2023
PO83 Utilization of a Virtual Clinical Trial to Characterize Sensitivity of the Linear-Quadratic Model
Tien C, Draeger E, Guan F, Carlson D, Chen Z. PO83 Utilization of a Virtual Clinical Trial to Characterize Sensitivity of the Linear-Quadratic Model. Brachytherapy 2023, 22: s110. DOI: 10.1016/j.brachy.2023.06.184.Peer-Reviewed Original ResearchTumor control probabilityClinical trialsLinear-quadratic modelNumber of patientsPatient cohort sizeTCP curvesRadiobiological parametersVirtual clinical trialsGy-1Cohort sizeRange of dosesPatient outcomesReference cohortPatientsHeterogeneous cohortVirtual patientsNew trialsRadiobiological parameter valuesClonogenic populationPatient ordersControl probabilityGyInput model parametersTrialsCohortPreliminary dosimetric comparison between fixed and rotating source stereotactic radiosurgery systems
Draeger E, Chen Z, Hansen J, Chiang V, Tien C. Preliminary dosimetric comparison between fixed and rotating source stereotactic radiosurgery systems. Journal Of Applied Clinical Medical Physics 2023, 24: e13907. PMID: 36660774, PMCID: PMC10161057, DOI: 10.1002/acm2.13907.Peer-Reviewed Original ResearchConceptsConformity indexRadiation Therapy Oncology Group conformity indexGK plansSuperior conformity indexNon-metastatic casesPaddick conformity indexDosimetric plan qualityGK patientsBrain metastasesRadiosurgery systemTrigeminal neuralgiaPrescription dosesGamma Knife systemMetastatic casesArteriovenous malformationsPituitary adenomasConformality indexLarge cohortDosimetric comparisonStereotactic radiosurgery systemGK IconPatientsCohortTreatment timeDosimetric results
2022
A small footprint couch‐top support device for image‐guided radiotherapy of heavy patients
Chen H, Morley K, Rodriguez R, Draeger E, Hassan M, Chen Z. A small footprint couch‐top support device for image‐guided radiotherapy of heavy patients. Journal Of Applied Clinical Medical Physics 2022, 23: e13788. PMID: 36267043, PMCID: PMC9797158, DOI: 10.1002/acm2.13788.Peer-Reviewed Original Research
2020
A prototype open-ended multichannel intracavitary-interstitial hybrid applicator for gynecological high-dose-rate brachytherapy
Tien CJ, Chen Z. A prototype open-ended multichannel intracavitary-interstitial hybrid applicator for gynecological high-dose-rate brachytherapy. Radiological Physics And Technology 2020, 13: 187-194. PMID: 32424632, DOI: 10.1007/s12194-020-00567-2.Peer-Reviewed Original ResearchConceptsPrescription doseRate brachytherapyHybrid applicatorPrior patientsRisk doseMinimum doseOAR D2ccMultichannel applicatorCentral tandemDoseTarget coverageInterstitial needlesPatientsApplicator bodyBrachytherapyDistal endOpen distal endsPeripheral needlesPeripheral channelsSilico studiesNeedleBowelBladderD2ccRectum
2018
Novel Eye Plaque Designs for Brachytherapy of Iris and Ciliary Body Melanoma and the First Clinical Application
Liu W, Kim JM, Young BK, Nath R, Chen Z, Decker RH, Astrahan MA, Pointdujour-Lim R. Novel Eye Plaque Designs for Brachytherapy of Iris and Ciliary Body Melanoma and the First Clinical Application. Ocular Oncology And Pathology 2018, 5: 220-228. PMID: 31049331, PMCID: PMC6489066, DOI: 10.1159/000493269.Peer-Reviewed Original ResearchIris melanomaCiliary bodyFirst clinical applicationPlaque designPoor patient tolerabilityCiliary body melanomaClinical applicationEye plaque brachytherapyPatient tolerabilityAdverse eventsCorneal edemaPlaque brachytherapyTumor apexTumor baseClinical casesMelanomaPatientsPlaquesSurgical maneuverabilityPlaque modelEffective dose distributionTreatment planningTolerabilityTreatmentImage-based treatment planningExtended duration of dilator use beyond 1 year may reduce vaginal stenosis after intravaginal high-dose-rate brachytherapy
Stahl JM, Qian JM, Tien CJ, Carlson DJ, Chen Z, Ratner ES, Park HS, Damast S. Extended duration of dilator use beyond 1 year may reduce vaginal stenosis after intravaginal high-dose-rate brachytherapy. Supportive Care In Cancer 2018, 27: 1425-1433. PMID: 30187220, DOI: 10.1007/s00520-018-4441-5.Peer-Reviewed Original ResearchConceptsVaginal stenosisEndometrial carcinomaMultivariable Cox proportional hazardsMultivariable Cox regression analysisVD useAcademic tertiary referral centerTertiary referral centerCox regression analysisLog-rank testCox proportional hazardsDevelopment of gradeDilator usePelvic radiotherapyReferral centerNoncompliant patientsPrimary outcomeAdjuvant brachytherapyEC patientsConclusionsThe riskRate brachytherapyProportional hazardsOptimal durationPatientsBrachytherapyStudy period
2017
Incorporating patient-specific CT-based ophthalmic anatomy in modeling iodine-125 eye plaque brachytherapy dose distributions
Tien CJ, Astrahan MA, Kim JM, Materin M, Chen Z, Nath R, Liu W. Incorporating patient-specific CT-based ophthalmic anatomy in modeling iodine-125 eye plaque brachytherapy dose distributions. Brachytherapy 2017, 16: 1057-1064. PMID: 28778599, DOI: 10.1016/j.brachy.2017.06.014.Peer-Reviewed Original ResearchConceptsEye modelDisc distanceDose differenceTumor apexPrescription doseOcular parametersPlaque SimulatorOcular structuresSubstantial dose differencesTarget volumePlaque positionDosimetric parametersPatientsClinical planningDosimetric impactSignificant differencesBrachytherapy planningSeed strengthPlaquesBrachytherapy dose distributionsDose distributionPatient-specific modelsDifferencesTumorsRetina
2016
State of dose prescription and compliance to international standard (ICRU-83) in intensity modulated radiation therapy among academic institutions
Das IJ, Andersen A, Chen Z, Dimofte A, Glatstein E, Hoisak J, Huang L, Langer MP, Lee C, Pacella M, Popple RA, Rice R, Smilowitz J, Sponseller P, Zhu T. State of dose prescription and compliance to international standard (ICRU-83) in intensity modulated radiation therapy among academic institutions. Practical Radiation Oncology 2016, 7: e145-e155. PMID: 28274405, DOI: 10.1016/j.prro.2016.11.003.Peer-Reviewed Original ResearchConceptsDose-volume histogramsDose prescriptionRadiation therapyHomogeneity indexICRU-83Stereotactic body radiation therapyBody radiation therapyTreatment sitesInstitutional review board clearanceLung sitesClinical trialsPelvic sitesPrescribed doseInternational guidelinesTumor siteArc therapyPatient treatmentTarget volumeTherapyPatientsDoseLevels of dosePrescriptionP-valueDose delivery
2015
Concomitant Imaging Dose and Cancer Risk in Image Guided Thoracic Radiation Therapy
Zhang Y, Wu H, Chen Z, Knisely JP, Nath R, Feng Z, Bao S, Deng J. Concomitant Imaging Dose and Cancer Risk in Image Guided Thoracic Radiation Therapy. International Journal Of Radiation Oncology • Biology • Physics 2015, 93: 523-531. PMID: 26460994, DOI: 10.1016/j.ijrobp.2015.06.034.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAge FactorsAgedAged, 80 and overAorta, ThoracicBody SizeBreastChildChild, PreschoolCone-Beam Computed TomographyFemaleHeartHumansLungMaleMiddle AgedMonte Carlo MethodOrgans at RiskPhantoms, ImagingPhotonsPrecision MedicineProtonsRadiation DosageRadiography, ThoracicRadiotherapy, Image-GuidedRisk AssessmentSex FactorsSpinal CordThoracic WallThoraxConceptsConcomitant imaging doseThoracic radiation therapyCancer riskRadiation therapyMean dosesCardiac substructuresKilovoltage cone-beamImaging doseAdverse eventsPediatric patientsMedian dosesCancer patientsRight ventricleExtra radiation doseSpinal cordHigh dosesPatientsCone beamPlanning CT imagesChest dimensionsDosesPatient sizeImaging guidanceTherapyDose
2014
SU‐E‐T‐518: Dosiemtric Impact of Patient Positioning Uncertainty in SBRT Treatments
Abbas H, Abolfath R, Nath R, Chen Z. SU‐E‐T‐518: Dosiemtric Impact of Patient Positioning Uncertainty in SBRT Treatments. Medical Physics 2014, 41: 346-346. DOI: 10.1118/1.4888851.Peer-Reviewed Original ResearchPatient positioning uncertaintiesDosimetric impactSuperior-inferior directionTreatment planLung SBRTCourse of treatmentSpine SBRT patientsOriginal treatment planLung doseCertain patientsAnterior-posterior positionPractice guidelinesIsocenter positioningSBRT treatmentSBRT patientsMinimum doseMaximum doseSBRTPatientsDoseMinimal dosimetric impactSpine SBRTProstateMonitor unitsTreatment planning system
2011
Testicular Doses in Image-Guided Radiotherapy of Prostate Cancer
Deng J, Chen Z, Yu JB, Roberts KB, Peschel RE, Nath R. Testicular Doses in Image-Guided Radiotherapy of Prostate Cancer. International Journal Of Radiation Oncology • Biology • Physics 2011, 82: e39-e47. PMID: 21489702, DOI: 10.1016/j.ijrobp.2011.01.071.Peer-Reviewed Original ResearchConceptsImage-guided radiotherapyTesticular dosesFull-fan modeProstate cancerFemoral headLess doseCBCT scansHalf-fan modeProstate cancer patientsKilovoltage cone-beamCancer patientsIntensity-modulated radiotherapy (IMRT) treatmentKilovoltage CBCTSuperior-inferior directionCone beamDosesCBCT fieldProstate patientsRectumDoseProstateMore doseRadiotherapy treatmentPatientsRadiotherapyKilovoltage Imaging Doses in the Radiotherapy of Pediatric Cancer Patients
Deng J, Chen Z, Roberts KB, Nath R. Kilovoltage Imaging Doses in the Radiotherapy of Pediatric Cancer Patients. International Journal Of Radiation Oncology • Biology • Physics 2011, 82: 1680-1688. PMID: 21477943, DOI: 10.1016/j.ijrobp.2011.01.062.Peer-Reviewed Original ResearchConceptsPediatric cancer patientsCancer patientsTesticular shieldingSpinal cordKilovoltage cone-beamCBCT dosesMean dosesClinical conditionsDose reductionLarge dosesFemoral headPatientsCBCT scansCone beamDosesFull-fan modeOptical nerveCBCT fieldCordDose increaseImaging dosesScanning protocolOARsRadiotherapyHalf-fan mode
2009
Monte Carlo Investigation of Stereotactic Radiosurgery of Spinal Metastases
Deng J, Chen Z, Knisely J, Decker R, Chiang V, Nath R. Monte Carlo Investigation of Stereotactic Radiosurgery of Spinal Metastases. IFMBE Proceedings 2009, 25/1: 13-16. DOI: 10.1007/978-3-642-03474-9_4.Peer-Reviewed Original ResearchSpinal metastasesStereotactic radiosurgeryDose-volume histogramsMean doseAnalytical anisotropic algorithmRisk of recurrenceTarget dose coverageDose distributionPencil beam convolutionSpinal cordDose coverageTarget dosePTV doseTreatment planMetastasisHomogeneity indexDoseRadiosurgeryPBC resultsPatientsTreatment planning systemPatient anatomyCommercial treatment planning systemDose discrepanciesAccurate dose distribution
2008
A Constrained Non-rigid Registration Algorithm for Use in Prostate Image-Guided Radiotherapy
Greene W, Chelikani S, Purushothaman K, Chen Z, Knisely J, Staib L, Papademetris X, Duncan J. A Constrained Non-rigid Registration Algorithm for Use in Prostate Image-Guided Radiotherapy. Lecture Notes In Computer Science 2008, 11: 780-788. PMID: 18979817, PMCID: PMC2790815, DOI: 10.1007/978-3-540-85988-8_93.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsArtificial IntelligenceHumansImaging, Three-DimensionalMalePattern Recognition, AutomatedProstatic NeoplasmsRadiographic Image EnhancementRadiographic Image Interpretation, Computer-AssistedRadiotherapy, Computer-AssistedReproducibility of ResultsSensitivity and SpecificitySubtraction TechniqueTomography, X-Ray ComputedConceptsTreatment planProstate image-guided radiotherapyOriginal treatment planRadiation dosageImage-guided radiotherapyTreatment daysRadiotherapy treatment plansCritical organsDifferent patientsPatient dataDifferent treatment daysBladderRectumProstateFemurBone motionCT imagesDosageReal patient dataPatientsRadiotherapy
2004
Iodine 125 Versus Palladium 103 Implants for Prostate Cancer
Peschel RE, Colberg JW, Chen Z, Nath R, Wilson LD. Iodine 125 Versus Palladium 103 Implants for Prostate Cancer. The Cancer Journal 2004, 10: 170-174. PMID: 15285926, DOI: 10.1097/00130404-200405000-00006.Peer-Reviewed Original ResearchConceptsExternal beam radiation therapyMinimum tumor doseDisease-free survival ratesComplication rateTumor doseProstate cancerRadiation therapyClinical outcomesPrognostic groupsBiochemical disease-free survival ratesSurvival rateBiochemical disease-free survivalDisease-free survivalHigh complication ratePoor prognostic groupProstate-specific antigenHormonal therapyT stageGleason scoreSingle institutionTransperineal implantationFavorable groupGrade 3Treatment groupsPatients
1999
Optimum timing for image-based dose evaluation of 125I and 103Pd prostate seed implants
Yue N, Chen Z, Peschel R, Dicker A, Waterman F, Nath R. Optimum timing for image-based dose evaluation of 125I and 103Pd prostate seed implants. International Journal Of Radiation Oncology • Biology • Physics 1999, 45: 1063-1072. PMID: 10571216, DOI: 10.1016/s0360-3016(99)00282-5.Peer-Reviewed Original ResearchConceptsDose-volume histogramsProstate volumeDose coverageConventional dose-volume histogramsSeed implantsEdema magnitudeMagnitude of edemaOptimum timingPostimplant dose-volume histogramDose evaluationOptimal patient managementProstate seed implantationPreimplant planImplant patientsPermanent brachytherapy implantsProstate seed implantsPatient managementProstate cancerSeed implantationSurgical proceduresEdemaProstateDose distributionDays postimplantationPatientsLong‐term complications with prostate implants: Iodine‐125 vs. palladium‐103
Peschel R, Chen Z, Roberts K, Nath R. Long‐term complications with prostate implants: Iodine‐125 vs. palladium‐103. International Journal Of Cancer 1999, 7: 278-288. PMID: 10580897, DOI: 10.1002/(sici)1520-6823(1999)7:5<278::aid-roi3>3.0.co;2-3.Peer-Reviewed Original ResearchMeSH KeywordsActuarial AnalysisBrachytherapyCell DeathFollow-Up StudiesForecastingHumansIodine RadioisotopesLongitudinal StudiesMaleModels, BiologicalNeoplasm StagingPalladiumProbabilityProstatic NeoplasmsRadioisotopesRadiopharmaceuticalsRadiotherapy DosageRelative Biological EffectivenessRetrospective StudiesTreatment OutcomeConceptsLong-term complicationsMinimum tumor dosesComplication ratePd-103Lower overall complication ratePalladium-103Long-term complication rateIodine-125Overall complication rateHigh complication rateProstate cancer patientsProstate implantsActuarial probabilityGrade IIILog10 cell killCancer patientsVs. 6Tumor dosesClinical practiceCell killProstate cancer brachytherapyEffective doseNormal tissuesPatientsTissue beds
1998
Correlation of medical dosimetry quality indicators to the local tumor control in patients with prostate cancer treated with iodine‐125 interstitial implants
Nath R, Roberts K, Ng M, Peschel R, Chen Z. Correlation of medical dosimetry quality indicators to the local tumor control in patients with prostate cancer treated with iodine‐125 interstitial implants. Medical Physics 1998, 25: 2293-2307. PMID: 9874821, DOI: 10.1118/1.598440.Peer-Reviewed Original ResearchConceptsSurvival rateProstate cancerInterstitial implantsLocal recurrence-free survival rateRecurrence-free survival ratesLocal control rateLocal tumor controlExcellent clinical resultsProstate cancer patientsUnfavorable groupClinical efficacyCancer patientsControl rateTumor controlClinical resultsFavorable groupDose coveragePatientsDosimetric parametersDosimetry parametersIsodose surfaceSignificant differencesVirginia studyUnfavorable parametersCancer