scholarly journals Proton Beam Therapy in the Treatment of Periorbital Malignancies

2021 ◽  
Vol 7 (4) ◽  
pp. 42-51
Author(s):  
Nicholas J. Damico ◽  
Anna K. Wu ◽  
Michael Z. Kharouta ◽  
Tal Eitan ◽  
Rajesh Pidikiti ◽  
...  
Keyword(s):  
Overall Survival ◽  
Radiation Therapy ◽  
Pituitary Gland ◽  
Proton Beam ◽  
Organs At Risk ◽  
Proton Beam Therapy ◽  
Lacrimal Glands ◽  
Optic Nerves ◽  
Volumetric Arc Therapy ◽  
Arc Therapy

Abstract Purpose Periorbital tumor location presents a significant challenge with 3-dimensional conformal radiation therapy or intensity modulated radiation therapy due to high tumor dose needed in the setting of close proximity to orbital structures with lower tolerance. Proton beam therapy (PBT) is felt to be an effective modality in such cases due to its sharp dose gradient. Materials and Methods We reviewed our institutional PBT registry and identified 17 patients with tumor epicenters within 2 cm of the eye and optic apparatus treated with passive scatter PBT with comparison volumetric arc therapy plans available. Maximum and mean doses to organs at risk of interest, including optic nerves, optic chiasm, lens, eye ball, pituitary, cochlea, lacrimal gland, and surrounding brain, were compared using the paired Wilcoxon signed rank test. Overall survival was determined using the Kaplan-Meier method. Results Median age was 67. Median follow-up was 19.7 months. Fourteen patients underwent upfront resection and received postoperative radiation and 3 received definitive radiation. One patient received elective neck radiation, 2 underwent reirradiation, and 3 had concurrent chemotherapy. There was a statistically significant reduction in mean dose to the optic nerves and chiasm, brain, pituitary gland, lacrimal glands, and cochlea as well as in the maximum dose to the optic nerves and chiasm, pituitary gland, lacrimal glands, and cochlea with PBT. The 18-month cumulative incidence of local failure was 19.1% and 1-year overall survival was 80.9%. Conclusion Proton beam therapy resulted in significant dose reductions to several periorbital and optic structures compared with volumetric arc therapy. Proton beam therapy appears to be the optimal radiation modality in such cases to minimize risk of toxicity to periorbital organs at risk.

scholarly journals Outcomes and Toxicities of Proton and Photon Radiation Therapy for Testicular Seminoma

2020 ◽  
Vol 7 (2) ◽  
pp. 11-20
Author(s):  
Dario Pasalic ◽  
Surendra Prajapati ◽  
Ethan B. Ludmir ◽  
Chad Tang ◽  
Seungtaek Choi ◽  
...  
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Survival Rate ◽  
Proton Beam ◽  
Organs At Risk ◽  
Proton Beam Therapy ◽  
Photon Radiation ◽  
Secondary Malignancies ◽  
Testicular Seminoma

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.

scholarly journals Dosimetric Comparison of Lung-Sparing Radiation Therapy between Volumetric Arc Therapy and Helical Tomotherapy for Unresectable Malignant Pleural Mesothelioma

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Berrin Pehlivan ◽  
Kansu Sengul ◽  
Abdullah Yesil ◽  
Nilgul Nalbant ◽  
Osman Ozturk ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Malignant Pleural Mesothelioma ◽  
Helical Tomotherapy ◽  
Organs At Risk ◽  
Target Volume ◽  
Pleural Mesothelioma ◽  
Dosimetric Comparison ◽  
Volumetric Arc Therapy ◽  
Arc Therapy ◽  
Target Volumes

Objective. To compare volumetric arc therapy (VMAT) and helical tomotherapy (HT) plans in terms of dosimetric parameters in positron emission tomography- (PET-) computerized tomography- (CT-) based radiation therapy planning in unresectable malignant pleural mesothelioma (MPM). Methods. CT and coregistered PET-CT data from seven patients with histologically-proven MPM were utilized for VMAT and HT plans. Target volumes and organs at risk (OARs) were delineated. The prescription doses for planning target volume 1 (PTV1) and PTV2 were 45.0 Gy and 54 Gy in 1.8 Gy/fr, respectively. Each technique was evaluated in terms of target volume coverage and OAR doses. Findings. Although the maximum (p=0.001) and mean (p<0.001) doses of PTV1, and PTV2 (p<0.001 for maximum and p=0.001 for mean doses) favored the HT technique over VMAT, both techniques efficiently covered the target volumes. Additionally, HT also provided more homogeneous dose distribution (p<0.001) and numerically lower doses received by most OARs, but again both rotational techniques were successful in keeping the OAR doses below the universally accepted limits. The major disadvantage of the HT technique was the requirement for longer treatment times (7.4 versus 2.5 minutes/fr; p<0.001) to accomplish the intended treatment. Conclusion. Results of this dosimetric comparison clearly demonstrated the possibility of safe hemithoracic irradiation of medically/technically unresectable MPM patients with either of the two rotational RT techniques, namely the VMAT and HT. Clinically, considering their poor prognosis, these promising findings may open a potential new window for curative treatment of unresectable MPM patients, if further confirmed by future clinical studies.

scholarly journals RONC-04. RE-IRRADIATION AFTER TREATMENT OF MEDULLOBLASTOMA; RELAPSED CASES AND SECOND CANCER CASES

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii456-iii457
Author(s):  
Toshinori Soejima ◽  
Nobutoshi Fukumitsu ◽  
Yusuke Demizu ◽  
Masayuki Mima ◽  
Takeshi Suzuki ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Brain Tumor ◽  
Proton Beam ◽  
Organs At Risk ◽  
Gamma Knife Radiosurgery ◽  
Proton Beam Therapy ◽  
Late Complications ◽  
Second Cancer ◽  
Reduce Radiation Dose

Abstract PURPOSE Late complications such as brainstem necrosis are great concern of re-irradiation for brain tumor. Proton beam therapy can reduce radiation dose of organs at risk such as brainstem, so is expected to reduce late complications. PATIENTS AND METHODS Patients with medulloblastoma treated with re-irradiation from January 2015 to February 2019 at the Kobe Children’s Hospital and the Kobe Proton Center were reviewed. There were three cases of relapsed medulloblastoma and three cases of second cancer (glioblastomas). RESULTS In relapsed cases, all three cases treated with 12 Gy in 8 fractions cranio-spinal irradiation followed by gamma knife radiosurgery (one) or 28.8 Gy (RBE) in 16 fractions of proton beam therapy (two). Follow-up periods were 8 to 19 months (median 12 months) and all three cases survived without relapse. In second cancer cases, all three cases were treated with 40.05 Gy per 15 fractions of radiation therapy (2 cases were treated with photon and one case with proton). However, all cases relapsed and two cases died of disease. CONCLUSION Twelve Gy in 8 fractions cranio-spinal irradiation followed by 28.8 Gy (RBE) in 16 fractions of proton beam therapy is thought to be useful for the relapsed case. Re-irradiation for second cancer was disappointing and further study is warranted.

scholarly journals 455 Proton Beam Therapy in Rectal Cancer: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
M Fok ◽  
S Toh ◽  
J E Maducolil ◽  
H Fowler ◽  
R Clifford ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Proton Beam ◽  
Organs At Risk ◽  
Meta Analysis ◽  
Locally Advanced ◽  
Significant Risk ◽  
Proton Beam Therapy ◽  
Recurrent Rectal Cancer ◽  
Pelvic Bone ◽  
Dosimetric Data

Abstract Introduction Radiotherapy for locally advanced rectal cancer is conventionally performed using photon-based radiotherapy (PBR), carrying significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) potentially delivers equivalent dosimetric radiation to the targeted tissue with improved sparing of OAR. We aimed to compare dosimetric irradiation of OAR for PBT versus PBR in patients with rectal cancer and assess any oncological outcomes. Method An extensive electronic literature search was performed from inception till April 2020 and subsequent meta-analysis performed. Results Six articles met the inclusion criteria. Dosimetric data of irradiation delivered to OAR for PBT and PBR were calculated for the same patients. PBT had significantly less irradiated small bowel compared to 3DCRT and IMRT, (MD -16.95, 95% CI [-24.03, -9.88], p &lt; 0.00001) and (MD -6.96, 95% CI [-12.99, -0.94], p = 0.02) respectively. Similar results were observed for bladder and pelvic bone marrow. Two studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43% and 68%. Conclusions Dosimetric treatment plans have less irradiation of OAR for rectal cancer with PBT compared to PBR. There is a need for further research in PBT and rectal cancer, as promising results have been shown in recurrent rectal cancer.

Range optimization for target and organs at risk in dynamic adaptive passive scattering proton beam therapy – A proof of concept

2018 ◽  
Vol 56 ◽  
pp. 66-73
Author(s):  
Shunsuke Moriya ◽  
Hidenobu Tachibana ◽  
Kenji Hotta ◽  
Naoki Nakamura ◽  
Takeji Sakae ◽  
...  
Keyword(s):  
At Risk ◽  
Proton Beam ◽  
Organs At Risk ◽  
Proton Beam Therapy ◽  
Proof Of Concept ◽  
Passive Scattering

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.

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