Skip to Main Content

Zhe Jay Chen, PhD, FAAPM

Professor of Therapeutic Radiology
DownloadHi-Res Photo

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

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

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 Subject Headings (MeSH)

Brachytherapy; Dose-Response Relationship, Radiation; Electrons; Gamma Rays; Photons; Radiotherapy; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; X-Rays

Research at a Glance

Yale Co-Authors

Frequent collaborators of Zhe Jay Chen's published research.

Publications

2024

2023

2022

Academic Achievements & Community Involvement

  • activity

    American Association of Physicists in Medicine (AAPM)

  • activity

    Medical Physics

  • activity

    American Association of Physicists in Medicine

  • activity

    Connecticut Area Medical Physics Society

  • activity

    American Association of Physicists in Medicine (AAPM)

Get In Touch

Contacts

Academic Office Number
Office Fax Number
Mailing Address

Therapeutic Radiology

PO Box 208040

New Haven, CT 06520-8040

United States

Locations

  • Winchester Building

    Academic Office

    25 York Street, Ste Suite 215

    New Haven, CT 06511