scholarly journals Inverse planning for radiofrequency ablation in cancer therapy using multiple damage models

2021 ◽  
Author(s):  
Dionne M Aleman ◽  
Shefali Kulkarni-Thaker ◽  
Aaron Fenster
Keyword(s):  
Radiofrequency Ablation ◽  
Treatment Time ◽  
Organs At Risk ◽  
Treatment Quality ◽  
Mathematical Framework ◽  
Thermal Dose ◽  
Invasive Treatment ◽  
Inverse Planning ◽  
Damage Models ◽  
Source Voltage

Radiofrequency ablation (RFA) offers localized and minimally invasive treatment of small-to-medium sized inoperable tumors. In RFA, tissue is ablated with high temperatures obtained from electrodes (needles) inserted percutaneously or via an open surgery into the target. RFA treatments are generally not planned in a systematic way, and do not account for nearby organs-at-risk (OARs), potentially leading to sub-optimal treatments and inconsistent treatment quality. We therefore develop a mathematical framework to design RFA treatment plans that provide complete ablation while minimizing healthy tissue damage. Borrowing techniques from radiosurgery inverse planning, we design a two-stage approach where we first identify needle positions and orientations, called needle orientation optimization, and then compute the treatment time for optimal thermal dose delivery, called thermal dose optimization. Several different damage models are used to determine both target and OAR damage. We present numerical results on three clinical case studies. Our findings indicate a need for high source voltage for short tip length (conducting portion of the needle) or fewer needles, and low source voltage for long tip length or more needles to achieve full coverage. Further, more needles yields a larger ablation volume and consequently more OAR damage. Finally, the choice of damage model impacts the source voltage, tip length, and needle quantity.

scholarly journals Optical signatures of radiofrequency ablation in biological tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pranav Lanka ◽  
Kalloor Joseph Francis ◽  
Hindrik Kruit ◽  
Andrea Farina ◽  
Rinaldo Cubeddu ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Treatment Time ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Tissue Response ◽  
Optical Monitoring ◽  
Diffuse Optical Spectroscopy ◽  
Spectral Changes ◽  
Scattering Spectra ◽  
Optical Behavior

AbstractAccurate monitoring of treatment is crucial in minimally-invasive radiofrequency ablation in oncology and cardiovascular disease. We investigated alterations in optical properties of ex-vivo bovine tissues of the liver, heart, muscle, and brain, undergoing the treatment. Time-domain diffuse optical spectroscopy was used, which enabled us to disentangle and quantify absorption and reduced scattering spectra. In addition to the well-known global (1) decrease in absorption, and (2) increase in reduced scattering, we uncovered new features based on sensitive detection of spectral changes. These absorption spectrum features are: (3) emergence of a peak around 840 nm, (4) redshift of the 760 nm deoxyhemoglobin peak, and (5) blueshift of the 970 nm water peak. Treatment temperatures above 100 °C led to (6) increased absorption at shorter wavelengths, and (7) further decrease in reduced scattering. This optical behavior provides new insights into tissue response to thermal treatment and sets the stage for optical monitoring of radiofrequency ablation.

An Analytical Evaluation of the Optimal Thermal Dose Delivery Parameters for Thermal Therapies

2003 ◽  
Author(s):  
Kung-Shan Cheng ◽  
Robert B. Roemer
Keyword(s):  
Blood Flow ◽  
Treatment Time ◽  
Heating Time ◽  
Treatment Temperature ◽  
Thermal Dose ◽  
Dose Delivery ◽  
Thermal Therapies ◽  
Initial Power ◽  
High Treatment ◽  
Optimal Heating

This study derives the first analytic solution for evaluating the optimal treatment parameters needed for delivering a desired thermal dose during thermal therapies consisting of a single heating pulse. Each treatment is divided into four time periods (two power-on and two power-off), and the thermal dose delivered during each of those periods is evaluated using the non-linear Sapareto and Dewey equation relating thermal dose to temperature and time. The results reveal that the thermal dose delivered during the second power-on period when T>43C (TD2) and the initial power-off period when T>43C (TD3) contribute the major portions of the total thermal dose needed for a successful treatment (taken as 240 CEM43°C), and that TD3 dominates for treatments with higher peak temperatures. For a fixed perfusion value, the analytical results show that once the maximum treatment temperature and the total thermal dose (e.g., 240 CEM43°C) are specified, then the required heating time and the applied power magnitude are uniquely determined. These are the optimal heating parameters since lower/higher values result in under-dosing/over-dosing of the treated region. It is also shown that higher maximum treatment temperatures result in shorter treatment times, and for each patient blood flow there is a maximum allowable temperature that can be used to reach the desired thermal dose. In addition, since TD2 and TD3 contribute most of the total thermal dose, and they are both significantly affected by the blood flow present for high treatment temperatures, these results show that perfusion effects must be considered when attempting to optimize high temperature thermal therapy treatments (no excess thermal dose delivered, minimum power applied and shortest treatment time attained).

scholarly journals Successful surgical rescue of delayed onset diaphragmatic hernia following radiofrequency ablation using a thoracoscopic approach for hepatocellular carcinoma: a case report

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Atsushi Morito ◽  
Shigeki Nakagawa ◽  
Katsunori Imai ◽  
Norio Uemura ◽  
Hirohisa Okabe ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Small Intestine ◽  
Radiofrequency Ablation ◽  
Diaphragmatic Hernia ◽  
Invasive Treatment ◽  
Thoracoscopic Approach ◽  
Case Presentation ◽  
Medial Segment ◽  
Liver Surface ◽  
The Right

Abstract Background Radiofrequency ablation (RFA) is widely used as a minimally invasive treatment for hepatocellular carcinoma (HCC). RFA has a low risk of complications, especially compared with liver resection. Nevertheless, various complications have been reported after RFA for HCC; however, diaphragmatic hernia (DH) is extremely rare. Case presentation A 78-year-old man underwent thoracoscopic RFA for HCC located at the medial segment adjacent to the diaphragm approximately 7 years before being transported to the emergency department due complaints of nausea and abdominal pain. Computed tomography revealed a prolapsed small intestine through a defect in the right diaphragm, and emergency surgery was performed. The cause of diaphragmatic hernia was the scar of RFA. We confirmed that the small intestine had prolapsed into the right diaphragm, and we resected the necrotic small intestine and repaired the right diaphragm. Herein, we report a case of ileal strangulation due to diaphragmatic hernia after thoracoscopic RFA. Conclusions Care should be taken when performing thoracoscopic RFA, especially for tumors located on the liver surface adjacent to the diaphragm. Patients should be carefully followed up for possible DH, even after a long postoperative interval.

scholarly journals Ultrasound-Guided Moving Shot Radiofrequency Ablation of Benign Soft Tissue Neoplasm

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 830
Author(s):  
Wei-Che Lin ◽  
Yi-Fan Tai ◽  
Meng-Hsiang Chen ◽  
Sheng-Dean Luo ◽  
Faye Huang ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Soft Tissue ◽  
General Anesthesia ◽  
Local Anesthesia ◽  
Venous Malformation ◽  
Volume Reduction ◽  
The Other ◽  
Invasive Treatment ◽  
Soft Tissue Neoplasm

Background and Objective: To evaluate the effectiveness of radiofrequency ablation (RFA) using the moving-shot technique for benign soft tissue neoplasm. Materials and Methods: This retrospective study reviewed eight patients with benign soft tissue neoplasm presenting with cosmetic concerns and/or symptomatic issues who refused surgery. Six patients had vascular malformation, including four with venous malformation and two with congenital hemangioma. The other two patients had neurofibroma. All patients underwent RFA using the moving-shot technique. Imaging and clinical follow-up were performed in all patients. Follow-up image modalities included ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging. The volume reduction ratio (VRR), cosmetic scale (CS), and complications were evaluated. Results: Among the seven patients having received single-stage RFA, there were significant volume reductions between baseline (33.3 ± 21.2 cm3), midterm follow-up (5.1 ± 3.8 cm3, p = 0.020), and final follow-up (3.6 ± 1.4 cm3, p = 0.022) volumes. The VRR was 84.5 ± 9.2% at final follow-up. There were also significant improvements in the CS (from 3.71 to 1.57, p = 0.017). The remaining patient, in the process of a scheduled two-stage RFA, had a 33.8% VRR after the first RFA. The overall VRR among the eight patients was 77.5%. No complications or re-growth of the targeted lesions were noted during the follow-up period. Of the eight patients, two received RFA under local anesthesia, while the other six patients were under general anesthesia. Conclusions: RFA using the moving-shot technique is an effective, safe, and minimally invasive treatment for benign soft tissue neoplasms, achieving mass volume reduction within 6 months and significant esthetic improvement, either with local anesthesia or with general anesthesia under certain conditions.

TU-G-BRB-02: A New Mathematical Framework for IMRT Inverse Planning with Voxel-Dependent Optimization Parameters

2012 ◽  
Vol 39 (6Part24) ◽  
pp. 3919-3919 ◽  
Author(s):  
M Zarepisheh ◽  
A Uribe-Sanchez ◽  
N Li ◽  
X Jia ◽  
S Jiang
Keyword(s):  
Mathematical Framework ◽  
Inverse Planning ◽  
Optimization Parameters

Application of ultrasound-guided biopsy and percutaneous radiofrequency ablation in 2 cases with phosphaturic mesenchymal tumor and literature review

2020 ◽  
pp. 1-9
Author(s):  
Meng-Fei Xian ◽  
Kang-Ming Pan ◽  
Jian-Chao Zhang ◽  
Mei-Qing Cheng ◽  
Hui Huang ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Musculoskeletal Complaints ◽  
Percutaneous Radiofrequency Ablation ◽  
Phosphaturic Mesenchymal Tumor ◽  
Ultrasound Guided ◽  
Invasive Treatment ◽  
Mesenchymal Tumors ◽  
Total Resection ◽  
Guided Biopsy ◽  
Ultrasound Guided Biopsy

Tumor-induced osteomalacia (TIO) is a vanishingly rare paraneoplastic syndrome which is usually caused by phosphaturic mesenchymal tumors (PMTs). The conventional treatment for PMTs is total resection, and ultrasound-guided radiofrequency ablation (RFA) can also be used for the treatment of PMTs patients, especially for patients in whom complete resection may lead to serious complications. We report two cases with PMT who presented syndrome with progressive musculoskeletal complaints and performed ultrasound-guided biopsy and RFA. Ultrasound-guided RFA, which is a safe and effective minimally invasive treatment option, appears to be a valuable alternative to surgery for patients presenting with PMT. We are the first reported case of RFA guided by ultrasonography in the treatment of PMT.

Linac Based Total Marrow Irradiation and Myeloablative Chemotherapy In Allogeneic Stem Cell Transplantation for High Risk Patients.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4526-4526
Author(s):  
Pritesh R. Patel ◽  
Bulent Aydogan ◽  
Damiano Rondelli
Keyword(s):  
Linear Accelerator ◽  
Treatment Time ◽  
Conflicts Of Interest ◽  
Organs At Risk ◽  
Chronic Gvhd ◽  
Ct Scanning ◽  
Test Dose ◽  
Target Volume ◽  
Whole Body ◽  
Total Marrow Irradiation

Abstract Abstract 4526 Intensity modulated total marrow irradiation (IM-TMI) represents an innovative technique to irradiate the bone marrow in hematologic malignancies. IM-TMI has been performed previously using tomotherapy in combination with a reduced intensity preparative regimen. Here we report 2 cases where IM-TMI 300cGy was delivered using a linear accelerator in combination with fludarabine/IV busulfan. To plan IM-TMI, 5 mm-slice CT scanning from top of the head to the mid femur was performed with immobilization using a customized whole body alpha cradle. All bones (excluding the arms and lower extremities) were contoured as the clinical target volume. A 3 mm margin was added to obtain the planning target volume (PTV). The organs at risk (OAR) including the brain, lenses, lungs, liver, kidney, small bowel and heart were identified and contoured. The IM-TMI technique consisted of three separate treatment plans: the head and neck; trunk; and pelvis. Patients received fludarabine 40mg/m2 on days -8 to -5. IV busulfan was given on days -5 to -2 targeting an AUC of 4800microM/min based on a pretransplant test dose. IM-TMI was delivered on day -5. The patients received a total of 300 cGy IM-TMI dose in two fractions, 8 hours apart. Two patients were treated: one is a 63 year old male with multiple myeloma who relapsed within 6 months after an autologous transplant with new cytogenetic abnormalities; and the second is a 52 years old female with AML who failed initial induction chemotherapy and at the time of transplant was in complete remission after receiving a second induction and one consolidation chemotherapy. Both patients received PBSC from HLA matched siblings. IM-TMI technique achieved 95% coverage of the PTV. The mean doses to the lenses and lungs were 99 and 195 cGy, respectively. Overall doses delivered to OAR were reduced by 20–67% on average when compared to standard total body irradiation. Treatment time was 44 min and 32 min for the beam-on and set-up, respectively, using the Varian 21 EX linac and MV imaging. Both patients suffered Bearman grade 1 mucositis. No other extramedullary toxicities were observed. Both engrafted in a timely manner achieving neutrophil >0.5 × 109/L at day 13 and 14, and platelet >20 × 109/L at day 8 and 9, respectively. Full donor chimerism was noted by day +30. After follow up of 246 and 218 days, respectively, both patients are alive and in remission. One developed a grade 2 acute GVHD and none of them has chronic GVHD. This study demonstrates for the first time the use of IM-TMI using a linear accelerator. The possibility of adding higher doses of IM-TMI to a myeloablative regimen without toxicity will be tested in a dose escalating clinical trial. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jingjing Xia ◽  
Qiang Li ◽  
Pin-Yu Chen ◽  
Zhuhuang Zhou ◽  
Chiao-Yin Wang ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Tissue Section ◽  
Image Data ◽  
Ablation Zone ◽  
Invasive Treatment ◽  
Linear Probe ◽  
Electrode Displacement ◽  
Angle Effect ◽  
Highly Correlated ◽  
Experimental Findings

Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5 MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones.

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