Zhe Jay Chen, PhD, FAAPM
Professor of Therapeutic RadiologyCards
Appointments
Additional Titles
Vice Chair for Physics Research and Education, Therapeutic Radiology
Director, Cesium Irradiation Shared Resource for Yale Cancer Center, Therapeutic Radiology
Smilow Chief Physicist
Director of Medical Physics Residency Program
Contact Info
Therapeutic Radiology
PO Box 208040
New Haven, CT 06520-8040
United States
Appointments
Additional Titles
Vice Chair for Physics Research and Education, Therapeutic Radiology
Director, Cesium Irradiation Shared Resource for Yale Cancer Center, Therapeutic Radiology
Smilow Chief Physicist
Director of Medical Physics Residency Program
Contact Info
Therapeutic Radiology
PO Box 208040
New Haven, CT 06520-8040
United States
Appointments
Additional Titles
Vice Chair for Physics Research and Education, Therapeutic Radiology
Director, Cesium Irradiation Shared Resource for Yale Cancer Center, Therapeutic Radiology
Smilow Chief Physicist
Director of Medical Physics Residency Program
Contact Info
Therapeutic Radiology
PO Box 208040
New Haven, CT 06520-8040
United States
About
Titles
Professor of Therapeutic Radiology
Vice Chair for Physics Research and Education, Therapeutic Radiology; Director, Cesium Irradiation Shared Resource for Yale Cancer Center, Therapeutic Radiology; Smilow Chief Physicist; Director of Medical Physics Residency Program
Biography
Dr. Zhe (Jay) Chen received his B.S. degree in theoretical physics from Fudan University in Shanghai, China in 1982. In the same year, he was selected by Nobel Laureate T.D. Lee's China-US Physics Scholarship program to pursue graduate study in physics in the United States. After receiving a Ph.D. degree in theoretical condensed matter physics from the City University of New York in 1989, he continued postdoctoral research in physics at Brown University from 1989 to 1992. Driven by the desire to put his training in theoretical physics to more practical applications, he joined the Department of Radiation Oncology of the State University of New York (SUNY) at Stony Brook in 1992. He found the application of radiation physics and radiobiology in radiation therapy not only helpful to cancer patients but also intellectually stimulating and satisfying to a physicist. He became a clinical medical physicist and an assistant professor of research in the Health Science Center and SUNY School of Medicine at Stony Brook. In 1995, he joined the Department of Therapeutic Radiology at Yale-New Haven Hospital and Yale University School of Medicine and has stayed here since. In addition to providing clinical medical physics support in daily patient care, he has been actively involved in teaching physics of radiation therapy to radiation oncology and medical physics residents and in conducting original research towards better understanding and effective use of physics in radiation therapy. He has authored and/or coauthored over 100 peer-reviewed research articles, 14 book chapters and reviews, and over 180 published research abstracts. He has been a research investigator on 5 federal government supported research grants and was the principal investigator of a NIH R01 research grant investigating the effects of prostate edema on the treatment of early-stage prostate cancer using permanent interstitial brachytherapy.
Appointments
Therapeutic Radiology
ProfessorPrimary
Other Departments & Organizations
Education & Training
- Postdoctoral fellow
- Brown University (1992)
- PhD
- City University of New York (1989)
- MPhil
- City University of New York (1985)
- BS
- Fudan University (1982)
Research
Overview
An example of my research in basic radiation dosimetry involved the determination of dose rate constant (DRC) for radioactive sources used in interstitial brachytherapy. The DRC is a fundamental quantity that links the intrinsic dosimetry properties of a radioactive source to the proper fulfillment of prescription dose in patient dosimetry. An accurate determination of DRC has been regarded as one of the most important tasks in characterizing the basic properties of radioactive sources. However, accurate determination of DRC for the sources emitting photons of less than 50 keV has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of doses near the source. Existing experimental techniques have large overall uncertainties on the order of 8-10% at one standard deviation and 15% at the 95% confidence level.
We have developed a general formalism for DRC that permitted detailed elucidation of the general properties underlying the determination of DRC. Based on this theoretical finding, we have subsequently developed a new photon spectrometry technique for accurate determination of the DRC of low-energy interstitial brachytherapy sources. This new technique eliminated many of the difficulties associated with the existing experimental techniques and has provided new and independent determinations of DRC for over twenty low-energy brachytherapy source models. Its application has led to the discovery of a 15% discrepancy in the DRC reported for a newly marketed cesium-131 source and has helped resolve a large discrepancy in the DRCs reported in literature for a novel polymer-encapsulated palladium-103 source. The photon spectrometry technique is efficient and robust. We are developing it into a national resource for DRC determination and for periodic quality assurance check of DRC.
An example of my research work in treatment plan optimization and evaluation involved the derivation of a new radiobiological formalism for biologically effective dose (BED) of permanent interstitial brachytherapy (PIB) using sources of different decay half-lives. In PIB, the cancer cells are subjected to continuous photon irradiation. Because tumor cell repopulation and sub-lethal damage repair occur simultaneously during dose delivery, the net cell kill and therefore the clinical efficacy of PIB depend not only on the delivered dose but also on the interplay between the temporal patterns of dose delivery and cellular kinetics.
The BED formula captures this interplay and has enabled systematic evaluation of the potential clinical impacts of using mixed sources on cancers presenting different biological properties. This formalism has also enabled us to systematically examine the radiobiological effects of prostate edema in PIB for early stage prostate cancer and many of the theoretical issues related to the design of an effective dose compensation approach for edema-induced dose deficits.
This latter application has provided some of the preliminary data for a R01 research project currently funded by NIH since September 2008 (R01CA134627-01 Prostate Edema in Permanent Interstitial Brachytherapy, PI: Zhe Chen, Ph.D). The R01 project aims to quantitatively characterize the dosimetric and radiobiologic effects of prostate edema and to develop effective therapeutic interventions so that the efficacy of PIB can be optimized for each individual prostate cancer patient.
Other examples of my research work have dealt with clinical dosimetry and quality assurance for radiation therapy techniques ranging from intensity-modulated radiation therapy (IMRT), total-skin electron therapy (TSET) for cultaneous T-cell lymphoma, total-body irradiation (TBI) for bone marrow transplant and image guidance in the planning, delivery and evaluation of radiation therapy.
- Optically stimulated luminescence dosimetry for in vivo verification of total-body irradiation (TBI) for bone marrow transplant
- Intervention strategies for effective management of edema-induced dose variations in permanent interstitial brachytherapy for prostate cancer
- Photon spectrometry for dosimetric characterization of low energy photon-emitting radioactive sources in interstitial brachytherapy
- Quantifying and managing the dosimetric effects of respiratory motion on image-guided stereotactic body radiosurgery for inoperable lung tumors
- Image-guided adaptive radiotherapy for prostate cancer
Medical Research Interests
Public Health Interests
Research at a Glance
Yale Co-Authors
Publications Timeline
Research Interests
Jun Deng, PhD, DABR, FAAPM, FASTRO
Christopher J. Tien, PhD, DABR, FAAPM
Kenneth B. Roberts, MD
Lawrence Staib, PhD
Emily Draeger, PhD, DABR
James Duncan, PhD
Brachytherapy
Radiotherapy Planning, Computer-Assisted
Photons
Dose-Response Relationship, Radiation
Electrons
Radiotherapy, Intensity-Modulated
Publications
2024
Thursday, July 11, 20244:00 PM - 5:00 PM PP01 Presentation Time: 4:00 PM Investigating Shielding as a Dose-Shaping Tool in Flattening Distal Dose Profiles for Single-Channel Vaginal Cylinders
Tien C, Mullane S, Draeger E, Rivard M, Chen Z. Thursday, July 11, 20244:00 PM - 5:00 PM PP01 Presentation Time: 4:00 PM Investigating Shielding as a Dose-Shaping Tool in Flattening Distal Dose Profiles for Single-Channel Vaginal Cylinders. Brachytherapy 2024, 23: s26-s27. DOI: 10.1016/j.brachy.2024.08.020.Peer-Reviewed Original ResearchConceptsModel-based dose calculation algorithmsSingle-channel vaginal cylinderDose profilesDose distributionVaginal cylinderCentral axisCustomized shieldingRegions of high doseAnisotropic dose distributionUniform dose profileDose calculation algorithmWater-equivalent materialDose calculation methodMonte CarloIr-192 seedsDose gridIr-192MC simulationsRelative doseShielding materialsCalculation algorithmSource transitionDose optimizationLateral radiusShieldingPO0116 Design and Characterization of a Brachytherapy Applicator with Modulated Shielding (MOSH) for the Treatment of Cervical Cancer
Schwipper C, Mullane S, Draeger E, Chen Z, Rivard M, Tien C. PO0116 Design and Characterization of a Brachytherapy Applicator with Modulated Shielding (MOSH) for the Treatment of Cervical Cancer. Brachytherapy 2024, 23: s92. DOI: 10.1016/j.brachy.2024.08.134.Peer-Reviewed Original ResearchConceptsDose distributionBrachytherapy applicationsOAR dosesIr-192TG-43 dose calculation formalismShield geometryReduces dose to OARAAPM TG-43 formalismShielding materialsDose calculation formalismHigh-Z shieldingReduced OAR dosesCalculated dose distributionsTG-43 formalismDose-volume objectivesDose to OARsTreatment of cervical cancerHDR brachytherapy applicatorsHigh-risk clinical target volumeIr-192 sourceImproved dose distributionClinical target volumeSparing OARsTOPAS MCYb-169AAPM Task Group Report 267: A joint AAPM GEC‐ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy
Chen Z, Li X, Brenner D, Hellebust T, Hoskin P, Joiner M, Kirisits C, Nath R, Rivard M, Thomadsen B, Zaider M. AAPM Task Group Report 267: A joint AAPM GEC‐ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy. Medical Physics 2024, 51: 3850-3923. PMID: 38721942, DOI: 10.1002/mp.17062.Peer-Reviewed Original ResearchConceptsDose delivery patternClinical medical physicistsBrachytherapy modalitiesMedical physicistsAAPM Task Group ReportAmerican Association of PhysicsBrachytherapy treatment planningTask group reportRadioactive sourcesDevelopment of biophysical modelsEuropean Society for Radiotherapy & OncologyGEC-ESTRORadiobiological effectsAAPMRadiation oncologyBrachytherapyBiophysical modelTreatment planningPhysicistsClinical effectsClinical backgroundIrradiated tissueDelivery patternsPractice guidelinesTreatment techniques
2023
Editorial: Innovations, advances, and challenges in precision radiation oncology physics
Guan F, Bronk L, Yue J, Mohan R, Chen Z. Editorial: Innovations, advances, and challenges in precision radiation oncology physics. Precision Radiation Oncology 2023, 7: 222-224. DOI: 10.1002/pro6.1216.Peer-Reviewed Original ResearchPO61 Can Current Monotherapy High-Dose-Rate Prostate Brachytherapy Prescriptions Overcome Intrafractional DNA Damage Repair and 192Ir Source Decay?
Guan F, Draeger E, Carlson D, Chen Z, Tien C. PO61 Can Current Monotherapy High-Dose-Rate Prostate Brachytherapy Prescriptions Overcome Intrafractional DNA Damage Repair and 192Ir Source Decay? Brachytherapy 2023, 22: s97-s98. DOI: 10.1016/j.brachy.2023.06.162.Peer-Reviewed Original ResearchPO83 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 ResearchConceptsTumor 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 parametersTrialsCohortCharacterization of GafchromicTM EBT4 film with clinical kV/MV photons and MeV electrons
Guan F, Chen H, Draeger E, Li Y, Aydin R, Tien C, Chen Z. Characterization of GafchromicTM EBT4 film with clinical kV/MV photons and MeV electrons. Precision Radiation Oncology 2023, 7: 84-91. DOI: 10.1002/pro6.1204.Peer-Reviewed Original ResearchCitationsConceptsX-ray beamMeV electron beamMV photon beamElectron beamMV photonsBeam energyMeV electronsPhoton beamsEnergy dependenceKilovoltage x-ray beamsMinimal energy dependenceClinical photonPhotonsBeamRadiation typesMeVElectronsDependence experimentsFilmsDose-response dependenceResponse dependenceDependenceEnergyNoise ratioEBT3Radiobiological evaluation of the stepping-source effect in single-fraction monotherapy high-dose-rate prostate brachytherapy
Tien C, Chen Z. Radiobiological evaluation of the stepping-source effect in single-fraction monotherapy high-dose-rate prostate brachytherapy. Brachytherapy 2023, 22: 593-606. PMID: 37263898, DOI: 10.1016/j.brachy.2023.03.003.Peer-Reviewed Original ResearchCitationsAltmetricDosimetric response of Gafchromic™ EBT‐XD film to therapeutic protons
Guan F, Wang X, Yang M, Draeger E, Han D, Iga K, Guo F, Perles L, Li Y, Sahoo N, Mohan R, Chen Z. Dosimetric response of Gafchromic™ EBT‐XD film to therapeutic protons. Precision Radiation Oncology 2023, 7: 15-26. PMID: 37868341, PMCID: PMC10586355, DOI: 10.1002/pro6.1187.Peer-Reviewed Original ResearchCitationsConceptsLinear energy transferEBT-XD filmsTherapeutic protonsFilm calibrationProton linear energy transferUltra-high Dose Rate FLASH RadiotherapyDynamic dose rangeMV photon beamDose-averaged LET valuesDose rate dependenceProton beamlineProton beamPhoton beamsFLASH beamSpot scanning proton beamsDosimetric responseLET dependenceFLASH radiotherapyHigh-dose applicationFilm responseLET valuesEnergy transferBeamProtonsGafchromicDose prescription and reporting in stereotactic body radiotherapy: A multi-institutional study
Das I, Yadav P, Andersen A, Chen Z, Huang L, Langer M, Lee C, Li L, Popple R, Rice R, Schiff P, Zhu T, Abazeed M. Dose prescription and reporting in stereotactic body radiotherapy: A multi-institutional study. Radiotherapy And Oncology 2023, 182: 109571. PMID: 36822361, PMCID: PMC10121952, DOI: 10.1016/j.radonc.2023.109571.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsDose prescriptionTreatment-related toxicityClinical outcome comparisonStereotactic body radiotherapyMulti-institutional studyTreatment guidelinesTreatment disparitiesBody radiotherapyPTV volumeClinical trialsTreatment protocolOutcome comparisonsTreatment efficacyAbstractTextHypofractionated treatmentDosimetric parametersDose parametersDosimetric variabilityDosimetric variationsStandardized reportingLack of standardization
Academic Achievements & Community Involvement
activity American Association of Physicists in Medicine (AAPM)
CommitteesMemberDetailsChair of Task Group No. 267 - Biophysical models and tools for the planning and evaluation of selected brachytherapy modalities09/25/2014 - Presentactivity Medical Physics
Peer Review Groups and Grant Study SectionsMemberDetailsGuest Associate Editor & Reviewer2005 - Presentactivity American Association of Physicists in Medicine
Professional OrganizationsMemberDetailsMember04/26/1993 - Presentactivity Connecticut Area Medical Physics Society
Professional OrganizationsMemberDetailsMember1996 - Presentactivity American Association of Physicists in Medicine (AAPM)
CommitteesMemberDetailsMember, Working Group on Brachytherapy Clinical Applications02/05/2013 - Present
News & Links
News
- March 13, 2023
Christopher J. Tien, PhD awarded pilot grant
- April 05, 2018Source: Research Features
Personalised tracking of radiation doses is becoming a reality
- February 28, 2018Source: Imaging Igloo
Professional Spotlight: Taking Ownership: Mohamed Badawi
- August 01, 2017Source: Molecular Cancer Therapeutics
Local DNA Repair Inhibition for Sustained Radiosensitization of High-Grade Gliomas
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Therapeutic Radiology
PO Box 208040
New Haven, CT 06520-8040
United States
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