scholarly journals Proposed Parameters for a Circular Particle Accelerator for Proton Beam Therapy Obtained by Genetic Algorithm

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Gustavo Lobato Campos ◽  
Tarcísio P. R. Campos

This paper brings to light optimized proposal for a circular particle accelerator for proton beam therapy purposes (named as ACPT). The methodology applied is based on computational metaheuristics based on genetic algorithms (GA) were used to obtain optimized parameters of the equipment. Some fundamental concepts in the metaheuristics developed in Matlab® software will be presented. Four parameters were considered for the proposed modeling for the equipment, being: potential difference, magnetic field, length and radius of the resonant cavity. As result, this article showed optimized parameters for two ACPT, one of them used for ocular radiation therapy, as well some parameters that will allow teletherapy, called in order ACPT – 65 and ACPT – 250, obtained through metaheuristics based in GA.

Rare Tumors ◽  
2019 ◽  
Vol 11 ◽  
pp. 203636131987851 ◽  
Author(s):  
Nathan Y Yu ◽  
Sujay A Vora

Retroperitoneal chordomas are exceedingly rare and account for less than 5% of all primary bone malignancies. Their etiology remains unknown. We report a rare case of an extravertebral chordoma of the retroperitoneum in a 71-year-old man treated with surgical resection and post-operative spot-scanning proton beam therapy. We describe how to safely treat a retroperitoneal target to a prescription dose over 70 Gy (relative biological effectiveness) with spot-scanning proton beam therapy and also report a dosimetric comparison of spot-scanning proton beam therapy versus intensity-modulated radiation therapy. This case not only highlights a rare diagnosis of an extravertebral retroperitoneal chordoma but it also draws attention to the dosimetric advantages of proton beam therapy and illustrates a promising radiotherapeutic option for retroperitoneal targets.


2014 ◽  
Vol 32 (26) ◽  
pp. 2855-2863 ◽  
Author(s):  
Timur Mitin ◽  
Anthony L. Zietman

Proton beam therapy, the most common form of heavy-particle radiation therapy, is not a new invention, but it has gained considerable public attention because of the high cost of installing and operating the rapidly increasing number of treatment centers. This article reviews the physical properties of proton beam therapy and focuses on the up-to-date clinical evidence comparing proton beam therapy with the more standard and widely available radiation therapy treatment alternatives. In a cost-conscious era of health care, the hypothetical benefits of proton beam therapy will have to be supported by demonstrable clinical gains. Proton beam therapy represents, through its scale and its cost, a battleground for the policy debate around managing expensive technology in modern medicine.


2020 ◽  
Author(s):  
Guo Li ◽  
Yun-Fei Xia ◽  
Yi-Xiang Huang ◽  
Deniz Okat ◽  
Bo Qiu ◽  
...  

Abstract Background: Proton beam therapy (PBT) is a new-emerging cancer treatment in China. The treatment costs are high and not yet covered by Chinese public medical insurance. The advanced form of PBT, intensity-modulated proton radiation therapy (IMPT), has been confirmed to reduce normal tissue complication probability (NTCP) compared with conventional intensity-modulated photon-radiation therapy (IMRT) in patients with oropharyngeal cancer (OPC). This study evaluated the cost-effectiveness of IMPT versus IMRT for OPC patients in China, aiming at guiding proper use of PBT. Methods: On the basis of published data, a 7-state Markov model was designed for cost-effectiveness analysis, and an evaluation of average level was performed on a base case of 56-year-old under the hypothesis that IMPT could make a 25% NTCP-reduction concerning to long-term symptomatic dysphagia and xerostomia. Model robustness was examined using probabilistic sensitivity analysis, cohort analysis and tornado diagram. One-way sensitivity analyses were performed to identify cost-effective scenarios. IMPT was considered as cost-effective if the incremental cost-effectiveness ratio (ICER) was below the societal willingness-to-pay (WTP) threshold (3 times the gross domestic product per capita / quality-adjusted life year (QALY)).Results: Compared with IMRT, IMPT could provide an extra 0.724 QALYs at an additional cost of 34,926.6 US dollars ($), and made an ICER of $48,229.8/ QALY for the base case. At current WTP level of China ($30,828/QALY), cost-effective scenarios of IMPT existed in the following independent conditions: ≥ 57.3% NTCP-reduction (IMPT compared with IMRT) in dysphagia and xerostomia; patient age ≤ 38-year-old; or the cost of IMPT ≤ $37,398.1. The estimated cost-effective population that benefit from using PBT to treat OPC increased remarkably in the past 10 years with the economic growth, and reached to 559.7 million (about 40.0% of the China’s total population) in the year 2020. Conclusions: Currently, using PBT to treat OPC could be cost-effective in considerable proportion of China’s population. Considering the economic growth, the gradual increment of medical insurance coverage, as well as the proton treatment cost reduction along with more proton facility opening in the near future, it is estimated that PBT would benefit more Chinese OPC patients with respect to cost-effectiveness.


2020 ◽  
Vol 7 (2) ◽  
pp. 11-20
Author(s):  
Dario Pasalic ◽  
Surendra Prajapati ◽  
Ethan B. Ludmir ◽  
Chad Tang ◽  
Seungtaek Choi ◽  
...  

Abstract Purpose To determine the clinical outcomes and toxicities of proton beam therapy (PBT) versus 3D-conformal photon radiation therapy (XRT) in patients with testicular seminoma. Materials and Methods This observational study evaluated consecutive patients with testicular seminoma who were treated with inguinal orchiectomy and radiation therapy at a single, tertiary, high-volume center in 2008-19. Acute toxicity was scored with the Common Terminology Criteria for Adverse Events V 4.0. Organs at risk were contoured retrospectively by 2 investigators. Recurrences and secondary malignancies were based on routine follow-up imaging, either computed tomography or magnetic resonance imaging. Results Fifty-five patients were treated with radiation therapy, 11 in the PBT-arm and 44 in the XRT-arm, with a median follow-up interval of 61 months (interquartile range [IQR]: 32-79 months). Acute treatment-related diarrhea, grade 1 to 2, was more common among XRT-treated patients (0% vs 29.5%, P = .039), and dermatitis, grade 1, was more likely among PBT-treated patients (27.3% vs 2.3%, P = .004). Dosimetrically, PBT-treated patients, relative to XRT-treated patients, had lower dose to organs at risk including the kidney, bladder, femoral head, spinal cord, bowel, pancreas, and stomach. The 5-year overall survival rate was 100% and disease-free survival rate was 96.4% for all patients. Two patients, all in the XRT-arm, had disease recurrence: 1 in the pelvis and 1 in the lung. Three patients, all in the XRT-arm, were diagnosed with a secondary malignancy: 1 in-field pancreaticoblastoma, 1 in-field colon adenocarcinoma, and a stage IV T-cell lymphoma. Conclusion Proton beam therapy for testicular seminoma resulted in excellent clinical outcomes and was associated with lower rates of acute diarrhea but higher rates of acute dermatitis. Proton beam therapy resulted in no in-field secondary malignancies and a more favorable dosimetric profile for organs at risk relative to XRT. Reduced dose to organs at risk, such as the kidneys, may result in long-term improvement in function.


2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 271-271
Author(s):  
Sachiyo Shirakawa ◽  
Ippei Matsumoto ◽  
Kazuki Terashima ◽  
Makoto Shinzeki ◽  
Sadaki Asari ◽  
...  

271 Background: Evaluation of tumor response to radiation therapy in pancreatic ductal adenocarcinoma (PDA) using conventional radiological tests is difficult due to generally small size and inflammatory or fibrotic changes of radiated tissue. Although increasing evidence has shown that 18-F-fluorodeoxyglucose-positoron emission tomography (FDG-PET) can assess functional changes in various tumors, available data in PDA with radiation therapy is scarce. In this study, we investigated the role of FDG-PET in long-term monitoring tumor response to proton beam therapy (PBT) for PDA. Methods: Thirty-four locally advanced PDA patients with pre- and post-PBT FDG-PET data were included in this study. Local tumor responses by computed tomography (CT) and FDG-PET were defined as below: response group in CT (complete response: CR, partial response: PR, stable disease: SD, progressive disease: PD) was defined according to Response Evaluation Criteria in Solid Tumors, but only evaluation of primary tumor; and in FDG-PET, CR was defined as disappearance of FDG uptake, PR as decrease, SD as unchange, and PD as increase, compared to pre-PBT data. We evaluated tumor response at three different time points: 0-3, 3-6, and 6-12 months after PBT. Also serum CA19-9 values were evaluated. Results: Radiation doses were 50.4-70.2 GyE and 28 (82%) patients received concomitant chemotherapy. During the follow-up period (median 19 months), a total of 90 FDG-PET tests were performed. At the first time point, SD was noted in 90% (9/10) of patients by CT, whereas CR or PR in all by FDG-PET. At the second point, 39% (7/18) of patients demonstrated PR by CT, whereas 91% CR or PR by FDG-PET. Two patients with PD by FDG-PET were diagnosed as SD by CT, while one patient with PD by CT was diagnosed as PR by FDG-PET. At the third point, four patients with PD by FDG-PET were diagnosed as PR or SD by CT. Serum CA19-9 values supported FDG-PET findings. In four of 14 patients with serial FDG-PET, the maximum effects were noted at the second point. Conclusions: Serial FDG-PET can detect changes in local tumor response to PBT for PDA earlier and more sensitively than CT. Of note, there is the risk for false positive in early post-PBT FDG-PET.


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