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Title: Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit

Abstract

Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth−dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8 MeV proton, 190.1 MeV alpha, and 1060 MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam's Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owingmore » to the beam broadening caused by scattering, can be a good choice for the large-size tumors.« less

Authors:
 [1];  [1];  [2]
  1. Physics Department, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of)
  2. (Italy)
Publication Date:
OSTI Identifier:
22577871
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Dosimetry; Journal Volume: 41; Journal Issue: 2; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; BRAGG CURVE; CARBON IONS; COMPUTERIZED SIMULATION; ION BEAMS; MELANOMAS; MONTE CARLO METHOD; PHANTOMS; PROTON BEAMS; RADIOTHERAPY

Citation Formats

Mahdipour, Seyed Ali, Mowlavi, Ali Asghar, E-mail: amowlavi@hsu.ac.ir, and ICTP, Associate Federation Scheme, Medical Physics Field, Trieste. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit. United States: N. p., 2016. Web. doi:10.1016/J.MEDDOS.2015.10.005.
Mahdipour, Seyed Ali, Mowlavi, Ali Asghar, E-mail: amowlavi@hsu.ac.ir, & ICTP, Associate Federation Scheme, Medical Physics Field, Trieste. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit. United States. doi:10.1016/J.MEDDOS.2015.10.005.
Mahdipour, Seyed Ali, Mowlavi, Ali Asghar, E-mail: amowlavi@hsu.ac.ir, and ICTP, Associate Federation Scheme, Medical Physics Field, Trieste. 2016. "Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit". United States. doi:10.1016/J.MEDDOS.2015.10.005.
@article{osti_22577871,
title = {Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit},
author = {Mahdipour, Seyed Ali and Mowlavi, Ali Asghar, E-mail: amowlavi@hsu.ac.ir and ICTP, Associate Federation Scheme, Medical Physics Field, Trieste},
abstractNote = {Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth−dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8 MeV proton, 190.1 MeV alpha, and 1060 MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam's Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owing to the beam broadening caused by scattering, can be a good choice for the large-size tumors.},
doi = {10.1016/J.MEDDOS.2015.10.005},
journal = {Medical Dosimetry},
number = 2,
volume = 41,
place = {United States},
year = 2016,
month = 7
}
  • Purpose: Proton therapy exhibits several advantages over photon therapy due to depth-dose distributions from proton interactions within the target material. However, uncertainties associated with protons beam range in the patient limit the advantage of proton therapy applications. To quantify beam range, positron-emitting nuclei (PEN) and prompt gamma (PG) techniques have been developed. These techniques use de-excitation photons to describe the location of the beam in the patient. To develop a detector system for implementing the PG technique for range verification applications in proton therapy, we studied the yields, energy and angular distributions of the secondary particles emitted from a PMMAmore » phantom. Methods: Proton pencil beams of various energies incident onto a PMMA phantom with dimensions of 5 x 5 x 50 cm3 were used for simulation with the Geant4 toolkit using the standard electromagnetic packages as well as the packages based on the binary-cascade nuclear model. The emitted secondary particles are analyzed . Results: For 160 MeV incident protons, the yields of secondary neutrons and photons per 100 incident protons were ~6 and ~15 respectively. Secondary photon energy spectrum showed several energy peaks in the range between 0 and 10 MeV. The energy peaks located between 4 and 6 MeV were attributed to originate from direct proton interactions with 12C (~ 4.4 MeV) and 16O (~ 6 MeV), respectively. Most of the escaping secondary neutrons were found to have energies between 10 and 100 MeV. Isotropic emissions were found for lower energy neutrons (<10 MeV) and photons for all energies, while higher energy neutrons were emitted predominantly in the forward direction. The yields of emitted photons and neutrons increased with the increase of incident proton energies. Conclusions: A detector system is currently being developed incorporating the yields, energy and angular distributions of secondary particles from proton interactions obtained from this study.« less
  • Proton beam therapy for uveal malignant melanoma has been advocated as effective therapy because of documented reduction in tumor size and few clinical complications. However, some eyes have been removed because of adverse effects. The authors report the clinical courses and pathologic findings of five eyes enucleated after proton beam irradiation. Neovascular glaucoma had developed in three eyes, two eyes had vitreous hemorrhage, and two had extraocular extension. The tumors in the radiation treatment field showed continued postirradiation growth clinically in four of the five eyes, and mitotic activity histologically in all five cases. Two and one half years aftermore » irradiation, and nearly 2 years after subsequent enucleation, one of those two patients had biopsy-proven liver metastases, and later died. Despite the considerable success rate of proton beam irradiation, the potential for clinical complications and subsequent tumor growth remains.« less
  • Four patients with posterior uveal melanomas treated by cobalt 60 episcleral plaque therapy developed the intraocular recurrence of choroidal melanoma at a site distant from and noncontiguous to their original lesions. Three of the four patients died of metastatic melanoma. The proportion of eyes with posterior uveal melanoma treated with cobalt 60 brachytherapy who subsequently develop this type of local recurrence appears to be low (0.68%).
  • The authors analyzed the clinical and follow-up data on 277 selected patients with primary choroidal or ciliochoroidal melanoma who were treated with /sup 60/Co plaque radiotherapy between 1976 and 1982. Local recurrence of the irradiated melanoma developed in 39 (14%) patients during the follow-up interval. The 5-year tumor recurrence rate (Kaplan-Meier) was estimated to be 12%. Multivariate prognostic factor analysis (Cox proportional hazards modeling) identified the largest linear tumor dimension and proximity of the posterior margin of the tumor to the optic nerve head as predictors of recurrence. The 5-year survival rate of patients whose tumors recurred (58%) was significantlymore » (log-rank test P = 0.0023) worse than that of patients whose tumor remained clinically controlled (82%).« less
  • One hundred sixty-four patients with uveal melanoma were treated with helium ion irradiation prior to May 1984, and the data were analyzed in June 1989. Most uveal melanomas were large, with a mean tumor thickness of 6.5 mm; approximately 60% of the patients had tumors that extended anterior to the equator. A complete follow-up was obtained for all patients. One hundred twelve patients were alive at the time of this report; 18% of the patients developed clinical and laboratory evidence of metastases and eventually died of widespread tumor. Eighty-four percent of eyes were retained. Data were analyzed with a numbermore » of parametric and nonparametric techniques. Larger tumors and those located in close proximity to the optic nerve and fovea had a higher incidence of most complications, especially visual loss.« less