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R van Hillegersberg

Publications and source records attributed to R van Hillegersberg.

At least 19 recordsLinked to original sources
PubMed2007

Targeting difficult accessible breast lesions: MRI-guided needle localization using a freehand technique in a 3.0 T closed bore magnet.

PURPOSE: To report the accuracy of magnetic resonance imaging (MRI)-guided needle localization for diagnosis of MRI detected suspicious breast lesions located in difficult accessible regions of the breast, using the freehand method in a 3.0 T closed bore magnet. MATERIALS AND METHODS: In five patients with five MRI-only breast lesions underwent MRI-guided needle localization for histopathologic evaluation of the lesions. All interventional procedures were performed in a 3.0 T MRI system with the patient in prone position and by using a dedicated phased array breast coil. MRI-guided needle localizations were performed by using a freehand technique. In our study, the high-resolution scan allowed preprocedural localization of all lesions without use of contrast enhancement. In all cases contrast-enhanced MRI was performed after insertion of the wire to confirm the tip of the wire in direct contact with the enhancing lesion. RESULTS: Needle localizations were performed in five patients. Histopathologic evaluation of tissue after surgery excision biopsy revealed one lymph node, three invasive ductal carcinoma and one ductal carcinoma in situ. Lesion size varied from 6 to 30 mm. Mean duration time was 25 min. No complications occurred during the intervention method. In the patient with the benign lesion control MRI of the breast after 6 months confirmed lesion removal. CONCLUSIONS: MRI-guided needle localization by using a freehand technique in a 3.0 T closed bore magnet is a safe and accurate method for diagnosis of difficult accessible breast lesions only visible on MRI.

Biopsy, Needle↗
PubMed2006

[MRI-guided biopsy of suspicious abnormalities in the breast].

In a 55-year-old woman, an echographically occult breast tumour was only visible in one direction on mammography. MRI-guided needle localisation of the lesion followed by surgical excision biopsy were then carried out for diagnostic purposes. In a second woman, 61 years of age, mammographic needle localisation of a deep, echographically occult, lesion was unsuccessful. She then also underwent MRI-guided needle localisation followed by surgical excision biopsy. A third woman, also 61 years of age, with known carcinoma underwent an MRI staging study. This revealed a second, mammographically and echographically occult, lesion for which MRI-guided large-core needle biopsy was done. MRI of the breast has a high sensitivity for the detection of invasive breast carcinoma. MRI of the breast reveals suspicious lesions that cannot be seen on the conventional mammogram or by echography in 15-25% of the cases. In order to obtain tissue from these lesions for histopathology, MRI-guided biopsy techniques have been developed. The most commonly used methods are MRI-guided needle localisation followed by surgical excision biopsy and MRI-guided large-core needle biopsy. The demand for MRI-guided breast interventions is growing because of the increasing use of MRI of the breast in clinical practice.

Biopsy, Fine-Needle↗
PubMed2006

First experience with robot-assisted thoracoscopic esophagolymphadenectomy for esophageal cancer.

BACKGROUND: Transthoracic esophagectomy with extended lymph node dissection is associated with higher morbidity rates than transhiatal esophagectomy. This morbidity rate could be reduced by the use of minimally invasive techniques. The feasibility of robot-assisted thoracoscopic esophagectomy (RTE) with mediastinal lymphadenectomy was assessed prospectively. METHODS: This study investigated 21 consecutive patients with esophageal cancer who underwent RTE using the Da Vinci robotic system. Continuity was restored with a gastric conduit and a cervical anastomosis. RESULTS: A total of 18 (86%) procedures were completed thoracoscopically. The operating time for the thoracoscopic phase was 180 min (range, 120-240 min), and the median blood loss was 400 ml (range, 150-700 ml). A median of 20 (range, 9-30) lymph nodes were retrieved. The median intensive care unit stay was 4 days (range, 1-129 days), and the hospital stay was 18 days (range, 11-182 days). Pulmonary complications occurred in 10 patients (48%), and one patient (5%) died of a tracheoneoesophageal fistula. CONCLUSIONS: In this initial experience, robot-assisted thoracoscopic esophagectomy was found to be feasible, providing an effective lymphadenectomy with low blood loss. Standardization of the technique and increased experience should reduce the complication rate, which is in the range of the rate for open transthoracic dissection.

Adenocarcinoma↗
PubMed2006

[Better treatment for patients with colorectal liver metastases].

Three patients, 61, 58 and 63 years old, presented with non-resectable liver metastases from colorectal cancer. The first patient, a man, who had a solitary lesion in the liver and severe cardiovascular morbidity, was successfully treated with laser-induced interstitial thermotherapy. The second patient, a woman, had large multiple liver metastases and two concomitant isolated pulmonary metastases. Following chemotherapy with fluorouracil, leucovorin and oxaliplatin, all lesions were downsized and a hemihepatectomy and pulmonary wedge resections were able to be performed in two stages. At the last follow-up, both patients were disease-free after 12 and 24 months respectively. The third patient, a man, presenting with multiple synchronous liver metastases, showed a significant decrease of hepatic tumour involvement after six courses of capecitabine. At present he is in a good condition and his disease is stable. Surgical resection ofcolorectal liver metastases leads to a 5-year survival rate of up to 45% in selected patients. Unfortunately, only 10 to 20% of patients are amenable to surgical resection. In the remaining group, a combination of new treatment options using local tumour ablative therapies and novel chemotherapeutic regimens provide alternative strategies with the potential of long-term survival.

Antineoplastic Agents↗
PubMed2006

Selective portal clamping to minimize hepatic ischaemia-reperfusion damage and avoid accelerated outgrowth of experimental colorectal liver metastases.

BACKGROUND: Temporary vascular clamping during local ablation for colorectal liver metastases increases destruction volumes. However, it also causes ischaemia-reperfusion (IR) injury to the liver parenchyma and accelerates the outgrowth of microscopic tumour deposits. The aim of this study was to investigate the effects of selective portal clamping on hepatocellular damage and tumour growth. METHODS: Mice carrying pre-established hepatic colorectal micrometastases underwent either simultaneous clamping of both the portal vein and the hepatic artery or selective clamping of the portal vein to the median and left liver lobes for 45 min. Sham-operated mice served as controls. Hepatic injury and tumour growth were assessed over time. RESULTS: Standard inflow occlusion resulted in a rise in liver enzymes, a local inflammatory response and hepatocellular necrosis. The outgrowth of pre-established micrometastases was accelerated three- to fourfold in clamped compared with non-clamped liver lobes (27.4 versus 7.8 per cent, P < 0.010). Conversely, selective portal clamping induced minimal liver injury, tissue inflammation or hepatocellular necrosis, and completely stopped the accelerated outgrowth of micrometastases. CONCLUSION: Selective portal clamping does not induce liver tissue damage or accelerate micrometastasis outgrowth and may therefore be the preferable clamping method during local ablative treatment of hepatic metastases.

Animals↗
PubMed2005

Adverse effects of radiofrequency ablation of liver tumours in the Netherlands.

BACKGROUND: Radiofrequency ablation (RFA) is a new treatment for liver tumours. Complications encountered after RFA in the Netherlands were evaluated in the present study. METHODS: Between June 1999 and November 2003 patients undergoing RFA of irresectable liver tumours in eight medical centres were registered prospectively. RESULTS: One hundred and forty-three RFA procedures were performed in 122 patients. RFA was combined with partial hepatectomy in 37 instances. Death occurred after two procedures (1.4 per cent), and was mainly due to concomitant partial hepatectomy. A total of 19 major complications occurred after ten procedures, including biliary tract damage (seven patients), liver failure (four), hepatic abscess (three), peritoneal infection (two), intrahepatic haematoma (one), hepatic artery aneurysm (one) and pulmonary embolism (one). Twenty-four minor complications were related to concomitant partial hepatectomy or laparotomy. The overall complication rate was 20.3 per cent and the rate of complications related directly to RFA was 9.8 per cent. CONCLUSION: The procedure-specific complication rate was almost 10 per cent and it is recommended that RFA should be performed only by an experienced team comprising a hepatobiliary surgeon, gastroenterologist, hepatologist and interventional radiologist. Biliary stricture, hepatic vascular damage and hepatic abscesses were the most common major complications.

Adult↗
PubMed2005

Outcome of regional and local ablative therapies for hepatocellular carcinoma: a collective review.

BACKGROUND: Transcatheter arterial (chemo) embolization (TACE), cryoablation (CA) and percutaneous ethanol injection (PEI) were the first regional and local ablative techniques that came into use for irresectable HCC. Radiofrequency ablation (RFA) and interstitial laser coagulation (ILC) followed and have now evolved rapidly. It would not be ethical to compare resection with ablation in patients well enough to undergo major surgery. Therefore, hepatic resection and hepatic transplantation remain the only curative treatment options for HCC. METHODS: On the basis of a Medline literature search and the authors' experiences, the principles, current status and prospects of TACE and local ablative techniques in HCC are reviewed. RESULTS: Complete tumour necrosis can be achieved in 60-100% of patients treated with PEI (70-100%), cryoablation (60-85%), RFA (80-90%) or ILC (70-97%). After TACE significant tumour response is achieved in 17-61.9% but complete tumour response is rare (0-4.8%) as viable tumour cells remain after TACE. Five-year survival rates are available for TACE (1-8%), PEI (0-70%) and cryoablation (40%). Only PEI and RFA were compared in one RCT. RFA was associated with fewer treatment sessions and a higher complete necrosis rate. Furthermore, all techniques are associated with low morbidity and mortality, but cryoablation seems to be associated with a higher morbidity rate. CONCLUSION: TACE has shown to be a valuable therapy with survival benefits in strictly selected patients with unresectable HCC. RFA and PEI are now considered as the local ablative techniques of choice for the treatment of, preferably small, HCC. When tumours are located close to bile ducts or large vessels, PEI remains a valuable therapy. Completeness of ablation can be more easily monitored during cryoablation and another advantage of cryoablation is the possibility of edge freezing. The results of ILC are comparable to RFA with only few side effects and high tumour response rates.

Carcinoma, Hepatocellular↗
PubMed2003

[Primary adenocarcinoma of the small intestine].

Three patients, a woman aged 46 years and two men aged 81 and 62 years, presented with abdominal pain, nausea, vomiting and/or weight loss. A small intestine follow-through series revealed a significant stenosis in all 3 patients. A laparotomic partial resection of the affected jejunum and corresponding mesentery was performed. A primary adenocarcinoma of the small intestine was diagnosed; pathology revealed that the resections were radical, and pT3N0, pT2N0 and pT3N0 stage tumours respectively. The first patient underwent a repeat operation four months later due to similar complaints caused by a tumour recurrence; fifteen months later she died from recurrent disease. The second patient was disease-free 3 years after surgery. In the third patient, liver and peritoneal metastases developed 16 months after surgery; he died 10 months after palliative chemotherapy had been initiated. Adenocarcinoma of the small intestine is a rare disease and patients often present late with aspecific complaints. This, combined with the fact that these tumours tend to follow an aggressive course, results in a poor five-year survival rate of 10-35%. Surgery is the only curative treatment currently available. A greater awareness of this type of tumour is needed for treatment results to improve.

Abdominal Pain↗
PubMed2002

[Increased perioperative blood loss during treatment with paroxetine].

A 63-year-old man who took paroxetine for depression developed massive peroperative haemorrhage during a pancreaticoduodenectomy as a result of paroxetine-induced thrombocytopathy. He lost 4 litres of blood. After administration of 8 units of fresh frozen plasma and 2 times 5 units of thrombocyte concentrate, hemostatic control was obtained and the operation could be continued. Paroxetine is a non-tricyclic serotonin reuptake inhibitor prescribed for the treatment of depression. Since this drug also blocks serotonin reuptake in platelets, a clinically significant platelet dysfunction can occur under certain conditions. Because serotonin promotes platelet aggregation, too low an amount of serotonin in the platelets can result in thrombocytopathy. Before major surgery, it is advised to perform extensive clotting tests if there is any hint of haemorrhagic diathesis in the anamnesis. In case of a prolonged bleeding time, paroxetine treatment should be stopped perioperatively.

Antidepressive Agents, Second-Generation↗
PubMed2002

Endovascular photodynamic therapy with aminolaevulinic acid prevents balloon induced intimal hyperplasia and constrictive remodelling.

BACKGROUND AND OBJECTIVE: intimal hyperplasia (IH) and constrictive remodelling are important causes of restenosis following endovascular interventions, such as percutaneous transluminal angioplasty. Photodynamic therapy (PDT) with 5-aminolaevulinic (ALA) may prevent restenosis by cellular depletion and the elimination of cholinergic innervation. STUDY DESIGN/MATERIALS AND METHODS: rats (n=90) were subdivided into 4 main groups. In the experimental group (n=36: 3 replications x 4 doses x 3 examination time-points), ALA was administered (200mg/kg i.v.) 2-3h before balloon injury (BI) of the common iliac artery followed by endovascular illumination with 633nm at either 12.5, 25, 50 or 100J/cm diffuser length (dl BI+PDT group). As control groups served the BI+Light only (LO) group (n=36) that received no ALA, the BI only group (n=9) (BI), and a group (n=9) that received a Sham procedure (Sham group). RESULTS: planimetric analysis showed IH of 0.28+/-0.12mm(2) (BI), 0.27+/-0.12mm(2) (BI+LO at 100J/cmdl) in contrast to 0.02+/-0.02mm(2) after BI+PDT at 100J/cmdl at 16 weeks (p<0.05). In the BI+PDT groups, a light-dose increase of a factor 2 led to an IH decrease of 17% (p<0.05). In the BI and BI+LO groups constrictive remodelling was found, in contrast to BI+PDT treated groups at 16 weeks. The staining of cholinergic innervation of the tunic media of the blood vessel wall in BI+PDT showed no damage at the highest fluence. CONCLUSION: endovascular ALA-PDT prevents IH and constrictive remodelling after BI without damage of cholinergic innervation of the tunica media. The effective light fluence rate in the rat is 50-100J/cmdl.

Aminolevulinic Acid↗
PubMed2001

Metabolic activity and DNA integrity in human hepatic metastases after interstitial laser coagulation (ILC).

BACKGROUND AND OBJECTIVE: For investigations into interstitial laser coagulation (ILC) of solid tumors, tissue whitening is used as a parameter for the extent of coagulation. This obvious demarcation is associated with global thermal denaturation, but it is not clear whether this finding is a good indicator of the exact outer boundary of the lethal tissue effect. STUDY DESIGN/MATERIALS AND METHODS: ILC with portal inflow occlusion was performed in human hepatic metastases of colorectal carcinoma directly after surgical resection (n = 5) or before surgical resection (n = 5) with laser parameters adapted to tumor diameter. Mitochondrial NADH-diaphorase activity and DNA integrity were assessed by histoenzymatic staining. RESULTS: In 7 of 10 tumors (mean diameter, 3.7 cm), an area of macroscopic coagulation (mean diameter, 4.2 cm) encircled the tumor in all three axes. Macroscopic coagulation corresponded to absent metabolism and disintegrated DNA. Furthermore, the macroscopic volumes of coagulation produced in tumor were comparable to the dimensions in normal porcine liver with the same laser parameters. CONCLUSION: ILC with portal inflow occlusion results in areas with complete cell avitality in the zone of tissue whitening in human hepatic liver metastases.

Colorectal Neoplasms↗
PubMed2001

Fractionated illumination for oesophageal ALA-PDT: effect on blood flow and PpIX formation.

The effect of fractionating the 633 nm illumination of 5-aminolaevulinic (ALA)-based photodynamic therapy (PDT) of the normal rat oesophagus was studied. Fractionation of the illumination could enhance the PDT effect in two ways: (a) delay of the vascular shutdown or relaxation of the vasoconstriction induced by ALA-PDT and (b) use of newly formed protoporphyrin IX (PpIX), produced during the dark interval. Forty rats were randomly allocated to two groups of 20 animals each. To study vascular effects, in group 1 illumination with 633 nm (100 mW/cm) was performed at 3 h after oral ALA administration (200 mg/kg) either continuously with 20 J/cm diffuser length (n = 5) or fractionated 2 x 10 J/cm with a 150 s interval (n = 5), five animals served as controls. Blood flow was measured with a laser Doppler flowmeter. To study the effect of renewed PpIX forming, animals in group 2 were illuminated continuously at 3 h after ALA with 20 J/cm (n = 5) or 40 J/cm (n = 5) or fractionated 2 x 20 J/cm with a 3 h interval (n = 5), five animals served as controls. In all animals the in vivo fluence rate and PpIX fluorescence were measured during illuminations and animals were killed at 48 h after PDT. ALA-PDT did not cause any significant vasoconstriction. Fluorescence measurements and dosimetric results in group 1 did not differ between animals illuminated continuously or fractionated with a 150 s interval. In group 2, during a 3 h dark interval, PpIX fluorescence increased and was bleached during the second illumination. The tissue optical properties changed during the 3 h dark interval, resulting in a lower in vivo fluence rate (p < or = 0.001). Fractionation did not result in more oesophageal damage. It was concluded that a 150 s interval during illumination in ALA-PDT does not increase oesophageal blood flow. During an interval of 3 h new PpIX is formed. In the present study, fractionated illumination using short or long time intervals did not result in more damage. Thus, this study shows no evidence for improved PDT effect with fractionated light delivery.

Aminolevulinic Acid↗
PubMed2000

[Treatment of non-resectable liver tumors with percutaneous interstitial laser coagulation while interrupting blood circulation to the liver].

OBJECTIVE: To evaluate, in patients with hepatocellular carcinoma or colorectal carcinoma disseminated to the liver, treatment with interstitial laser coagulation (ILC) during temporary occlusion of vascular inflow in the liver: feasibility, complications and initial tumour response. DESIGN: Prospective, descriptive. METHODS: Patients were included if their tumours were surgically irresectable and smaller than 4 cm in diameter and did not exceed a number of 3. ILC was performed under general anaesthesia, basically via a percutaneous approach. Vascular inflow was occluded during laser treatment. Twenty-four hours after ILC a triphasic spiral CT was performed to assess the result of the treatment. RESULTS: In 10 patients 14 hepatic tumours were lasered in 12 treatment sessions (10 percutaneous and 2 at laparotomy). After 5 treatment sessions, complications were observed of which pain at the insertion site of the catheters was the most frequent. For 6 out of the 10 patients with percutaneous procedures, discharge was within 24 hours after ILC. Nine out of the 14 tumours (65%) were completely coagulated. CONCLUSION: ILC with vascular inflow occlusion is a safe and feasible technique that can be performed during a short hospital stay. Initial tumour response is 65% and these results justify determination of duration of response in a larger group of patients.

Aged↗
PubMed2000

Fractionated illumination in oesophageal ALA-PDT: effect on ferrochelatase activity.

BACKGROUND AND OBJECTIVE: Administration of 5-aminolevulinic acid (ALA) induces accumulation of the photosensitive compound protoporphyrin IX (PpIX) in certain tissues. PplX can be used as photosensitizer in photodynamic therapy (PDT). More selective or higher PpIX accumulation in the area to be treated could optimize the results of ALA-PDT. Porphobilinogen deaminase (PBGD) is rate-limiting in PpIX formation whereas ferrochelatase converts PpIX into haem by chelation of ferrous iron into PpIX. This results in a moment of close interaction (ferrochelatase binding to PpIX) during which ferrochelatase could selectively be destroyed resulting in an increased PpIX concentration. The aim of the present study was to investigate whether illumination before PDT can selectively destroy ferrochelatase. and whether this results in higher PpIX accumulation and thereby increases the PDT effect. Furthermore, the effect of a second ALA dose was tested. STUDY DESIGN/MATERIALS AND METHODS: Oesophageal tissue of 60 rats were allocated to 2 groups of 30 animals each. In one group, enzyme and PpIX measurements were performed after ALA administration (200 mg/kg orally, n=20), or a second dose of 200 mg/kg ALA at 4 h (n=10), half of each group with and without illumination at 1 h with 12.5 J/cm diffuser length. In the second group, PDT was performed. Ten animals were illuminated at 3 h after ALA administration with 20 (n=5) or 32.5 J/cm (n=5), 10 animals were illuminated at 1 h (12.5 J/cm) and received intra-oesophageal PDT treatment (20 J/cm) at 3 h (n=5) or 4 h (n=5) after ALA. Additionally, 10 animals received a second dose of 200 mg/kg ALA at 4 h and were illuminated (20 J/cm) at 7 h after the first dose of ALA with (n=5) or without (n=5) illumination at 4 h (12.5 J/cm). RESULTS: Illumination with 12.5 J/cm at 1 h after ALA administration caused inhibition of the activity of ferrochelatase at 3 and 4 h after ALA (P=0.02 and P<0.001, respectively), but not at 7 h (P=0.3). In animals sacrificed at 4 h the ratio PBGD:ferrochelatase was higher in animals illuminated at 1 h compared to non-illuminated animals (P<0.001). PpIX concentration was highest (42.7 +/- 3.2 pmol/mg protein) at 3 h after ALA administration and did not increase by illumination at 1 h. Administration of a second dose of ALA did not result in higher PpIX accumulation. After PDT, no difference in epithelial or muscular damage was found between the various groups. CONCLUSION: Illumination at 1 h after ALA administration can cause selective destruction of ferrochelatase, resulting in a higher ratio of PBGD:ferrochelatase. This does not result in accumulation of more porphyrins, even when a second dose of ALA is given. Therefore, under the conditions used in this study fractionated illumination does not enhance ALA-PDT-induced epithelial ablation of the rat oesophagus.

Aminolevulinic Acid↗
PubMed2000

Porphyrin biosynthesis in human Barrett's oesophagus and adenocarcinoma after ingestion of 5-aminolaevulinic acid.

5-Aminolaevulinic acid (ALA)-induced porphyrin biosynthesis, which is used for ALA-based photodynamic therapy (ALA-PDT), was studied in tissues of 10 patients with Barrett's oesophagus (BE) and adenocarcinoma of the oesophagus (AC) undergoing oesophagectomy at a mean time interval of 6.7 h after the ingestion of ALA (60 mg kg(-1)). In BE, AC, squamous epithelium (SQ) and gastric cardia, the activities of the haem biosynthetic enzymes porphobilinogen deaminase (PBG-D) and ferrochelatase (FC) and the PDT power index--the ratio between PBG-D and FC in BE and AC in comparison with SQ--were determined before ALA ingestion. Following ALA administration, ALA, porphobilinogen, uroporphyrin I and PPIX were determined in tissues and plasma. The PDT power index did not predict the level of intracellular accumulation of PPIX found at 6.7 h. In BE, there was no selectivity of PPIX accumulation compared to SQ, whereas in half of patients with AC selectivity was found. Higher haem biosynthetic enzyme activities (i.e. PBG-D) and lower PPIX precursor concentrations were found in BE and AC compared to SQ. It is therefore possible that PPIX levels will peak at earlier time intervals in BE and AC compared to SQ.

Adenocarcinoma↗
PubMed1999

Kinetics, localization, and mechanism of 5-aminolevulinic acid-induced porphyrin accumulation in normal and Barrett's-like rat esophagus.

BACKGROUND AND OBJECTIVES: Photodynamic therapy may selectively destroy Barrett's epithelium in the esophagus. To optimize photosensitizer administration, the kinetics of 5-aminolevulinic acid (ALA)-induced porphyrin accumulation in the normal and Barrett's-like esophagus were studied in the rat. STUDY DESIGN/MATERIALS AND METHODS: Animals received 200 mg/kg ALA intravenously (n = 21) or orally (n = 21). Six rats served as controls. At t = 1, 2, 3, 4, 6, 12, and 24 hr, porphyrin concentration in the esophagus was measured by using chemical extraction, and porphyrin localization was determined by laser scanning microscopy (LSM). In addition, in 20 animals, porphobilinogen deaminase, ferrochelatase, and iron concentration were determined. In a second group (n = 24), an esophagojejunostomy was performed to induce a Barrett's-like esophagus. After 18 weeks, animals received ALA, and LSM was performed at t = 1, 2, 3, 4, 6, 8, and 12 hr. RESULTS: Porphyrin accumulation in normal mucosa was 3.5-fold higher than in muscularis, with a maximum at 3 hr after ALA administration. With LSM, strong homogeneous fluorescence of the squamous epithelium was shown, with minor fluorescence of submucosa and muscularis. In Barrett's-like epithelium, fluorescence was heterogeneous but was also restricted to epithelial cells. There was no difference in fluorescence intensity between Barrett's-like and adjacent squamous epithelium. Porphobilinogen deaminase activity was higher and iron concentration was lower in the mucosa than in the muscularis (P < 0.001). CONCLUSION: ALA-induced porphyrin accumulation selectively occurs in esophageal mucosa, whether normal or Barrett's-like, compared with the muscularis, with a maximum at 3 hr after ALA administration. Selectivity may be caused by a different activity of heme-synthetic enzymes or relative iron deficiency in the mucosa.

Administration, Oral↗
PubMed1999

Critical temperature and heating time for coagulation damage: implications for interstitial laser coagulation (ILC) of tumors.

BACKGROUND: Interstitial laser coagulation (ILC) is a method of local tissue destruction for solid tumors such as irresectable hepatic metastases from colorectal cancer. With the availability of new magnetic resonance (MR) techniques, which allow real time tissue temperature mapping, it is essential to know the critical temperature and exposure times leading to cell death. MATERIALS AND METHODS/STUDY DESIGN: Samples (8 mm(3)) of solid rat tumor (CC-531, syngenic to the WAG/Rij rat strain), were warmed in tubes for four different temperatures (40, 50, 60 or 80 degrees C) and four different exposure times (3, 6, 12, or 24 minutes). Combinations were replicated in five-fold. Cell viability was assessed with three methods: Trypan blue exclusion test in collagenase/dispase dissociated samples, NADH activity in snap frozen samples and outgrowth for 2 weeks under the renal capsule of WAG/Rij rats. RESULTS: Results of the three methods revealed that viability was not affected with heating at 40 and 50 degrees C except for 24 minutes at 50 degrees C. At higher temperatures cell death occurred at all exposure times. CONCLUSION: The temperature range resulting in sufficient tissue coagulation for cell death is between 50 degrees C and 60 degrees C for a short duration (<3 minutes). These data can be used to achieve complete tumor destruction and minimal surrounding tissue damage during real-time MR-controlled ILC.

Animals↗