Background: This paper compares the calculated dose to target and normal tissues when using pencil beam (PBC), superposition/convolution (AAA) and Monte Carlo (MC) algorithms for whole breast (WBI) and accelerated partial breast irradiation (APBI) treatment plans.
Methods: Plans for 10 patients who met all dosimetry constraints on a prospective APBI protocol when using PBC calculations were recomputed with AAA and MC, keeping the monitor units and beam angles fixed. Similar calculations were performed for WBI plans on the same patients. Doses to target and normal tissue volumes were tested for significance using the paired Student's t-test.
Results: For WBI plans the average dose to target volumes when using PBC calculations was not significantly different than AAA calculations, the average PBC dose to the ipsilateral breast was 10.5% higher than the AAA calculations and the average MC dose to the ipsilateral breast was 11.8% lower than the PBC calculations. For ABPI plans there were no differences in dose to the planning target volume, ipsilateral breast, heart, ipsilateral lung, or contra-lateral lung. Although not significant, the maximum PBC dose to the contra-lateral breast was 1.9% higher than AAA and the PBC dose to the clinical target volume was 2.1% higher than AAA. When WBI technique is switched to APBI, there was significant reduction in dose to the ipsilateral breast when using PBC, a significant reduction in dose to the ipsilateral lung when using AAA, and a significant reduction in dose to the ipsilateral breast and lung and contra-lateral lung when using MC.
Conclusions: There is very good agreement between PBC, AAA and MC for all target and most normal tissues when treating with APBI and WBI and most of the differences in doses to target and normal tissues are not clinically significant. However, a commonly used dosimetry constraint, as recommended by the ASTRO consensus document for APBI, that no point in the contra-lateral breast volume should receive >3% of the prescribed dose needs to be relaxed to >5%.
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http://dx.doi.org/10.1186/1748-717X-5-120 | DOI Listing |
J Clin Med
January 2025
Department of Audiology and Otoneurological Explorations, Civil Hospitals of Lyon, 69003 Lyon, France.
: Objective: To discuss therapeutic outcomes in patients with symptomatic near-narrow internal auditory canal (NNIAC). : We retrospectively analyzed the records of 26 symptomatic patients diagnosed with NNIAC, who had been treated with anti-epileptic drugs. In addition to clinical and radiological data, we recorded I-III latencies of auditory brainstem responses prior to and after medical therapy.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
January 2025
Department of Radiation Oncology, New York University Langone Health and Perlmutter Cancer Center, New York, NY.
Background: In patients with breast cancer, prone radiation therapy (RT) has been shown to reduce heart and lung dose. Though prone positioning is routinely used for whole breast RT, its use when treating the regional lymph nodes (RLNs) is not widespread.
Methods: In this phase I-II trial for stage IB-IIA breast cancer treated with lumpectomy or mastectomy, patients received 40.
Adv Radiat Oncol
December 2024
Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
Purpose: Breast cancer radiation therapy (RT) techniques have historically delivered mean heart doses (MHDs) in the range of 5 Gy, which have been found to predispose patients to cardiopulmonary toxicities. The purpose of this study was to apply artificial intelligence (AI) cardiac substructure auto-segmentation to evaluate the corresponding substructure doses, whether there are laterality- and technique-specific differences in these doses, and if the doses are significantly associated with cardiorespiratory fitness after state-of-the-art RT planning and delivery for breast cancer.
Methods And Materials: Cardiopulmonary substructures were AI auto-segmented.
Front Oncol
December 2024
Department of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
Background: This study aimed to investigate the effect of couch rotation angles on non-coplanar volumetric modulated arc therapy (ncVMAT) plan for stereotactic body radiotherapy (SBRT) in lung cancer patients and to evaluate the feasibility of clinically applying ncVMAT for SBRT.
Methods: Twenty-four lung cancer patients with a single lesion eligible for SBRT were enrolled in the study. Seven dual partial-arc VMAT plans with varying couch angles were designed for every patient.
Cancers (Basel)
December 2024
Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Background/objectives: Studies have shown that dose to the parotid gland stem cell rich (SCR) regions should be reduced to lower the risk of xerostomia after radiotherapy (RT). This study aimed to assess whether stem cell sparing (SCS)-RT can be adopted in routine clinical practice.
Methods: Multiple planning studies were performed to compare SCS-RT with standard (ST)-RT using 30 head and neck cancer patients.
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