International Journal of Particle Therapy最新文献

{"title":"Early Experience Using Proton Beam Therapy for Extremity Soft Tissue Sarcoma: A Multicenter Study.","authors":"Brady S Laughlin,&nbsp;Michael A Golafshar,&nbsp;Safia Ahmed,&nbsp;Matthew Prince,&nbsp;Justin D Anderson,&nbsp;Tamara Vern-Gross,&nbsp;Mahesh Seetharam,&nbsp;Krista Goulding,&nbsp;Ivy Petersen,&nbsp;Todd DeWees,&nbsp;Jonathan B Ashman","doi":"10.14338/IJPT-21-00037.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00037.1","url":null,"abstract":"<p><strong>Purpose: </strong>Proton beam therapy (PBT) may provide an advantage when planning well-selected patients with extremity soft tissue sarcoma (eSTS), specifically for large, anatomically challenging cases. We analyzed our early experience with PBT on toxicity and outcomes.</p><p><strong>Materials and methods: </strong>A retrospective study was performed for eSTS treated between June 2016 and October 2020 with pencil beam scanning PBT at 2 institutions. Diagnostic, treatment, and toxicity characteristics were gathered from baseline to last follow-up or death. Wound complications were defined as secondary operations for wound repair (debridement, drainage, skin graft, and muscle flap) or nonoperative management requiring hospitalization. Statistical analysis was performed with R software.</p><p><strong>Results: </strong>Twenty consecutive patients with a median age 51.5 years (range, 19-78 years) were included. Median follow-up was 13.7 months (range, 1.7-48.1 months). Tumor presentation was primary (n = 17) or recurrent after prior combined modality therapy (n = 3). Tumor location was either lower extremity (n = 16) or upper extremity (n = 4). Radiation was delivered preoperatively in most patients (n = 18). Median pretreatment tumor size was 7.9 cm (range, 1.3 -30.0 cm). The 1-year locoregional control was 100%. Four patients (20%) had developed metastatic disease by end of follow-up. Maximum toxicity for acute dermatitis was grade 2 in 8 patients (40%) and grade 3 in 3 patients (15%). After preoperative radiation and surgical resection, acute wound complications occurred in 6 patients (35%). Tumor size was larger in patients with acute wound complications compared with those without (medians 16 cm, range [12-30.0 cm] vs 6.3 cm, [1.3-14.4 cm], <i>P</i> = .003).</p><p><strong>Conclusion: </strong>PBT for well selected eSTS cases demonstrated excellent local control and similar acute wound complication rate comparable to historic controls. Long-term follow-up and further dosimetric analyses will provide further insight into potential advantages of PBT in this patient population.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"1-11"},"PeriodicalIF":1.7,"publicationDate":"2022-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238125/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462130","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":"Dosimetric Advantages of Silicone-Filled Vaginal Spacers in Pediatric Proton Therapy.","authors":"Ozgur Ates,&nbsp;Li Zhao,&nbsp;David Sobczak,&nbsp;Chia-Ho Hua,&nbsp;Matthew J Krasin","doi":"10.14338/IJPT-21-00044.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00044.1","url":null,"abstract":"<p><p>We introduce a custom-made silicone-filled vaginal spacer for use during treatment of female patients receiving pelvic proton radiation therapy. Commercially available vaginal dilators can be purchased as hollow objects; when filled with a media, they can act as a beam stopper and/or tissue spacer while pushing uninvolved vaginal wall away from a high-dose region. Dosimetric advantages of these specifically constructed silicone-filled vaginal spacers were investigated when compared to the unaltered commercially available product or no vaginal spacer in pediatric proton therapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"64-70"},"PeriodicalIF":1.7,"publicationDate":"2022-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238128/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462220","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":"Vaginal Sparing Radiotherapy Using IMPT and Daily Dilator Placement for Women with Anal Cancer.","authors":"Scott C Lester,&nbsp;Laura A McGrath,&nbsp;Rachael M Guenzel,&nbsp;Jenae C Quinn,&nbsp;Carolyn J Schultz,&nbsp;T Baron Bradley,&nbsp;Bret D Kazemba,&nbsp;Shima Ito,&nbsp;Christopher L Hallemeier","doi":"10.14338/IJPT-21-00025","DOIUrl":"https://doi.org/10.14338/IJPT-21-00025","url":null,"abstract":"<p><p>Sexual dysfunction is a common toxicity and detrimental for the quality of life of women treated with chemoradiotherapy for anal cancer. Sexual dysfunction occurs because the vagina is closely approximated to the anal canal and typically receives substantial doses of radiation. Strategies for mitigation have largely been focused on posttreatment therapy and symptom management. The use of daily vaginal dilator placement during radiotherapy to mitigate dose to the vagina has been previously explored with modest gains, while proton therapy is under active investigation for the treatment of anal cancer. Use of proton therapy for anal cancer reduces dose to some organs at risk but may inadvertently increase vaginal toxicity if the proton beam terminates in the vaginal tissue. Herein, we present the case histories of 2 women treated for squamous cell carcinoma of the anal canal with the novel combination of intensity-modulated proton therapy and daily vaginal dilator placement to maximally reduce dose to the vagina and protect it from areas of increased energy deposition at the end of the proton range.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"83-89"},"PeriodicalIF":1.7,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462131","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":"Feasibility Study of Using XRV-124 Scintillation Detector for Collinearity Measurement in Uniform Scanning Proton Therapy.","authors":"Biniam Tesfamicael,&nbsp;Colton Eckert,&nbsp;Suresh Rana","doi":"10.14338/IJPT-21-00040.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00040.1","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this work is to study the feasibility of using an XRV-124 scintillation detector in measuring the collinearity of the x-ray system and uniform scanning proton beam.</p><p><strong>Methods: </strong>A brass aperture for Snout 10 was manufactured. The center of the aperture had an opening of 1 cm in diameter (4 cm for the film measurements). The 2D kV x-ray images of the XRV-124 were acquired such that the marker inside the detector is aligned to the imaging isocenter. After obtaining the optimal camera settings, a uniform scanning proton beam was delivered for various ranges (12 g/cm² to 28 g/cm² in step size of 2 g/cm²). For each range, 10 monitor units (MU) of the first layer were delivered to the XRV-124 detector. Collinearity tests were repeated by using EDR2 and EBT3 films following our current quality assurance protocol in practice. The results from the XRV-124 measurements were compared against the collinearity results from EDR2 and EBT3 films.</p><p><strong>Results and discussion: </strong>The collinearity results were evaluated in the horizontal (x) and vertical (y) directions. The average deviation in collinearity in the x-direction was -0.24 ± 0.30 mm, 0.57 ± 0.39 mm, and -0.27 ± 0.14 mm for EDR2, EBT3, and XRV-124, respectively. In the y-direction, the average deviation was 0.39 ± 0.07 mm, 0.29 ± 0.14 mm, and 0.39 ± 0.03 mm for EDR2, EBT3, and XRV-124, respectively.</p><p><strong>Conclusion: </strong>The measurement results from the XRV-124 and films are in good agreement. Compared to film, the use of the XRV-124 detector for collinearity measurements in uniform scanning protons is more efficient and provides results in real time.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"90-95"},"PeriodicalIF":1.7,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238126/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462222","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":"Prostate Cancer Treatment with Pencil Beam Proton Therapy Using Rectal Spacers sans Endorectal Balloons.","authors":"Matthew Forsthoefel,&nbsp;Ryan Hankins,&nbsp;Elizabeth Ballew,&nbsp;Cara Frame,&nbsp;David DeBlois,&nbsp;Dalong Pang,&nbsp;Pranay Krishnan,&nbsp;Keith Unger,&nbsp;Keith Kowalczyk,&nbsp;John Lynch,&nbsp;Anatoly Dritschilo,&nbsp;Sean P Collins,&nbsp;Jonathan W Lischalk","doi":"10.14338/IJPT-21-00039","DOIUrl":"https://doi.org/10.14338/IJPT-21-00039","url":null,"abstract":"<p><strong>Purpose: </strong>Proton beam radiotherapy (PBT) has been used for the definitive treatment of localized prostate cancer with low rates of high-grade toxicity and excellent patient-reported quality-of-life metrics. Technological advances such as pencil beam scanning (PBS), Monte Carlo dose calculations, and polyethylene glycol gel rectal spacers have optimized prostate proton therapy. Here, we report the early clinical outcomes of patients treated for localized prostate cancer using modern PBS-PBT with hydrogel rectal spacing and fiducial tracking without the use of endorectal balloons.</p><p><strong>Materials and methods: </strong>This is a single institutional review of consecutive patients treated with histologically confirmed localized prostate cancer. Prior to treatment, all patients underwent placement of fiducials into the prostate and insertion of a hydrogel rectal spacer. Patients were typically given a prescription dose of 7920 cGy at 180 cGy per fraction using a Monte Carlo dose calculation algorithm. Acute and late toxicity were evaluated using the Common Terminology Criteria for Adverse Events (CTCAE), version 5. Biochemical failure was defined using the Phoenix definition.</p><p><strong>Results: </strong>From July 2018 to April 2020, 33 patients were treated (median age, 75 years). No severe acute toxicities were observed. The most common acute toxicity was urinary frequency. With a median follow-up of 18 months, there were no high-grade genitourinary late toxicities; however, one grade 3 gastrointestinal toxicity was observed. Late erectile dysfunction was common. One treatment failure was observed at 21 months in a patient treated for high-risk prostate cancer.</p><p><strong>Conclusion: </strong>Early clinical outcomes of patients treated with PBS-PBT using Monte Carlo-based planning, fiducial placement, and rectal spacers sans endorectal balloons demonstrate minimal treatment-related toxicity with good oncologic outcomes. Rectal spacer stabilization without the use of endorectal balloons is feasible for the use of PBS-PBT.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"28-41"},"PeriodicalIF":1.7,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238133/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462132","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":"Proceedings to the 7th Annual Conference of the Particle Therapy Cooperative Group North America (PTCOG-NA)","authors":"A. Garda, Lindsay Morris, R. Finley, Sheri S Spreiter, N. Deiter, John V. Kruse, S. Ito, M. Haddock, Ivy, Petersen, Chin-Cheng Chen, F. Yu, Ping-Chung Tsai, J. Moreau, Chavanon Apinorasethkul, D. Boos, A. Shim, Haibo Lin, J. I. Choi","doi":"10.14338/IJPT-22-PTCOG-NA-8.4","DOIUrl":"https://doi.org/10.14338/IJPT-22-PTCOG-NA-8.4","url":null,"abstract":"Purpose : Cancer cells produce innate immune signals following detection of radiation-induced cytosolic DNA via signaling pathways such as cGAS-STING. High linear energy transfer (LET) radiations induce more DNA double-strand breaks (DSBs) per unit dose than low-LET radiations, potentially enhancing immunogenic effects. This work explores the in vitro dose response characteristics of pro-immunogenic interferon-beta (IFN b ) and cGAS-STING antagonist three-prime repair exonuclease 1 (TREX1) from varying-LET radiations. Methods : IFN b and TREX1 expression were measured in MCC13 cells irradiated with graded doses of x-rays or fast neutrons (comparable LET to carbon-12) via ELISA, immunofluorescence, and qPCR assays. Laboratory measurement of the RBE for IFN b production (RBE IFN b ) and TREX1 upregulation (RBE TREX1 ) was compared to the modeled RBE for DSB induction (RBE DSB ) from Monte Carlo DNA damage simulations. RBE IFN b models were applied to radiation transport simulations to quantify the potential secretion of IFN b from representative proton, helium-4, and carbon-12 beams. Results : Maximum IFN b secretions occurred at 5.7 Gy and 14.0 Gy for neutrons and x-rays, respectively (RBE IFN b of 2.5). TREX1 signal increased linearly, with a four-fold higher upregulation per unit dose for fast neutrons (RBE TREX1 of 4.0). Monte Carlo modeling suggests an enhanced Bragg peak-to-entrance ratio for IFNb production in charged particle beams. Conclusion : High-LET radiation initiates larger IFNb and TREX1 responses per unit dose than low-LET radiations. RBE IFN b is comparable to published values for RBE DSB , whereas RBE TREX1 is roughly twofold higher. Therapeutic advantages of high-LET versus low-LET radiation remain unclear. Potential TREX1-targeted interventions may enable IFNb-mediated immunogenic responses at lower doses of high-LET radiations. Aim : To implement lattice radiotherapy using proton pencil beam scanning, and demonstrate treatments that are spatially fractionated in physical dose (PD), with significant escalation of biologic dose (BD) and dose-averaged linear energy transfer (LET d ) in the vicinity of the high PD regions. Method : For 5 patients with bulky tumors, spatial proton dose fractionation inside the GTV was achieved using proton lattice radiotherapy (pLRT). This involves a 3D lattice of 1.5-cm diameter spherical dose regions separated by 3 cm on average. pLRT plans were created with Eclipse (Varian Medical Systems). Two fields with an opening angle of at least 40 degrees were used to reduce skin dose at entrance. Dose valleys between spheres were kept below 40% of the peak PD. The resulting LET d distributions were calculated with an in-house GPU-based Monte Carlo simulation. BD was estimated from LET d and PD by using published formulae that are based on the linear-quadratic model, as well as a simpler model that assumes a linear relationship between BD and the product of LET d (in keV/ l m) and PD: BD ¼ 1.1PD(0.08LET d","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"82 - 122"},"PeriodicalIF":1.7,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48743679","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":"Dosimetric Comparison of Various Spot Placement Techniques in Proton Pencil Beam Scanning.","authors":"Mahboob Ur Rehman,&nbsp;Omar A Zeidan,&nbsp;Twyla Willoughby,&nbsp;Sanford L Meeks,&nbsp;Patrick Kelly,&nbsp;Kevin Erhart","doi":"10.14338/IJPT-21-00022.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00022.1","url":null,"abstract":"<p><strong>Purpose: </strong>To present quantitative dosimetric evaluations of five proton pencil beam spot placement techniques.</p><p><strong>Materials and methods: </strong>The spot placement techniques that were investigated include two grid-based (rectilinear grid and hexagonal grid, both commonly available in commercial planning systems) and three boundary-contoured (concentric contours, hybrid, and optimized) techniques. Treatment plans were created for two different target volumes, one spherical and one conical. An optimal set of planning parameters was defined for all treatment plans and the impact of spot placement techniques on the plan quality was evaluated in terms of lateral/distal dose falloff, normal tissue sparing, conformity and homogeneity of dose distributions, as well as total number of spots used.</p><p><strong>Results: </strong>The results of this work highlight that for grid-based spot placement techniques, the dose conformity is dependent on target cross-sectional shape perpendicular to beam direction, which changes for each energy layer. This variable conformity problem is mitigated by using boundary contoured spot placement techniques. However, in the case of concentric contours, the conformity is improved but at the cost of decreased homogeneity inside the target. Hybrid and optimized spot placement techniques, which use contoured spots at the boundary and gridlike interior spot patterns, provide more uniform dose distributions inside the target volume while maintaining the improved dose conformity. The optimized spot placement technique improved target coverage, homogeneity of dose, and minimal number of spots. The dependence of these results on spot size is also presented for both target shapes.</p><p><strong>Conclusion: </strong>This work illustrates that boundary-contoured spot placement techniques offer marked improvement in dosimetry metrics when compared to commercially available grid-based techniques for a range of proton scanned beam spot sizes.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 1","pages":"54-63"},"PeriodicalIF":1.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238129/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40462133","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":"Hyperfractionated-Accelerated Reirradiation with Proton Therapy for Radiation-Associated Breast Angiosarcoma","authors":"W. S. Looi, J. Bradley, Xiaoying Liang, Christiana M. Shaw, Mark M. Leyngold, R. M. Mailhot Vega, E. Brooks, M. Rutenberg, L. Spiguel, F. Giap, N. Mendenhall","doi":"10.14338/ijpt-21-00031.1","DOIUrl":"https://doi.org/10.14338/ijpt-21-00031.1","url":null,"abstract":"Purpose Radiation-associated angiosarcoma (RAAS) is a rare complication among patients treated with radiation therapy for breast cancer. Hyperfractionated-accelerated reirradiation (HART) improves local control after surgery. Proton therapy may further improve the therapeutic ratio by mitigating potential toxicity. Materials and Methods Six patients enrolled in a prospective registry with localized RAAS received HART with proton therapy between 2015 and 2021. HART was delivered twice or thrice daily in fraction sizes of 1.5 or 1.0 Gy, respectively. All patients received 45 Gy to a large elective volume followed by boosts to a median dose of 65 (range, 60-75) Gy. Toxicity was recorded prospectively by using the Common Terminology Criteria for Adverse Events, version 4.0. Results The median follow-up duration was 1.5 (range, 0.25-2.9) years. The median age at RAAS diagnosis was 73 (range, 60-83) years with a median latency of 8.9 (range, 5-14) years between radiation therapy completion and RAAS diagnosis. The median mean heart dose was 2.2 (range, 0.1-4.96) Gy. HART was delivered postoperatively (n = 1), preoperatively (n = 3), preoperatively for local recurrence after initial management with mastectomy (n = 1), and as definitive treatment (n = 1). All patients had local control of disease throughout follow-up. Three of 4 patients treated preoperatively had a pathologic complete response. The patient treated definitively had a complete metabolic response on her posttreatment PET/CT (positron emission tomography–computed tomography) scan. Two patients developed distant metastatic disease despite local control and died of their disease. Acute grade 3 toxicity occurred in 3 patients: 2 patients undergoing preoperative HART experienced wound dehiscence and 1 postoperatively developed grade 3 wound infection, which resolved. Conclusion HART with proton therapy appears effective for local control of RAAS with a high rate of pathologic complete response and no local recurrences to date. However, vigilant surveillance for distant metastasis should occur. Toxicity is comparable to that in photon/electron series. Proton therapy for RAAS may maximize normal tissue sparing in this large-volume reirradiation setting.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"55 - 67"},"PeriodicalIF":1.7,"publicationDate":"2022-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46235465","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":"Dosimetric Results for Adjuvant Proton Radiation Therapy of HPV-Associated Oropharynx Cancer","authors":"C. Wright, J. Baron, Daniel Y. Lee, Michele M. Kim, A. Barsky, B. Teo, J. Lukens, S. Swisher-McClure, A. Lin","doi":"10.14338/IJPT-D-21-00018","DOIUrl":"https://doi.org/10.14338/IJPT-D-21-00018","url":null,"abstract":"Purpose One significant advantage of proton therapy is its ability to improve normal tissue sparing and toxicity mitigation, which is relevant in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Here, we report our institutional experience and dosimetric results with adjuvant proton radiation therapy (PRT) versus intensity-modulated radiotherapy (IMRT) for Human Papilloma Virus (HPV)-associated OPSCC. Materials and Methods This was a retrospective, single institutional study of all patients treated with adjuvant PRT for HPV-associated OPSCC from 2015 to 2019. Each patient had a treatment-approved equivalent IMRT plan to serve as a reference. Endpoints included dosimetric outcomes to the organs at risk (OARs), local regional control (LRC), progression-free survival (PFS), and overall survival (OS). Descriptive statistics, a 2-tailed paired t test for dosimetric comparisons, and the Kaplan-Meier method for disease outcomes were used. Results Fifty-three patients were identified. Doses delivered to OARs compared favorably for PRT versus IMRT, particularly for the pharyngeal constrictors, esophagus, larynx, oral cavity, and submandibular and parotid glands. The achieved normal tissue sparing did not negatively impact disease outcomes, with 2-year LRC, PFS, and OS of 97.0%, 90.3%, and 97.5%, respectively. Conclusion Our study suggests that meaningful normal tissue sparing in the postoperative setting is achievable with PRT, without impacting disease outcomes.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"47 - 54"},"PeriodicalIF":1.7,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46578073","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":"Proton Radiotherapy for Patients With Oligometastatic Breast Cancer Involving the Sternum.","authors":"Andrew Johnson,&nbsp;Nicolas Depauw,&nbsp;Stephen Zieminski,&nbsp;Rachel Jimenez","doi":"10.14338/IJPT-21-00014","DOIUrl":"https://doi.org/10.14338/IJPT-21-00014","url":null,"abstract":"<p><strong>Introduction: </strong>A subset of metastatic breast cancer patients present with oligometastatic disease involving the sternum. Given the proximity to traditional target structures, a proton radiation field can be expanded to include this region, providing definitive therapy for patients who are otherwise metastatic. We evaluated the feasibility and outcomes of a small series of patients who received comprehensive nodal irradiation inclusive of an isolated sternal metastasis using proton pencil beam scanning.</p><p><strong>Materials and methods: </strong>Four patients with a diagnosis of metastatic breast cancer with an isolated metastasis to the sternum received multimodality therapy with curative intent and then underwent adjuvant pencil beam scanning with definitive treatment to the sternum. Dosimetric parameters and treatment outcomes were evaluated.</p><p><strong>Results: </strong>With respect to treatment coverage, proton therapy was able to deliver comprehensive target structure coverage while maintaining modest doses to the organs at risk compared with photon techniques. At a median follow-up of 28 months from diagnosis, none of the patients have experienced relapse within the radiation portal or developed additional sites of metastatic disease.</p><p><strong>Conclusion: </strong>Pencil beam scanning for oligometastatic breast cancer with isolated sternal lesions appears feasible without undue normal tissue exposure. Current treatment outcomes appear promising.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"66-71"},"PeriodicalIF":1.7,"publicationDate":"2021-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592766","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}