scholarly journals Techniques for Treating Bilateral Breast Cancer Patients Using Pencil Beam Scanning Technology

2019 ◽  
Vol 6 (2) ◽  
pp. 1-11
Author(s):  
Melissa A. L. Vyfhuis ◽  
Mingyao Zhu ◽  
Benjamin Agyepong ◽  
Elizabeth M. Nichols
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Proton Therapy ◽  
Radiation Therapy Oncology Group ◽  
Bilateral Breast Cancer ◽  
Breast Conservation ◽  
Target Coverage ◽  
Optimization Approach ◽  
Intensity Modulated ◽  
Breast Conservation Treatment

Abstract Purpose: Patients with bilateral breast cancer (BBC), who require postmastectomy radiation therapy or radiation as part of breast conservation treatment, present a unique technical challenge. Even with modern techniques, such as intensity modulated radiation therapy or volumetric modulated arc therapy (VMAT), adequate target coverage is rarely achieved without the expense of increased integral dose to important organs at risk (OARs), such as the heart and lungs. Therefore, we present several BBC techniques and a treatment algorithm using intensity-modulated proton therapy (IMPT) for patients treated at our center. Materials and Methods: We describe 3 different BBC treatment techniques using IMPT on patients treated at our center, with comparison VMAT plans to demonstrate the dosimetric benefit of proton therapy in these patients. Following RADCOMP (Radiation Therapy Oncology Group, Philadelphia, Pennsylvania) guidelines, a single physician approved all target volumes and OARs. Plans were designed so that ≥ 95% of the prescribed dose covered ≥ 95% of all targets. Parameters for dosimetric volume histograms for the clinical targets and OARs are reported for the 2 radiation methods. Results: All methods demonstrated acceptable target coverage with 95% of the prescription planning target volume reaching a mean (± SD) of 98.0% (± 0.87%) and 97.5% (± 2.39%), for VMAT and IMPT plans, respectively. Conformity and homogeneity were also similar between the 2 techniques. Proton therapy provided observed improvements in mean heart dose (average heart mean [SD], 9.98 Gy [± 0.87 Gy] versus 2.12 Gy [± 0.96 Gy]) and total lung 5% prescription dose (V5; mean [SD] total lung V5, 97.9% [± 2.84%]), compared with 39.8% [± 9.39%]). All IMPT methods spared critical OARs; however, the single, 0° anterior-posterior plan allowed for the shortest treatment time. Conclusion: Both VMAT and all 3 IMPT techniques provided excellent target coverage in patients with BBC; however, proton therapy was superior in decreasing the dose to OARs. A single-field optimization approach should be the IMPT method of choice when feasible.

Dosimetric Effects on skin of supine Immobilization Device in Intensity Modulated Radiation Therapy for breast cancer: a retrospective study

2020 ◽  
Author(s):  
Ran Lv ◽  
Guangyi Yang ◽  
Yongzhi Huang ◽  
Yanhong Wang
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Breast Conservation ◽  
Intensity Modulated Radiation Therapy ◽  
Radical Mastectomy ◽  
Skin Dose ◽  
Left Group ◽  
Intensity Modulated ◽  
Group A ◽  
Left And Right

Abstract BackgroundBreast immobilization devices are commonly used in supine breast radiotherapy while the dose perturbation effect is often overlooked in Intensity Modulated Radiation Therapy for breast cancer (BC). This study is to assess the dosimetric effect of supine immobilization devices on skin with a commercial treatment planning system.Methods40 women with BC were divided into four groups according to the type of primary surgery, group A and B corresponding to patients with left and right BC after radical mastectomy, received a radiotherapy of 50 Gy in 25 fractions, group C and D corresponding to patients with left and right BC after breast-conservation surgery, received a prescription of 40.05 Gy in15 fractions and tumor bed simultaneous integrated boost to 45 Gy. A 0.2 cm thick skin contour and two sets of body contours were outlined for each patient. Dose calculations were conducted for the two sets of contours using the same plan, the dose difference was assessed by comparing the dose-volume histogram parameter results and by plan subtraction.ResultsThe supine immobilization devices for BC caused a significantly increase in the skin dose which may finally lead to skin toxicity. The mean dose increased by approximately 0.5 Gy and 0.45 Gy in left (group A) and right (group B) BC after radical mastectomy, 2.7 Gy and 3.25 Gy in left (group C) and right (group D) BC after BCS; corresponding to group A, B, C, D, the V10 of skin increased1.27%,1.83%, 1.36%, 2.88% ; the V20 of skin increased 0.85%, 1.87%, 2.76%, 4.86%; the V30 of skin increased 1.3%, 1.24%, 10.58%, 11.91%; the V40 of skin increased 1.29%, 0.65%, 10%, 10.51%. The dose encompassing of planning target volume, as well as the HI and CI, showed little distinction between plan- and plan+.ConclusionThe supine immobilization devices significantly increased the dose of skin, especially for patients with BCS. The immobilization devices should be included in the external contour to account for the dose attenuation and skin dose increment.Trial registrationThis is a retrospectively study and it has no intervention on human health care, so this study was not registered.

scholarly journals Early Clinical Outcomes of Intensity Modulated Radiation Therapy/Intensity Modulated Proton Therapy Combination in Comparison with Intensity Modulated Radiation Therapy Alone in Oropharynx Cancer Patients

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1549
Author(s):  
Han Gyul Yoon ◽  
Yong Chan Ahn ◽  
Dongryul Oh ◽  
Jae Myoung Noh ◽  
Seung Gyu Park ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Proton Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Combination Group ◽  
Intensity Modulated Proton Therapy ◽  
Oropharynx Cancer ◽  
Intensity Modulated ◽  
Before And After ◽  
Grade 3 ◽  
Early Clinical Outcomes

Purpose: To report the early clinical outcomes of combining intensity-modulated radiation therapy (IMRT) and intensity-modulated proton therapy (IMPT) in comparison with IMRT alone in treating oropharynx cancer (OPC) patients. Materials and Methods: The medical records of 148 OPC patients who underwent definitive radiotherapy (RT) with concurrent systemic therapy, from January 2016 till December 2019 at Samsung Medical Center, were retrospectively reviewed. During the 5.5 weeks’ RT course, the initial 16 (or 18) fractions were delivered by IMRT in all patients, and the subsequent 12 (or 10) fractions were either by IMRT in 81 patients (IMRT only) or by IMPT in 67 (IMRT/IMPT combination), respectively, based on comparison of adaptive re-plan profiles and availability of equipment. Propensity-score matching (PSM) was done on 76 patients (38 from each group) for comparative analyses. Results: With the median follow-up of 24.7 months, there was no significant difference in overall survival and progression free survival between groups, both before and after PSM. Before PSM, the IMRT/IMPT combination group experienced grade ≥ 3 acute toxicities less frequently: mucositis in 37.0% and 13.4% (p < 0.001); and analgesic quantification algorithm (AQA) in 37.0% and 19.4% (p = 0.019), respectively. The same trends were observed after PSM: mucositis in 39.5% and 15.8% (p = 0.021); and AQA in 47.4% and 21.1% (p = 0.016), respectively. In multivariate logistic regression, grade ≥ 3 mucositis was significantly less frequent in the IMRT/IMPT combination group, both before and after PSM (p = 0.027 and 0.024, respectively). AQA score ≥ 3 was also less frequent in the IMRT/IMPT combination group, both before and after PSM (p = 0.085 and 0.018, respectively). Conclusions: In treating the OPC patients, with comparable early oncologic outcomes, more favorable acute toxicity profiles were achieved following IMRT/IMPT combination than IMRT alone.

scholarly journals Intensity-modulated radiotherapy using two static ports of tomotherapy for breast cancer after conservative surgery: dosimetric comparison with other treatment methods and 3-year clinical results

2017 ◽  
Vol 58 (4) ◽  
pp. 529-536 ◽  
Author(s):  
Aiko Nagai ◽  
Yuta Shibamoto ◽  
Masanori Yoshida ◽  
Koji Inoda ◽  
Yuzo Kikuchi
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Adverse Events ◽  
External Beam Radiation ◽  
Radiation Dermatitis ◽  
Tumor Control ◽  
Beam Radiation ◽  
Mean Values ◽  
Intensity Modulated ◽  
Dose Volume

Abstract This study investigated the differences in dose–volume parameters for the breast and normal tissues during TomoDirectTM (TD) intensity-modulated radiation therapy (IMRT), TD-3D conformal radiotherapy (3DCRT) and 3DCRT plans, all using two beams, and analyzed treatment outcomes of two-beam TD-IMRT for breast cancer after breast-conserving surgery. Between August 2011 and January 2015, 152 patients were treated using two-beam TD-IMRT with 50 Gy/25 fractions. Among them, 20 patients with left-sided breast cancer were randomly chosen, and two-beam TD-IMRT, TD-3DCRT and 3DCRT plans were created for each patient. The homogeneity and conformity indices and various dose–volume parameters for the planning target volume and OARs were evaluated. Clinical outcomes were evaluated at 3 years. Toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 4.0. TD-IMRT and TD-3DCRT showed better whole-breast coverage than 3DCRT (P &lt; 0.001). Most of the mean values of dosimetric endpoints for OARs were better in TD-IMRT than in TD-3DCRT and 3DCRT. Overall survival rates were 97.7% and local control rates were 99.1% at 3 years. Regional control and distant metastasis control rates at 3 years were 98.6% and 96.8%, respectively. Twenty-four of the 152 patients had Grade 2 or higher acute radiation dermatitis. Four patients (4/146 = 2.7%) had Grade 2 radiation pneumonitis. There were no late adverse events of Grade 2 or higher. Two-beam TD-IMRT appeared to yield better dose distribution for whole-breast external-beam radiation therapy than TD-3DCRT and two-beam 3DCRT. The treatment appeared to provide low skin toxicity and acceptable tumor control.

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