David Melodelima - Academia.edu (original) (raw)

Papers by David Melodelima

International Journal of Hyperthermia, 2007

Interstitial ultrasound applicators have been proposed for treating deep-seated tumors that can n... more Interstitial ultrasound applicators have been proposed for treating deep-seated tumors that can not be reached with extracorporeal High Intensity Focused Ultrasound. In addition, interstitial ultrasound offers several advantages compared with conventional ablation technology (radiofrequency, microwaves, cryotherapy …) in terms of penetration, speed of coagulation, ability to direct and control the thermal lesion and compatibility with image monitoring. The ultrasound source is brought as close as possible to the target in order to minimize the effects of attenuation and phase aberration along the ultrasound pathway. The present paper is a review of the interstitial applicators that were described during the last decade in the literature. It is presented in three sections. The technical aspects common to all applicators are first described. For example, most described applicators are sideview applicators which active element is water-cooled and operates at rather high frequency (above 3MHz) in order to promote heating. Then the different potential techniques for monitoring treatment administered by the interstitial route are presented and illustrated through a review of imageguided interstitial thermal ablation. Three major techniques of imaging are used for guiding interstitial treatment: MRI, ultrasound and fluoroscopy. The third section will go further in detail on diverse described medical applications.

2009 IEEE International Ultrasonics Symposium, 2009

Current development of HIFU strategies for the treatment of localized abdominal tumors are limite... more Current development of HIFU strategies for the treatment of localized abdominal tumors are limited by organ motion during respiration. In preliminary studies, a numerical model simulated the effects of in-vivo movements on HIFU treatments in the liver. It was shown that a HIFU treatment performed during respiration with juxtaposition of millimetrics lesions is modified in shape and homogeneity. Here, we report recent results from a comparative study which evaluated in simulation and in in-vivo experiments, the interest of using, during respiratory, a toroidal-shaped HIFU device developed for the treatment of liver metastases from colorectal cancer. These experiments were performed during an open procedure, on 9 pigs divided into 3 groups. On the first group, a spherical HIFU transducer was used to juxtapose 49 millimetrics lesions in the liver during respiration. The second group was treated during respiration with a 3 MHz toroi?dal-shaped HIFU transducer. The last group (control) was treated during apnea. For each animal, sequences of ultrasound images were acquired in the liver. Then, a combined method of modeling based on ultrasound speckle tracking and BHTE equation resolution, was used to quantify liver motion and to simulate HIFU treatments during breathing. Liver motions were mainly encountered in the cranial-caudal direction with a frequency comparable to the respiratory frequency (f = 0.2 Hz). Magnitude of the motion was 8.2-10.0 mm. Results of the modeling were well fitted to the observations made on in-vivo gross samples. In vivo lesions created with the spherical device were stretched by 64% and then were split in the tissues. The toroidal-shaped HIFU strategy allowed the generation of homogeneous lesions (12% stretching). These results provide a preliminary validation of the method for modeling liver motion effects. This method was used to demonstrate the effectiveness of a new HIFU device which shows promise for HIFU therapy during respiration.

The Journal of the Acoustical Society of America, 2008

... auteur(s) : David Melodelima ( ) 1 , William Apoutou N'Djin 1 , Hubert Parmentier 1 ... more ... auteur(s) : David Melodelima ( ) 1 , William Apoutou N'Djin 1 , Hubert Parmentier 1 , Michel Rivoire 2 , Jean-Yves Chapelon 1. ... paper presents in vivo evidence that the coagulated volume obtained from a 40 s total exposure in the liver was 7.0+/-2.5 cm(3) (min 1.5 - max 20.0 cm ...

In the liver, the efficacy of radiofrequency or HIFU ablation is impaired by blood perfusion. Thi... more In the liver, the efficacy of radiofrequency or HIFU ablation is impaired by blood perfusion. This can be overcome by hepatic inflow occlusion using a Pringle manoeuver. Here we report the in vivo evaluation of ablations performed in the liver using a surgical toroidal High Intensity Focused Ultrasound (HIFU) device used during an open procedure with and without hepatic inflow

Annals of Surgical Oncology, 2012

Background. Bleeding is the main cause of postoperative complications of hepatic surgery. To mini... more Background. Bleeding is the main cause of postoperative complications of hepatic surgery. To minimize intraoperative bleeding during hepatectomy, resections are generally carried out under hepatic vascular control despite the risk of liver dysfunction in patients with chronic liver disease. This study evaluates the feasibility and safety of highintensity focused ultrasound (HIFU)-assisted hepatic resection during an open procedure in an animal model. Methods. Three groups of 12-14-week-old Landrace pigs (n = 7/group) were used to evaluate HIFU-assisted liver resection (group A) vs liver resection with or without portal triad clamping (groups B and C). In each pig, liver resection was performed on the right and left paramedian lobes. The following were evaluated and compared in the 3 groups: total blood loss, blood loss/cm 2 of resection area, clip density, procedure duration, morbidity, and mortality.

Physics in Medicine and Biology, 2010

The pig is an ideal animal model for preclinical evaluation of HIFU treatments, especially in the... more The pig is an ideal animal model for preclinical evaluation of HIFU treatments, especially in the liver. However, there is no liver tumor model available for pigs. In this work, we propose to study an in vivo tumor-mimic model as a tool for evaluating if a sonographycally guided HIFU treatment, delivered by a toroidal-shaped device dedicated for the treatment of liver metastases, is correctly located in the liver. One centimeter tumor-mimics were created in liver tissues. These tumor-mimics were detectable on ultrasound imaging and on gross pathology. Two studies were carried out. First, an in vivo study of tolerance at mid-term (30 days, 10 pigs) revealed that tumor-mimics are suitable for studying HIFU treatments at a preclinical stage, since local and biological tolerances were excellent. The dimensions of the tumor-mimics were reproducible (diameter at day 0: 9.7 +/- 2.0 mm) and were the same as a function of time (p = 0.64). A second in vivo study was carried out in ten pigs. Tumor mimics were used as targets in liver tissues in order to determine if the HIFU treatment is correctly located in the liver. A procedure of extensive HIFU ablation using multiple HIFU lesions juxtaposed manually was then tested on eight tumor-mimics. In 88% of the cases (seven out of eight), tumor-mimics were treated with negative margins (>or=1 mm) in all directions. On average, negative margins measured 10.0 +/- 6.7 mm. These tumor-mimics constitute an excellent reference for studying in vivo the accuracy of HIFU therapy in the liver.

Physics in Medicine and Biology, 2009

In the liver, the efficacy of radiofrequency or high-intensity focused ultrasound (HIFU) ablation... more In the liver, the efficacy of radiofrequency or high-intensity focused ultrasound (HIFU) ablation is impaired by blood perfusion. This can be overcome by hepatic inflow occlusion. Here we report the in vivo evaluation of ablations performed in the liver using a surgical toroidal HIFU device used during an open procedure with and without hepatic inflow occlusion. The HIFU device was composed of 256 toroidal-shaped emitters working at 3 MHz and an integrated ultrasound imaging probe working at 7.5 MHz. Using an intermittent Pringle maneuver (IPM), thermal ablations were created in three pigs with hepatic inflow occlusion (IPM group) and in three pigs with normal perfusion (NoIPM group). The ablations were studied on sonograms, macroscopically and microscopically 14 days after the treatment. In the NoIPM group, the average coagulated volume obtained after a 40 s exposure was 7.4 +/- 3.8 cm(3) (2.2-16.6). In the IPM group, the average ablated volume was 6.3 +/- 2.9 cm(3) (2.6-12.1). There was no significant difference between the two groups in terms of ablated volume (p = 0.25), diameter (p = 0.37) or depth (p = 0.61). Therefore, a toroidal-shaped HIFU device allows treatment in the liver that can be considered as independent from hepatic inflow occlusion.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2007

To date, the efficacy of ablative technologies such as HIFU for the treatment of liver tumors in ... more To date, the efficacy of ablative technologies such as HIFU for the treatment of liver tumors in humans has been studied in animal models without tumors or in small animals like rats and rabbits with established tumors. Because of the small size of these animals, the lesion produced by HIFU devices has to be small. Thus, the local and systemic effects of the treatment as encountered in humans cannot be studied. The purpose of this study was to use an in vivo tumor-mimic model to evaluate the accuracy of HIFU ablation in the liver in preclinical studies. Tumor mimics were created in in vivo porcine livers by injecting a 1-cc warm mixture of agarose, cellulose, glycerol and methylene blue, which formed 1-cm hyperechoic discrete lesions on sonograms. Three studies were carried out: (i) in vitro experiments were conducted to study the acoustical proprieties of the tumor mimics; (ii) in vivo experiments were conducted in 10 pigs to evaluate the tolerance of the tumor mimics when injected...

A toroidial-shaped HIFU medical device with integrated ultrasound imaging was developed for the t... more A toroidial-shaped HIFU medical device with integrated ultrasound imaging was developed for the treatment of colorectal liver metastasis. The HIFU toroidïal-shaped transducer contained 256-elements (working frequency: 3 MHz) and allows creating a single conical lesion of 7 cm3 in 40 seconds (Ifocal = 1700 W.cm-2). Volumes of treatment can then be significantly increase by juxtaposing single lesions. Presented here is the use of this device in an animal model as a complementary tool to improve surgical resection in the liver. A zone of coagulative necrosis before transecting the liver was performed using this device in order to minimize blood loss and dissection time during hepatectomy. Resection assisted by HIFU (RA-HIFU) was compared with classical dissections with clamping (RC) and without clamping (Control). For each technique 14 partial liver resections were performed in seven pigs. Blood loss per dissection surface area was the main outcome parameter. Blood loss during liver transection was significantly lower in RA-HIFU (7.4+/-3.3 ml.cm-2) than in RC (34%) and Control (47%). The duration of transection in RA-HIFU (13+/-3 min) was significantly shorter than in RC (44%) and Control (28%). Precoagulation also resulted in the use of significantly fewer clips; the number of clips used per square centimetre was 50% lower in RA-HIFU (0.8+/-0.2 cm-2) than in the other groups.

2006 IEEE Ultrasonics Symposium, 2006

In many applications, high intensity focused ultrasound (HIFU) treatments are guided using ultras... more In many applications, high intensity focused ultrasound (HIFU) treatments are guided using ultrasound imaging. To date, efficacy of ablative technologies such as HIFU for the treatment of liver tumor has been studied in animal models without any tumor or in small animals like rat and rabbit with established tumor. The purpose of this study was to use an in vivo

Ultrasound in Medicine & Biology, 2004

Running title : Combination of thermal and cavitation effects 2 Combination of thermal and cavita... more Running title : Combination of thermal and cavitation effects 2 Combination of thermal and cavitation effects to generate deep lesions with an endocavitary applicator using a plane transducer: Ex vivo studies.

Organs motion is a key component in the treatment of abdominal lesions by HIFU, since it may infl... more Organs motion is a key component in the treatment of abdominal lesions by HIFU, since it may influence the efficacy and treatment time. Previous studies on HIFU treatments showed the effect of motor-controlled translations applied to in vitro liver samples. In vivo organs motions are more complex and could lead to various effects on HIFU treatments. Here we report that

The development of new cauterization techniques for hepatic resection is critical for improving t... more The development of new cauterization techniques for hepatic resection is critical for improving the safety of the procedure. Previous studies showed the feasibility of using HIFU or radiofrequency precoagulation to limit blood loss during dissection of the organ. Here we report a new therapeutic modality using high intensity focused ultrasound (HIFU) to perform a bloodless hepatic resection that could represent

9th International Symposium on Therapeutic Ultrasound, 2010

2007 Ieee Ultrasonics Symposium Proceedings, Vols 1-6, 2007

Accurate HIFU treatments of abdominal tumors is difficult because of organs motions during breath... more Accurate HIFU treatments of abdominal tumors is difficult because of organs motions during breathing. Here we report that a combined method can be used for simulating HIFU lesion in the liver by considering effective in vivo motion. Sequences of ultrasound images were acquired in vivo during an open procedure on 4 pigs using a 2D ultrasound imaging probe working at a frequency of 12 MHz. Sequences were acquired during either breathing or apnea. Effects of real liver motions on a HIFU treatment were modeled on the basis of the combination of two techniques. An accurate ultrasound correlation-based method was used to estimate liver motion using speckle tracking. Effects of liver motion on HIFU lesions were observed by including these measured displacements in numerical simulations based on Bio Heat Transfer Equation. A first set of data was acquired on 2 pigs during breathing showed that the main movements were encountered in the cranial-caudal direction (f=0.2 MHz, average magnitude: 13.3 plusmn 1.1 mm (range 9.0 - 15.5)). A second set of data was acquired on 2 pigs during breathing and apnea in order to separate the motion due to cardiovascular activity only (f=0.96 MHz, magnitude < 0.5 mm). The results of simulated HIFU lesions considering real in vivo liver motion revealed that the lesions were significantly different in terms of size and homogeneity between control (no motion) and breathing samples. Therefore this study provides a useful and practical mean of determining the influence of effective 2D actual in vivo motions on HIFU treatments which can be applied to the liver or to any other moving organ.

2007 IEEE Ultrasonics Symposium Proceedings, 2007

... for 1-cc injections were 9.7 ± 1.0 mm (min.5.6.max.12.0 mm)) on sonogram and 10.1 ± 0.7 mm (m... more ... for 1-cc injections were 9.7 ± 1.0 mm (min.5.6.max.12.0 mm)) on sonogram and 10.1 ± 0.7 mm (min.6.3.max.11.5 mm)) on ... EH, Malafa M., Resection of Colorectal Liver Metastases: Current Perspectives, Cancer Control 2006 13: 32-41 [3] Melodelima D., N'Djin WA, Parmentier ...

The Journal of the Acoustical Society of America, 2013

Surgical resection is the only treatment of colorectal liver metastases that can ensure long-term... more Surgical resection is the only treatment of colorectal liver metastases that can ensure long-term survival and cure in some patients. However, only 20% of patients are suitable for surgery. As a result, many nonresectional modalities of treatment have been assessed to provide an alternative to liver resection. Several limitations have been observed when using these techniques and available evidence is limited. Here, we report that a new design of high intensity focused ultrasound transducer can significantly enlarge the coagulated volume over short periods of time and that treatment in the liver can be guided in real-time using an integrated ultrasound imaging probe. Our long-term objective is to develop a device that can be used during surgery for eventual clinical use in conjunction with resection. Eight ultrasound emitters, divided into 256 elements, were created by sectioning a single toroid piezocomposite transducer. The focal zone was conical in shape and located 70 mm from the transducer; enabling the treatment of deep-seated tumors. A single thermal lesion was created when the eight emitters performed alternative and consecutive 5-s ultrasound exposures. This article presents in vivo evidence that the coagulated volume obtained from a 40 s total exposure in the liver was 7.0 ؎ 2.5 cm 3 (minimum 1.5 -maximum 20.0 cm 3 ) with an average diameter of 17.5 ؎ 3.8 mm (minimum 10.0 -maximum 29.0 mm). All lesions were visible with high contrast on sonograms. The correlation between the diameter of lesions observed on sonograms and during gross examination was 92%. This method also allowed the user to easily enlarge the coagulated volume by juxtaposing single lesions. This approach may have a role in treating unresectable colorectal liver metastases and may also be used in conjunction with resection to extend its limits. (E-mail: David.Melodelima@inserm.fr)

Ultrasound in Medicine & Biology, 2008

Presented in this article is a tumor-mimic model that allows the evaluation, before clinical tria... more Presented in this article is a tumor-mimic model that allows the evaluation, before clinical trials, of the targeting accuracy of a high intensity focused ultrasound (HIFU) device for the treatment of the liver. The tumor-mimic models are made by injecting a warm solution that polymerizes in hepatic tissue and forms a 1 cm discrete lesion that is detectable by ultrasound imaging and gross pathology. First, the acoustical characteristics of the tumor-mimics model were measured in order to determine if this model could be used as a target for the evaluation of the accuracy of HIFU treatments without modifying HIFU lesions in terms of size, shape and homogeneity. On average (n ‫؍‬ 10), the attenuation was 0.39 ؎ 0.05 dB.cm ؊1 at 1 MHz, the ultrasound propagation velocity was 1523 ؎ 1 m.s ؊1 and the acoustic impedance was 1.84 ؎ 0.00 MRayls. Next, the tumor-mimic models were used in vitro in order to verify, at a preclinical stage, that lesions created by HIFU devices guided by ultrasound imaging are properly positioned in tissues. The HIFU device used in this study is a 256-element phased-array toroid transducer working at a frequency of 3 MHz with an integrated ultrasound imaging probe working at a frequency of 7.5 MHz. An initial series of in vitro experiments has shown that there is no significant difference in the dimensions of the HIFU lesions created in the liver with or without tumor-mimic models (p ‫؍‬ 0.3049 and p ‫؍‬ 0.8796 for the diameter and depth, respectively). A second in vitro study showed that HIFU treatments performed on five tumor-mimics with safety margins of at least 1 mm were properly positioned. The margins obtained were on average 9.3 ؎ 2.7 mm (min. 3.0 -max. 20.0 mm). This article presents in vitro evidence that these tumor-mimics are identifiable by ultrasound imaging, they do not modify the geometry of HIFU lesions and, thus, they constitute a viable model of tumor-mimics indicated for HIFU therapy. (

PloS one, 2015

Surgery is the only curative treatment in patients with colorectal liver metastases (CLM), but on... more Surgery is the only curative treatment in patients with colorectal liver metastases (CLM), but only 10-20% of patients are eligible. High Intensity Focused Ultrasound (HIFU) technology is of proven value in several indications, notably prostate cancer. Its intra-operative use in patients with CLM has not previously been studied. Preclinical work suggested the safety and feasibility of a new HIFU device capable of ablating volumes of up to 2cm x 2cm in a few seconds. We conducted a prospective, single-centre phase I-IIa trial. HIFU was delivered immediately before scheduled hepatectomy. To demonstrate the safety and efficacy of rapidly ablating liver parenchyma, ablations were performed on healthy tissue within the areas scheduled for resection. In total, 30 ablations were carried out in 15 patients. These ablations were all generated within 40 seconds and on average measured 27.5mm x 21.0mm. The phase I study (n = 6) showed that use of the HIFU device was feasible and safe and did n...