Dosimetric characterization of foam padding with posterior fields in palliative radiation therapy
Patients undergoing external beam radiation therapy for the palliative treatment of painful bony metastases may have difficulty maintaining a still position on a rigid uncovered couch top, both during CT simulation as well as during patient setup, image guidance, and treatment on the linear accelerator. For these patients, a thin foam pad or mattress is sometimes used to mitigate patient discomfort. It was desired to quantify the effect of the padding in cases in which the patient is to be treated supine with posterior beams when the majority of the beam weighting traverses both the couch and the pad. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 4, 2023 Category: Radiology Authors: Jessica M. Fagerstrom Source Type: research
Vertebral artery sparing volumetric modulated arc therapy in nasopharyngeal carcinoma
In this study, we evaluated the feasibility of VA-sparing volumetric modulated arc therapy (VMAT) techniques. A total of 20 patients with nasopharyngeal carcinoma treated by a TrueBeam linear accelerator were enrolled in this study. The original VMAT plan was designed without the contouring of VAs as organs at risk (OARs). (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 4, 2023 Category: Radiology Authors: Szu-Huai Lu, Hao-Ting Lan, Yi-Chun Tsai, Ya-Fang Chen, Shih-Fan Lai, Hsiang-Kuang Liang, Bing-Shen Huang, Wan-Yu Chen, Chun-Wei Wang Tags: Research article Source Type: research
Quality rectal hydrogel placement allows for gel-enabled dose-escalated EBRT (GEDE-EBRT) without rectal interference in prostate cancer
Multiple trials have shown that dose-escalation of radiation for prostate cancer provides a biochemical progression-free survival benefit (bPFS); however, rectal constraints are often limiting. In this dosimetric study, we hypothesized that a well-placed rectal hydrogel (RH) would permit improved dose-escalation and target coverage. We selected patients with good-quality RH and created plans with and without RH, prescribing 70 Gy in 28 fractions to the prostate and proximal seminal vesicles (PSV), and a peripheral zone (PZ) boost to 84 Gy, 98 Gy, or 112 Gy. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 2, 2023 Category: Radiology Authors: Jamie S.K. Takayesu, Paul Heckman, Eric Short, Patrick Hurley, Vrinda Narayana, Patrick W. McLaughlin Tags: Research Article Source Type: research
From protons to Picasso: recreating famous paintings using proton beams as a “Paintbrush”
In pencil-beam-scanning proton therapy, the dose is painted spot-by-spot, layer-by-layer, allowing for significantly more control compared to conventional radiation. This work intends to showcase the impressive ability of intensity-modulated proton therapy (IMPT) to shape complex dose distributions by recreating some of history's most renowned artworks as treatment plans. Five (5) well-recognized paintings were recreated in our clinical treatment planning system using a water phantom as a “canvas” and radiation dose as “paint.” For each “painting,” colors were assigned to various isodose levels, and the treatme...
Source: Medical Dosimetry - September 2, 2023 Category: Radiology Authors: Lee Xu Source Type: research
Risk evaluation of secondary malignancies after radiotherapy of breast cancer in light of the continuous development of planning techniques
Secondary cancer risk is a significant concern for women treated with breast radiation therapy due to improved long-term survival rates. We evaluated the potential of new advanced automated planning algorithms together with hybrid techniques to minimize the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for early staged breast cancer. Using CT data set of 25 patients, we generated 4 different radiation treatment plans of different complexity, including 3-dimensional conformal radiotherapy (3D-CRT), field-in-field (FinF), hybrid-IMRT (HMRT) and automated hybrid-VMAT (HVMAT) techn...
Source: Medical Dosimetry - August 31, 2023 Category: Radiology Authors: Savino Cilla, Francesco Deodato, Carmela Romano, Gabriella Macchia, Milly Buwenge, Mariangela Boccardi, Donato Pezzulla, Antonio Pierro, Alice Zamagni, Alessio Giuseppe Morganti Tags: Research Article Source Type: research
Regional nodal irradiation in breast cancer patients: Effects of deep inspiration breath hold on the internal mammary chain location
The purpose of this study was to investigate the impact of deep inspiration breath hold (DIBH) on the positioning of thoracic structures and provide treatment planning recommendations for internal mammary chain (IMC) irradiation in breast cancer patients. Thirty-two breast cancer patients from our database underwent both DIBH and free breathing (FB) treatment planning. Contouring of the axillary lymph node clinical target volumes (CTVs: level I, II, III, IV, and IMC according to ESTRO), the internal mammary artery (IMA), the heart, and the left anterior descending artery (LAD) was performed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 28, 2023 Category: Radiology Authors: Felix V ölk, Kai Joachim Borm, Mathias Düsberg, Stephanie Elisabeth Combs, Stefan Knippen, Marciana Nona Duma Tags: Research Article Source Type: research
Breaking barriers: Stereotactic ablative proton and photon radiation therapy for renal cell carcinoma with extensive metastases: A case report
Patients with advanced renal cancer (RCC) often have limited success with systemic therapy due to tumor heterogeneity. However, stereotactic ablative radiotherapy (SABR) has been shown to have a beneficial therapeutic effect for oligometastatic disease when used early. Despite this, current guidelines recommend the use of tyrosine kinase inhibitors (TKIs) as the first-line therapeutic agent for patients with recurrent or metastatic kidney cancer. Additionally, there is limited data on the combination of systemic treatment and SABR for extensive metastatic RCC due to concerns about high toxicity. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 8, 2023 Category: Radiology Authors: Ming-Wei Ma, Zi-Shen Wang, Hong-Zhen Li, Xian-Shu Gao, Chao Liu, Xue-Ying Ren, Wei-Li Zhang, Kai-Wei Yang Source Type: research
A planning-based feasibility study of MR-Linac treatment for anal cancer radiation therapy
The hybrid magnetic resonance image (MRI) scanner and radiation therapy linear accelerator (MR-Linac) has the potential to enhance clinical outcomes for anal cancer (AC) patients with improved soft tissue visualization and daily plan adaption but has planning and delivery limitations due to the incorporation of MRI. We aimed to identify if Elekta Unity MR-Linac-based radiation therapy is feasible for anal cancer. Ten prospectively enrolled AC patients treated with radical chemoradiotherapy were replanned for MR-Linac treatment using departmental planning criteria. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 26, 2023 Category: Radiology Authors: Drew Smith, Kellie Knight, Jenny Sim, Daryl Lim Joon, Farshad Foroudi, Vincent Khoo Tags: Research Article Source Type: research
Evaluating Pareto optimal tradeoffs for hippocampal avoidance whole brain radiotherapy with knowledge-based multicriteria optimization
The goal of this study is to investigate the Pareto optimal tradeoffs between target coverage and hippocampal sparing using knowledge-based multicriteria optimization (MCO). Ten prior clinical cases were selected that were treated with hippocampal avoidance whole brain radiotherapy (HA-WBRT) using VMAT. A new, balanced plan was generated for each case using an in-house RapidPlan model in the Eclipse V16.1 treatment planning system. The MCO decision support tool was used to create 4 Pareto optimal plans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 24, 2023 Category: Radiology Authors: Tsegawbizu Gebru, Kirk Luca, Jonathan Wolf, Oluwatosin Kayode, Xiaofeng Yang, Justin Roper, Jiahan Zhang Tags: Research Article Source Type: research
Robust VMAT treatment planning for extremity soft tissue sarcomas
Volumetric modulated arc therapy (VMAT) is a frequently employed and guideline-recommended radiotherapy (RT) modality for extremity soft tissue sarcomas (eSTS). Prior studies have demonstrated that significant tumor volume changes during treatment result in loss of target volume coverage with highly conformal techniques such as VMAT, but few solutions exist to these issues aside from adaptive replanning. Here, we describe a related but novel phenomenon in which relatively minor changes in surface volume contour (whether due to daily setup uncertainty, edema of peritumoral tissue, or progression or pseudo-progression of tum...
Source: Medical Dosimetry - July 15, 2023 Category: Radiology Authors: Joshua Barrus, Katelyn Fernando, Mark Addington, Nishele Lenards, Ashley Hunzeker, David J Konieczkowski Tags: Research Article Source Type: research
Verification of Qfix Encompass ™ couch modeling using the Acuros XB algorithm and HypeArc™ using a high-spatial-resolution two-dimensional diode array
We modeled the Qfix Encompass ™ immobilization system and further verified the calculated dose distribution of the AcurosXB (AXB) dose calculation algorithm using SRS MapCHECKⓇ (SRSMC) in the HyperArc™ (HA) clinical plan. An Encompass system with a StereoPHAN™ QA phantom was scanned by SOMATOM go.Sim and imported to an E clipse™ treatment planning system to create a treatment plan for Encompass modeling. The Encompass modeling was performed in the StereoPHAN with a pinpoint ion chamber for 6 MV and 6 MV flattening filter free (6 MV FFF), and 2 × 2 cm2, 4 × 4 cm2, and 6 × 6 cm2 irradiation field siz...
Source: Medical Dosimetry - July 15, 2023 Category: Radiology Authors: Takumi Yamada, Hisashi Nakano, Satoshi Tanabe, Tatsuya Sakai, Shunpei Tanabe, Tetsuya Oka, Hironori Sakai, Tomoya Oshikane, Toshimichi Nakano, Atsushi Ohta, Tsutomu Kanazawa, Motoki Kaidu, Hiroyuki Ishikawa Tags: Research Article Source Type: research
Evaluation of the applicability of the lattice radiotherapy technique at the National Cancer Institute - INCA
This study aims to verify the technical feasibility for Spatially Fractionated Radiation Therapy treatment using the Lattice technique performed with VMAT at the National Cancer Institute Jos é Alencar Gomes da Silva - INCA, Unit I. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 4, 2023 Category: Radiology Authors: Fernanda Pedroso Partichelli, Marina de Arruda Botelho Tags: Research Article Source Type: research
Dosimetry implications of VMAT delivery angles and intra-fraction motion for SBRT prostate treatments
For a cohort of retrospectively treated patients with prostate carcinoma using a Stereotactic body radiation therapy (SBRT) technique and with implanted localization fiducials, this study determined whether there were any correlations between theoretical fiducial visibility using intra-fraction megavoltage imaging and intra-fraction motion induced dosimetric effects. Treatment planning data for 20 retrospective patients that used a SBRT prostate technique were investigated in this study. An in-house script was created that split each of the 360-degree volumetric modulated arc therapy arcs into 12 sectors, with each sector ...
Source: Medical Dosimetry - June 29, 2023 Category: Radiology Authors: Dimitrij Dimiskovski, Trent Aland Source Type: research
Accelerated hypofractionated magnetic resonance-guided adaptive radiotherapy for oligoprogressive non-small cell lung cancer
Given the positive results from recent randomized controlled trials in patients with oligometastatic, oligoprogressive, or oligoresidual disease, the role of radiotherapy has expanded in patients with metastatic non-small cell lung cancer (NSCLC). While small metastatic lesions are commonly treated with stereotactic body radiotherapy (SBRT), treatment of the primary tumor and involved regional lymph nodes may require prolonged fractionation schedules to ensure safety especially when treating larger volumes in proximity to critical organs-at-risk (OARs). (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 15, 2023 Category: Radiology Authors: Alonso La Rosa, Kathryn E. Mittauer, Michael D. Chuong, Matthew D. Hall, Tugce Kutuk, Nema Bassiri, James McCulloch, Diane Alvarez, Robert Herrera, Alonso N. Gutierrez, Ranjini Tolakanahalli, Minesh P. Mehta, Rupesh Kotecha Source Type: research
Improved planning efficiency in multiple brain lesion SRS VMAT cases using Eclipse scripting
Though dosimetry has a multitude of treatment modalities, software, and workflows to aid in the treatment planning process, treatment planners are still responsible for several tedious and monotonous tasks that could decrease their planning efficiency. The purpose of this study was to determine if scripting could improve treatment planning efficiency for multiple brain lesion stereotactic radiosurgery (SRS) volumetric arc therapy cases by reducing planning time commitment. A script was developed for multiple brain lesion SRS cases using Eclipse scripting application programming interface with the intention of improving tre...
Source: Medical Dosimetry - June 2, 2023 Category: Radiology Authors: Rebecca Barrett, Rob Hale, Nishele Lenards, Ashley Hunzeker, Sabrina Zeiler Source Type: research
