Interstitial laser thermotherapy (ILT) of breast cancer.

AIM: To find out if ILT can be used as radical treatment of breast cancer. METHOD: Twenty-four patients, aged 39-84 (mean 61), with invasive breast cancer were treated with ILT. All underwent mammography, ultrasound and core biopsy before treatment. The tumour was an invasive ductal carcinoma in 15 patients, a lobular carcinoma in eight and lobular-ductal cancer in one. Average tumour diameter was 14 mm on ultrasound (5-35). Patients were treated in the outpatient clinics under local anaesthesia. Probes were placed under ultrasound guidance, in 19 patients, and ILT was performed with a diode laser at a steady-state temperature of 48 degrees C for 30 min using temperature feedback control. Standard surgical excision was performed 12 (4-23) days after ILT and was preceded by Doppler ultrasound. RESULTS: Treatment-induced necrosis of invasive cancer was 33% (range 0-100) and was complete in three patients. At follow-up before surgery, the extent of laser damage could not be judged with ultrasound, although abolished tumour blood flow was demonstrated after treatment resulting in large necroses. Efficacy of treatment varied negatively with tumour size. The inefficacy of ILT was mainly due to the underestimation of tumour size by mammography and ultrasound and the shortcomings of these methods to demonstrate tumour borders, tumour irregularity and carcinoma in situ (CIS). ILT was well tolerated. Five patients had breast tenderness, and three patients had pain, during the first day after treatment. Small skin necroses were observed in two patients. CONCLUSION: Small breast cancers can be treated radically with ILT. The method may become useful in the treatment of breast cancer but needs further refinement, even for small well-defined breast cancers, if it is going to be employed for radical treatment.

Resistance to tumour challenge after tumour laser thermotherapy is associated with a cellular immune response.

Previous studies in our laboratory have shown that interstitial laser thermotherapy (ILT) of an experimental liver tumour is superior to surgical excision, at least partly due to a laser-induced immunological effect. The aim of the present study was to investigate the time-response relationship of the ILT-induced immunisation and the cellular response of macrophages and lymphocytes. A dimethylhydrazine-induced adenocarcinoma was transplanted into the liver of syngeneic rats. Rats with tumour were treated 6-8 days later (tumour size 0.25-0.40 cm(3)) with ILT of tumour or resection of the tumour-bearing lobe. Two groups of rats without tumour were treated with resection of a normal liver lobe or ILT of normal liver. A challenging tumour was implanted into the liver of each rat 2, 5 or 10 weeks after primary treatment. Rats were killed 6, 12 and 48 days (or earlier due to their condition) after challenge (n = 8 in all groups). Immunohistochemical techniques were used to determine lymphocytes (CD8, CD4) and macrophages (ED1, ED2) in rats having had treatment of a primary tumour. Interstitial laser thermotherapy of the first tumour was followed by eradication of challenging tumour and absence of tumour spread. This contrasted with rapid growth and spread of challenging tumour in the other groups. In the challenging vital tumour tissue and in the interface between the tumour and surroundings, the number of ED1 macrophages and CD8 lymphocytes was higher in rats having been treated with the ILT of tumour than in those having undergone resection of the tumour-bearing lobe. The number of ED2 macrophages and CD4 lymphocytes was low and did not vary between these two groups. Interstitial laser thermotherapy elicited an immune response that eradicated a challenging tumour and was associated with increased numbers of tumour-infiltrating macrophages and CD8 lymphocytes.

Interstitial laser thermotherapy of a rat liver adenocarcinoma.

The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was implanted into the left lateral lobe of the rat liver, and treatment was performed 8 days later. Rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46°C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection, with no difference in local control. Using inoculation of tumour cell suspensions into the lateral and the median lobes of the liver simultaneously and treating the lateral lobe tumour only, we found that laser thermotherapy reduced take and growth of the untreated tumour in the median lobe indicating that laser thermotherapy may induce immunologic effects. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour as compared to resection. It is suggested that this can be at least partly explained by a laser-induced immunologic effect.

Electrically mediated drug delivery for treatment of an adenocarcinoma transplanted into rat liver.

BACKGROUND: In this study, electrochemotherapy (ECT), i.e. tumour treatment based on local augmentation of intracellular drug delivery from short, intense electric pulses, was evaluated in rats with an adenocarcinoma implanted into the liver. Tumour response and concentrations of macrophages and T-lymphocytes (CD4 and CD8) in and around the tumour were measured. MATERIALS AND METHODS: Rats were treated with permeabilizing electric pulses, bleomycin, or both, eight days after implantation of the tumour, while one group received sham treatment. RESULTS: Treatment with electric pulses and bleomycin resulted in a significantly reduced lesion volume and 92% cure rate (12 out of 13, p<0.0002 compared to the other treatment groups). The highest concentration of CD8 lymphocytes was found in tumours treated with electric pulses and bleomycin. Macrophages were found mainly in tumours treated with electric pulses, with or without bleomycin. CONCLUSION: Electrochemotherapy using millisecond exponential pulses and bleomycin is efficient in a rat liver tumour model and appears to stimulate the host's immune system.

Comparison between interstitial laser thermotherapy and excision of an adenocarcinoma transplanted into rat liver.

The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was transplanted (implanted if not stated otherwise) into the left lateral lobe of the rat liver, and treatment was performed 8 days later. In the main experiment, rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46 degrees C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection of the tumour-bearing lobe, with no difference in local control. Metastatic spread after resection of the median liver lobe was similar to that observed after sham procedures for thermotherapy or resection, suggesting that the advantage of thermotherapy was not due to a difference in surgical trauma. Additional studies showed that laser thermotherapy reduced intraperitoneal spread when treatment was suboptimal or in a tumour inoculation model and suggested that immunological mechanisms might be involved. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour compared with resection.

Interstitial laser thermotherapy of adenocarcinoma transplanted into rat liver.

OBJECTIVE: To examine the effect of different temperatures and exposure times in interstitial laser thermotherapy. DESIGN: Controlled laboratory study. SETTING: University hospital, Sweden. MATERIAL: 48 male Wistar FU rats with dimethylhydrazine-induced adenocarcinoma transplanted into the liver. INTERVENTION: Treatment was given with an Nd:YAG laser and a feedback system for temperature regulation. Light was delivered into the centre of the tumour and the feedback thermistor probe was placed 3 mm from the tumour margin. Rats were treated at steady-state temperatures at the feedback thermistor of 43, 46, or 50 degrees C for 30 minutes, and at a steady-state temperature of 46 degrees C at the feedback thermistor also for 10 and 20 minutes. MAIN OUTCOME MEASUREMENT: Tumour control as assessed 6 days after treatment using light microscopical examination including immunohistochemical determination of bromodeoxyuridine (BrdU) incorporation into DNA as a measure of cell viability. RESULTS: Complete tumour necrosis was achieved in all rats treated for 30 minutes, in 6/8 rats treated for 10 minutes and in 6/8 rats treated for 20 minutes at 46 degrees C. During steady-state thermotherapy, temperatures at the tumour margin were about 11 degrees higher than at the feedback thermistor (range 54-61 degrees C). The surrounding liver tissue also became necrotic so that the total necrosis volume exceeded the pretreatment tumour volume. CONCLUSION: Interstitial laser thermotherapy at temperatures ranging from 54-61 degrees C at the tumour margin ensures total necrosis of a transplanted rat liver carcinoma provided that treatment is given for 30 minutes.

Interstitial laser thermotherapy in pig liver: effect of inflow occlusion on extent of necrosis and ultrasound image.

BACKGROUND/AIMS: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. METHODOLOGY: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3W or without inflow occlusion at 5 W (target temperature 43 degrees C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. RESULTS: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did not occur, unoccluded blood flow was associated with hypoechoic lesions. Following inflow occlusion, maximum lesion width 2 and 6 days after thermotherapy averaged 21.9 +/- 1.3 and 20.2 +/- 0.8 (means +/- SEM) mm, respectively. This was larger than the corresponding values of 10.8 +/- 0.8 and 11.1 +/- 2.0 observed after treatment without inflow occlusion at 3W (p < 0.01). Increase in laser power from 3 to 5W in experiments without inflow occlusion produced early carbonization and a slight increase in lesion size that did not match that produced by inflow occlusion. Ultrasound gave a correct prediction of necrosis size after treatment with inflow occlusion but overestimated the necrosis when inflow occlusion was not used. Ultrasound was furthermore unable to predict size of necrosis in individual experiments. CONCLUSION: Blood flow has a major influence on lesion size in interstitial laser thermotherapy of the liver and affects ultrasonographic images. Also, it appears that intraoperative ultrasonography cannot monitor lesion size with an accuracy that is sufficient for clinical use.

Hepatic inflow occlusion increases the efficacy of interstitial laser-induced thermotherapy in rat.

Interstitial laser-induced thermotherapy (ILT) destroys tumors thermally. ILT was performed for treatment of liver tumors in rats to investigate the effect of hepatic inflow occlusion on temperature distribution and lesion size. Tumors were irradiated for 20 min with near-infrared light from a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. The laser light at a power of 1.5 W was delivered through a plane-cut optical fiber, the tip of which was placed in the tumor. Rats in group I received ILT without interruption of hepatic blood flow. Those in group II received ILT during hepatic inflow occlusion. Liver temperatures were measured during treatment. After 3 days the animals were sacrificed and the size of the lesions was measured. Occlusion of the hepatic inflow during ILT increased the maximum lesion diameter, as measured at the liver surface, by 47%. Linear interpolation between the temperatures measured at 6 and 12 mm distance from the fiber tip revealed that the temperature at the necrotic border just before the end of treatment was approximately 45 degrees C in both the occluded and nonoccluded groups, indicating that the hepatic inflow occlusion caused no increase in tissue thermal sensitivity. This study shows that occlusion of the hepatic inflow during interstitial laser-induced thermotherapy causes a significant increase in lesion size, which could have implications for the treatment of hepatic tumors.

Pectin-supplemented enteral diet reduces the severity of methotrexate induced enterocolitis in rats.

BACKGROUND: Administration of methotrexate (MTX) to rats fed an elemental diet results in a high mortality from severe enterocolitis. Previous studies have shown that pectin is an important precursor of substrates for intestinal structure and function and may facilitate intestinal recovery after enterocolitis. The aim of this study is to evaluate the effect of pectin on MTX-induced enterocolitis in rats. METHODS: Rats received intragastric infusion of either 1% pectin-supplemented or pectin-free elemental diet from the beginning of the study via a gastrostomy. On the 4th day animals received either MTX, 20 mg/kg intraperitoneally, or saline injection and were killed on the 7th day for sampling. RESULTS: Pectin supplementation significantly decreased body weight loss, organ water content, and intestinal myeloperoxidase levels and increased mucosal protein, DNA, and RNA content in enterocolitis rats. The intestinal permeability was increased by administration of MTX, and pectin supplementation significantly reversed the increased permeability in the distal small bowel and colon. Pectin supplementation also lowered the magnitude of bacterial translocation, decreased plasma endotoxin levels, and restored bowel microecology. CONCLUSIONS: Pectin significantly decreased MTX-induced intestinal injury and improved bowel integrity.

Sclerotherapy of edematous gallbladders with different agents. An experimental study in pigs.

Different sclerosing agents were tried in experiments with 32 pigs to achieve ablation of gallbladders rendered edematous by mechanical lithotripsy with the Rotolith lithotriptor. In 16 pigs sclerotherapy was performed with 6% acetic acid, Carnoy's solution, 95% ethanol + 3% sodium-tetradecylsulfate (STS) and hot metrizoate, respectively. These animals were sacrificed immediately after the procedure. Histologic examination showed persistent surface epithelium and glandular epithelium in all specimens. In 6 pigs, the sclerotherapy was done with Carnoy's solution, 95% ethanol + 3% STS and hot metrizoate, respectively, and the pigs were killed 6 days later. Fibrosis of the gallbladder remnants was seen in these animals, but also remnants of surface and glandular epithelium. Hot metrizoate was used in another 10 pigs and these animals were sacrificed after 8 weeks. At histologic examination fibrosis was seen in the gallbladder remnants of 9 surviving animals, but also areas of preserved muscular layer, and development of mucinous cysts were found in more than 50% of the specimens. Thus, none of the sclerosants was able to produce a total ablation of the gallbladder mucosa.

Nucleic acid labeling with [3H]orotic acid and nucleotide profile in rats in protein deprivation, enteral and parenteral essential amino acid administration, and 5-fluorouracil treatment.

Rats were fed a 0% casein diet for 1 week, with or without enteral or parenteral administration of essential amino acids, or a 25% casein diet, in one group supplemented with 5-fluorouracil treatment. Ninety minutes before sacrifice the rats were given a tracer of [3H]orotic acid. Incorporation into the acid soluble fraction, RNA, and DNA was determined in liver, small intestine, bone marrow, and kidney. Nucleotide profile was examined in liver and intestine. Protein deficiency caused inter alia a decrease in body weight; a decrease in RNA/DNA ratio and an increase in the specific RNA labeling in liver and kidney; an altered nucleotide profile in the liver; an increase in the nucleotide/DNA and RNA/DNA ratios and a decrease in the specific labeling of the acid soluble fraction, RNA, and DNA in the bone marrow. These changes were prevented to the same extent by giving essential amino acids, either orally or intravenously. The minor changes in intestinal nucleotide profile in protein deprivation were prevented to a slightly larger extent by amino acids orally than parenterally. 5-Fluorouracil treatment gave a decrease in the RNA/DNA ratio in the liver and kidney but an increase in the nucleotide/DNA and RNA/DNA ratios in the bone marrow. Nucleotide profiles were unaltered. The amount of DNA per gram of tissue decreased in bone marrow and increased in kidney. Parenteral administration per se resulted in almost no changes.

Effect of experimental folate deficiency on lipid metabolism in liver and brain.

1. Rats were given a purified folate-deficient diet containing 5 g succinylsulphathiazole/kg for 4-5 months in two experiments. Control rats were supplemented with folic acid in the drinking-water. 2. Weight gain was much below normal in the folate-deprived rats after the first month. Very low folate levels were recorded in blood, liver and peripheral nerve (12-33% of control). In the central nervous system, including the cerebrospinal fluid, the folate depletion was less conspicuous (50-80% of control). Only marginal signs of anaemia were found and no signs of neurological dysfunction were detected, using nerve conduction velocity measurement and co-ordination tests. 3. Light and electron microscopy of the folate deficient liver revealed fatty infiltration, and enlargement of liver parenchymal cells, nuclei and nucleoli. There was often a considerable amount of bile ductular cells in the lobuli but no cirrhosis. The morphological changes resembled those observed in choline deficiency. 4. Phospholipid N-methylation in liver was depressed in folate-deficiency. This was probably due to a decreased availability of S-adenosylmethionine caused by the low concentrations of methylated folate in liver. Intraperitoneal administration of methionine did not normalize phospholipid methylation. 5. In folate deficiency the proportion of ethanolamine phosphoglyceride in liver was increased at the expense of choline phosphoglyceride, which is consistent with a decreased phospholipid methylation. Also an increase in liver triacylglycerol was noted, in accordance with the morphological observations. Brain lipid composition was unchanged. 6. After the injection of labelled ethanolamine, isotope accumulated in liver phosphoethanolamine in folate deficiency, probably due to an impairment of the CTP:ethanolaminephosphate cytidylyltransferase (EC 2.7.7.14) reaction. The mechanism of this impairment is discussed. 7. Although the low concentrations of folate was the main nutritional change in the deprived animals, changes with respect to vitamin B12 and maybe also choline cannot be excluded. We conclude that some of the changes in folate deficiency, i.e. fatty liver and decreased biosynthesis of liver phospholipids may be due to a precipitated deficiency of lipotropic agents, whereas other differences may be specific for deficiency of folate per se, such as changes in liver phospholipid fatty acids and some of the morphological aberrations.

Ribonucleic acid labelling perfused livers of protein-fed and protein-deprived rats.

Several observations suggest an increased RNA synthesis in livers of protein-deprived rats, though the RNA/DNA ratio is decreased. A number of hormones may be involved in these changes. Therefore, we studied in RNA metabolism in isolated perfused livers taken from protein-fed and protein-deprived rats. (3H)-orotic acid was given to the rats 2 h before liver explantation, and (14C)-orotic acid was added to the perfusate. Other rats, called controls in vivo, whose livers were not transplanted were also given (3H)-orotic acid followed by (14C)-orotic acid. The livers of these rats, which were not hormone supplemented, were labelled for the same length of times as the livers in vitro. The ratio specific RNA radioactivity/specific nucleotide radioactivity x RNA/DNA was determined and taken as a measure of the RNA synthesis per liver cell. In the controls in vivo, this ratio was significantly higher for protein-deprived than for protein-fed rats. In livers from the protein-fed rats, labelling in vitro increased significantly when growth hormone, hydrocortisone, insulin and tri-iodothyronine were added to the perfusate. Labelling was also significantly higher in these livers than in the controls in vivo. In livers from protein-deprived rats, the ratio in question was the same whether the hormones were added to the perfusate or not, and was significantly lower than in the controls in vivo. Differences in RNA labelling are thus obtained in our in vitro system. Gel electrophoresis of RNA demonstrated normal RNA labelling, showing that the system is suitable for studying liver RNA synthesis. Further refinement can be made by studying the labelling of UTP and CTP. The results might suggest that the liver from a protein-fed rat, explanted in vitro, may increase its RNA synthesis under the influence of the four hormones in question, and that the RNA synthesis of the liver of a protein-deprived rat is high in-vivo and that it might decrease, when it is explanted to in vitro conditions.