Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “THERMOTHERAPY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed2004

Thermal analysis of laser interstitial thermotherapy in ex vivo fibro-fatty tissue using exponential functions.

A therapeutic procedure to treat small, surface breast tumours up to 10 mm in radius plus a 5 mm margin of healthy, surrounding tissue using laser interstitial thermotherapy (LITT) is currently being investigated. The purpose of this study is to analyse and model the thermal and coagulative response of ex vivo fibro-fatty tissue, a model for breast tissue, during experimental laser interstitial thermotherapy at 980 nm. Laser radiation at 980 nm was delivered interstitially through a diffusing tip optical fibre inserted into a fibro-fatty tissue model to produce controlled heating at powers ranging from 3.2 to 8.0 W. Tissue temperature was measured with thermocouples placed at 15 positions around the fibre. The induced coagulation zone was measured on gross anatomical sections. Thermal analysis indicates that a finite sum of exponential functions is an approximate solution to the heat conduction equation that more accurately predicts the time-temperature dependence in tissue prior to carbonization (T < 100 degrees C) during LITT than the traditional model using a single exponential function. Analysis of the ellipsoid coagulation volume induced in tissue indicates that the 980 nm wavelength does not penetrate deep enough in fibro-fatty tissue to produce a desired 30 mm diameter (14.1 x 10(3) mm3) coagulation volume without unwanted tissue liquefaction and carbonization.

Adipose Tissue↗
PubMed2002

Mediating transurethral microwave thermotherapy by intraprostatic and periprostatic injections of mepivacaine epinephrine: effects on treatment time, energy consumption, and patient comfort.

BACKGROUND AND PURPOSE: Profound intraprostatic blood flow may complicate reaching a therapeutic temperature in the prostate during transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia (BPH). A retrospective survey is presented describing the effect of intraprostatic and periprostatic administration of mepivacaine epinephrine on treatment time, intraprostatic blood flow, energy delivery, and patient comfort. PATIENTS AND METHODS: Fifteen consecutive obstructed patients with lower urinary tract symptoms attributable to BPH received TUMT (ProstaLund Feedback Treatment). In order to improve patient comfort, injections of 10 mL of 0.5% mepivacaine epinephrine were administered in three locations into the prostate prior to treatment. The results were compared with those of a reference group consisting of 35 consecutive patients who had received ProstaLund Feedback Treatment without administration of mepivacaine epinephrine. RESULTS: Patients who received intraprostatic mepivacaine epinephrine had a shorter treatment time (32+/-9 minutes v 61+/-6 minutes), required less energy (65+/-27 kJ v 172+/-32 kJ), and had a lower calculated intraprostatic blood flow (13+/-5 units/minute v 26+/-12 units/minute) than the reference group. Patients receiving mepivacaine epinephrine also required less analgesic medication during the treatment. The clinical outcome in terms of symptom scores and peak uroflow rates appeared to be similar for the two groups. CONCLUSION: Intraprostatic injection of mepivacaine epinephrine prior to TUMT seems to have beneficial effects. It may represent an important improvement of thermotherapy and enable successful treatment of those patients who previously failed secondary to a profound intraprostatic blood flow.

Anesthetics, Local↗
PubMed2002

Treatment of benign prostatic hyperplasia with water-induced thermotherapy: experience of a single institution.

PURPOSE: To evaluate the efficacy of and tolerance for water-induced thermotherapy (WIT). PATIENTS AND METHODS: Between June 1998 and December 1999, 50 patients were treated with WIT protocol. The patients were divided in two groups according to the achieved treatment temperature and the volume of the inflated treatment balloon. In Group 1, the treatment temperature was set at 60 degrees C, and the treatment balloon was inflated to 50F. In Group II, 29 patients were treated with a temperature of 62 degrees C, and the treatment balloon was inflated to a maximum of 60F. RESULTS: In Group I, the catheter was permanently removed in eight of the nine patients who had previously had permanent indwelling bladder catheters (88.8%). The average Qmax was 11.5 mL/sec; the quality of life (QoL) index was 1.3, and the International Prostate Symptom Score (IPSS) was 6.2. The remaining five patients were not catheter dependent prior to WIT. Three of these patients (60%) demonstrated Qmax improvements from 11.7 to 17.1 mL/sec. In Group II, 11 of the 15 patients (73.3%) who had been catheter dependent resumed spontaneous micturition with a Qmax of 10.7 mL/sec and an IPSS of 8.5. CONCLUSION: Water-induced thermotherapy can be performed easily on an outpatient basis under local anesthesia. It is well tolerated by most patients, and the early results are encouraging.

Aged↗
PubMed1992

Interstitial 1.06 Nd:YAG laser thermotherapy for brain tumors under real-time monitoring of MRI: experimental study and phase I clinical trial.

This paper presents the experimental and clinical results of interstitial 1.06 Nd:YAG laser thermotherapy (ILTT) for brain tumors under real-time monitoring by magnetic resonance imaging. The authors chose a laser heat source for interstitial thermotherapy of brain tumors for several important reasons: (1) Laser heat delivery is less complicated and more controlled; (2) laser effects on tissue can be tested, monitored, and controlled by MRI. A 1.064 nm Nd:YAG laser and a specially designed laser optic fiber (ILTT) were used in C.W. mode this study. The laser was used at 4 W at a C.W. mode pulse and total exposure duration was 10 minutes (total energy was 2400 joules). Temperature distribution was determined with a microprocessor-based thermometer and by the levels of the signal intensity under MRI. The relationship between the temperature and MRI signal intensity allowed exploration of the possibility of using MRI as a noninvasive temperature monitoring method. Two patients with glioblastoma and one patient with a brain metastasis were treated with this modality. The results and indications are presented and discussed.

Brain Neoplasms↗
PubMed1996

Transurethral microwave thermotherapy v sham treatment: double-blind randomized study.

Transurethral microwave thermotherapy (TUMT) is a single-session, 1-hour office-based treatment for benign prostatic hyperplasia. A randomized, double-blind study has been conducted at our institutions involving 115 patients who, after satisfying the entry criteria, were randomized in a 2:1 fashion to receive TUMT or a sham treatment. Three months' unblinding revealed both statistically and clinically significant improvement in the efficacy measures for the real treatment compared with the sham. The mean Madsen Symptom Score decreased 55% and the mean peak flow rate increased 58% in the TUMT-treated patients v 28% and 27% in the sham-treated patients (P < 0.001). Also, the TUMT-treated patients improved in mean AUA Symptom Score by 43% v 26% for sham-treated patients (P < 0.01). Reclassification of patients after therapy showed a greater shift to the mild category of AUA Symptom Score: 37% for TUMT patients v 6.5% for sham-treated patients. In addition, prostate-specific antigen elevation to >4 times baseline was noted 1 week after TUMT v no statistically significant change for sham-treated patients. This double-blind study demonstrates that thermotherapy's efficacy is not placebo related and that the mechanism of action is related to thermal ablation of transition zone adenoma.

Aged↗
PubMed2000

Intraprostatic temperature monitoring during transurethral microwave thermotherapy: status and future developments.

Transurethral microwave thermotherapy is being applied as a minimally invasive treatment for alleviating the symptoms of urinary outlet obstruction associated with benign prostatic hyperplasia. Treatment progress has traditionally been guided in its effective power by rectally and urethrally measured temperatures, whereas intraprostatic temperatures would be preferred for feedback purposes. A critical evaluation is presented of intraprostatic thermometry techniques that have been suggested, the techniques currently being used and investigated, and the problems that remain to be solved. Techniques for noninvasive temperature measurement and detecting tissue response during thermal therapy are discussed in more detail. Results presented in the literature have shown magnetic resonance imaging and ultrasonic imaging to be adequate thermometry modalities. For treatment monitoring of transurethral microwave thermotherapy, ultrasonic imaging is especially promising. Future research will indicate whether the promise evolves into a sound clinical technique.

Body Temperature↗
PubMed2000

Predictors of treatment outcome for high-energy transurethral microwave thermotherapy.

BACKGROUND AND PURPOSE: Transurethral microwave thermotherapy (TUMT) is an innovative alternative to transurethral resection of the prostate (TURP) for the treatment of lower urinary tract symptoms (LUTS) suggestive of bladder outflow obstruction (BOO). Although the results are satisfactory for the majority of the patients, a considerable number of patients have an unfavorable outcome. Thus, the identification of features able to predict efficacy of TUMT for individual candidates is an important issue. MATERIALS AND METHODS: The available literature in MEDLINE covering the predictive role of various baseline measures for the outcome of high-energy TUMT was reviewed. Direct comparison among various studies was not possible because of differences in thermotherapy devices, treatment protocols, and the definition of a good response to treatment. RESULTS: Predictive features have been detected only for the Prostatron device. A small prostate volume, a low grade of BOO, and advanced age were independent predictors of poor outcome. The strongest predictive feature was the amount of energy delivered during treatment. Histologic characteristics (epithelial:stromal ratio and microvessel density) have not proved predictive for therapeutic outcome. The role of intraprostatic vascularization, as a regulator of the temperature during treatment, seems to be of the greatest importance, but results have not been presented yet. CONCLUSION: The value of baseline clinical measures for the selection of the best candidates for TUMT is limited at best. Variations in the internal structure of the individual prostate seem to play the most important role in regulating the amount of energy absorbed during treatment, and further research must focus on this item.

Dose-Response Relationship, Radiation↗
PubMed2000

High-energy microwave thermotherapy in patients in urinary retention.

PURPOSE: To study the outcome of high-energy transurethral microwave thermotherapy (TUMT) in patients with obstructive benign prostatic hyperplasia (BPH). PATIENT AND METHODS: Between September 1995 and March 1998, patients presenting with urinary retention secondary to BPH were recruited into the study. Their mean age was 67.2 years (range 50-85 years). The mean catheterization time prior to treatment was 3 months (range 15 days-1 year). Among the 200 patients treated during this period, 30 were high anesthesia risk (American Society of Anesthesiologists Class III/IV). The patients were treated in a single 1-hour session using high-energy (Prostatron 2.5) software, the range of energy transmitted being 111.9 to 214.2 kJ (mean 196.3 kJ). Symptoms were scored according to the International Prostatic Symptom Score (IPSS). The mean prostate volume subjected to TUMT was 59 cc (range 40-149.7 cc). The patients were followed every 3 months with measurements of peak flow rate, postvoiding residual urine volume estimation, and IPSS. RESULTS: Of the 200 patients, 33 were lost to follow-up, 155 were responsive (catheter free with physiologically acceptable peak flow rate), and 12 (7%) were nonresponsive. Only 4 patients (2%) experienced deterioration in their flow rates during the follow-up period of 2 years. They underwent transurethral resection. High-energy thermotherapy resulted in irritative voiding complaints in 80% of patients for 2 to 4 weeks. CONCLUSION: The initial results were encouraging, and the 2-year follow-up has shown appreciable sustainability in the treatment outcome, particularly in patients at high anesthesia risk.

Aged↗
PubMedDate not supplied

Feedback microwave thermotherapy with the ProstaLund Compact Device for obstructive benign prostatic hyperplasia: 12-month response rates and complications.

PURPOSE: To evaluate the effectiveness of the ProstaLund Compact Device in the treatment of benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: A series of 38 consecutive patients with a mean age of 72.6+/-8.2 years, 19 with an indwelling catheter, underwent transurethral microwave thermotherapy (TUMT) with the ProstaLund Compact Device. Pretreatment evaluation included transrectal ultrasonography (TRUS), urodynamics, and cystoscopy for all patients and flow rate (Qmax), postvoiding residual urine volume (PVR), International Prostate Symptom Score (IPSS), and quality-of-life (QoL) assessment for those without a catheter. The mean prostate volume was 63.5+/-30 cc. The Qmax, IPSS, and QoL studies were repeated at 3, 6, and 12 months, while urodynamics, cystoscopy, and TRUS were repeated at 6 and 12 months. RESULTS: The treatment lasted a mean of 43.1+/-17.1 minutes, achieved a maximal intraprostatic temperature of 58.7+/-7.2 degrees C, and destroyed 18.4+/-14.3 g of prostatic tissue. Twelve months post-treatment, for the patients without a catheter preoperatively, the IPSS was improved from 21.5+/-6.3 to 6.5+/-3.1 (P<0.001), Qmax from 7.2+/-3.1 mL/sec to 18.1+/-7.4 mL/sec (P<0.001), detrusor pressure at Qmax from 87.5+/-15 cm H2O to 48.4+/-16.4 cm H2O (P<0.001), and PVR from 113.2+/-78.2 mL to 34.6+/-36.7 mL (P<0.01). The good-response rates for IPSS ( or=50% improvement), Qmax (>or=15 mL/sec or >or=50% improvement), PVR (<50 mL or >or=50% decrease), and QoL (<or=2) were 73.7%, 84.2%, 73.7%, and 94.7%, respectively. For the patients with a catheter preoperatively, the IPSS improved from 9.5+/-6 at 3 months to 5.1+/-5.3 (P<0.05) at the end of the follow-up period. The Qmax was 13.2+/-6.4 mL/sec at 3 months and remained stable throughout the follow-up period. Patient good-response rates for IPSS (<or=7), PVR (<150 mL), and QoL (<or=2) were 75%, 87.5% and 75%, respectively. Only two patients were unable to void after the treatment. Complications were similar to those presented in the literature, and bladder stone formation was noted as well (five patients). CONCLUSIONS: ProstaLund thermotherapy is a highly promising alternative treatment for BPH, improving substantially both objective and subjective measures of bladder outflow obstruction.

Aged↗
PubMed1999

Laser-induced thermotherapy combined with hepatic arterial embolization in the treatment of liver tumors in a rat tumor model.

OBJECTIVE: To assess the effect of combined laser-induced thermotherapy (LITT) and hepatic arterial embolization with degradable starch microspheres (DSM) on tumor response and intrahepatic temperature distribution in rats with liver tumors. SUMMARY BACKGROUND DATA: Laser-induced thermotherapy is a promising in situ ablation technique for malignant liver tumors. However, clinical use is still limited, mainly because of the small size of the inducible coagulation necroses. This results in insufficient tumor destruction. METHODS: Colon carcinoma CC531 was implanted in 60 WAG rat livers. Fourteen days later, a silicon catheter was implanted in the hepatic artery for DSM administration. Tumors were exposed to 1064 nm Nd:YAG laser light at 2 watts for 10 minutes from a diffuser tip applicator placed in the tumor. The animals were randomized into a sham-operated control (group I) and three test groups. Group II received DSM alone, group III received LITT alone, and group IV received DSM + LITT. Tumor control was examined 1, 7, and 14 days after treatment. RESULTS: A complete tumor remission was achieved in all rats treated with LITT + DSM (group IV). In contrast, tumor progression was seen in animals treated with LITT alone (group III) or DSM alone (group II), as well as in the sham-operated controls (group I). CONCLUSIONS: The authors' results suggest that the combination of LITT and DSM considerably increases the efficacy of LITT in the treatment of liver metastases in the rat.

Animals↗
PubMed1994

Magnetic resonance imaging-controlled laser-induced interstitial thermotherapy.

RATIONALE AND OBJECTIVES: Laser-induced interstitial thermotherapy (LITT) may become an attractive modality for minimally invasive tumor therapy. Magnetic resonance imaging (MRI) could be used to assist this procedure. METHODS: A T1-weighted turbo fast low-angle shot (FLASH) sequence for on-line monitoring of the laser-influenced region (liver, muscle) was investigated. Sequence parameters were optimized for maximal image contrast. Magnetic resonance imaging-controlled LITT was performed in vitro, in vivo (rabbits), and in 8 human investigations (6 patients). Special laser applicators were used to establish a uniform laser light distribution. RESULTS: With the MRI sequence used, the LITT region is visualized as a bright area outlined by a dark border. This dark border corresponds to an isotherm of 45 +/- 2 degrees C depending on the sequence parameters used. CONCLUSION: With the T1-weighted turbo-FLASH sequence, MRI can be used for on-line monitoring of interstitial laser-induced thermotherapy in moving organs.

Aged↗
PubMed2001

Histopathological correlation to MRI findings during and after laser-induced thermotherapy in a pig pancreas model.

RATIONALE AND OBJECTIVES: To investigate whether percutaneous laser-induced thermotherapy (LITT) with continuous magnetic resonance (MR) monitoring of thermal effects within the pancreas is feasible in a porcine model. METHODS: Laser applicators were placed in the pancreas of 15 female pigs. A temperature-sensitive (thermo--fast low-angle shot) sequence was used for continuous monitoring of thermal effects during LITT at 1.5 T. Follow-up MR images were acquired, the pigs were observed for 7 days, and then a pathological examination was performed after sacrifice. RESULTS: Continuous MR monitoring visualized thermal effects in pancreatic tissue and thermal damage of the spleen (n = 1), the left kidney (n = 1), and peripancreatic fat (n = 4) but missed the thermal damage of the duodenum (n = 2). Thermal-induced lesions (10--32-mm diameter) were clearly visualized on contrast-enhanced T1-weighted images. CONCLUSIONS: Laser-induced thermotherapy of pancreatic tissue was feasible in this porcine model, and online monitoring was practicable. Further studies are necessary to increase the accuracy of online MR imaging of thermal effects.

Amylases↗
PubMed1995

Changes in pressure-flow parameters in patients treated with transurethral microwave thermotherapy.

PURPOSE: We document changes in pressure-flow study parameters in patients treated by transurethral microwave thermotherapy. MATERIALS AND METHODS: Pressure-flow study tracings before and after therapy from 75 patients with benign prostatic hyperplasia were analyzed. Patients were stratified according to the predominant type of obstruction at screening (constrictive or obstructive). RESULTS: An improvement in Madsen score and flow rates was noted at 6 months in both groups. In contrast to compressive obstruction patients, however, those with constrictive obstruction also showed significant changes in pressure-flow study parameters, including detrusor pressure at maximum flow, maximum flow rate and urethral resistance factor. CONCLUSIONS: Patients with predominantly constrictive obstruction are the best candidates for microwave thermotherapy.

Humans↗
PubMed1996

Pressure-flow study analyses in patients treated with high energy thermotherapy.

PURPOSE: We evaluated the urodynamic changes after high energy microwave thermotherapy in patients with lower urinary tract symptoms and benign prostatic enlargement. MATERIALS AND METHODS: A total of 120 patients was available for analysis with urodynamic investigation and pressure-flow studies before and 6 months after treatment. Several obstruction parameters were used to evaluate treatment outcome. RESULTS: A significant decrease (p < 0.001) in all obstruction parameters was noted. Mean detrusor pressure at maximum flow decreased from 64.7 to 39.1 cm. water, urethral resistance factor from 41.8 to 23.5 cm. water and linear passive urethral resistance relation from 3.0 to 1.4. Analysis of subgroups showed better results in patients with greater degrees of obstruction. CONCLUSIONS: High energy thermotherapy results in a significant and substantial decrease in bladder outlet obstruction.

Aged↗
PubMed2000

Retinal vascular changes associated with transpupillary thermotherapy for choroidal melanomas.

PURPOSE: To define retinal vascular changes after transpupillary thermotherapy (TTT) for choroidal melanomas and assess their clinical impact. METHODS: Stereoscopic fluorescein angiogram pairs of 29 patients pre- and post-treatment with TTT were examined for patterns of vascular damage, and the patients were studied for ensuing complications. RESULTS: Widespread retinal capillary loss was confined within the treatment margins except in cases of coexisting large retinal artery or vein occlusions. Artery occlusions occurred in 83%, involving a large artery in 23%. Venous occlusions occurred in 69%, involving large veins in 10%. Subretinal choroidal neovascularization occurred in four cases, in one causing hemorrhage that broke through into the vitreous. No retinal neovascularization occurred. Choroidal vasculature was relatively preserved at the periphery of the treated area. Foveal vascular damage caused visual loss in six cases. Vascular changes beyond the treatment margins did not affect the fovea in any case. Retinal fibrosis affected two cases. Diabetic patients fared no worse than healthy counterparts. CONCLUSIONS: Transpupillary thermotherapy produces characteristic retinal vascular changes that may reduce vision when affecting the fovea. Vascular changes are confined within the treatment margins except in cases of associated large vessel occlusion. There is a small risk of neovascularization, both retinal and choroidal.

Adult↗
PubMed1998

Quantification of the 3-D electromagnetic power absorption rate in tissue during transurethral prostatic microwave thermotherapy using heat transfer model.

Experiments were performed in a tissue microwave-equivalent phantom gel to quantitatively examine the volumetric heating produced by a microwave antenna with a peripheral cooling system for the transurethral prostatic thermotherapy. Based on previous research, expression for the specific absorption rate (SAR) of microwave energy in the gel was extended to three dimensions, which includes its dependence on radial, angular, and axial direction. A theoretical heat transfer model was developed to study the temperature distribution in the gel by introducing this proposed SAR expression. The parameters in this expression and the convection coefficient due to the chilled water running around the antenna were determined using a least-square residual fit of the theoretical temperature predictions to the experimentally measured steady-state temperature field within the gel. The analytical expression of the three-dimensional SAR distribution obtained in this study will help provide a better understanding of the microwave heating pattern in the prostatic tissue and, thus, to aid in designing improved applicators. It can also be used in the future as an accurate input to heat transfer models which predict temperature distributions during the transurethral microwave thermotherapy.

Gels↗
PubMed1996

Pros-Eight transurethral radiofrequency thermotherapy for benign prostatic hyperplasia: preliminary clinical results.

BACKGROUND: We have developed a new transurethral thermotherapy device using 8MHz radiofrequency (RF) for the treatment of patients with symptomatic benign prostatic hyperplasia (BPH). We report the safety and effectiveness of the initial clinical experience with this device. METHODS: Sixty patients with symptomatic BPH were subjected to a single 1-hour treatment under local anesthesia. The treatment device uses extracorporeal RF capacitive heating in combination with radiative heating and conductive cooling of the urethra. RESULTS: In the 49 patients evaluable at 3 months, the mean International Prostate Symptom Score decreased from 17.8 to 13.1 (P < 0.0001) and the Quality of Life score decreased from 4.4 to 3.4 (P < 0.0005). Maximum flow rate increased from 8.1 to 9.7 mL/s (P < 0.05) at 3 months. Overall effectiveness by Homma's response criteria was as follows; excellent 4.1%, good 10.2%, fair 38.8% and poor 46.9%. Side effects were minimal. Gross hematuria was seen in 3 patients and erosion of the external urethral meatus was seen in 2 patients, but none had urinary retention. CONCLUSIONS: In this initial clinical trial, transurethral RF thermotherapy was safe and resulted in modest symptomatic improvement. Further investigations for optimizing the treatment protocol seem warranted.

Aged↗