2023
Preliminary 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
Dosimetric study of Varian Universal Multi-Channel Cylinder System for High-Dose-Rate 192Ir Brachytherapy
Tien CJ, Damast S, Chen ZJ. Dosimetric study of Varian Universal Multi-Channel Cylinder System for High-Dose-Rate 192Ir Brachytherapy. Brachytherapy 2022, 21: 244-254. PMID: 34996715, DOI: 10.1016/j.brachy.2021.11.001.Peer-Reviewed Original Research
2019
High-dose-rate brachytherapy as monotherapy for prostate cancer: The impact of cellular repair and source decay
Tien CJ, Carlson DJ, Nath R, Chen ZJ. High-dose-rate brachytherapy as monotherapy for prostate cancer: The impact of cellular repair and source decay. Brachytherapy 2019, 18: 701-710. PMID: 31109870, DOI: 10.1016/j.brachy.2019.04.005.Peer-Reviewed Original Research
2018
Monte Carlo dosimetry modeling of focused kV x‐ray radiotherapy of eye diseases with potential nanoparticle dose enhancement
Yan H, Ma X, Sun W, Mendez S, Stryker S, Starr‐Baier S, Delliturri G, Zhu D, Nath R, Chen Z, Roberts K, MacDonald CA, Liu W. Monte Carlo dosimetry modeling of focused kV x‐ray radiotherapy of eye diseases with potential nanoparticle dose enhancement. Medical Physics 2018, 45: 4720-4733. PMID: 30133705, DOI: 10.1002/mp.13144.Peer-Reviewed Original ResearchConceptsX-ray beamMC simulation programEye plaque treatmentCentral axis depth doseMC simulationsDose distributionBeam focusingEye Physics plaquesPhantom irradiationDose enhancementEnergy spectrumDepth doseLens modelingDosimetry modelingPhotoelectric absorptionKV rangeKV X-ray beamsBeamEBT3 filmSimulation programEnergy regimeModelingX-ray techniquesHalf maximumMore flexibility
2017
Comparison of 2D and 3D modeled tumor motion estimation/prediction for dynamic tumor tracking during arc radiotherapy
Liu W, Ma X, Yan H, Chen Z, Nath R, Li H. Comparison of 2D and 3D modeled tumor motion estimation/prediction for dynamic tumor tracking during arc radiotherapy. Physics In Medicine And Biology 2017, 62: n168-n179. PMID: 28263949, DOI: 10.1088/1361-6560/aa64c8.Peer-Reviewed Original ResearchConceptsSystem latencyMotion trackingReal-time imaging techniqueMotion compensation frameworkTracking accuracyBeam directionRespiratory motion dataEstimation/predictionPotential dosimetric advantagesAdditional kVTumor trackingDepth directionTracking latencyView planeDosimetric advantagesMotion dataTracking errorDynamic tumor trackingImaging techniquesBlockage problemDetection errorBlockage issueUnresolved motionTrackingCompensation framework
2011
Experimental characterization of the dosimetric properties of a newly designed I-Seed model AgX100 125I interstitial brachytherapy source
Chen Z, Bongiorni P, Nath R. Experimental characterization of the dosimetric properties of a newly designed I-Seed model AgX100 125I interstitial brachytherapy source. Brachytherapy 2011, 11: 476-482. PMID: 22104352, PMCID: PMC3330133, DOI: 10.1016/j.brachy.2011.08.009.Peer-Reviewed Original Research
2010
Response to “Comment on ‘AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137’” [Med. Phys. 36, 5310–5322 (2009)]
Nath R, Bice WS, Butler WM, Chen Z, Meigooni AS, Narayana V, Rivard MJ, Yu Y. Response to “Comment on ‘AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137’” [Med. Phys. 36, 5310–5322 (2009)]. Medical Physics 2010, 37: 1933-1933. PMID: 20443515, DOI: 10.1118/1.3358143.Peer-Reviewed Original ResearchA photon spectrometric dose‐rate constant determination for the Advantage™ Pd‐103 brachytherapy source
Chen ZJ, Bongiorni P, Nath R. A photon spectrometric dose‐rate constant determination for the Advantage™ Pd‐103 brachytherapy source. Medical Physics 2010, 37: 672-674. PMID: 20229876, PMCID: PMC2821420, DOI: 10.1118/1.3298011.Peer-Reviewed Original Research
2009
AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137
Nath R, Bice WS, Butler WM, Chen Z, Meigooni AS, Narayana V, Rivard MJ, Yu Y. AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137. Medical Physics 2009, 36: 5310-5322. PMID: 19994539, PMCID: PMC2776817, DOI: 10.1118/1.3246613.Peer-Reviewed Original ResearchConceptsBiological equivalent doseTumor volumeDose prescriptionStandard of careProstate cancer patientsPermanent interstitial brachytherapyAcute single dosesEffects of edemaCancer patientsSurgical traumaIntraoperative implantationSingle dosesClinical trialsProstate cancerRadiobiological modelsCurrent recommendationsInterstitial brachytherapyMore specific guidelinesRoutine patient treatmentsDifferent dose distributionsTreatment planPatient treatmentTarget volumeMost implantsDose distribution
2008
Ice as a water-equivalent solid medium for brachytherapy dosimetric measurements
Song H, Chen Z, Yue N, Wu Q, Yin FF. Ice as a water-equivalent solid medium for brachytherapy dosimetric measurements. Radiation And Environmental Biophysics 2008, 48: 145-151. PMID: 19066926, DOI: 10.1007/s00411-008-0205-9.Peer-Reviewed Original ResearchConceptsSolid phantomWater conversion factorNon-negligible uncertaintiesMono-energetic photonsPrecise positioningLow-energy photon-emitting brachytherapy sourcesChemical compositionBrachytherapy sourcesPositioning advantageDosimetric measurementsExperimental determinationNecessary precisionDosimetric characteristicsPhantomIceBrachytherapy dosimetryPositioningConversion factorPhotonsUncertaintyKeV
2007
Silver fluorescent x‐ray yield and its influence on the dose rate constant for nine low‐energy brachytherapy source models
Nath R, Chen ZJ. Silver fluorescent x‐ray yield and its influence on the dose rate constant for nine low‐energy brachytherapy source models. Medical Physics 2007, 34: 3785-3793. PMID: 17985624, DOI: 10.1118/1.2775665.Peer-Reviewed Original ResearchPhoton spectrometry for the determination of the dose‐rate constant of low‐energy photon‐emitting brachytherapy sources
Chen ZJ, Nath R. Photon spectrometry for the determination of the dose‐rate constant of low‐energy photon‐emitting brachytherapy sources. Medical Physics 2007, 34: 1412-1430. PMID: 17500473, DOI: 10.1118/1.2713217.Peer-Reviewed Original ResearchConceptsPhoton spectrometry techniquePhoton spectrometryHigh-resolution gamma-ray spectrometerDosimetry techniquesLow-energy photonsPhoton energy spectrumMono-energetic photonsGamma-ray spectrometerLow-energy photon-emitting brachytherapy sourcesBrachytherapy sourcesLow-energy sourcesAbsolute dosimeterPhoton characteristicsEnergy dependenceDetector sensitivityDetector sizeSolid phantomDose rate measurementsPhotonsDosimetric propertiesRadiation dosimetryDose rate constantDose rateSpectrometry techniquesAccurate measurement
2006
Application of Gafchromic® film in the dosimetry of an intravascular brachytherapy source
Song H, Roa DE, Yue N, d'Errico F, Chen Z, Nath R. Application of Gafchromic® film in the dosimetry of an intravascular brachytherapy source. Medical Physics 2006, 33: 2519-2524. PMID: 16898455, DOI: 10.1118/1.2208930.Peer-Reviewed Original ResearchPotential impact of prostate edema on the dosimetry of permanent seed implants using the new (model CS‐1) seeds
Chen Z, Deng J, Roberts K, Nath R. Potential impact of prostate edema on the dosimetry of permanent seed implants using the new (model CS‐1) seeds. Medical Physics 2006, 33: 968-975. PMID: 16696473, DOI: 10.1118/1.2179170.Peer-Reviewed Original Research
2005
Dose rate constant of a Cesium‐131 interstitial brachytherapy seed measured by thermoluminescent dosimetry and gamma‐ray spectrometry
Chen Z, Bongiorni P, Nath R. Dose rate constant of a Cesium‐131 interstitial brachytherapy seed measured by thermoluminescent dosimetry and gamma‐ray spectrometry. Medical Physics 2005, 32: 3279-3285. PMID: 16372409, DOI: 10.1118/1.2098127.Peer-Reviewed Original ResearchDose rate dependence of the relative biological effectiveness of 103Pd for continuous low dose rate irradiation of BA1112 rhabdomyosarcoma cells in vitro relative to acute exposures
Nath R, Bongiorni P, Chen Z, Gragnano J, Rockwell S. Dose rate dependence of the relative biological effectiveness of 103Pd for continuous low dose rate irradiation of BA1112 rhabdomyosarcoma cells in vitro relative to acute exposures. International Journal Of Radiation Biology 2005, 81: 689-699. PMID: 16368647, DOI: 10.1080/09553000500401551.Peer-Reviewed Original ResearchConceptsContinuous low dose rate irradiationDose rate irradiationLow dose rate irradiationRate irradiationInterstitial brachytherapyHigh dose rate irradiationAcute exposureRhabdomyosarcoma cellsPermanent interstitial brachytherapyRelative biological effectivenessBA1112 tumorsSame dose rateSurvival curvesHigh linear energy transferAcute irradiationTumor cellsCell survival curvesBiological effectivenessLow dose rateDose-rate effectDose rateBrachytherapy
2003
Entropy-Based Dual-Portal-to-3-DCT Registration Incorporating Pixel Correlation
Bansal R, Staib LH, Chen Z, Rangarajan A, Knisely J, Nath R, Duncan JS. Entropy-Based Dual-Portal-to-3-DCT Registration Incorporating Pixel Correlation. IEEE Transactions On Medical Imaging 2003, 22: 29. PMID: 12703758, DOI: 10.1109/tmi.2002.806430.Peer-Reviewed Original ResearchConceptsRegistration frameworkImage dataMutual information-based registration algorithmRegistration parametersPortal imagesUltrasound image dataReal patient dataTomography image dataImage pixelsPixel correlationRegistration algorithmPatient setup verificationSegmentationPixel intensityMarkov random processInitial versionTransformation parametersAppropriate entropyImagesAlgorithmPatient dataFrameworkCT imagesLine processSetup verification
2002
Independent monitor unit calculation for intensity modulated radiotherapy using the MIMiC multileaf collimator
Chen Z, Xing L, Nath R. Independent monitor unit calculation for intensity modulated radiotherapy using the MIMiC multileaf collimator. Medical Physics 2002, 29: 2041-2051. PMID: 12349925, DOI: 10.1118/1.1500397.Peer-Reviewed Original ResearchEdema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants—a bio-mathematical model
Yue N, Chen Z, Nath R. Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants—a bio-mathematical model. Physics In Medicine And Biology 2002, 47: 1185-1204. PMID: 11996063, DOI: 10.1088/0031-9155/47/7/313.Peer-Reviewed Original ResearchConceptsTumor potential doubling timeContinuous low dose rate irradiationTumor cell survivalSeed implantsBio-mathematical modelCell survivalExternal beam radiotherapyPresence of edemaProstate seed implantationLow dose rate irradiationEdema magnitudeEffects of edemaPotential doubling timeTypical edemaDose rate irradiationProstate volumeSurgical traumaPermanent seed implantsSeed implantationSignificant edemaTreatment strategiesSurgical proceduresBeam radiotherapyEdemaDose coverage
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