey in which patients with diffuse large B-cell lymphoma selected treatment plans between pairs of hypothetical options that varied in travel time, follow-up arrangement, oncologist continuity, 2-year overall survival, and intensive care unit admission rate. We determined importance weights (which represent attributes' value to participants) using generalized estimating equations. RESULTS Three hundred and two patients (62%) responded. When all follow-up care was at the center providing treatment, plans requiring longer travel times were less attractive ( v 30 minutes, importance weights [95% CI] of –0.54 [–0.80 to –0.27], –0.57 [–0.84 to –0.29], and –0.17 [–0.49 to 0.14] for 60, 90, and 120 minutes). However, the negative impact of travel on treatment plan choice was mitigated by offering shared follow-up (importance weights [95% CI] of 0.63 [0.33 to 0.93], 0.32 [0.08 to 0.57], and 0.26 [0.04 to 0.47] at 60, 90, and 120 minutes). Black participants were less likely to choose plans requiring longer travel, regardless of follow-up arrangement, as indicated by lower value importance weights for longer travel times. CONCLUSION Reducing travel burden through shared follow-up may increase patients' willingness to travel to receive cellular therapies, but additional measures are required to facilitate equitable access.


2017 ◽  
Author(s):  
Saeideh Mohseni Nezhad

The objective of this study is to present a Quantum Model for designing and predicting suitable treatment plans for different psychological disorders. The theory has been extracted from Quantum Field Theories and is modeled on a Conceptual Isolated Human (CIH), which is a totally abstract idea. The Quantum limit of the model explains the way disorders are formed, and its classical limit forecasts the observable CIH behavior. Then, a pattern has been presented for treatment plans based on the CIH Quantum Model, which is named ‘Systematic Balancing’. Finally, Systematic Balancing is presented in this article in order to explain and predict the treatment plan for the category of 'Disruptive, Impulse-Control, and Conduct Disorders in DSM-5'.


2020 ◽  
Vol 9 (8) ◽  
pp. e255985718
Author(s):  
Daniela Atili Brandini ◽  
Denise Pedrini ◽  
Caio Vinicius Lourenço Debortoli ◽  
Luiza Monzoli Côvre ◽  
Marina Fuzette Amaral

The prognosis of dental trauma depends on professionals with solid and updated knowledge. The objective was to evaluate the ability of undergraduate dentistry students to develop treatment plans for dental trauma. This cross-sectional, observational, quantitative  study had a sample of 242 participants. A clinical case involving avulsion of tooth 11 and complex coronary root fracture of tooth 21 was selected. All data relating to the patient's exams were added to a clinical record, which was delivered to students in the final year of the undergraduate dentistry course for three years consecutive. The students were instructed to develop a treatment plan for this case. The factors most considered in avulsion treatment plans were: how, when and where the trauma occurred, the patient's age and systemic condition. Of the students, 39.7% developed an adequate treatment plan, the main mistake being the lack of occlusal adjustment. In addition, 9,9% of students had an adequate treatment plan for coronary artery fracture. The recovery of periodontal biological space and the indication of intraradicular retainers were the main difficulties. It is concluded that undergraduate dentistry students had great difficulty in formulating treatment plans suitable for more severe cases of dentoalveolar trauma involving several specialties.


2018 ◽  
Vol 129 (Suppl1) ◽  
pp. 118-124 ◽  
Author(s):  
Alexis Dimitriadis ◽  
Ian Paddick

OBJECTIVEStereotactic radiosurgery (SRS) is characterized by high levels of conformity and steep dose gradients from the periphery of the target to surrounding tissue. Clinical studies have backed up the importance of these factors through evidence of symptomatic complications. Available data suggest that there are threshold doses above which the risk of symptomatic radionecrosis increases with the volume irradiated. Therefore, radiosurgical treatment plans should be optimized by minimizing dose to the surrounding tissue while maximizing dose to the target volume. Several metrics have been proposed to quantify radiosurgical plan quality, but all present certain weaknesses. To overcome limitations of the currently used metrics, a novel metric is proposed, the efficiency index (η50%), which is based on the principle of calculating integral doses: η50% = integral doseTV/integral dosePIV50%.METHODSThe value of η50% can be easily calculated by dividing the integral dose (mean dose × volume) to the target volume (TV) by the integral dose to the volume of 50% of the prescription isodose (PIV50%). Alternatively, differential dose-volume histograms (DVHs) of the TV and PIV50% can be used. The resulting η50% value is effectively the proportion of energy within the PIV50% that falls into the target. This value has theoretical limits of 0 and 1, with 1 being perfect. The index combines conformity, gradient, and mean dose to the target into a single value. The value of η50% was retrospectively calculated for 100 clinical SRS plans.RESULTSThe value of η50% for the 100 clinical SRS plans ranged from 37.7% to 58.0% with a mean value of 49.0%. This study also showed that the same principles used for the calculation of η50% can be adapted to produce an index suitable for multiple-target plans (Gη12Gy). Furthermore, the authors present another adaptation of the index that may play a role in plan optimization by calculating and minimizing the proportion of energy delivered to surrounding organs at risk (OARη50%).CONCLUSIONSThe proposed efficiency index is a novel approach in quantifying plan quality by combining conformity, gradient, and mean dose into a single value. It quantifies the ratio of the dose “doing good” versus the dose “doing harm,” and its adaptations can be used for multiple-target plan optimization and OAR sparing.


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