Frederik J Vernimmen1, Shaheeda Fredericks2, Neil D Wallace3, Anthony P Fitzgerald4. 1. Department of Radiation Oncology, Cork University Hospital, Wilton, Cork, Ireland. Electronic address: Frederik.Vernimmen@hse.ie. 2. iThemba LABS, Faure, Cape Town, South Africa. 3. Cork University Hospital, Wilton, Cork, Ireland. 4. School of Public Health, Department of Statistics, University College Cork, Ireland.
Abstract
PURPOSE: To investigate the occurrence of second malignancies resulting from the secondary radiation from a passively scattered proton beam. METHODS AND MATERIALS: A cohort of patients with long-term follow-up was defined. All were treated at the same institution with the same proton delivery system, consisting of a 200 MeV fixed, horizontal, passively scattered beam combined with a robotic chair. This setup allows for stereotactic positioning and permits fractionated treatments. The majority of patients underwent cranial or intracranial stereotactic radiation therapy. Patients with previous photon therapy or a follow-up of 24 months or less were excluded. For out-of-field secondary malignancies (SMs), the observed incidence in the study population was compared to the risk of developing a malignancy in the general population, taking patient sex into account. RESULTS: From September 1993 to May 2016, a total of 524 patients received proton beam therapy, and 322 patients could be evaluated for this study (164 female and 158 male). Age ranged from 2 to 85 years, with a median of 40 years. Follow-up ranged from 25 to 276 months, with a median of 150 months (12.5 years). During the study observation period, 7 patients had out-of-field new malignant disease. Three female patients developed a malignancy, compared with an expected incidence of 4.09 (standardized incidence ratio, 0.73 [95% confidence interval, 0.24-2.27]); 4 male patients developed a malignancy, versus an expected incidence of 3.99 (standardized incidence ratio, 1.00 [95% confidence interval, 0.38-2.67]). New intracranial disease developed in 9 patients: 8 meningiomas and 1 carcinoma. CONCLUSIONS: For out-of-field SMs, no increased risk of developing a variety of malignancies was observed. For in-field SMs, only 1 malignant histology was noted 15 years after the original proton therapy. No SM was observed in children and young adults.
PURPOSE: To investigate the occurrence of second malignancies resulting from the secondary radiation from a passively scattered proton beam. METHODS AND MATERIALS: A cohort of patients with long-term follow-up was defined. All were treated at the same institution with the same proton delivery system, consisting of a 200 MeV fixed, horizontal, passively scattered beam combined with a robotic chair. This setup allows for stereotactic positioning and permits fractionated treatments. The majority of patients underwent cranial or intracranial stereotactic radiation therapy. Patients with previous photon therapy or a follow-up of 24 months or less were excluded. For out-of-field secondary malignancies (SMs), the observed incidence in the study population was compared to the risk of developing a malignancy in the general population, taking patient sex into account. RESULTS: From September 1993 to May 2016, a total of 524 patients received proton beam therapy, and 322 patients could be evaluated for this study (164 female and 158 male). Age ranged from 2 to 85 years, with a median of 40 years. Follow-up ranged from 25 to 276 months, with a median of 150 months (12.5 years). During the study observation period, 7 patients had out-of-field new malignant disease. Three female patients developed a malignancy, compared with an expected incidence of 4.09 (standardized incidence ratio, 0.73 [95% confidence interval, 0.24-2.27]); 4 male patients developed a malignancy, versus an expected incidence of 3.99 (standardized incidence ratio, 1.00 [95% confidence interval, 0.38-2.67]). New intracranial disease developed in 9 patients: 8 meningiomas and 1 carcinoma. CONCLUSIONS: For out-of-field SMs, no increased risk of developing a variety of malignancies was observed. For in-field SMs, only 1 malignant histology was noted 15 years after the original proton therapy. No SM was observed in children and young adults.
Authors: Carles Domingo; Juan Ignacio Lagares; Maite Romero-Expósito; Beatriz Sánchez-Nieto; Jaime J Nieto-Camero; Jose Antonio Terrón; Leticia Irazola; Alexandru Dasu; Francisco Sánchez-Doblado Journal: Front Oncol Date: 2022-05-25 Impact factor: 5.738
Authors: Camilla S Byskov; Christian R Hansen; Rikke H Dahlrot; Lene Haldbo-Classen; Charlotte A Haslund; Flemming Kjær-Kristoffersen; Thomas O Kristensen; Yasmin Lassen-Ramshad; Slávka Lukacova; Aida Muhic; Petra W Nyström; Britta Weber; Jesper F Kallehauge Journal: Phys Imaging Radiat Oncol Date: 2021-11-28