Radiation Oncology Department - UCSF Comprehensive Cancer Center - Pouliot's Research Group

Étienne was the first student to join Dr. Pouliot's research group based in California. In 2000 he followed his doctorate supervisor from Québec City to San Francisco. He started a UCSF postdoctorate fellowship in 2004 working on Inverse Planning applied on HDR. He recently accepted a research position at Accuray, Sunnyvale with the mission to apply his computer planning knowledge to the CyberKnife technology. Proud of his achievement, we'll miss his always serein point of view, great creativity and productivity.

Etienne will continue to collaborate with our group on different projects.

Étienne Lessard Ph.D.

Education

Ph.D. physics, 2004, Université Laval, Québec, Canada - Thesis Abstract(PDF)

M. Sc. physics, 2000, Université Laval, Québec, Canada
B.Sc. physics, 1999, Université Laval, Québec, Canada

Research

Inverse Planning Dose Optimization For Brachytherapy

Description

Dr. Lessard research on treatment planning optimization aims at improving the efficiency of brachytherapy cancer treatment while reducing the side effects and complication.

IPSA for high dose rate

High dose rate (HDR) brachytherapy is a promising radiation treatment modality that uses temporarily implanted catheters to deliver the curative dose directly in the tumor. A programmable robotic device (the afterloader) moves a single tiny radioactive source (192Ir) along the catheters using a flexible cable attached to the source. With this flexible system, a wide variety of dose distributions can be generated from a given implant simply by adjusting the length of time (dwell time) that the source dwells at any location within the implanted catheters (dwell position). The challenge is to select the optimal sequence of dwell times related to the unique clinical situation of each patient. This treatment-planning problem can be formalized as a combinatorial optimization problem. An inverse planning (IP) approach has been adopted to guide the optimization process. This means that the optimization is guided by clinical objectives described by means of dose constraints specified to each digitized anatomical structure. A simulated annealing (SA) optimization engine has been designed to solve this particular problem in a short time for clinical applications.

Our in-house inverse planning by simulated annealing (IPSA) algorithm has been successfully implanted in several institutions for evaluation: UCSF San Francisco, CHUQ Quebec City, NIH Bethesda, SRCC Toronto, CHUM Montreal, CCHS Newark, CAV Nancy and IGR Paris. At the moment of writing this text (January 2006), about a thousand patients have been treated with IPSA's treatment plans for a wide variety of anatomical sites. Clinical studies performed by clinicians using IPSA demonstrated that the algorithm produces superior treatment plans from a dosimetric point of view than the conventional optimization methods. IPSA improves the target dose coverage while minimizing the dose delivered to organs at risk and provides consistent results from one patient to another. Both dosimetric indices and overall procedure time were improved with the clinical introduction of IPSA. This optimization tool will be implemented in Nucletron new treatment planning software Oncentra Brachy.

IPSA for permanent implant

The IPSA algorithm was extended to produce treatment plans for prostate permanent implant (PPI). In this case, the challenge is to select the optimal distribution of the radioactive seeds in the prostate in order to irradiate the target volume adequately while protecting the surrounding organs at risk and respecting several user defined seed placement rules. The IPSA algorithm works for both pre-planning and intra-operative planning taking into account implanted needles and seeds. This optimization tool was implemented in Nucletron treatment planning software Spot-Pro.

Book Chapter

Pouiot J., Lessard E., and Hsu I-C., Brachytherapy Physics Second Edition, Chapter 21 Advanced 3D Planning. Medical Physics Publishing, 2005.

Publications - The six most significants (numbered)

Kubicky C.D. Yeh B., Joe B.N., Lessard E., Pouliot J., and Hsu I.C., Inverse Planning for the Magnetic Resonance Imaging (MRI)-Based Intracavitary Brachytherapy for Cervical Cancer: A Feasibility Study, Submitted to Int. J. Radiation Oncology Biol. Phys. Sept. 2006.
Kim, Y., Hsu, I., Lessard, E., Kurhanewicz J. Noworolski S.M. and Pouliot, J., Class solution in inverse planned HDR prostate brachytherapy for dose escalation of DIL defined by combined MRI/MRSI", Submitted to Radiotherapy and Oncology, August 2006.
Kim, Y., Hsu, I., Lessard, E. and Pouliot, J., Dosimetric Impact of Cranio-Caudal Catheter Displacement Between Fractions in CT-Based HDR Brachytherapy of Prostate Cancer, Submitted to J. A. Med. Phys. 2006.
Alterovitz R., Lessard E., Pouliot J., Hsu I-C., O'Brien J. and Goldberg K., Optimization of HDR brachytherapy dose distributions using linear programming with penalty costs, Med. Phys. 2006. In press.

Lessard E., Kwa S.L.S., Pickett B., Roach III, M., and Pouliot J., Class Solution for Inversly Planned Permanent Prostate Implants to Mimic An Experienced Dosimetrist for Pre And Real-Time Treatment Planning, Med. Phys., 33(8), 2773-2779; 2006.

The optimization algorithm was extended to optimize permanent prostate implant. This paper introduces the concept of class solution to the field of permanent prostate implants. A class solution is a set of inverse planning parameters relevant to one anatomical site that has been tuned to cover variations over a wide range of patients. The class solution can be used as a starting point for every patient, dramatically reducing the time needed to plan individual patient treatments. This innovative technology has opened the door to intra-operative treatment planning and real-time treatment planning.

6 ^st

Sumida I, Shiomi H, Yoshioka Y, Inoue T, Lessard E., Hsu I-C. and Pouliot J., Optimization of Dose Distribution For HDR Brachytherapy of the Prostate Using Attraction-Repulsion Model, Int. J. Radiation Oncology Biol. Phys., 64(2), 643-649; 2006.
Citrin D., Ning H., Guion P. Li G., Susil R.C. Miller R.W., Lessard E., Pouliot J., Huchen X., Capala J., Coleman C.N. Camphausen K., and Ménard C., Inverse treatment planning based on MRI for HDR prostate brachytherapy, Int. J. Radiation Oncology Biol. Phys. 61 (4); 1267-1275, 2005

Mahmoudieh A., C. Tremblay, L. beaulieu, B. Lachance, F. Harel, E. Lessard, J. Pouliot, E. Vigneault, "Anatomy based inverse planning dose optimization in HDR prostate implant: A toxicity study" Radiotherapy and Oncology 75 (2005) 318-324.

This paper presents a toxicity study five years after the clinical introduction of the optimization algorithm mentioned above. Compare to conventional treatment planning method, it improves the target coverage while sparing the organs at risk. We conclude that the organ at risk protection and the minimal toxicity obtained opens the possibility to deliver a higher dose without increasing undesirable side effects. The algorithm also significantly reduces the treatment planning time.

2 ^st

Mahmoudieh A., C. Tremblay, L. beaulieu, B. Lachance, F. Harel, E. Lessard, J. Pouliot, E. Vigneault, "Anatomy based inverse planning dose optimization in HDR prostate implant: A toxicity study" Radiotherapy and Oncology 75 (2005) 318-324.

DeWitt K.D., I-C Hsu, V.K. Weinberg, E. Lessard and J. Pouliot "3-D Inverse treatment planning for the Tandem and Ovoid Applicator in Cervical Cancer" ? Int. J. Radiat. Oncol. Biol. Phys. 63(4) pp 1270-1274 (2005).

This paper presents an original treatment planning method for cervical cancer HDR brachytherapy. This is a good example of clinical research made by a radio oncology resident under our supervision. This study uses a systematic approach for delineating the target and organs at risk on CT images and defining the clinical objective for the optimization algorithm. The optimization algorithm provides consistent results maintaining or improving target coverage while significantly decreasing the dose to the organs at risk. This method was clinically introduced for cervical cancer HDR brachytherapy at UCSF and opened the door to further refinement with CT/MRI image fusion technology.

5 ^st

I-C Hsu, A. Sharma, K. Shinohara, J. Speight, M. Braty, Y. Kim, E. Lessard and J. Pouliot, "Using Dental Putty for Fixation of Transrectal Ultrasound Guided Temporary Prostate Implant—The UCSF Technique", Accepted for publication in Tech. in Cancer Res. and Treatment (2004)
Citrin D., Ning H., Guion H., Li G., Susil R.C., Miller R.W., Lessard E., Pouliot J., Huchen X., Capala J., Coleman C.N., Camphausen K., Menard C., ?Inverse Treatment Planning Based on MRI for HDR Prostate Brachytherapy? Int. J. Radiat. Oncol. Biol. Phys. 61(4) pp 1267-1275 (2005).
I-C Hsu, E. Lessard, V. Weinberg, and J. Pouliot, "Comparison of Inverse Planning Simulated Annealing and Geometrical Optimization for Prostate High Dose Rate Brachytherapy", Brachytherapy, 3 2004, 147-153.
Y. Kim, I.-C. Hsu, E. Lessard, and J. Pouliot "Dose uncertainty due to CT slice thickness in CT-based high dose rate brachytherapy of the prostate cancer" Med. Phys. 31(9) pp. 2543-2548 (2004)
C. Ménard, R.C. Susil, P. Choyke, G.S. Gustafson, W. Kammerer, H. Ning, R.W. Miller, K.L. Ullman, N.S. Crouse, S. Smith, E. Lessard, J. Pouliot, V. Wright, E. McVeigh, C. N. Coleman, K. Camphausen, "MRI-guided HDR prostate brachytherapy in a standard 1.5T scanner" Int. J. Radiation Oncology Biol. Phys. 59(5) pp. 1414–1423 (2004).
Y. Kim, I-C Hsu, E. Lessard, J. Vujic and J. Pouliot, "Prostate volume change and dosimetric impact of edema between HDR brachytherapy fractions", Int. J. Radiat. Oncol. Biol. Phys. 59(4) pp. 1208-1216 (2004)

J. Pouliot, Y. Kim, E. Lessard, I-C Hsu, D.B. Vigneron and J. Kurhanewicz, "Inverse planning for HDR prostate brachytherapy use to boost dominant intra-prostatic lesion defined by magnetic resonance spectroscopy imaging" Int. J. Radiat. Oncol. Biol. Phys. 59(4) pp. 1196-1207 (2004).

This work leaded to the acquisition of a DOD Idea Development Award (PC030909). In this paper we have demonstrated the feasibility of local dose escalation for prostate HDR brachytherapy. We have exploited the high specificity of combined MRI/MRS for detecting and localizing cancerous cells within the prostate. We use our optimization algorithm to boost the dose delivered to this region to 120-150%, while preserving the prostate coverage and keeping the dose delivered to the organs at risk to the same level.

4 ^st

B. Lachance, D. Beliveau-Nadeau, E. Lessard, et al. "Early clinical experience with anatomy-based inverse planning dose optimization for high-dose-rate boost of the prostate" Int. J. Radiat. Oncol. Biol. Phys. 54, pp 86-100 (2002).

Lessard, E., Hsu I-C. and Pouliot J., Inverse Planning For Interstitial Gynecological Template Brachytherapy: Truly Anatomy Based Planning, Int. J. Radiation Oncology Biol. Phys. 54 (5), pp1243-1251, 2002.

This paper presents an original treatment planning method for interstitial gynecological HDR brachytherapy. The interstitial gynecological implants are complex and irregular making the treatment planning difficult and often impractical with the conventional methods. This study demonstrates that the algorithm fulfills all the clinical objectives automatically, rapidly and independently of the implant complexity. This method was clinically introduced for interstitial gynecological HDR brachytherapy at UCSF. This publication has encouraged other institutions to perform interstitial gynecological HDR brachytherapy at their clinics.

3 ^st

Lessard E. and Pouliot J., Inverse Planning Anatomy-based dose optimization for HDR-Brachytherapy of the prostate using fast simulated annealing algorithm and dedicated objective function, Med. Phys. 28 (5), 773-779, 2001.

This paper reports on the development of an optimization algorithm for HDR prostate brachytherapy. Soon after the redaction of this paper, the algorithm was clinically introduced at CHUQ (Laval University, Canada) for prostate cancer brachytherapy. This work has generated research projects for several graduate students. It has also opened the door to the development of an advance optimization algorithm applicable to all anatomical sites. This further work was the research topic of my doctorate thesis and was completed at UCSF (University of California, San Francisco) as a visiting scholar.

1 ^st

Meeting Presentations

Alterovitz R., Lessard E., Pouliot J., Hsu I-C., O'Brien J.F., and Goldberg K., "High-dose-rate Brachytherapy Dose Optimization for Prostate Cancer Using Linear Programming," Institute for Operations Research and the Management Sciences (INFORMS) Annual Meeting, San Francisco, CA, November 2005.

Lessard E. and J. Pouliot, ?Planification inverse en curietherapie ? Centre Hospitalier Universitaire de Montréal, Montréal, Canada, July 2005.

Kwa S.L.S., Lessard E., Moerland M.A., Pouliot J., ?Objective comparison of rapid strand and free selectSeeds loading for permanent prostate implants using an inverse planning approach? AAPM meeting, Seattle, USA, July 2005.

Lessard E, Beaulieu B., Hsu I-C., and Pouliot J., ?Inversely planned catheter position for high dose rate brachytherapy of the prostate? AAPM meeting, Seattle, USA, July 2005.

Vigneault E., Beaulieu L., Harel F., Lachance B., Lessard E., Poiliot P., Martin A-G., ?Early Clinical Outcome with Biopsy Results of HDR Prostate Boost using Inverse Planning: The Quebec Experience? ABS meeting, San Francisco, USA, June 2005.

Lessard E., Kwa S., Pickett B., Roach III M., and J. Pouliot, ?Class solution for inversely planned permanent prostate implants to mimic an experienced dosimetrist for pre and live treatment planning? GEC-ESTRO meeting, Budapest, Hungary, May 2005.

Vigneault E., Martin A.G., Pouliot J., Beaulieu., Lessard E., Harel F., Lachance B., ?Clinical outcome based on two years biopsy for HDR prostate boost using inverse planning: the Quebec Experience? GEC-ESTRO meeting, Budapest, Hungary, May 2005.

Beaulieu L. Varfalvy N., Aubin N. Lessard E. Pouliot J. ?Inverse planning by Simulated Annealing (IPSA) for Permanent Seed treatments? Nucletron Symposium, Amsterdam, The Netherlands, Octobre 2004.

C. Ménard, D. Citrin, R.C. Susil, P. Choyke, H. Ning, R.W. Miller, K/L. Ullman, P. Guion, J. Pouliot, E. Lessard, J. Capala, C.N. Coleman, K. Camphausen "High dose rate brachytherapy for prostate cancer using interventional MRI at 1.5TÓ (Oral) 5th interventional MRI Symposium, Boston, USA, October 2004.

Beaulieu L. Varfalvy N., Aubin N. Lessard E. Pouliot J. Clinical Validation of a new inverse planning algorithm for permanent prostate implant, ESTRO meeting, Amsterdam, The Netherlands, Octobre 2004.

Jean Pouliot and Etienne Lessard "Inverse Planning for prostate permanent implant designed for Nucletron SPOT-PRO treatment planning system" (oral, invited speaker) 46th AAPM Annual Meeting: Nucletron users meeting, Pittsburg, Pennsylvania, USA, July 2004.

Jean Pouliot, Etienne Lessard and I-Chow Hsu "Inverse Planning for HDR Brachytherapy" (oral, invited speaker) Institut Gustave Roussy, Paris, France, June 2004

Kim Huang, Jean Pouliot, Etienne Lessard, Vivian Weinberg, Joycelyn Speight, Lee-May Chen and I-Chow Hsu, ÒInitial Clinical Results of Inverse Planned High Dose Rate Interstitial Implants for Cervical CancerÓ (oral) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

Etienne Lessard, I-Chow Hsu, Joycelyn Speight, Eric Vigneault, Bernard Lachance, Mario Chrétien, Annie Letourneau, Luc Beaulieu, Cynthia Ménard, Holly Ning and Jean Pouliot, "Clinical benefits of a class solution for inversely planned HDR prostate brachytherapy" (poster) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

Joycelyn Speight, Etienne Lessard and Jean Pouliot "Lower D70% and D50% doses are delivered to penile bulb with IPSA HDR" (poster) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

Jean Pouliot, Etienne Lessard and I-Chow Hsu "Number of catheters in prostate High Dose Rate Brachytherapy: the role of inverse planning" (poster) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

Jean Pouliot, Yongbok Kim, Etienne Lessard, I-Chow Hsu and John Kurhanewicz "Targeting dominant intraprostatic lesion using functional imaging with MR spectroscopy and HDR brachytherapy " (poster) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

C. Ménard, R.C. Susil, P. Choyke, G.S. Gustafson, W. Kammerer, H. Ning, R.W. Miller, K.L. Ullman, N.S. Crouse, S. Smith, E. Lessard, J. Pouliot, V. Wright, E. McVeigh, C. N. Coleman, K. Camphausen "MRI-guided HDR prostate brachytherapy in a standard 1.5T scanner" (poster) Joint Brachytherapy Meeting GEC/ESTRO-ABS-GLAC , Barcelona, Spain, May 2004.

Etienne Lessard, Eric Vigneault, Bernard Lachance, Mario Chrétien, Annie Letourneau, Luc Beaulieu, I-Chow Hsu, Joycelyn Speight, Cynthia Ménard, Holly Ning, Jean Pouliot, "Algorithme de planification inversé pour les traitements de cancers par curiethérapie de haut débit de dose" (oral) : 72ième Congrès de lÕACFAS, Montréal, Canada, May 2004.

Joycelyn Speight, Etienne Lessard and Jean Pouliot "Lower D70% and D50% doses are delivered to penile bulb with IPSA HDR" (oral) American Radium Society 86th Annual Meeting, San Francisco, California, USA, April 2004.

I-Chow Hsu, Etienne Lessard, Joycelyn Speight, Jean Pouliot, Eric Vigneault, Bernard Lachance, Luc Beaulieu, Cynthia Ménard, Holly Ning "Inverse Planning for HDR Brachytherapy: Report of Clinical Implementation from Three Centers" (poster) American Radium Society 86th Annual Meeting, San Francisco, California, USA, April 2004.

Luc Beaulieu, Christine Tremblay, Etienne Lessard, Jean Pouliot, Bernard Lachance, and Éric Vigneault "Is there a preferred number of catheters in prostate HDR brachytherapy?" (oral) CARO Annual Meeting, Montréal, Québec, Canada, October 2003.

Kelly DeWitt, I-Chow Hsu, Vivian Weinberg, Etienne Lessard, Jean Pouliot "Comparison of anatomy-based inverse planning dose optimization with conventional dose prescription methods for high-dose-rate treatment of the cervix' (poster discussion) 45th ASTRO Annual Meeting, Salt Lake City, Utah, USA, October 2003.

Cynthia Chuang, I-Chow Hsu, Etienne Lessard and Jean Pouliot'The Feasibility of CT-Based Inverse Planning for Breast HDR Brachytherapy' (oral) 45th AAPM Annual Meeting, San Diego, California, USA, August 2003.

Jean Pouliot, Yongbok Kim, Etienne Lessard, I-Chow Hsu and John Kurhanewicz 'Magnetic-Resonance Spectroscopy Targeting for Inverse Planned HDR Prostate Brachytherapy' (oral) 45th AAPM Annual Meeting, San Diego, California, USA, August 2003.

Yongbok Kim, I-Chow J. Hsu, Etienne Lessard and Jean Pouliot "Prostate Volume Change and Dosimetric Impact of Edema Between CT-Based HDR Brachytherapy Fractions" (oral) 45th AAPM Annual Meeting, San Diego, California, USA, August 2003.

Jean Pouliot, Etienne Lessard, I-Chow Hsu "Inverse planning for HDR and PDR brachytherapy" (oral, invited speaker) 3ième Séminaire Francophone de Curiethérapie, Avignon, France, May 2003.

Kelly DeWitt, I-Chow Hsu, Vivian Weinberg, Etienne Lessard, Jean Pouliot "Comparison of anatomy-based inverse planning dose optimization with conventional dose prescription methods for high-dose-rate treatment of the cervix" (poster) 24th ABS Annual Meeting, New York, New York, USA, May 2003.

Jean Pouliot, Etienne Lessard, I-Chow Hsu "Use of inverse planning optimization for HDR Brachytherapy" (oral, invited speaker) 7th Int. Symposium on 3D conformal RT and IMRT, San Francisco, California, USA, April 2003.

Jean Pouliot, Etienne Lessard, I-Chow Hsu "Inverse Planning for HDR and LDR Prostate Brachytherapy" (oral, invited speaker) Wescan annual meeting, Winnipeg, Canada, March 2003.

Jean Pouliot, Etienne Lessard, I-Chow Hsu "Inverse Planning for Gynecological cancers treated with HDR Brachytherapy" (oral, invited speaker) Centre Hospitalier Universitaire de Québec, Quebec, Canada, February 2003.

Jean Pouliot, Etienne Lessard, I-Chow Hsu "Inverse planning for HDR prostate Brachytherapy" (oral, invited speaker) NIH Scientific Meetings, Bethesda, Ma, USA, January 2003.

Jean Pouliot, Etienne Lessard and I-Chow Hsu "Toward Image-Based Inverse Planning for IO-HDR Brachytherapy, Therapy using Mobile Systems" (oral, invited speaker) 1st Int. Workshop on Intra-Operative Rad. Sydney, Australia, December 2003.

Etienne Lessard, I-Chow Hsu, Ben Fisch and Jean Pouliot "Inverse planning ability to protect the bulb of the penis and other organs at risk in HDR-Brachytherapy of the prostate" (poster) 44th ASTRO Annual Meeting, New Orleans, Louisiana, USA, October 2002.
Etienne Lessard, I-Chow Hsu, Ben Fisch and Jean Pouliot "Inverse planning ability to protect the bulb of the penis in HDR brachytherapy of the prostate" (oral) 44th AAPM Annual Meeting, Montréal, Québec, Canada, July 2002.

Etienne Lessard, Linh Ho, I-Chow Hsu, Nancy Lee and Jean Pouliot "Clinical benefit of inverse planning for Rotterdam nasopharyngeal applicator" (poster) 44th AAPM Annual Meeting, Montréal, Québec, Canada, July 2002.

Dominic Béliveau-Nadeau, Bernard Lachance, Luc Beaulieu, Etienne Lessard, Jean Pouliot et Éric Vigneault "Evaluation of the point-source approximation accuracy for Ir-192 used in inverse planned optimizated prostate HDR treatment" (poster) 44th AAPM Annual Meeting, Montréal, Québec, Canada, July 2002.

Jean Pouliot, Etienne Lessard and I-Chow Hsu "Inverse planning for HDR-Brachytherapy: clinical implementation" (poster) 44th ASTRO Annual Meeting, New Orleans, Louisiana , USA, October 2002.

Jean Pouliot and Etienne Lessard "Anatomical conformal inverse planning dose optimization" (oral, invited speaker) 11th Annual Int. Brachytherapy Conference, Santa Fe, New Mexico, USA, June 2002.

Etienne Lessard, I-Chow Hsu and Jean Pouliot "Planning dose optimization of interstitial GYN-template high dose rate brachytherapy boost" (poster) 11th Annual Int. Brachytherapy Conference, Santa Fe, New Mexico, USA, June 2002.

Dominic Béliveau-Nadeau, Bernard Lachance, Éric Vigneault, Etienne Lessard et Luc Beaulieu "Etude comparative de deux algorithmes de planification relative au traitement par haut débit de dose du cancer de la prostat" (oral) 70ième Congrès de lÕACFAS, Québec, Canada, May 2002.

Jean Pouliot, Etienne Lessard, Claire Charra-Brunaud, Yongbok Kim, Joycelyn Speight and I-Chow Hsu "Inverse planning for HDR-Brachytherapy: Clinical implementation" (oral) 23rd ABS Annual Meeting, Orlando, Florida, USA, May 2002.

I-Chow Hsu, Etienne Lessard, V. Weinberg and Jean Pouliot "Comparison of inverse planning and geometrical optimization for prostate HDR-brachytherapy" (oral) 23rd ABS Annual Meeting, Orlando, Florida, USA, May 2002.

Jean Pouliot, Richard Taschereau, Etienne Lessard, Yongbok Kim and I-Chow Hsu "Biological Effectiveness Improvement of High Dose Rate Prostate Brachytherapy" (oral) Joint Breast & Prostate Cancer Retreat, South San Francisco, California, USA, March 2002.

Etienne Lessard, Jean Pouliot and I-Chow Hsu "Anatomy Conformal Dose Optimization for HDR-Brachytherapy of the prostate" (poster) Joint Breast & Prostate Cancer Retreat, South San Francisco, California, USA, March 2002.

Etienne Lessard, I-Chow Hsu and Jean Pouliot "Planning dose optimization of interstitial GYN-template high dose rate brachytherapy boost" (poster) 43rd ASTRO Annual Meeting, San Francisco, California, USA, November 2001.

Etienne Lessard, I-Chow Hsu and Jean Pouliot "Inverse Planning Anatomy conformal dose optimization for HDR-brachytherapy using fast simulated annealing algorithm and adaptable objective function" (oral) 43rd AAPM Annual Meeting, Salt Lake City, Utah, USA, July 2001.

Etienne Lessard, Bernard Lachance, Éric Vigneault and Jean Pouliot "Inverse Planning Anatomy conformal dose optimization for high dose rate brachytherapy using fast simulated annealing algorithm and adaptable objective function" (oral, 1st place young investigator competition) CAP Annual Meeting, Victoria, British Colombia, Canada, June 2001.

Bernard Lachance, Dominique Nadeau, Etienne Lessard, Mario Chretien, Luc Beaulieu, Éric Vigneault and Jean Pouliot "Early clinical experience with anatomy-based inverse planning dose optimization for HDR boost of the prostate" (oral) 43rd AAPM Annual Meeting, Salt Lake City, Utah, USA, July 2001.

Etienne Lessard, I-Chow Hsu, Bernard Lachance, Éric Vigneault and Jean Pouliot "Inverse Planning Anatomy-based dose optimization for HDR-brachytherapy of the prostate" (poster) 22nd ABS Annual Meeting, Vancouver, British Colombia, Canada, May 2001.

Bernard Lachance, Dominique Nadeau, Etienne Lessard, Éric Vigneault, Luc Beaulieu, Jean Pouliot and Mario Chretien "Early clinical experience with anatomy based inverse planning dose optimization for HDR boost of the prostate" (poster) 22nd ABS Annual Meeting, Vancouver, British Colombia, Canada, May 2001.

Jean Pouliot, Etienne Lessard, I-Chow Hsu, Bernard Lachance and Éric Vigneault "Anatomy-based inverse planning dose optimization for HDR-Brachytherapy of the prostate" (oral) 10th Annual International Brachytherapy Conference, Madrid, Spain, August 2000.

Etienne Lessard and Jean Pouliot "Anatomy-based dose optimization for HDR brachytherapy of the prostate using fast simulated annealing algorithm" (poster) 42nd AAPM Annual Meeting, Chicago, USA, July 2000.

Information

Étienne Lessard, Ph.D.
Department of Radiation Oncology

UCSF Comprehensive Cancer Center
1600 Divisadero Street, Suite H1031
San Francisco, CA 94143-1708
tel: 415/353-9845
fax: 415/353-9883
email: lessard@radonc17.ucsf.edu