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1.
Langenbecks Arch Surg ; 402(4): 637-644, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28012035

RESUMEN

OBJECTIVES: To evaluate the safety and feasibility of sorafenib prior to surgery for downsizing tumors in patients with non-metastatic cT1-3 renal tumors together with a characterization of functional intratumoral heterogeneity (ITH). MATERIALS AND METHODS: The effects of 4-week sorafenib prior to curative surgery were assessed in a prospective, single-center, randomized, placebo-controlled, double-blinded, pilot trial in patients with T1-3N0M0 renal cell carcinoma (RCC). Patients received sorafenib or placebo for 28 days prior to surgery. MRI was performed at baseline and prior to surgery to calculate tumor volume. The clinical responses were further characterized on the molecular level by immunohistochemical stainings for Ki-67, cleaved caspase-3, and CD31. RESULTS: After enrolling 20 patients into the study, 14 patients were randomized, of which 12 patients were available for analysis. While no significant change in tumor volume was seen for placebo (range = -24.2-0.2%) a reduction of 29.0% (range = -4.9-61.1%) was detected for sorafenib (p < 0.05). Primary renal tumor diameter changed from 10.6 cm (range = 6.5-10.8) to 10.7 cm (range = 6.7-11.1) in the placebo group, and from 5.4 cm (range = 4.3-7.3) to 4.4 cm (range = 3.5-6.8) for the sorafenib group, at baseline vs. 28 days of treatment. Correlative assessment of proliferation, apoptosis, and microvessel density revealed an enhanced degree of functional ITH in treated patients suggesting adaptive and/or regenerative processes with potential relevance for the development of drug resistance. CONCLUSIONS: Sorafenib in standard dosage, given preoperatively for 28 days, was clinically active in downsizing tumors in patients with locally confined, non-metastatic RCC together but led to an enhanced functional ITH in the residual tumor tissue.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/cirugía , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/patología , Niacinamida/análogos & derivados , Compuestos de Fenilurea/uso terapéutico , Adulto , Anciano , Carcinoma de Células Renales/patología , Método Doble Ciego , Femenino , Hepatectomía , Humanos , Neoplasias Renales/cirugía , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Niacinamida/uso terapéutico , Proyectos Piloto , Estudios Prospectivos , Sorafenib , Resultado del Tratamiento
2.
Scand J Urol ; 50(4): 313-8, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27125534

RESUMEN

OBJECTIVE: The aim of this retrospective cohort study was to investigate long-term risk factors for reintervention after photoselective vaporization of the prostate (PVP). MATERIAL AND METHODS: In total, 566 consecutive patients with benign prostatic hyperplasia (BPH) underwent PVP between February 2005 and April 2011. Mean follow-up was 36.42 ± 21.4 months. Perioperative parameters were evaluated, including surgery time, delivered energy, catheterization and duration of hospitalization, intraoperative and postoperative complications, as well as reintervention rates in manifest reobstruction. Follow-up comprised the International Prostate Symptom Score and quality of life questionnaire (IPPS-QoL), maximal flow rate (Qmax) and postvoiding residual volume (PVR). RESULTS: Mean operation time was 69.8 ± 29.3 min. Mean catheterization and hospitalization times were 1.49 ± 1.19 days and 2.67 ± 2.19 days, respectively. There was ongoing oral anticoagulation for 20.1% of the patients (n = 114). The overall retreatment rate was 17.6% (101 out of 566 patients) after a mean time of 9.21 months (range 0-64 months). Of these, 88 patients (15.55%) had a reobstruction and 13 (2.3%) had urethral strictures. In multivariate analysis, age, prostate volume, total applied energy, specific laser energy usage, preoperative symptomatic (IPSS/QoL) and functional obstruction grade (Qmax/PVR) were not identified as risk factors for reintervention. A poor postoperative Qmax (< 15 ml/s) measured immediately after removal of the transurethral catheter was identified as a risk factor for undergoing a reintervention (p = 0.005). CONCLUSIONS: PVP is an effective method for BPH treatment, allowing for sustained long-term improvement of the voiding function. Poor immediate postoperative urinary flow after removal of the transurethral catheter (Qmax < 15 ml/s) is a significant risk factor for reintervention.


Asunto(s)
Hiperplasia Prostática/cirugía , Resección Transuretral de la Próstata , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
3.
Eur Urol ; 70(3): 447-55, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26777228

RESUMEN

BACKGROUND: Magnetic resonance imaging-guided transurethral ultrasound ablation (MRI-TULSA) is a novel minimally invasive technology for ablating prostate tissue, potentially offering good disease control of localized cancer and low morbidity. OBJECTIVE: To determine the clinical safety and feasibility of MRI-TULSA for whole-gland prostate ablation in a primary treatment setting of localized prostate cancer (PCa). DESIGN, SETTING, AND PARTICIPANTS: A single-arm prospective phase 1 study was performed at three tertiary referral centers in Canada, Germany, and the United States. Thirty patients (median age: 69 yr; interquartile range [IQR]: 67-71 yr) with biopsy-proven low-risk (80%) and intermediate-risk (20%) PCa were treated and followed for 12 mo. INTERVENTION: MRI-TULSA treatment was delivered with the therapeutic intent of conservative whole-gland ablation including 3-mm safety margins and 10% residual viable prostate expected around the capsule. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary end points were safety (adverse events) and feasibility (technical accuracy and precision of conformal thermal ablation). Exploratory outcomes included quality of life, prostate-specific antigen (PSA), and biopsy at 12 mo. RESULTS AND LIMITATIONS: Median treatment time was 36min (IQR: 26-44) and prostate volume was 44ml (IQR: 38-48). Spatial control of thermal ablation was ±1.3mm on MRI thermometry. Common Terminology Criteria for Adverse Events included hematuria (43% grade [G] 1; 6.7% G2), urinary tract infections (33% G2), acute urinary retention (10% G1; 17% G2), and epididymitis (3.3% G3). There were no rectal injuries. Median pretreatment International Prostate Symptom Score 8 (IQR: 5-13) returned to 6 (IQR: 4-10) at 3 mo (mean change: -2; 95% confidence interval [CI], -4 to 1). Median pretreatment International Index of Erectile Function 13 (IQR: 6-28) recovered to 13 (IQR: 5-25) at 12 mo (mean change: -1; 95% CI, -5 to 3). Median PSA decreased 87% at 1 mo and was stable at 0.8 ng/ml (IQR: 0.6-1.1) to 12 mo. Positive biopsies showed 61% reduction in total cancer length, clinically significant disease in 9 of 29 patients (31%; 95% CI, 15-51), and any disease in 16 of 29 patients (55%; 95% CI, 36-74). CONCLUSIONS: MRI-TULSA was feasible, safe, and technically precise for whole-gland prostate ablation in patients with localized PCa. Phase 1 data are sufficiently compelling to study MRI-TULSA further in a larger prospective trial with reduced safety margins. PATIENT SUMMARY: We used magnetic resonance imaging-guided transurethral ultrasound to heat and ablate the prostate in men with prostate cancer. We showed that the treatment can be targeted within a narrow range (1mm) and has a well-tolerated side effect profile. A larger study is under way. TRIAL REGISTRATION: NCT01686958, DRKS00005311.


Asunto(s)
Ultrasonido Enfocado de Alta Intensidad de Ablación , Neoplasias de la Próstata/cirugía , Resección Transuretral de la Próstata/métodos , Anciano , Anciano de 80 o más Años , Biopsia , Epididimitis/etiología , Disfunción Eréctil/etiología , Estudios de Factibilidad , Hematuria/etiología , Ultrasonido Enfocado de Alta Intensidad de Ablación/efectos adversos , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tempo Operativo , Erección Peniana , Estudios Prospectivos , Próstata/patología , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/patología , Calidad de Vida , Recuperación de la Función , Cirugía Asistida por Computador , Evaluación de Síntomas , Resección Transuretral de la Próstata/efectos adversos , Retención Urinaria/etiología , Infecciones Urinarias/etiología
4.
Eur Urol ; 69(1): 94-102, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26283011

RESUMEN

BACKGROUND: The GOLIATH study is a 2-yr trial comparing transurethral resection of prostate (TURP) to photoselective vaporization with the GreenLight XPS Laser System (GL-XPS) for the treatment of benign prostatic obstruction (BPO). Noninferiority of GL-XPS to TURP was demonstrated based on a 6-mo follow-up from the study. OBJECTIVE: To determine whether treatment effects observed at 6 mo between GL-XPS and TURP was maintained at the 2-yr follow-up. DESIGN, SETTING, AND PARTICIPANTS: Prospective randomized controlled trial at 29 centers in nine European countries involving 281 patients with BPO. INTERVENTION: Photoselective vaporization using the 180-W GreenLight GL-XPS or conventional (monopolar or bipolar) TURP. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was the International Prostate Symptom Score for which a margin of three was used to evaluate the noninferiority of GL-XPS. Secondary outcomes included Qmax, prostate volume, prostate specific antigen, Overactive Bladder Questionnaire Short Form, International Consultation on Incontinence Questionnaire Short Form, occurrence of surgical retreatment, and freedom from complications. RESULTS AND LIMITATIONS: One hundred and thirty-six patients were treated using GL-XPS and 133 using TURP. Noninferiority of GL-XPS on International Prostate Symptom Score, Qmax, and freedom from complications was demonstrated at 6-mo and was sustained at 2-yr. The proportion of patients complication-free through 24-mo was 83.6% GL-XPS versus 78.9% TURP. Reductions in prostate volume and prostate specific antigen were similar in both arms and sustained over the course of the trial. Compared with the 1(st) yr of the study, very few adverse events or retreatments were reported in either arm. Treatment differences in the Overactive Bladder Questionnaire Short Form observed at 12-mo were not statistically significant at 24-mo. A limitation was that patients and treating physicians were not blinded to the therapy. CONCLUSIONS: Twenty-four-mo follow-up data demonstrated that GL-XPS provides a durable surgical option for the treatment of BPO that exhibits efficacy and safety outcomes similar to TURP. PATIENT SUMMARY: The long-term effectiveness and safety of GLP-XLS was similar to conventional TURP for the treatment of prostate enlargement.


Asunto(s)
Láseres de Estado Sólido/uso terapéutico , Próstata/patología , Hiperplasia Prostática/cirugía , Resección Transuretral de la Próstata/métodos , Estudios de Seguimiento , Humanos , Láseres de Estado Sólido/efectos adversos , Masculino , Tamaño de los Órganos , Satisfacción del Paciente , Estudios Prospectivos , Antígeno Prostático Específico/sangre , Hiperplasia Prostática/sangre , Hiperplasia Prostática/patología , Calidad de Vida , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Resección Transuretral de la Próstata/efectos adversos , Resultado del Tratamiento , Incontinencia Urinaria/etiología
5.
J Endourol ; 29(12): 1396-405, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26154571

RESUMEN

PURPOSE: To investigate the value of multiparametric magnetic resonance imaging (mpMRI) and to predict extracapsular extension (ECE), seminal vesicle (SV) infiltration, and a negative surgical margin (SM) status at radical prostatectomy (RP) for different prostate cancer (PC) risk groups. PATIENTS AND METHODS: In the study, 805 men underwent 3 tesla mpMRI without endorectal coil before MRI/transrectal ultrasonography-fusion guided prostate biopsy. MRIs were analyzed using the prostate imaging reporting and data system. The cohort was classified into risk groups according to National Comprehensive Cancer Network (NCCN) criteria. Of 132 men who subsequently underwent RP, pathologic stage and SM status at RP were used as reference. Retrospectively, we investigated a European Society of Urogenital Radiology (ESUR) score for ECE and SV-infiltration. Statistical analyses included regression analyses, receiver operating characteristics (ROC), and Youden Index to assess an ESUR-score cutoff. RESULTS: Area under the curve in ROC curve analyses was 0.82 for ESUR-ECE score to detect pT(3a)-disease and 0.77 for ESUR-SV score for pT(3b). Using a cutoff of 4 for ECE and of 2 for SV, the positive predictive value of the ECE-score for harboring pT(3) was 50.0%, 90.0%, and 88.8% for the low-, intermediate- and high-risk cohort. Retrospectively, the use of the ESUR-ECE score preoperatively would have changed the initial surgical plan, according to NCCN criteria, in 31.1% of patients. In the high-risk subgroup, 9/35 (25.7%) patients were correctly assessed as not harboring pT(3) by imaging (ECE score <4), and would have allowed secure robot-assisted radical prostatectomy and nerve-sparing surgery (NSS). When T3 suspicion on preoperative MRI would be taken into account, intraoperative frozen-sections (IFS) might avoid positive SM in 12/18 high-risk patients and an oncologic secure NSS in 8/20 intermediate-risk patients. CONCLUSION: Prediction of pT(3) disease is crucial to plan NSS and to achieve negative SM in RP. Standardized ECE scoring on mpMRI is an independent predictor of pT(3) and may help to plan RP with oncologic security, even in high-risk patients. In addition, it allows more accurate selection of a subgroup of patients for systematic and MRI-guided IFS.


Asunto(s)
Imagen por Resonancia Magnética , Prostatectomía/métodos , Neoplasias de la Próstata/diagnóstico , Vesículas Seminales/patología , Anciano , Biopsia , Estudios de Cohortes , Secciones por Congelación , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Neoplasia Residual , Tamaño de los Órganos , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Curva ROC , Análisis de Regresión , Estudios Retrospectivos , Medición de Riesgo , Resultado del Tratamiento
6.
Eur Urol ; 68(5): 837-47, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25952317

RESUMEN

BACKGROUND: Understanding how to sequence targeted therapies for metastatic renal cell carcinoma (mRCC) is important for maximisation of clinical benefit. OBJECTIVES: To prospectively evaluate sequential use of the multikinase inhibitors sorafenib followed by sunitinib (So-Su) versus sunitinib followed by sorafenib (Su-So) in patients with mRCC. DESIGN, SETTING, AND PARTICIPANTS: The multicentre, randomised, open-label, phase 3 SWITCH study assessed So-Su versus Su-So in patients with mRCC without prior systemic therapy, and stratified by Memorial Sloan Kettering Cancer Center risk score (favourable or intermediate). INTERVENTION: Patients were randomised to sorafenib 400mg twice daily followed, on progression or intolerable toxicity, by sunitinib 50mg once daily (4 wk on, 2 wk off) (So-Su), or vice versa (Su-So). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was improvement in progression-free survival (PFS) with So-Su versus Su-So, assessed from randomisation to progression or death during second-line therapy. Secondary endpoints included overall survival (OS) and safety. RESULTS AND LIMITATIONS: In total, 365 patients were randomised (So-Su, n=182; Su-So, n=183). There was no significant difference in total PFS between So-Su and Su-So (median 12.5 vs 14.9 mo; hazard ratio [HR] 1.01; 90% confidence interval [CI] 0.81-1.27; p=0.5 for superiority). OS was similar for So-Su and Su-So (median 31.5 and 30.2 mo; HR 1.00, 90% CI 0.77-1.30; p=0.5 for superiority). More So-Su patients than Su-So patients reached protocol-defined second-line therapy (57% vs 42%). Overall, adverse event rates were generally similar between the treatment arms. The most frequent any-grade treatment-emergent first-line adverse events were diarrhoea (54%) and hand-foot skin reaction (39%) for sorafenib; and diarrhoea (40%) and fatigue (40%) for sunitinib. CONCLUSIONS: Total PFS was not superior with So-Su versus Su-So. These results demonstrate that sorafenib followed by sunitinib and vice versa provide similar clinical benefit in mRCC. PATIENT SUMMARY: We investigated if total progression-free survival (PFS) is improved in patients with advanced/metastatic kidney cancer who are treated with sorafenib and then with sunitinib (So-Su), compared with sunitinib and then sorafenib (Su-So). We found that total PFS was not improved with So-Su compared with Su-So, but both treatment options were similarly effective in patients with advanced/metastatic kidney cancer. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00732914, www.clinicaltrials.gov.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Encefálicas/tratamiento farmacológico , Carcinoma de Células Renales/tratamiento farmacológico , Indoles/administración & dosificación , Neoplasias Renales/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Niacinamida/análogos & derivados , Compuestos de Fenilurea/administración & dosificación , Pirroles/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Óseas/secundario , Neoplasias Encefálicas/secundario , Carcinoma de Células Renales/secundario , Supervivencia sin Enfermedad , Femenino , Humanos , Neoplasias Renales/patología , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/secundario , Ganglios Linfáticos/patología , Masculino , Persona de Mediana Edad , Niacinamida/administración & dosificación , Modelos de Riesgos Proporcionales , Sorafenib , Sunitinib
7.
J Urol ; 193(2): 570-8, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25219699

RESUMEN

PURPOSE: We present the 1-year results of the GOLIATH prospective randomized controlled trial comparing transurethral resection of the prostate to GreenLight XPS for the treatment of men with nonneurogenic lower urinary tract symptoms due to prostate enlargement. The updated results at 1 year show that transurethral resection of the prostate and GreenLight XPS remain equivalent, and confirm the therapeutic durability of both procedures. We also report 1-year followup data from several functional questionnaires (OABq-SF, ICIQ-SF and IIEF-5) and objective assessments. MATERIALS AND METHODS: A total of 291 patients were enrolled at 29 sites in 9 European countries. Patients were randomized 1:1 to undergo GreenLight XPS or transurethral resection of the prostate. The trial was designed to evaluate the hypothesis that GreenLight XPS is noninferior to transurethral resection of the prostate on the International Prostate Symptom Score at 6 months. Several objective parameters were assessed, including maximum urinary flow rate, post-void residual urine volume, prostate volume and prostate specific antigen, in addition to functional questionnaires and adverse events at each followup. RESULTS: Of the 291 enrolled patients 281 were randomized and 269 received treatment. Noninferiority of GreenLight XPS was maintained at 12 months. Maximum urinary flow rate, post-void residual urine volume, prostate volume and prostate specific antigen were not statistically different between the treatment arms at 12 months. The complication-free rate at 1 year was 84.6% after GreenLight XPS vs 80.5% after transurethral resection of the prostate. At 12 months 4 patients treated with GreenLight XPS and 4 who underwent transurethral resection of the prostate had unresolved urinary incontinence. CONCLUSIONS: Followup at 1 year demonstrated that photoselective vaporization of the prostate produced efficacy outcomes similar to those of transurethral resection of the prostate. The complication-free rates and overall reintervention rates were comparable between the treatment groups.


Asunto(s)
Síntomas del Sistema Urinario Inferior/cirugía , Hiperplasia Prostática/cirugía , Resección Transuretral de la Próstata/métodos , Obstrucción del Cuello de la Vejiga Urinaria/cirugía , Humanos , Síntomas del Sistema Urinario Inferior/etiología , Masculino , Estudios Prospectivos , Hiperplasia Prostática/complicaciones , Factores de Tiempo , Resultado del Tratamiento , Obstrucción del Cuello de la Vejiga Urinaria/etiología
8.
J Urol ; 190(4): 1380-6, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23608676

RESUMEN

PURPOSE: Diagnosis and precise risk stratification of prostate cancer is essential for individualized treatment decisions. Magnetic resonance imaging/transrectal ultrasound fusion has shown encouraging results for detecting clinically significant prostate cancer. We critically evaluated magnetic resonance imaging targeted, transrectal ultrasound guided transperineal fusion biopsy in routine clinical practice. MATERIALS AND METHODS: Included in this prospective study were 347 consecutive patients with findings suspicious for prostate cancer. Median age was 65 years (range 42 to 84) and mean prostate specific antigen was 9.85 ng/ml (range 0.5 to 104). Of the men 49% previously underwent transrectal ultrasound guided biopsies, which were negative, and 51% underwent primary biopsy. In all patients 3 Tesla multiparametric magnetic resonance imaging was done. Systematic stereotactic prostate biopsies plus magnetic resonance imaging targeted, transrectal ultrasound guided biopsies were performed in those with abnormalities on magnetic resonance imaging. Imaging data and biopsy results were analyzed. A self-designed questionnaire was sent to all men on further clinical history and biopsy adverse effects. RESULTS: Of 347 patients biopsy samples of 200 (58%) showed prostate cancer and 73.5% of biopsy proven prostate cancer were clinically relevant according to National Comprehensive Cancer Network (NCCN) criteria. On multiparametric magnetic resonance imaging 104 men had findings highly suspicious for prostate cancer. The tumor detection rate was 82.6% (86 of 104 men) with a Gleason score of 7 or greater in 72%. Overall targeted cores detected significantly more cancer than systematic biopsies (30% vs 8.2%). Of 94 patients without cancer suspicious lesions on magnetic resonance imaging 11 (11.7%) were diagnosed with intermediate risk disease. Regarding adverse effects, 152 of 300 patients (50.6%) reported mild hematuria, 26% had temporary erectile dysfunction and 2.6% needed short-term catheterization after biopsy. Nonseptic febrile urinary tract infections developed in 3 patients (1%). CONCLUSIONS: Magnetic resonance imaging targeted, transrectal ultrasound guided transperineal fusion biopsy provides high detection of clinically significant tumors. Since multiparametric magnetic resonance imaging still has some limitations, systematic biopsies should currently not be omitted. The morbidity of the transperineal saturation approach is reasonable and mainly self-limiting.


Asunto(s)
Biopsia Guiada por Imagen , Neoplasias de la Próstata/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja/métodos , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Perineo , Estudios Prospectivos , Neoplasias de la Próstata/diagnóstico por imagen , Recto , Ultrasonografía Intervencional
9.
Magn Reson Imaging ; 21(5): 545-51, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12878265

RESUMEN

Regional hyperthermia in combination with chemotherapy and/or radiotherapy has proven to be an effective treatment concept for locally advanced deep-seated tumors. Simultaneous MR-imaging could be a promising approach for therapy optimization. Purpose of this study was the in vivo investigation of temperature induced longitudinal relaxation time (T(1)) and blood flow changes in a tumor model. Using a 1.5 Tesla MR system, the T(1) sensitivity on temperature and the onset of tissue changes at temperatures >44 degrees C were investigated in muscle samples. Also, fourteen Syrian Golden Hamsters with amelanotic melanoma A-MEL-3 were examined during heating of the tumors. Temperature induced blood flow and T(1) changes were determined continuously during hyperthermia. Changes of T(1) correlated linearly with temperature over a wide range (27-44 degrees C) in the tissue sample. Tissue changes became notable above 44 degrees C. In the tumor model, relative changes of T(1) (unlike blood flow) showed linear correlation with temperature over the entire range of hyperthermia relevant temperatures (32-44 degrees C). For a low thermal dose, T(1) allows the assessment of temperature changes in tumors in vivo. At higher thermal doses, in addition to temperature changes, T(1) also shows tissue changes. Both temperature and tissue changes supply important information for hyperthermia.


Asunto(s)
Hipertermia Inducida , Imagen por Resonancia Magnética , Melanoma Amelanótico/irrigación sanguínea , Melanoma Experimental/irrigación sanguínea , Animales , Cricetinae , Masculino , Mesocricetus , Músculo Esquelético/irrigación sanguínea
10.
J Hepatol ; 38(4): 476-82, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12663240

RESUMEN

BACKGROUND/AIMS: 5-Aminolevulinic acid (ALA), a precursor of porphyrins is used for photodynamic diagnosis and therapy within topical or systemic applications. A potential toxic effect on the human liver is of major interest and therefore we investigated the impact of a repeated application of ALA without illumination on cultures of human hepatocytes. METHODS: After ALA treatment of hepatocytes in vitro the porphyrin synthesis, albumin secretion, liver-specific enzyme release, and malondialdehyde levels were determined. In order to reduce levels of reactive oxygen substances, mannitol and the antioxidant enzymes superoxide dismutase and catalase were supplemented. RESULTS: Porphyrin biosynthesis by human hepatocytes in vitro was repeatedly stimulated by ALA (0.001-1.0 mM), which was indicated by an accumulation of protoporphyrin IX. A repetitive treatment (up to four times) of hepatocytes with ALA resulted in an impairment of the hepatic function and viability, depending on the ALA concentration (0.1-1.0 mM) and frequency of application (2-3 times). This was also accompanied by increased malondialdehyde levels indicating enhanced lipid peroxidation. Only superoxide dismutase was able to reduce cellular damage and prevent specific function. CONCLUSIONS: Repeated, not single, ALA treatment without illumination may cause deleterious effects to the liver, which are mediated by oxygen radicals and inhibited by an antioxidant.


Asunto(s)
Ácido Aminolevulínico/farmacología , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Fármacos Fotosensibilizantes/farmacología , Antioxidantes/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Hepatocitos/citología , Humanos , Técnicas In Vitro , Peroxidación de Lípido/efectos de los fármacos , Masculino , Porfirinas/biosíntesis , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/farmacología
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