Abstract:Purpose
We evaluated acute toxicity profiles and dosimetric data for children with salivary gland tumors treated with adjuvant photon/electron-based radiation therapy (X/E RT) or proton therapy (PRT).
Methods and Materials
We identified 24 patients who had received adjuvant radiotherapy for salivary gland tumors. Data was extracted from the medical records and the treatment planning systems. Toxicity was scored according to the Common Terminology Criteria for Adverse Effects 4.0.
Results
Eleven patients re… Show more
“…Similar oral cavity sparing and mean oral cavity doses have been reported by others using spot-scanning proton therapy in comparative treatment planning for patients receiving ipsilateral head-and-neck radiation [ 26 ] and in clinical results of multi-field optimized intensity modulated proton therapy in nasopharyngeal cancer [ 27 ]. The observations of our proton cohort are in line with a retrospective study of proton therapy versus mixed photon-electron radiotherapy for pediatric salivary tumors, which found proton therapy was associated with reduced radiation dose to the oral cavity and reduced incidence of grade 2–3 oral mucositis [ 28 ]. Fig.…”
BackgroundTo evaluate acute toxicity endpoints in a cohort of patients receiving head and neck radiation with proton therapy or intensity modulated radiation therapy (IMRT).MethodsForty patients received comprehensive head and neck radiation including bilateral cervical nodal radiation, given with or without chemotherapy, for tumors of the nasopharynx, nasal cavity or paranasal sinuses, any T stage, N0-2. Fourteen received comprehensive treatment with proton therapy, and 26 were treated with IMRT, either comprehensively or matched to proton therapy delivered to the primary tumor site. Toxicity endpoints assessed included g-tube dependence at the completion of radiation and at 3 months after radiation, opioid pain medication requirement compared to pretreatment normalized as equivalent morphine dose (EMD) at completion of treatment, and at 1 and 3 months after radiation.ResultsIn a multivariable model including confounding variables of concurrent chemotherapy and involved nodal disease, comprehensive head and neck radiation therapy using proton therapy was associated with a lower opioid pain requirement at the completion of radiation and a lower rate of gastrostomy tube dependence by the completion of radiation therapy and at 3 months after radiation compared to IMRT. Proton therapy was associated with statistically significant lower mean doses to the oral cavity, esophagus, larynx, and parotid glands. In subgroup analysis of 32 patients receiving concurrent chemotherapy, there was a statistically significant correlation with a greater opioid pain medication requirement at the completion of radiation and both increasing mean dose to the oral cavity and to the esophagus.ConclusionsProton therapy was associated with significantly reduced radiation dose to assessed non-target normal tissues and a reduced rate of gastrostomy tube dependence and opioid pain medication requirements. This warrants further evaluation in larger studies, ideally with patient-reported toxicity outcomes and quality of life endpoints.
“…Similar oral cavity sparing and mean oral cavity doses have been reported by others using spot-scanning proton therapy in comparative treatment planning for patients receiving ipsilateral head-and-neck radiation [ 26 ] and in clinical results of multi-field optimized intensity modulated proton therapy in nasopharyngeal cancer [ 27 ]. The observations of our proton cohort are in line with a retrospective study of proton therapy versus mixed photon-electron radiotherapy for pediatric salivary tumors, which found proton therapy was associated with reduced radiation dose to the oral cavity and reduced incidence of grade 2–3 oral mucositis [ 28 ]. Fig.…”
BackgroundTo evaluate acute toxicity endpoints in a cohort of patients receiving head and neck radiation with proton therapy or intensity modulated radiation therapy (IMRT).MethodsForty patients received comprehensive head and neck radiation including bilateral cervical nodal radiation, given with or without chemotherapy, for tumors of the nasopharynx, nasal cavity or paranasal sinuses, any T stage, N0-2. Fourteen received comprehensive treatment with proton therapy, and 26 were treated with IMRT, either comprehensively or matched to proton therapy delivered to the primary tumor site. Toxicity endpoints assessed included g-tube dependence at the completion of radiation and at 3 months after radiation, opioid pain medication requirement compared to pretreatment normalized as equivalent morphine dose (EMD) at completion of treatment, and at 1 and 3 months after radiation.ResultsIn a multivariable model including confounding variables of concurrent chemotherapy and involved nodal disease, comprehensive head and neck radiation therapy using proton therapy was associated with a lower opioid pain requirement at the completion of radiation and a lower rate of gastrostomy tube dependence by the completion of radiation therapy and at 3 months after radiation compared to IMRT. Proton therapy was associated with statistically significant lower mean doses to the oral cavity, esophagus, larynx, and parotid glands. In subgroup analysis of 32 patients receiving concurrent chemotherapy, there was a statistically significant correlation with a greater opioid pain medication requirement at the completion of radiation and both increasing mean dose to the oral cavity and to the esophagus.ConclusionsProton therapy was associated with significantly reduced radiation dose to assessed non-target normal tissues and a reduced rate of gastrostomy tube dependence and opioid pain medication requirements. This warrants further evaluation in larger studies, ideally with patient-reported toxicity outcomes and quality of life endpoints.
“…More recently, numerous reports have been published documenting the theoretical advantages of proton therapy over photon therapy for head and neck cancer [23–25]. The first use of multi-field optimization for IMPT was reported in 2014 for head and neck malignancies [16]; indeed, IMPT (as opposed to passively scattered proton therapy) has been shown in treatment-planning comparisons to be the most effective in reducing the doses to the spinal cord, parotid, and brainstem [13, 26]. Although patients in our retrospective analysis had not been randomized to receive one type of therapy over the other, our results demonstrated a clear reduction in mean mandibular dose with IMPT (25.6 Gy vs. 41.2 Gy for IMRT, P <0.001), as well as a reduction of the volume of the mandible exposed to high radiation doses between 60 and 70 Gy, which are known to be related to the occurrence of ORN.…”
Purpose
We compared mandibular doses and osteoradionecrosis in patients with oropharyngeal cancer after intensity-modulated radiation therapy (IMRT) or intensity-modulated proton therapy (IMPT).
Methods and materials
We identified 584 patients who received definitive radiotherapy for oropharyngeal cancer from January 2011 through June 2014 at MD Anderson Cancer Center (534 IMRT and 50 IMPT). The dosimetric variables and osteoradionecrosis were compared with Chi-square test or Fisher’s exact test.
Results
Median follow-up time for all patients (534 IMRT and IMPT) was 33.8 months (33.8 months IMRT vs. 34.6 months IMPT, P=0.854), and median time to osteoradionecrosis was 11.4 months (range 6.74–16.1 months). Mandibular doses were lower for patients treated with IMPT (minimum 0.8 vs. 7.3 Gy; mean 25.6 vs. 41.2 Gy; P<0.001), and osteoradionecrosis rates were lower as well: 2% IMPT (1 grade 1), 7.7% IMRT (12 grade 4, 5 grade 3, and 1 grade 2 and 23 grade 1). Osteoradionecrosis location depended on the primary tumor site and high-dose field in the mandible.
Conclusions: Osteoradionecrosis events were significantly associated with higher dose irradiation to mandibular
Use of IMPT minimized excess irradiation of the mandible and consequently reduced the risk of osteoradionecrosis for oropharyngeal cancer.
“…There is a substantial body of evidence from in silico comparative planning studies across a broad range of tumour sites comparing dose distributions between photon RT and PT demonstrating superiority in regard to normal tissue sparing. [2][3][4][5][6][7]44,[81][82][83] Proponents of PT view these data as indicating that PT will become the treatment of choice for specific indications once its availability is wide enough, in part for its compliance with the generally agreed As Low As Reasonably Achievable (ALARA) principle.…”
Section: Planning and Dosimetric Evidencementioning
Particle therapy (PT) offers the potential for reduced normal tissue damage as well as escalation of target dose, thereby enhancing the therapeutic ratio in radiation therapy. Reflecting the building momentum of PT use worldwide, construction has recently commenced for The Australian Bragg Centre for Proton Therapy and Research in Adelaidethe first PT centre in Australia. This systematic review aims to update the clinical evidence base for PT, both proton beam and carbon ion therapy. The purpose is to inform clinical decision-making for referral of patients to PT centres in Australia as they become operational and overseas in the interim. Three major databases were searched by two independent researchers, and evidence quality was classified according to the National Health and Medical Research Council evidence hierarchy. One hundred and thirty-six studies were included, two-thirds related to proton beam therapy alone. PT at the very least provides equivalent tumour outcomes compared to photon controls with the possibility of improved control in the case of carbon ion therapy. There is suggestion of reduced morbidities in a range of tumour sites, supporting the predictions from dosimetric modelling and the wide international acceptance of PT for specific indications based on this. Though promising, this needs to be counterbalanced by the overall low quality of evidence found, with 90% of studies of level IV (case series) evidence. Prospective comparative clinical trials, supplemented by database-derived outcome information, preferably conducted within international and national networks, are strongly recommended as PT is introduced into Australasia.
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