International Journal of Particle Therapy最新文献

{"title":"Proton Therapy of Prostate and Pelvic Lymph Nodes for High Risk Prostate Cancer: Acute Toxicity.","authors":"Richard Choo,&nbsp;David W Hillman,&nbsp;Thomas Daniels,&nbsp;Carlos Vargas,&nbsp;Jean Claude Rwigema,&nbsp;Kimberly Corbin,&nbsp;Sameer Keole,&nbsp;Sujay Vora,&nbsp;Kenneth Merrell,&nbsp;Bradley Stish,&nbsp;Thomas Pisansky,&nbsp;Brian Davis,&nbsp;Adam Amundson,&nbsp;William Wong","doi":"10.14338/IJPT-20-00094.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00094.1","url":null,"abstract":"<p><strong>Purpose: </strong>To assess acute gastrointestinal (GI) and genitourinary (GU) toxicities of intensity-modulated proton therapy (IMPT) targeting the prostate/seminal vesicles and pelvic lymph nodes for prostate cancer.</p><p><strong>Materials and methods: </strong>A prospective study (ClinicalTrials.gov: NCT02874014), evaluating moderately hypofractionated IMPT for high-risk or unfavorable intermediate-risk prostate cancer, accrued a target sample size of 56 patients. The prostate/seminal vesicles and pelvic lymph nodes were treated simultaneously with 6750 and 4500 centigray radiobiologic equivalent (cGyRBE), respectively, in 25 daily fractions. All received androgen-deprivation therapy. Acute GI and GU toxicities were prospectively assessed from 7 GI and 9 GU categories of the Common Terminology Criteria for Adverse Events (version 4), at baseline, weekly during radiotherapy, and 3-month after radiotherapy. Fisher exact tests were used for comparisons of categorical data.</p><p><strong>Results: </strong>Median age was 75 years. Median follow-up was 25 months. Fifty-five patients were available for acute toxicity assessment. Sixty-two percent and 2%, respectively, experienced acute grade 1 and 2 GI toxicity. Grade 2 GI toxicity was proctitis. Sixty-five percent and 35%, respectively, had acute grade 1 and 2 GU toxicity. The 3 most frequent grade 2 GU toxicities were urinary frequency, urgency, and obstructive symptoms. None had acute grade ≥ 3 GI or GU toxicity. The presence of baseline GI and GU symptoms was associated with a greater likelihood of experiencing acute GI and GU toxicity, respectively. Of 45 patients with baseline GU symptoms, 44% experienced acute grade 2 GU toxicity, compared with only 10% among 10 with no baseline GU symptoms (<i>P</i> = 0.07). Although acute grade 1 and 2 GI and GU toxicities were common during radiotherapy, most resolved at 3 months after radiotherapy.</p><p><strong>Conclusion: </strong>A moderately hypofractionated IMPT targeting the prostate/seminal vesicles and regional pelvic lymph nodes was well tolerated with no acute grade ≥ 3 GI or GU toxicity. Patients with baseline GU symptoms had a higher rate of acute grade 2 GU toxicity.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 2","pages":"41-50"},"PeriodicalIF":1.7,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8489485/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39580492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparisons of 3-Dimensional Conformal and Intensity-Modulated Neutron Therapy for Head and Neck Cancers.","authors":"Natalie Viscariello, Matthew D Greer, Upendra Parvathaneni, Jay J Liao, George E Laramore, Robert D Stewart","doi":"10.14338/IJPT-20-00059.1","DOIUrl":"10.14338/IJPT-20-00059.1","url":null,"abstract":"<p><strong>Purpose: </strong>Neutron therapy is a high linear energy transfer modality that is useful for the treatment of radioresistant head and neck (H&N) cancers. It has been limited to 3-dimensioanal conformal-based fast-neutron therapy (3DCNT), but recent technical advances have enabled the clinical implementation of intensity-modulated neutron therapy (IMNT). This study evaluated the comparative dosimetry of IMNT and 3DCNT plans for the treatment of H&N cancers.</p><p><strong>Materials and methods: </strong>Seven H&N IMNT plans were retrospectively created for patients previously treated with 3DCNT at the University of Washington (Seattle). A custom RayStation model with neutron-specific scattering kernels was used for inverse planning. Organ-at-risk (OAR) objectives from the original 3DCNT plan were initially used and were then systematically reduced to investigate the feasibility of improving a therapeutic ratio, defined as the ratio of the mean tumor to OAR dose. The IMNT and 3DCNT plan quality was evaluated using the therapeutic ratio, isodose contours, and dose volume histograms.</p><p><strong>Results: </strong>When compared with the 3DCNT plans, IMNT reduces the OAR dose for the equivalent tumor coverage. Moreover, IMNT is most advantageous for OARs in close spatial proximity to the target. For the 7 patients with H&N cancers examined, the therapeutic ratio for IMNT increased by an average of 56% when compared with the 3DCNT. The maximum OAR dose was reduced by an average of 20.5% and 20.7% for the spinal cord and temporal lobe, respectively. The mean dose to the larynx decreased by an average of 80%.</p><p><strong>Conclusion: </strong>The IMNT significantly decreases the OAR doses compared with 3DCNT and provides comparable tumor coverage. Improvements in the therapeutic ratio with IMNT are especially significant for dose-limiting OARs near tumor targets. Moreover, IMNT provides superior sparing of healthy tissues and creates significant new opportunities to improve the care of patients with H&N cancers treated with neutron therapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 2","pages":"51-61"},"PeriodicalIF":1.7,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8489487/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39580493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biologically Effective Dose and Rectal Bleeding in Definitive Proton Therapy for Prostate Cancer","authors":"R. Bhangoo, M. Petersen, G. F. Bulman, C. Vargas, C. Thorpe, Jason Shen, W. Wong, J. Rwigema, T. Daniels, S. Keole, S. Schild, Y. Rong, T. DeWees","doi":"10.14338/IJPT-21-00007.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00007.1","url":null,"abstract":"Purpose and Objectives With increasing use of hypofractionation and extreme hypofractionation for prostate cancer, rectal dose-volume histogram (DVH) parameters that apply across dose fractionations may be helpful for treatment planning in clinical practice. We present an exploratory analysis of biologically effective rectal dose (BED) and equivalent rectal dose in 2 Gy fractions (EQD2) for rectal bleeding in patients treated with proton therapy across dose fractionations. Materials and Methods From 2016 to 2018, 243 patients with prostate cancer were treated with definitive proton therapy. Rectal DVH parameters were obtained from treatment plans, and rectal bleeding events were recorded. The BED and EQD2 transformations were applied to each rectal DVH parameter. Univariate analysis using logistic regression was used to determine DVH parameters that were significant predictors of grade ≥ 2 rectal bleeding. Youden index was used to determine optimum cutoffs for clinically meaningful DVH constraints. Stepwise model-selection criteria were then applied to fit a “best” multivariate logistic model for predicting Common Terminology Criteria for Adverse Events grade ≥ 2 rectal bleeding. Results Conventional fractionation, hypofractionation, and extreme hypofractionation were prescribed to 117 (48%), 84 (34%), and 42 (17.3%) patients, respectively. With a median follow-up of 20 (2.5-40) months, 10 (4.1%) patients experienced rectal bleeding. On univariate analysis, multiple rectal DVH parameters were significantly associated with rectal bleeding across BED, EQD2, and nominal doses. The BED volume receiving 55 Gy > 13.91% was found to be statistically and clinically significant. The BED volume receiving 55 Gy remained statistically significant for an association with rectal bleeding in the multivariate model (odds ratio, 9.81; 95% confidence interval, 2.4-40.5; P = .002). Conclusion In patients undergoing definitive proton therapy for prostate cancer, dose to the rectum and volume of the rectum receiving the dose were significantly associated with rectal bleeding across conventional fractionation, hypofractionation, and extreme hypofractionation when using BED and EQD2 transformations.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"37 - 46"},"PeriodicalIF":1.7,"publicationDate":"2021-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49418638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear Fragmentation Imaging for Carbon-Ion Radiation Therapy Monitoring: an In Silico Study","authors":"A. Bey, Jiasen Ma, K. Furutani, M. Herman, Jedediah E. Johnson, R. Foote, C. Beltran","doi":"10.14338/ijpt-20-00040.1","DOIUrl":"https://doi.org/10.14338/ijpt-20-00040.1","url":null,"abstract":"Purpose This article presents an in vivo imaging technique based on nuclear fragmentation of carbon ions in irradiated tissues for potential real-time monitoring of carbon-ion radiation therapy (CIRT) treatment delivery and quality assurance purposes in clinical settings. Materials and Methods A proof-of-concept imaging and monitoring system (IMS) was devised to implement the technique. Monte Carlo simulations were performed for a prospective pencil-beam scanning CIRT nozzle. The development IMS benchmark considered a 5×5-cm2 pixelated charged-particle detector stack positioned downstream from a target phantom and list-mode data acquisition. The abundance and production origins, that is, vertices, of the detected fragments were studied. Fragment trajectories were approximated by straight lines and a beam back-projection algorithm was built to reconstruct the vertices. The spatial distribution of the vertices was then used to determine plan relevant markers. Results The IMS technique was applied for a simulated CIRT case, a primary brain tumor. Four treatment plan monitoring markers were conclusively recovered: a depth dose distribution correlated profile, ion beam range, treatment target boundaries, and the beam spot position. Promising millimeter-scale (3-mm, ≤10% uncertainty) beam range and submillimeter (≤0.6-mm precision for shifts <3 cm) beam spot position verification accuracies were obtained for typical therapeutic energies between 150 and 290 MeV/u. Conclusions This work demonstrated a viable online monitoring technique for CIRT treatment delivery. The method's strong advantage is that it requires few signal inputs (position and timing), which can be simultaneously acquired with readily available technology. Future investigations will probe the technique's applicability to motion-sensitive organ sites and patient tissue heterogeneities. In-beam measurements with candidate detector-acquisition systems are ultimately essential to validate the IMS benchmark performance and subsequent deployment in the clinic.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"25 - 36"},"PeriodicalIF":1.7,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47093002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demonstration of the FLASH Effect Within the Spread-out Bragg Peak After Abdominal Irradiation of Mice","authors":"T. Evans, J. Cooley, M. Wagner, Tianning Yu, T. Zwart","doi":"10.14338/IJPT-20-00095","DOIUrl":"https://doi.org/10.14338/IJPT-20-00095","url":null,"abstract":"Purpose The effects of FLASH-level dose rates delivered at the spread-out Bragg peak (SOBP) on normal tissue damage in mice were investigated. Materials and Methods Fifty nontumor-bearing mice received abdominal irradiation, 30 at FLASH dose rates (100 Gy/s) and 20 at conventional dose rates (0.1 Gy/s). Total dose values ranged from 10 to 19 Gy, delivered in a single spot by a synchrocyclotron proton therapy system. Centered on the abdomen, the collimated field delivered was an 11-mm diameter circle with a water-equivalent depth of 2.4 cm from entrance to distal 80% dose. A ridge filter was used to provide dose uniformity over the full 2.4-cm range. The spatial distribution was identical for both the FLASH and conventional deliveries. Results Overall survival and individual mouse weights were tracked for 21 days after the exposure date, and LD50 values were compared for the FLASH and conventional dose rate groups. Mice exposed to FLASH dose rates had a higher LD50 value as compared with mice exposed to conventional dose rates, with a dose-dependent improvement in survivability of 10% to 20%. The FLASH cohort also showed greater or equal percent population survival for each day of the study. Conclusion These results are preliminary confirmation of the potential for the combination of the advantages of the Bragg peak with the normal tissue sparing benefits of FLASH treatments. This experiment also confirms that pulsed synchrocyclotrons can be used for the purpose of FLASH research and treatment.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"68 - 75"},"PeriodicalIF":1.7,"publicationDate":"2021-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42812063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Advantage of Proton Therapy in Hypothalamic-Pituitary Axis and Hippocampus Avoidance for Children with Medulloblastoma.","authors":"Saif Aljabab,&nbsp;Shushan Rana,&nbsp;Shadonna Maes,&nbsp;Avril O'Ryan-Blair,&nbsp;Jackie Castro,&nbsp;Jack Zheng,&nbsp;Lia M Halasz,&nbsp;Phillip J Taddei","doi":"10.14338/IJPT-21-00001.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00001.1","url":null,"abstract":"<p><strong>Purpose: </strong>Craniospinal irradiation (CSI) improves clinical outcomes at the cost of long-term neuroendocrine and cognitive sequelae. The purpose of this pilot study was to determine whether hypothalamic-pituitary axis (HPA) and hippocampus avoidance (HPA-HA) with intensity-modulated proton therapy (IMPT) can potentially reduce this morbidity compared with standard x-ray CSI.</p><p><strong>Materials and methods: </strong>We retrospectively evaluated 10 patients with medulloblastoma (mean, 7 years; range, 4-14 years). Target volumes and organs at risk were delineated as per our local protocol and the ACNS0331 atlas. An experienced neuroradiologist verified the HPA and hippocampus contours. The primary objective was CSI and boost clinical target volume (CTV) covering 95% of the volume (D₉₅) > 99% coverage with robustness. Described proton therapy doses in grays are prescribed using a biological effectiveness relative to photon therapy of 1.1. The combined prescribed dose in the boost target was 54 Gy. Secondary objectives included the HPA and hippocampus composite average dose (D_mean ≤ 18 Gy). For each patient, volumetric modulated arc radiotherapy (VMAT) and tomotherapy (TOMO) plans existed previously, and a new plan was generated with 3 cranial and 1 or 2 spinal beams for pencil-beam scanning delivery. Statistical comparison was performed with 1-way analysis of variance.</p><p><strong>Results: </strong>Compared with standard CSI, HPA-HA CSI had statistically significant decreases in the composite doses received by the HPA (32.2 versus 17.9 Gy; <i>P</i> < .001) and hippocampi (39.8 versus 22.8 Gy; <i>P</i> < .001). The composite HPA D_mean was lower in IMPT plans (17.9 Gy) compared with that of VMAT (21.8 Gy) and TOMO (21.2 Gy) plans (<i>P</i> = .05). Hippocampi composite D_mean was also lower in IMPT plans (21 Gy) compared with that of VMAT (27.5 Gy) and TOMO (27.2 Gy) plans (<i>P</i> = .02). The IMPT CTV D₉₅ coverage was lower in IMPT plans (52.8 Gy) compared with that of VMAT (54.6 Gy) and TOMO (54.6 Gy) plans (<i>P</i> < .001) The spared mean volume was only 1.35% (19.8 cm³) of the whole-brain CTV volume (1476 cm³).</p><p><strong>Conclusion: </strong>We found that IMPT has the strong potential to reduce the dose to the HPA and hippocampus, compared with standard x-ray CSI while maintaining target coverage. A prospective clinical trial is required to establish the safety, efficacy, and toxicity of this novel CSI approach.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"43-54"},"PeriodicalIF":1.7,"publicationDate":"2021-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiation Necrosis with Proton Therapy in a Patient with Aarskog-Scott Syndrome and Medulloblastoma.","authors":"Vidya Puthenpura,&nbsp;Nicholas J DeNunzio,&nbsp;Xue Zeng,&nbsp;Drosoula Giantsoudi,&nbsp;Mariam Aboian,&nbsp;David Ebb,&nbsp;Kristopher T Kahle,&nbsp;Torunn I Yock,&nbsp;Asher M Marks","doi":"10.14338/IJPT-21-00013.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00013.1","url":null,"abstract":"<p><strong>Purpose: </strong>Medulloblastoma is known to be associated with multiple cancer-predisposition syndromes. In this article, we explore a possible association among a patient's Aarskog-Scott syndrome, development of medulloblastoma, and subsequent brainstem radiation necrosis.</p><p><strong>Case presentation: </strong>A 5-year-old male with Aarskog-Scott syndrome initially presented to his pediatrician with morning emesis, gait instability, and truncal weakness. He was ultimately found to have a posterior fossa tumor with pathology consistent with group 3 medulloblastoma. After receiving a gross total resection and standard proton beam radiation therapy with concurrent vincristine, he was noted to develop brainstem radiation necrosis, for which he underwent therapy with high-dose dexamethasone, bevacizumab, and hyperbaric oxygen therapy with radiographic improvement and clinical stabilization.</p><p><strong>Conclusion: </strong>Based on several possible pathologic correlates in the FDG1 pathway, there exists a potential association between this patient's Aarskog-Scott syndrome and medulloblastoma, which needs to be investigated further. In patients with underlying, rare genetic syndromes, further caution should be taken when evaluating chemotherapy and radiation dosimetry planning.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"58-65"},"PeriodicalIF":1.7,"publicationDate":"2021-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768897/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insurance Approval for Definitive Proton Therapy for Prostate Cancer.","authors":"William M Mendenhall,&nbsp;Eric D Brooks,&nbsp;Stephanie Smith,&nbsp;Christopher G Morris,&nbsp;Curtis B Bryant,&nbsp;Randal H Henderson,&nbsp;Romaine C Nichols,&nbsp;Kathy McIntyre,&nbsp;Stuart L Klein,&nbsp;Nancy P Mendenhall","doi":"10.14338/IJPT-21-00002.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00002.1","url":null,"abstract":"<p><strong>Purpose: </strong>To determine factors that influence insurance approval for definitive proton therapy (PT) for prostate cancer.</p><p><strong>Materials and methods: </strong>Between 2014 and 2018, 1592 insured patients with localized prostate cancer were evaluated and recommended to undergo definitive PT; 547 patients (34.4%) had commercial insurance, whereas 1045 patients (65.6%) had Medicare/Medicaid. Of those with Medicare, 164 patients (15.7%) had Medicare alone; 677 (64.8%) had supplemental plans; and 204 (19.5%) had secondary commercial insurance. Insurance that \"covered\" PT for prostate cancer implied that it was an indication designated in the coverage policy. \"Not covered\" means that the insurance policy did not list prostate cancer as an indication for PT. Of all 1592 patients, 1263 (79.3%) belonged to plans that covered PT per policy. However, approval for PT was still required via medical review for 619 patients (38.9%), comparative dosimetry for 56 patients (3.5%), peer-to-peer discussion for 234 patients (14.7%), and administrative law judge hearings for 3 patients (<0.1%). Multivariate analyses of factors affecting approval were conducted, including risk group (low/intermediate versus high), insurance type (commercial versus Medicare/Medicaid), whether PT was included as a covered benefit under the plan (covered versus not covered), and time period (2014-16 versus 2017 versus 2018).</p><p><strong>Results: </strong>On multivariate analysis, factors affecting PT approval for prostate treatment included coverage of PT per policy (97.1% had approval with insurance that covered PT versus 48.6% whose insurance did not cover PT; <i>P</i> < .001); insurance type (32.5% had approval with commercial insurance versus 97.4% with Medicare; <i>P</i> < .001); and time, with 877/987 patients (88.9%) approved between 2014 and 2016, 255/312 patients (81.7%) approved during 2017, and 255/293 patients (87.0%) approved thereafter (<i>P</i> = .02). Clinical factors, including risk group, had no bearing on insurance approval (<i>P</i> = .44).</p><p><strong>Conclusion: </strong>Proton insurance approval for prostate cancer has decreased, is most influenced by the type of insurance a patient belongs to, and is unrelated to clinical factors (risk group) in this study. More work is needed to help navigate appropriate access to care and to assist patients seeking definitive PT for prostate cancer treatment.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"36-42"},"PeriodicalIF":1.7,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768894/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring Radiation Toxicity Using Circulating Cell-Free DNA in Prostate Cancer Patients.","authors":"Natalie A Lockney,&nbsp;Randal H Henderson,&nbsp;Steven G Swarts,&nbsp;Zhenhuan Zhang,&nbsp;Bingrong Zhang,&nbsp;Jennifer Li,&nbsp;Robert A Zlotecki,&nbsp;Christopher G Morris,&nbsp;Katherine A Casey-Sawicki,&nbsp;Paul G Okunieff","doi":"10.14338/IJPT-D-21-00008","DOIUrl":"https://doi.org/10.14338/IJPT-D-21-00008","url":null,"abstract":"<p><strong>Background: </strong>After radiation therapy (RT), circulating plasma cell-free DNA (cfDNA) released in response to RT damage to tissue can be measured within hours. We examined for a correlation between cfDNA measured during the first week of therapy and early and late gastrointestinal (GI) and genitourinary (GU) toxicity.</p><p><strong>Material and methods: </strong>Patients were eligible for enrollment if they planned to receive proton or photon RT for nonmetastatic prostate cancer in the setting of an intact prostate or after prostatectomy. Blood was collected before treatment and on sequential treatment days for the first full week of therapy. Toxicity assessments were performed at baseline, weekly during RT, and 6 months and 12 months after RT. Data were analyzed to examine correlations among patient-reported GI and GU toxicities.</p><p><strong>Results: </strong>Fifty-four patients were evaluable for this study. Four (7%) and 3 (6%) patients experienced acute and late grade 2 GI toxicity, respectively. Twenty-two (41%) and 18 (35%) patients experienced acute and late grade 2 GU toxicity, respectively. No patients developed grade 3 or higher toxicity. Grade 2 acute GI toxicity, but not grade 2 acute GU toxicity, was significantly correlated with pre-RT cfDNA levels and on all days 1, 2, 3, 4, and 5 of RT (<i>P</i> < .005). Grade 2 late GI toxicity, but not GU toxicity, was significantly correlated with pre-RT cfDNA levels (<i>P</i> = .021).</p><p><strong>Conclusions: </strong>Based on this preliminary study, cfDNA levels can potentially predict the subset of patients destined to develop GI toxicity during prostate cancer treatment. Given that the toxicity profiles of the various fractionations and modalities are highly similar, the data support the expectation that cfDNA could provide a biological estimate to complement the dose-volume histogram. A test of this hypothesis is under evaluation in a National Cancer Institute-funded multi-institutional study.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"28-35"},"PeriodicalIF":1.7,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Effectiveness of Proton Therapy versus Photon Radiotherapy in Adolescents and Young Adults for Classical Hodgkin Lymphoma.","authors":"James E Bates,&nbsp;Stephanie Terezakis,&nbsp;Christopher G Morris,&nbsp;Avani D Rao,&nbsp;Shuchi Sehgal,&nbsp;Rahul Kumar,&nbsp;Raymond B Mailhot Vega,&nbsp;Nancy P Mendenhall,&nbsp;Bradford S Hoppe","doi":"10.14338/IJPT-21-00011.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00011.1","url":null,"abstract":"<p><strong>Purpose: </strong>Early stage (stages I-II) classical Hodgkin lymphoma (cHL) is a highly curable disease typically diagnosed in adolescents and young adults (AYAs). Proton therapy can also reduce the late toxicity burden in this population, but data on its comparative efficacy with photon radiotherapy in this population are sparse. We assessed outcomes in AYAs with cHL in a multi-institution retrospective review.</p><p><strong>Materials and methods: </strong>We identified 94 patients aged 15 to 40 years with stages I and II cHL treated with radiotherapy as part of their initial treatment between 2008 and 2017. We used Kaplan-Meier analyses and log-rank testing to evaluate survival differences between groups of patients.</p><p><strong>Results: </strong>A total of 91 patients were included in the analysis. The 2-year progression-free survival (PFS) rate was 89%. Of the 12 patients who experienced progression after radiotherapy, 4 occurred out-of-field, 2 occurred in-field, and 6 experienced both in- and out-of-field progression. There was no significant difference in 2-year PFS among AYA patients by radiotherapy dose received (≥ 30 Gy, 91%; < 30 Gy, 86%; <i>P</i> = .82). Likewise, there was no difference in 2-year PFS among patients who received either proton or photon radiotherapy (proton, 94%; photon, 83%; <i>P</i> = .07).</p><p><strong>Conclusion: </strong>Our cohort of AYA patients had comparable outcomes regardless of radiotherapy dose or modality used. For patients with significant risk of radiation-induced late effects, proton therapy is a reasonable treatment modality.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"21-27"},"PeriodicalIF":1.7,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768899/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}