Analysis of the Macular Region Following Panretinal Photocoagulation for the Treatment of Diabetic Retinopathy Using Optical Coherence Tomography.

Background: Diabetic retinopathy (DR) is the most prevalent microvascular complication of diabetes. Panretinal photocoagulation (PRP) is the established treatment for mitigating severe visual impairment resulting from proliferative DR. Objective: This study aims to investigate the impact of PRP on the macular region in patients with DR, utilizing optical coherence tomography (OCT) for assessment. Design: An experimental study was meticulously designed, implementing PRP as the primary intervention. Setting: The investigation was conducted within the Department of Ophthalmology at the Affiliated Huaian No.1 People's Hospital, Huai'an, Jiangsu, China. Participants: A total of 120 participants diagnosed with DR and undergoing treatment at our hospital were enrolled in the study. Interventions: The participants were randomly assigned to either the control group (CG, n = 60) or the study group (SG, n = 60). The CG received conventional drug treatment involving oral iodized lecithin, while the SG received PRP. OCT was employed to monitor changes in macular fovea volume and macular retinal thickness. Primary Outcome Measures: Evaluation criteria encompassed clinical efficacy, macular fovea volume, macular retinal thickness, IL-6 and VEGF levels, incidence of adverse reactions, and quality of life in both groups. Results: The study resulted in a higher total effective rate in the SG (96.67%) compared to the CG (80.00%) (χ2 = 8.09, P < .05). Post-treatment, reductions were observed in macular fovea volume and macular retinal thickness, with significantly lower SG values than CG values (P < .05). Both serum IL-6 and VEGF levels exhibited reductions in both groups after treatment, with the SG displaying a more significant decrease compared to the CG (P < .05). The occurrence of adverse reactions significantly decreased in the SG relative to the CG (P < .05). Quality of life scores for the SG was notably elevated compared to the CG (P < .05). Conclusions: PRP emerges as a highly valuable approach in the management of DR. It contributes to retinal thickness improvement within the macular region and inflammation reduction, and also enhances therapeutic outcomes, minimizes adverse reactions, and optimizes patients' quality of life. These findings warrant further clinical adoption and widespread promotion.

Diabetic retinopathy screening and treatment through the Brazilian National Health Insurance.

The current study aimed to investigate diabetic retinopathy (DR) screening and treatment coverages among diabetic patients evaluated through the Brazilian National Health Insurance from 2014 to 2019. The Brazilian Public Health System Information Database was used as the primary data source. DR screening coverage was calculated as the rate of procedures of clinical dilated fundus exam and color fundus photograph over the number of diabetic patients. DR treatment coverage was calculated as the rate of procedures of intravitreal injection, photocoagulation, and panretinal photocoagulation over the number of diabetic patients presumably in need of DR treatment. The overall screening coverage increased from 12.1% in 2014 to 21.2% in 2019 (p < 0.001) with substantial regional discrepancies so that North region was the only one with no changes along the period. The overall treatment coverage increased from 27.7% in 2014 to 44.1% in 2019, with Southeast and Midwest absorbing the demand for service from the North, Northeast and South. Despite an improvement along the past years, both screening and treatment coverages for DR in diabetes patients are ineffective in Brazil. Public health policies should address resources disparities throughout the country aiming to offer same healthcare conditions to patients regardless their geographic location.

Efficacy and safety of qiming granule combined with laser in the treatment of diabetic retinopathy: A protocol of randomized controlled trial.

BACKGROUND: Diabetic retinopathy is not only the most common complication of diabetes, but also 1 of the main causes of blindness, which seriously affects the physical and mental health of patients. Panretinal photocoagulation is a common method for the treatment of diabetic retinopathy, but it has some defects. Qiming granule has advantages in the treatment of diabetic retinopathy, but there is a lack of standard clinical research to verify it. Therefore, the purpose of this randomized controlled trial is to evaluate the efficacy and safety of qiming granule combined with laser in the treatment of diabetic retinopathy. METHODS: This is a prospective randomized controlled trial to study the efficacy and safety of Qiming granule combined with laser in the treatment of diabetic retinopathy. Approved by the Clinical Research Society of our hospital. The patients are randomly divided into a treatment group (Qiming granule combined with laser treatment group) or control group (simple laser treatment group). The patients are followed up for 12 months after 6 months of treatment. Observation indexes include total effective rate, corrected visual acuity, macular fovea thickness, adverse reactions and so on. Data are analyzed using the statistical software package SPSS version 18.0 (Chicago, IL). DISCUSSION: This study will evaluate the clinical efficacy and safety of qiming granule combined with laser in the treatment of diabetic retinopathy. The experimental results of this study will provide a reliable reference basis for clinical use of qiming granule combined with laser in the treatment of diabetic retinopathy. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/ZEQPB.

Laser interstitial thermotherapy (LiTT) in pediatric epilepsy surgery.

Laser interstitial thermotherapy (LiTT) is a novel stereotactic approach to the surgical treatment of severe drug-resistant focal epilepsies. This review extends our recent general review on this topic (Hoppe et al. Laser interstitial thermotherapy [LiTT] in epilepsy surgery. Seizure 2017; 48:45-52) with a focus on children (age <18 years). A PubMed search retrieved 25 uncontrolled case series reports that included a total of 179 pediatric patients as well as 7 review papers that specifically referred to using LiTT in pediatric epilepsy surgery (due August 31, 2018). Hypothalamic hamartomas (HH) represented the most frequent indication (64.2%) while therapeutic evidence for other more frequent etiologies underlying severe focal childhood epilepsies (e.g. focal cortical dysplasia, mesiotemporal sclerosis) is still scarce (n<20). For the published cases, the rate of severe complications was 3.4% and the overall complication rate was 23.5%. The seizure freedom rate (Engel class 1) was 57.5% (including patients with early follow-up and repeat thermoablations). None of the studies included the systematic evaluation of the cognitive outcome. Overall, the published evidence does not yet allow a scientific or clinical judgement on the utility of LiTT for pediatric epilepsy surgery. LiTT is likely to extend the neurosurgical toolbox with regard to deep brain lesions (e.g. HH). However, in cases that are equally accessible for both approaches therapeutic superiority of LiTT over open resective surgery still remains to be demonstrated. Recommendations for controlled though non-randomized outcome studies are provided.

Attenuation of choroidal neovascularization by dietary intake of ω-3 long-chain polyunsaturated fatty acids and lutein in mice.

Dietary ω-3 long-chain polyunsaturated fatty acids (LCPUFAs) and lutein each protect against age-related macular degeneration (AMD). We here examined the effects of ω-3 LCPUFAs and lutein supplementation in a mouse model of AMD. Mice were assigned to four groups: (1) a control group fed an ω-3 LCPUFA-free diet, (2) a lutein group fed an ω-3 LCPUFA-free diet with oral administration of lutein, (3) an ω-3 group fed an ω-3 LCPUFA-supplemented diet, and (4) an ω-3 + lutein group fed an ω-3 LCPUFA-supplemented diet with oral administration of lutein. Mice were fed the defined diets beginning 2 weeks before, and received lutein with an oral gavage needle beginning 1 week before, induction of choroidal neovascularization (CNV) by laser photocoagulation. The area of CNV measured in choroidal flat-mount preparations was significantly reduced in mice fed ω-3 LCPUFAs or lutein compared with those in the control group, and it was reduced in an additive manner in those receiving both ω-3 LCPUFAs and lutein. The concentrations of various inflammatory mediators in the retina or choroid were reduced in mice fed ω-3 LCPUFAs or lutein, but no additive effect was apparent. The generation of reactive oxygen species (ROS) in chorioretinal lesions revealed by dihydroethidium staining as well as the expression of NADPH oxidase 4 (Nox4) in the retina revealed by immunohistofluorescence and immunoblot analyses were attenuated by ω-3 LCPUFAs and lutein in a synergistic manner. Our results thus show that dietary intake of ω-3 LCPUFAs and lutein attenuated CNV in an additive manner and in association with suppression of inflammatory mediator production, ROS generation, and Nox4 expression. Dietary supplementation with both ω-3 LCPUFAs and lutein warrants further study as a means to protect against AMD.

GreenLight Laser for benign prostatic hyperplasia.

PURPOSE OF REVIEW: GreenLight photoselective vaporization (GL-PV) is now established in the treatment of benign prostatic enlargement. The present review outlines the available technical armamentarium and summarizes the current best evidence on functional and safety outcomes. Moreover, future technical developments and refinements are presented. RECENT FINDINGS: GL-PV has evolved to be the most commonly performed procedure, second to conventional transurethral resection of the prostate (TURP) for surgical management of benign prostatic obstruction (BPO). On the basis of the data published in the randomized controlled Goliath study, GL-PV with 180-W technology is noninferior in terms of functional outcomes compared with TURP considering short and intermediate follow-up with a complication-free rate of around 80% after 24 months.The ongoing push towards high-power lasers can be explained by their more effective tissue ablative effect, leading to shorter operating times. Comparative analysis between high-power and low-power laser systems demonstrated similar retreatment rates and most institutions are, therefore, now performing 180-W GL-PV.Performed as an outpatient procedure, GL-PV is cost-effective with a low hospital re-admission rate. Plasma kinetic vaporization of the prostate (PKVP) has recently emerged as a potential contender in the field; also GreenLight enucleation of the prostate (GreenLEP) might be even more effective than GL-PV. SUMMARY: GL-PV appears to be a well tolerated surgical alternative for patients suffering from BPO. Long-term follow-up data from 120-W and 180-W laser systems are still pending. Potential competitors have recently been brought to the market and further trials and long-term data will show, whether GL-PV will stand the test of time. Regardless of technical specifications, surgeon's experience remains essential to achieve good functional and safety outcomes.

Protective effects of Radix Pseudostellariae extract against retinal laser injury.

BACKGROUND: This study aimed to analyze the protective effects of a saponin extract from Radix Pseudostellariae (RP) on retinal laser injury based on a retinal photocoagulation model. METHODS: Fifty-eight rabbits were randomly divided into three groups: Group A (saponin extract orally), Group B (physiological saline), and Group C (control). The animals were sacrificed 1 day, 7 days, 14 days, and 30 days after photocoagulation and lesions were evaluated with fundus photography, light microscopy, and electron microscopy. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured, and expression levels of c-fos and Bax genes were also determined. RESULTS: The lesion sizes in Group A were smaller than in Group B. The levels of SOD in Group B were significantly lower than in groups A and C (P<0.001) at all time points. The MDA levels were significantly lower than in groups B and C (P<0.001) at the 1 month point, while the apoptosis rate of Group A was significantly lower than that of Group B at all time points. The expression levels of the c-fos gene in Group B were significantly higher than that in groups A and C, and expression levels of the Bax gene in Group A were significantly lower than that in groups B and C. CONCLUSION: The saponin extract of RP can inhibit oxidative stress, downregulate the levels of c-fos and Bax gene expression, and inhibit apoptosis in the retina after photocoagulation.

Photoselective vaporization with the green light laser vs transurethral resection of the prostate for treating benign prostate hyperplasia: a systematic review and meta-analysis.

OBJECTIVE: To assess the overall efficacy and safety of photoselective vaporization of the prostate (PVP) vs transurethral resection of the prostate (TURP) for treating patients with lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH). PATIENTS AND METHODS: A systematic search of the electronic databases, including MEDLINE, Embase, Web of Science and The Cochrane Library, as well as manual bibliography searches were performed. The pooled estimates of maximum flow rate (Q(max)), postvoid residual (PVR), quality of life (QoL), International Prostate Symptom Score (IPSS), operation duration, blood loss, catheterization time, hospital stay, capsule perforation, transfusion, transurethral resection (TUR) syndrome, urethral stricture and reintervention were calculated. RESULTS: At the 3-month follow-up, there was no significant difference in Q(max), PVR, QoL and IPSS between the TURP and PVP groups. At the 6-month follow-up, the pooled QoL favoured TURP, but there was no significant difference in the other variables between the two groups. PVP was associated with less blood loss, transfusion, capsular perforation, TUR syndrome, shorter catheterization time and hospital stay, but longer operation duration and higher reintervention rate. CONCLUSIONS: The efficacy of PVP was similar to that of TURP in relation to Q(max), PVR, QoL and IPSS, and it offered several advantages over TURP. As a promising minimal invasive technique, PVP could be used as an alternative surgical procedure for treating BPH.

Study of clinical applications and safety for Pascal® laser photocoagulation in retinal vascular disorders.

PURPOSE: To establish safe laser parameter standards for 10-30 ms Pascal(®) laser in clinical practice and to evaluate clinical and visual outcomes using this 532-nm multi-spot photocoagulation system. METHODS: Retrospective observational case series of 313 patients treated between 2006 and 2008. Evaluation of eight groups: A - panretinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR); B - focal laser treatment for clinically significant diabetic macular oedema; C - grid laser for diffuse diabetic macular oedema; D - sector PRP for ischaemic branch retinal vein occlusions (I-BRVO); E - full PRP for ischaemic central retinal vein occlusions (I-CRVO); F - macular laser treatment for macular oedema secondary to non-ischaemic BRVO; G - full PRP for rubeosis iridis and/or neovascular glaucoma (NVG) secondary to I-BRVO, I - CRVO or PDR; H - laser retinopexy for retinal breaks/degenerations. RESULTS: Mean LogMAR visual acuity for all procedures improved postlaser (p = 0.065), and laser prevented visual loss in 85% eyes. Topical anaesthesia was only required. At mean follow-up of 5 months, 72% procedures had a successful clinical outcome. Significantly higher powers were required for PRP using Pascal(®) compared to conventional laser (p = 0.001) in PDR, I-BRVO, I-CRVO and NVG. Sixty-seven per cent of patients (15/20) were successfully treated with single-session 20-ms PRP using a mean 1952 burns. There were no laser-associated adverse effects or ocular complications associated with multi-spot PRP or macular Pascal(®) arrays. CONCLUSIONS: The clinical efficacy using 10- to 30-ms pulse duration Pascal(®) laser is comparable to conventional standard protocols used for the treatment of vascular retinal disorders. Higher power, 10- to 30-ms pulse duration laser may be safely and effectively used in clinical practice.

Manual acupuncture for relieving pain associated with panretinal photocoagulation.

OBJECTIVE: The feasibility of manual acupuncture for reducing pain associated with panretinal photocoagulation (PRP) was investigated. METHODS: This was a prospective, comparative nonrandomized study on patients with proliferative diabetic retinopathy who were receiving PRP treatment. The protocol of PRP included three sequential sessions of treatment at 2-week intervals. Both the acupuncture (acuPRP) and control groups had no acupuncture in the first session. In the second session, acupuncture was given to the acuPRP group only. The third session of PRP completed the laser treatment course. Acupuncture performed only at GB 37 (Guangmíng) just before PRP, and the needle was removed after the treatment. An 11-point Likert-type verbal pain score test was given to all patients after each PRP treatment. RESULTS: Of 34 patients with proliferative diabetic retinopathy, 18 patients were allocated to the acuPRP group and 16 patients were allocated to the control group. After the first PRP treatment, there was no statistical difference in mean pain scores between the acuPRP and control groups (6.8±1.2 versus 6.3±2.1, respectively, p=0.383). After the second PRP treatment, the mean pain score in the acuPRP group was significantly lower, compared with the control group (3.9±1.8 versus 7.4±1.9, respectively, p<0.0001). Within the group, the mean pain scores were significantly higher during the second PRP treatment, compared with the first PRP treatment, in the control group (p=0.0003). In contrast, the mean pain scores were significantly lower during the second PRP treatment, compared with the first PRP treatment in the acuPRP group (p<0.0001). No adverse reactions or complications were noted. CONCLUSIONS: Acupuncture might help reduce pain during PRP treatment. However, further randomized studies are necessary to verify these preliminary results.

Combination of channel-TURP and ILC versus standard TURP or ILC for elderly with benign prostatic hyperplasia: a randomized prospective trial.

PURPOSE: A prospective randomized controlled trial was performed in elderly patients with benign prostatic hyperplasia (BPH) to evaluate the clinical effectiveness of channel transurethral resection of the prostate (C-TURP) combined with an interstitial laser coagulation (ILC) technique during a 4-year follow-up period. METHODS: A total of 150 consecutive BPH patients were randomized to an ILC+C-TURP group (n = 50), an ILC group (n = 50) and a TURP group (n = 50). Urinary tract infection, acute urinary retention and retrograde ejaculation were monitored, and the retreatment rate, international prostate symptom score (IPSS) and maximum flow rate (Q(max)) were measured. RESULTS: A total of 142 patients completed the follow-up and were recruited for further analysis. At 1 month, the proportion of patients with urinary tract infection was similar between the C-TURP+ILC group and the TURP group (8.5 and 6.5%, p > 0.05), but significantly higher than that in the ILC group (51%, p < 0.001). Acute urinary retention was found in 30.6% of patients in the ILC group, but was not observed in the C-TURP+ILC and TURP groups. In the TURP group, the rate of retrograde ejaculation was significantly higher than that in the other 2 groups (p < 0.001). The retreatment rate was 8.5, 36.7 and 2.2% in the C-TURP+ILC, ILC and TURP groups, respectively (p < 0.001). When compared with baseline, the IPSS in the C-TURP+ILC, ILC and TURP groups was decreased by 70.6, 45.4, and 81.0%, respectively (ILC vs. C-TURP+ILC or TURP, p < 0.01) at the 48-month follow-up. One month after surgery, the Q(max) was significantly increased in the C-TURP+ILC group and the TURP group when compared with that at baseline (p < 0.01). The TURP group had the highest and the ILC group had the lowest increase in the Q(max) at the 12-, 24-, and 48-month follow-ups (p < 0.05). CONCLUSIONS: C-TURP+ILC is a safe and effective modality for the treatment of BPH, and exhibits favorable short-term clinical response and long-term durability. It is relatively reasonable and acceptable for treatment of high-risk elderly patients or those with a limited life expectancy.

[Comparative experimental morphological study of efficacy and safety of near-infrared and visible wave-length laser iridoplasty].

The features of interaction of laser radiation with iris tissue were determined in experimental morphological study. The potential of laser irradiation with different spectral characteristics for pupil ectopia correction is estimated. The results of morphometry showed effectiveness of near-infrared diode laser radiation, that presents as an iris contraction in coagulation region with minimal tissue trauma. This fact allows us to propose a near-infrared diode laser radiation as a treatment option for correction of pupil form and location. Alternatively visible wave-length laser showed to be less effective and more traumatic.

Non-damaging retinal phototherapy: dynamic range of heat shock protein expression.

PURPOSE: Subthreshold retinal phototherapy demonstrated clinical efficacy for the treatment of diabetic macular edema without visible signs of retinal damage. To assess the range of cellular responses to sublethal hyperthermia, expression of the gene encoding a 70 kDa heat shock protein (HSP70) was evaluated after laser irradiation using a transgenic reporter mouse. METHODS: One hundred millisecond, 532 nm laser exposures with 400 µm beam diameter were applied to the retina surrounding the optic nerve in 32 mice. Transcription from the HSP70 promoter was assessed relative to the control eye using a bioluminescence assay at 7 hours after laser application. The retinal pigmented epithelium (RPE) viability threshold was determined with a fluorescence assay. A computational model was developed to estimate temperature and the extent of cell damage. RESULTS: A significant increase in HSP70 transcription was found at exposures over 20 mW, half the threshold power for RPE cell death. Computational modeling estimated peak temperature T = 49°C at HSP70 expression threshold. At RPE viability threshold, T = 57°C. Similar temperatures and damage indices were calculated for clinical subvisible retinal treatment parameters. CONCLUSIONS: Beneficial effects of laser therapy have been previously shown to extend beyond those resulting from destruction of tissue. One hundred millisecond laser exposures at approximately half the threshold power of RPE damage induced transcription of HSP70, an indication of cellular response to sublethal thermal stress. A computational model of retinal hyperthermia can guide further optimization of laser parameters for nondamaging phototherapy.

Low power laser treatment of the retina ameliorates neovascularisation in a transgenic mouse model of retinal neovascularisation.

This study was designed to determine if low power laser therapy can achieve amelioration of vasoproliferation yet preserve useful vision in the treated area in a transgenic mouse model of retinal neovascularisation. The mice were anaesthetised and the pupils dilated for ERG and fundus fluorescein angiography on postnatal day 32. The left eyes were treated with approximately 85 laser spots (532 nm, 50 ms, 300 microm diameter) at a power level of 20 mW at the cornea. The eyes were examined using ERG and fluorescein angiography, one, four and six weeks later. Flat mounts of FITC-dextran infused retinas, retinal histology and PEDF immunohistochemistry was studied one or six weeks after laser treatment. In untreated eyes the expected course of retinal neovascularisation in this model was observed. However, retinal neovascularisation in the laser treated eye was significantly reduced. The laser parameters chosen produced only mild lesions which took 10-20 s to become visible. ERG responses were comparable between the treated and untreated eyes, and histology showed only partial loss of photoreceptors in the treated eyes. PEDF intensity corresponded inversely with the extent of neovascularisation. Low power panretinal photocoagulation can inhibit retinal neovascularisation and yet preserve partial visual function in this transgenic mouse model of retinal neovascularisation.

Effect of diabetic retinopathy and panretinal photocoagulation on retinal nerve fiber layer and optic nerve appearance.

OBJECTIVE: To determine if panretinal photocoagulation (PRP) alters retinal nerve fiber layer (RNFL) thickness and optic nerve appearance. METHODS: Patients with diabetes who did and did not undergo PRP and nondiabetic control subjects were enrolled in a prospective study. Participants underwent optical coherence tomography of the peripapillary retina and optic nerve. Stereoscopic optic nerve photographs were graded in a masked fashion. RESULTS: Ninety-four eyes of 48 healthy individuals, 89 eyes of 55 diabetic patients who did not undergo PRP, and 37 eyes of 24 subjects with diabetes who underwent PRP were included in this study. Eyes that had been treated with PRP had thinner peripapillary RNFL compared with the other groups; this was statistically significantly different in the inferior (P = .004) and nasal (P = .003) regions. Optic nerve cupping did not increase with severity of disease classification, but the proportion of optic nerves graded as suspicious for glaucoma or as having nonglaucomatous optic neuropathy did (P = .008). These grading categories were associated with thinner RNFL measurements. CONCLUSIONS: Diabetic eyes that have been treated with PRP have thinner RNFL than nondiabetic eyes. Optic nerves in eyes treated with PRP are more likely to be graded as abnormal, but their appearance is not necessarily glaucomatous and may be related to thinning of the RNFL.

Macular pigment lutein is antiinflammatory in preventing choroidal neovascularization.

BACKGROUND: Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration, the most common cause of blindness in the developed countries. The aim of the current study was to investigate the effect of lutein supplementation on the development of the murine model of laser-induced CNV together with underlying molecular mechanisms. METHODS AND RESULTS: Mice were orally pretreated with lutein daily from 3 days before laser photocoagulation until the end of the study. The index of CNV volume was significantly suppressed by the treatment with lutein, compared with vehicle-treated animals. Lutein treatment led to significant inhibition of macrophage infiltration into CNV and of the in vivo and in vitro expression of inflammation-related molecules including vascular endothelial growth factor, monocyte chemotactic protein -1, and intercellular adhesion molecule-1. Importantly, lutein suppressed IkappaB-alpha degradation and nuclear translocation of nuclear factor (NF)-kappaB p65 both in vivo and in vitro. Additionally, the development of CNV was significantly suppressed by inhibiting NF-kappaB p65 nuclear translocation, to the levels seen in the lutein treatment. CONCLUSIONS: Lutein treatment led to significant suppression of CNV development together with inflammatory processes including NF-kappaB activation and subsequent upregulation of inflammatory molecules, providing molecular evidence of potential validity of lutein supplementation as a therapeutic strategy to suppress CNV.

Improving laser-induced thermotherapy of liver metastases--effects of arterial microembolization and complete blood flow occlusion.

INTRODUCTION: A prerequisite for an oncologically curative application of laser-induced thermotherapy (LITT) of liver metastases is complete tumor destruction. This increased effectiveness was achieved experimentally by combining LITT with interrupted hepatic perfusion. The aim of this study was to evaluate whether an interventional selective arterial microembolization might be as effective as complete blood flow occlusion using an open Pringle's maneuver. PATIENTS AND METHODS: We included patients with unresectable colorectal liver metastases. LITT was performed without interrupted hepatic perfusion (control group) compared to LITT in combination with interrupted perfusion either by embolization of intraarterial degradable starch microspheres (DSM) (percutaneous access) or by complete hepatic inflow occlusion (Pringle's maneuver; open access). Online monitoring was performed using intraoperative ultrasound or MRI. Volumetric techniques were used to assess metastases and postinterventional lesions. RESULTS: Fifty-six patients with 104 metastases (control group (25), DSM (37), and Pringle (42)) were treated. The preinterventional tumor volumes were significantly smaller than the postinterventional lesion volumes (control group: 9.8 vs. 25.3 cm3; DSM: 9.5 vs. 65.4 cm3; Pringle: 12.9 vs. 76.5 cm3). The morbidity rate was 21.4% without treatment-related mortalities. After 6 months follow-up, tumor recurrence was diagnosed in 6 patients (control group (4), LITT with DSM (1), and Pringle (1)). CONCLUSIONS: Combining LITT with blood flow occlusion leads to a significant increase in lesion size. The application of DSM offers a safe and effective alternative to the open access with Pringle's maneuver. Compared to LITT-monotherapy, this modality achieves significantly larger thermal lesions with the need of fewer applications.

Self-localization of laser induced tumour coagulation limited by heat diffusion through active tissue.

We analyse necrosis growth due to thermal coagulation induced by laser light absorption and limited by heat diffusion into the surrounding live tissue. The tissue is assumed to contain a tumour in the undamaged tissue where the blood perfusion rate does not change during the action. By contrast, normal tissue responds strongly to an increase in the tissue temperature and the blood perfusion rate can grow by tenfold. We study in detail necrosis formation under conditions typical of a real course of thermal therapy treatment. The duration of the treatment is about 5 minutes when a necrosis domain of about 1 cm or above is formed. In particular, if the tumour size is sufficiently large, i.e. it exceeds 1 cm, and the tissue response is not too delayed, i.e. the delay time does not exceed 1 min, then there are conditions under which the relative volume of the damaged normal tissue is small in comparison with the tumour volume after the tumour is totally coagulated.