| 1. |
- Möller, Páll H., et al.
(författare)
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Interstitial laser thermotherapy : Comparison between bare fibre and sapphire probe
- 1995
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 10:3, s. 193-200
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Tidskriftsartikel (refereegranskat)abstract
- A sapphire probe and a bare fibre were compared with respect to temperature control and distribution and light fluence in interstitial laser thermotherapy. Experiments were performed in processed liver using an Nd-YAG laser and output power levels of 1-4 W. The temperature was controlled at a distance of 10 mm using a feedback circuit with an automatic thermometry system and thermistor probes. With the sapphire probe, carbonization was rare at power levels of 1-2 W but was observed in half of the experiments at 3 W and in all experiments at 4 W. Using the bare fibre, carbonization was seen in almost all experiments. Absence of carbonization was associated with a moderate decrease in the penetration of light and excellent control of the temperature, whereas carbonization led to rapid impairment of light penetration and temperature control. In addition, the temperature gradient was smaller with the sapphire probe than with the bare fibre or when carbonization was absent. It is concluded that a diffuser tip, such as the sapphire probe, may be preferable to the bare fibre for interstitial laser thermotherapy because it gives a smaller temperature gradient and helps to avoid carbonization which results in preserved light penetration and improved temperature control.
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| 2. |
- Möller, Páll H., et al.
(författare)
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Interstitial laser thermotherapy in pig liver : Effect of inflow occlusion on extent of necrosis and ultrasound image
- 1997
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Ingår i: Hepato-Gastroenterology. - 0172-6390. ; 44:17, s. 1302-1311
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Tidskriftsartikel (refereegranskat)abstract
- 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 3 W or without inflow occlusion at 5 W (target temperature 43°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 3 W (p < 0.01). Increase in laser power from 3 to 5 W 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.
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| 3. |
- Ohlsson, Björn, et al.
(författare)
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Follow-up after curative surgery for colorectal carcinoma - Randomized comparison with no follow-up
- 1995
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Ingår i: Diseases of the Colon & Rectum. - 0012-3706. ; 38:6, s. 619-626
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: This study investigated the value of intense follow-up compared with no follow-up after curative surgery of cancer in the colon or rectum. METHODS: One hundred seven patients were randomized to no follow-up (control group; n=54) or intense follow-up (follow-up group; n=53) after surgery and early postoperative colonoscopy. Patients in the follow-up group were followed at frequent intervals with clinical examination, rigid proctosigmoidoscopy, colonoscopy, computed tomography of the pelvis (in patients operated with abdominoperineal resection), pulmonary x-ray, liver function tests, and determinations of carcinoembryonic antigen and fecal hemoglobin. Follow-up ranged from 5.5 to 8.8 years after primary surgery. RESULTS: Tumor recurred in 18 patients (33 percent) in the control group and in 17 patients (32 percent) in the follow-up group. Reresection with curative intent was performed in three patients in the control group and in five patients (four of whom were asymptomatic) in the follow-up group. In the follow-up group two asymptomatic patients with elevated carcinoembryonic antigen levels were disease-free three and five and one-half years after reresection and were the only patients apparently cured by reresection. No patient underwent surgery for metastatic disease in the liver or lungs. Symptomatic metachronous carcinoma was detected in one patient (control group) after three years. Five-year survival rate was 67 percent in the control group and 75 percent in the follow-up group (P >0.05); the corresponding cancer-specific survival rates were 71 percent and 78 percent, respectively. CONCLUSION: Intense follow-up after resection of colorectal cancer did not prolong survival in this study.
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