scholarly journals Evaluation of the relative biological effectiveness of spot-scanning proton irradiation in vitro

2016 ◽  
Vol 57 (3) ◽  
pp. 307-311 ◽  
Author(s):  
Kenichiro Maeda ◽  
Hironobu Yasui ◽  
Taeko Matsuura ◽  
Tohru Yamamori ◽  
Motofumi Suzuki ◽  
...  
Keyword(s):  
Proton Beam ◽  
Relative Biological Effectiveness ◽  
Chinese Hamster ◽  
University Hospital ◽  
Quadratic Model ◽  
Linear Quadratic ◽  
Proton Beams ◽  
Spot Scanning ◽  
Biological Effectiveness ◽  
Passive Scattering

Abstract Variations in relative biological effectiveness (RBE) from a fixed value of 1.1 are critical in proton beam therapy. To date, studies estimating RBE at multiple positions relative to the spread-out Bragg peak (SOBP) have been predominantly performed using passive scattering methods, and limited data are available for spot-scanning beams. Thus, to investigate the RBE of spot-scanning beams, Chinese hamster fibroblast V79 cells were irradiated using the beam line at the Hokkaido University Hospital Proton Therapy Center. Cells were placed at six different depths, including the entrance of the proton beam and the proximal and distal part of the SOBP. Surviving cell fractions were analyzed using colony formation assay, and cell survival curves were obtained by the curve fitted using a linear–quadratic model. RBE 10 and RBE 37 were 1.15 and 1.21 at the center of the SOBP, respectively. In contrast, the distal region showed higher RBE values (1.50 for RBE 10 and 1.85 for RBE 37 ). These results are in line with those of previous studies conducted using passive scattering proton beams. Taken together, these data strongly suggest that variations in RBE should be considered during treatment planning for spot-scanning beams as well as for passive scattering proton beams.

scholarly journals Phase II Study of Proton Beam Radiation Therapy for Patients With Breast Cancer Requiring Regional Nodal Irradiation

2019 ◽  
Vol 37 (30) ◽  
pp. 2778-2785 ◽  
Author(s):  
Rachel B. Jimenez ◽  
Shea Hickey ◽  
Nicolas DePauw ◽  
Beow Y. Yeap ◽  
Estelle Batin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Proton Beam ◽  
Relative Biological Effectiveness ◽  
Cardiac Biomarkers ◽  
Beam Radiation ◽  
Regional Nodal Irradiation ◽  
Locoregional Failure ◽  
Proton Beam Radiation ◽  
Biological Effectiveness ◽  
Grade 3

PURPOSE To evaluate the safety and efficacy of proton beam radiation therapy (RT) for patients with breast cancer who require regional nodal irradiation. METHODS Patients with nonmetastatic breast cancer who required postoperative RT to the breast/chest wall and regional lymphatics and who were considered suboptimal candidates for conventional RT were eligible. The primary end point was the incidence of grade 3 or higher radiation pneumonitis (RP) or any grade 4 toxicity within 3 months of RT. Secondary end points were 5-year locoregional failure, overall survival, and acute and late toxicities per Common Terminology Criteria for Adverse Events (version 4.0). Strain echocardiography and cardiac biomarkers were obtained before and after RT to assess early cardiac changes. RESULTS Seventy patients completed RT between 2011 and 2016. Median follow-up was 55 months (range, 17 to 82 months). Of 69 evaluable patients, median age was 45 years (range, 24 to 70 years). Sixty-three patients (91%) had left-sided breast cancer, two had bilateral breast cancer, and five had right-sided breast cancer. Sixty-five (94%) had stage II to III breast cancer. Sixty-eight (99%) received systemic chemotherapy. Fifty (72%) underwent immediate reconstruction. Median dose to the chest wall/breast was 49.7 Gy (relative biological effectiveness) and to the internal mammary nodes, 48.8 Gy (relative biological effectiveness), which indicates comprehensive coverage. Among 62 surviving patients, the 5-year rates for locoregional failure and overall survival were 1.5% and 91%, respectively. One patient developed grade 2 RP, and none developed grade 3 RP. No grade 4 toxicities occurred. The unplanned surgical re-intervention rate at 5 years was 33%. No significant changes in echocardiography or cardiac biomarkers after RT were found. CONCLUSION Proton beam RT for breast cancer has low toxicity rates and similar rates of disease control compared with historical data of conventional RT. No early cardiac changes were observed, which paves the way for randomized studies to compare proton beam RT with standard RT.

Report of the AAPM TG-256 on the relative biological effectiveness of proton beams in radiation therapy

2019 ◽  
Vol 46 (3) ◽  
pp. e53-e78 ◽  
Author(s):  
Harald Paganetti ◽  
Eleanor Blakely ◽  
Alejandro Carabe-Fernandez ◽  
David J. Carlson ◽  
Indra J. Das ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Relative Biological Effectiveness ◽  
Proton Beams ◽  
Biological Effectiveness

scholarly journals Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

2014 ◽  
Vol 90 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Pankaj Chaudhary ◽  
Thomas I. Marshall ◽  
Francesca M. Perozziello ◽  
Lorenzo Manti ◽  
Frederick J. Currell ◽  
...  
Keyword(s):  
Proton Beam ◽  
Relative Biological Effectiveness ◽  
Biological Effectiveness

scholarly journals Dosimetric advantages of proton beam therapy compared to intensity-modulated radiation therapy for retroperitoneal chordoma

Rare Tumors ◽  
2019 ◽  
Vol 11 ◽  
pp. 203636131987851 ◽  
Author(s):  
Nathan Y Yu ◽  
Sujay A Vora
Keyword(s):  
Radiation Therapy ◽  
Proton Beam ◽  
Intensity Modulated Radiation Therapy ◽  
Proton Beam Therapy ◽  
Intensity Modulated ◽  
Spot Scanning ◽  
Prescription Dose ◽  
Biological Effectiveness ◽  
Primary Bone ◽  
Rare Diagnosis

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.

scholarly journals Relative biological effectiveness of the 60-MeV therapeutic proton beam at the Institute of Nuclear Physics (IFJ PAN) in Kraków, Poland

2014 ◽  
Vol 53 (4) ◽  
pp. 745-754 ◽  
Author(s):  
Dorota Słonina ◽  
Beata Biesaga ◽  
Jan Swakoń ◽  
Damian Kabat ◽  
Leszek Grzanka ◽  
...  
Keyword(s):  
Proton Beam ◽  
Nuclear Physics ◽  
Relative Biological Effectiveness ◽  
Biological Effectiveness
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