Presidential Greeting - American Society for Laser Medicine and ...

54 American Society for Laser Medicine and Surgery Abstracts
Results: The maximum heat diffused from the (CDF) in the
simulation was 156.38C versus 1558C measured. The mean
volume of the tissue necrosis, estimated on MRI, for the ten rats
was 0.98 0.05 cc while simulations volumes were: 1.38 cc when
T ¼ 448C, 1.1 cc for T ¼ 468C and 1.00 cc when T ¼ 508C.
Conclusion: LITT treatment of the prostate is a promising
therapy method. It needs further more evaluation and
understanding of the heat extent in tissues to be a surgical method
applied in the routine hospitalization. Simulation has enabled
greater understanding of global impact of LITT.
#184
A PHANTOM FOR INTERSTITIAL LASER
THERMOTHERAPY OF PROSTATE CANCER
TRAINING
Pierre Nevoux, Pierre Colin, Bertrand Leroux,
Philippe Puech, Arnauld Villers, Serge Mordon,
Nacim Betrouni, Nasr Makni,
Mohamad Feras Marqa
CHRU Lille and Inserm, U703, Université Lille Nord de France,
CHRU Lille, Lille, France
Background: To construct a prostate phantom magnetic
resonance (MR) and ultrasound (US) imaging compatible to
locate, target and monitor a planned procedure of laser interstitial
thermotherapy (LITT) with a 980 nm diode laser.
Study: A removable portion with human prostate optical and
thermal properties was included in a 45 cc anatomically correct
prostate phantom. It was composed of gelatin. A defined volume of
coagulable gel was inserted into the prostate to recreate a tumor.
The other part was fixed and represented perineum and rectum.
The phantom was evaluated using transrectal ultrasound, MRI
and real-time thermometry. Diffusing fibers were inserted into
the model via an 18 G introducing catheter using either a
brachytherapy grid (transperineal access) or a transrectal probe
(transrectal access). Prostate cancer boundaries and laser fiber
placement were assessed by transrectal ultrasound sonography.
The laser treatment of a predetermined focal lesion was identified
and targeted by treatment planning simulation. LITT was
performed with a 980 nm diode laser (power 5 W) during
75 seconds (fluence rate of 1,145 J/cm 2 ).
Results: The phantom had characteristics of a prostate including
areas of interest in focal therapy: prostate cancer area, urethra,
rectum, sphincter and neurovascular bundles. The prostate model
allowed us to generate focal thermal lesions. Treatment was
feasible by both transperineal and transrectal access. LITT
procedures were performed on this model and treatment effects
were visible on MRI.
Conclusion: Current innovations in multimodality imaging
coupled with new therapeutics like LITT for treatment of localized
prostate cancer require preclinical evaluation. The described
prostate phantom is simple, allows treatment planning and
simulation and LITT training.
#185
MINIMALLY INVASIVE FOCAL LASER ABLATION
FOR PROSTATE TUMORS
Roger McNichols, Anil Shetty, Ashok Gowda
Visualase, Inc., Houston, TX
Background: Focal interstitial laser therapy (ILT) for localized
prostate cancer may overcome side effects associated with the
current standard, radical prostatectomy. The goal of this study
was to develop techniques for implementing MR-guided focal ILT
with real-time MR temperature monitoring in patients with lowrisk,
low-volume disease.
Study: Men with biopsy-confirmed, MR-imageable prostate
cancer with Gleason score < 7 were offered focal ILT. At
treatment, patients were placed supine inside the bore of the MR,
fitted with a perineal needle guide template and imaged in the
axial plane trough both the prostate and the template. Images
were transferred to a therapy workstation (Visualase, Inc.,
Houston, TX) and analyzed with software which allowed
identification of three fiducials on the template and subsequent
projection of needle guide trajectories through the prostate
volume. A 14-cm catheter with titanium stylet was inserted
through the designated guide hole to a target in the prostate. The
stylet was replaced with a laser applicator (400-mm-core-diameter
silica fiber with diffusing tip in a 1.65 mm water-cooled sheath)
connected to a 15-W 980-nm laser. During continuous MR
imaging, laser energy was delivered and the therapy workstation
transferred MR images in real-time to display temperature
changes in the tissue with an update rate of approximately
5 seconds. Laser doses of 7–12 W were delivered for 60–
120 seconds. Post-treatment contrast images were used to confirm
treatment zones.
Results: Reproducible, accurate placement of applicators into
targets was achieved. Real-time thermal monitoring was useful to
ensure target destruction while avoiding heating of structures
including rectal wall, neurovascular bundles, and urethra.
Conclusion: MR-guided ILT of prostate tumors with real-time
thermal imaging is technically feasible, safe, and has a low rate of
complications or side effects. However, focal ILT has not yet been
validated as an effective treatment for prostate cancer.
#186
COMPARISON OF TISSUE EFFECTS AFTER PAL,
WAL, SAL, UAL AND LAL
Afschin Fatemi
S-thetic Clinic, Duesseldorf, Germany
Background: There are different ways to do liposuction, just by
suction (SAL), power assisted (PAL), by Waterjet (WAL), by
ultrasound (UAL), laser assisted lipolysis (LAL). But how does the
tissue look like after impact, is there a ‘better’, less traumatic way
to do liposuction?
Study: Cadavers were treated with different techniques, the
effect on the tissues, especially on the fat cells and on the septal
fibers were analyzed. Abdominoplasty patients were treated and
the tissues analyzed the same way. The tissues were analyzed by
direct comparison after different ways of liposuction, by endoscopy
and in open surgery and the corresponding clinical results. In an
additional histological study, the effect on septal fibers were
analyzed.
Results: There were clearly visible differences between the
different kinds of liposuction: Some specific complications were
mostly due to the more or less traumatic effects of the cannula to
the septal fibres and the dermis. Histologies showed the effect on
microstructure. After LAL collagen tissue was partially
denaturated, attracting fibroblasts. PAL and LAL were the
techniques where most septal fibres were preserved.
Conclusion: Certain aesthetic and medical complications after
liposuction can be correlated to certain tissue effects after certain
types of liposuction. The tissue effect after laser assisted
Liposuction offers superior results because most septal fibres were