William R. Lees

Comparison of resection and radiofrequency ablation for treatment of solitary colorectal liver metastases

Liver resection is the treatment of choice for patients with solitary colorectal liver metastases. In recent years, however, radiofrequency ablation has been used increasingly in the treatment of colorectal liver metastases. In the absence of randomized clinical trials, this study aimed to compare outcome in patients with solitary colorectal liver metastases treated by surgery or by radiofrequency ablation.

Interstitial laser hyperthermia: a new approach to local destruction of tumours.

The use of local hyperthermia to treat cancer of the internal organs has been limited by the difficulty of controlling delivery of heat and limiting the effects to the tumour, but this can be overcome by using laser light transmitted through thin flexible fibres. Laser energy was delivered to tumours through fibres inserted percutaneously through needles directly into the centre of the tumour area. Ultrasound scanning was used to locate the tumour, position the fibres correctly within the tumour, and monitor the development of thermal necrosis in real time during laser exposure and through the subsequent period of healing. Five patients were treated (one with a tumour of the breast, one with a subcutaneous secondary tumour, one with a recurrent pancreatic tumour, and two with secondary tumours in the liver). Tumour necrosis was found on ultrasonography or computed tomography in all, and there were no immediate or delayed complications. In one patient the size of the isolated secondary tumour in the liver had not increased over 10 months, and he subsequently showed no other evidence of residual cancer. To develop this technique careful studies are essential to ensure that in every case the extent of thermal necrosis produced by absorption of the laser light can be matched to the full extent of the tumour being treated and that there is always sufficient adjacent normal tissue to ensure safe healing. These preliminary results suggest that this simple technique can be applied safely and effectively to common tumours in humans; more extensive trials in a range of cancers of solid organs are warranted.

Photodynamic Therapy for Prostate Cancer Recurrence After Radiotherapy: A Phase I Study

PURPOSE Photodynamic therapy, using a photosensitizing drug activated by red light, can destroy localized areas of cancer with safe healing and without the cumulative toxicity associated with ionizing radiation. We used photodynamic therapy in a phase I-II study to treat patients with locally recurrent prostate cancer after radiotherapy. MATERIALS AND METHODS Patients with an increasing prostate specific antigen (PSA) and biopsy proven local recurrence after radiotherapy were offered photodynamic therapy. Three days after intravenous administration of the photosensitizer meso-tetrahydroxyphenyl chlorin, light was applied using optical fibers inserted percutaneously through perineal needles positioned in the prostate with imaging guidance. Patients were followed with PSA measurements, prostate biopsies, computerized tomography or magnetic resonance imaging and questionnaires on urinary and sexual function. RESULTS Photodynamic therapy was given to 14 men using high light doses in 13. Treatment was well tolerated. PSA decreased in 9 patients (to undetectable levels in 2) and 5 had no viable tumor on posttreatment biopsies. After photodynamic therapy, contrast enhanced computerized tomography or magnetic resonance imaging showed necrosis involving up to 91% of the prostate cross section. In 4 men stress incontinence developed (troublesome in 2 and mild in 2) which is slowly improving. Sexual potency was impaired in 4 of the 7 men able to have intercourse before photodynamic therapy, which did not improve. There were no rectal complications directly related to photodynamic therapy, but in 1 patient a urethrorectal fistula developed following an ill-advised rectal biopsy 1 month after therapy. CONCLUSIONS Photodynamic therapy is a new option that could be suitable for organ confined prostate cancer recurrence after radiotherapy. With more precise light dosimetry, it may be possible to destroy essentially all glandular tissue within the prostate with few complications. These results suggest that photodynamic therapy merits further investigation.

Non-invasive perinatal necropsy by magnetic resonance imaging

BACKGROUND AT present necropsy is done in less than 60% of cases of perinatal death in the UK, despite the value of the procedure to the bereaved parents and their doctors. This low rate reflects the difficulty in discussing the examination during the acute distress after the death of a baby, and the personal and religious objections of many parents to necropsy. We compared post-mortem magnetic resonance imaging (MRI) of the fetus with internal perinatal necropsy to assess whether MRI examination is a feasible option for the 40% of cases where consent for necropsy is not given or requested. METHODS We examined 20 stillborn, miscarried, or aborted fetuses by MRI and necropsy. Scanning was done in a 1.5 T system, in accordance with our protocol, immediately before necropsy. The MRI and necropsy findings were compared to assess how much diagnostic information was obtained by each technique. FINDINGS In eight of the 20 cases the two examinations were in total agreement about the abnormalities present. In eight cases the necropsy provided more detailed information than MRI examination, but in four cases the MRI information was more extensive than that obtained at necropsy. In two of the latter cases, abnormalities of the central nervous system were seen only on MRI. Thus, in 12 (60%) of the 20 cases studied, MRI had equivalent or better diagnostic sensitivity than internal necropsy examination; in 18 (90%) of the 20 cases the two examinations were of similar clinical significance. INTERPRETATION MRI of the stillborn or aborted fetus provides non-invasive access to information previously available only from necropsy.

Autoimmune Pancreatitis: Clinical and Radiological Features and Objective Response to Steroid Therapy in a UK Series

OBJECTIVE:Most cases of autoimmune pancreatitis (AIP) have been reported from Japan. We present data on a UK series, including clinical and radiological features at presentation, and longitudinal response to immunosuppression.METHODS:Over an 18-month period, all patients diagnosed in our center with AIP were studied. Endoscopic biliary stenting was performed as required, and patients were treated with prednisolone, with response assessed longitudinally. In cases of disease relapse following steroid reduction, azathioprine was instituted.RESULTS:Eleven patients met diagnostic criteria for AIP. Diffuse pancreatic enlargement was seen in eight patients (73%), and pancreatic duct strictures in all. Seven patients required biliary stents. Extrapancreatic involvement occurred in all, including intrahepatic stricturing and renal disease. Eight weeks after starting steroids, the median serum bilirubin level had fallen from 38 μmol/L to 11 μmol/L (P = 0.001), and ALT from 97 IU/L to 39 IU/L (P = 0.002). Stents were removed in all cases, with no recurrence of jaundice. Improvements in mass lesions and pancreaticobiliary stricturing occurred in all patients. During a median 18-month follow-up, six patients relapsed, four of whom responded to azathioprine. Two patients discontinued steroids and remained well.CONCLUSIONS:Extrapancreatic disease was an important feature of AIP in this UK series. Initial response to immunosuppressive therapy was excellent, but disease relapse was common. Optimal long-term management remains to be established.

Survival after percutaneous, image-guided, thermal ablation of hepatic metastases from colorectal cancer.

PURPOSE: One-year, two-year, three-year, and four-year survival rates and median survival time for patients with inoperable liver metastases from colorectal cancer is 32, 10, and 3 percent and 7.4 to 11 months, respectively. Systemic chemotherapy produces a modest improvement to 48, 21, and 3 percent and 12 months, respectively. Regional chemotherapy produces a further improvement to 64, 25, and 5 percent and 15 to 17 months, respectively. For those with operable disease, hepatic resection survival rates are 90, 62, 48, and 40 percent, respectively, and survival time is 33 months. Thermal ablation is effective in producing necrosis in liver metastases. We report the impact on survival in 69 patients treated from 1993 to 1997, with follow-up to 1998. METHODS: Sixty-nine patients, 50 male, mean age 60 (range, 33–87) years were treated. Liver resection was not feasible because of disease extent in the liver, extrahepatic disease or concurrent medical conditions. The average number of liver metastases was 2.9 (range, 1–16), the mean maximal diameter was 3.9 (range, 1–8) cm, and the mean initial total liver tumor volume was 47 (range, 1–371) ml. Eighteen (26 percent) had undergone previous hepatic resection. Sixty-two of 67 (93 percent) received chemotherapy at some stage. Twenty (29 percent) had extrahepatic disease. RESULTS: One-year, two-year, three-year, and four-year survival rates and median survival time from liver metastasis diagnosis was 90, 60, 34, and 22 percent and 27 months, respectively. Forty of 69 (58 percent) developed new liver metastases, and 23 of 69 (33 percent) developed new extrahepatic disease. Of a subgroup of 24 patients with less than four metastases, <5 cm diameter, treated after January 1995, the median survival time was 33 months from first thermal ablationvs. 15 months for the remainder (P=0.0004). Major morbidity occurred in 3.2 percent, minor morbidity occurred in 12 percent, and there was one periprocedural death. CONCLUSIONS: Thermal ablation therapy improves survival in patients with inoperable but limited liver metastases. This is an improvement on the natural history of the disease and published chemotherapy results. Recent and ongoing technical refinements, not reflected in these results, are expected to further improve survival.

Fetal echocardiography in three and four dimensions

A three-dimensional (3D) acquisition system using an electromagnetic position sensor attached to a standard transducer on an unmodified ultrasound scanner was developed to capture two-dimensional (2D)-fetal echocardiograms at various positions and orientations. Operating in real-time directed M-mode allowed recording of 2D structural images and cardiac motion curves, from which the fetal cardiac phase could be determined. By digitising over 100 image frames for each scanning sequence, and by selecting frames at particular phases, 3D views of the fetal heart were reconstructed for each phase. Of 20 sequences of six fetuses scanned, 13 sequences successfully demonstrated usable 3D fetal heart structures, including four cardiac chambers, ventricular and atrial septa, foramen ovale and some of the cardiac valves and great vessels. Rearrangement of those phased 3D images into a cyclic sequence could generate dynamic 3D views of a beating fetal heart. We believe that, with further technical development, this new approach will be of use in the diagnosis of prenatal cardiac malformations and malfunctions, in in utero cardiac surgery and in fetal cardiology teaching.

Non-invasive screening for renal artery stenosis with ultrasound contrast enhancement.

Objective Our aim was to evaluate duplex ultrasound imaging in the identification of renal artery stenosis using a new technique to enhance the recorded Doppler signal. Design Colour Doppler studies of interlobar renal arteries were performed before and after enhancement using an intravenous contrast of galactose microparticle suspension containing microbubbles (Levovist, Schering) in patients with angiographically confirmed renal artery stenosis. Setting Blood Pressure Unit, St. Georges Hospital Medical School, and Department of Radiology, The Middlesex Hospital, London, UK. Participants Twenty-one consecutive hypertensive patients in whom the diagnosis of renal artery stenosis was made on digital subtraction angiography. Main outcome measures The diagnosis of haemodynamically significant renal artery stenosis (≥60% on angiography). Results With Levovist, there was a 20 db increase in the Doppler intensity and, as a result, intrarenal signals were much more clearly delineated and distinct spectral waveforms were obtained from all but one kidney, which was occluded. Significant associations were found between the degree of stenosis (as assessed by angiography) and the following Doppler parameters: diastolic velocity (F=7.6; P < 0.01), acceleration time (F=33.5, < 0.0001), peak systolic velocity (F=37.7, P < 0.0001) and acceleration (F=60.0; P < 0.0001). Without enhancement, there were five false-positive and two false-negative examinations (sensitivity 85%; specificity 79%) using the acceleration cut-off value of 3.5 m/s2 to identify haemodynamically significant renal artery stenosis (≥60% on angiography). After contrast enhancement, there were only three false-positive and one false-negative examinations (sensitivity 94% and specificity of 88%) using the acceleration cut-off value of 3.75 m/s2 and the examination time was reduced by approximately half (sensitivity and specificity of 90% using the acceleration cut-off value of 3.5 m/s2). Conclusions Our results suggest that renal duplex scanning using contrast enhancement is a promising new non-invasive technique in screening patients with suspected renal artery stenosis. Contrast enhancement produces more reproducible spectral waveforms, improves accuracy and halves the examination time.

CT mapping of the distribution of saline during radiofrequency ablation with perfusion electrodes

PurposeDuring radiofrequency (RF) ablation, adjunctive saline increases the size of the ablation zone and therefore electrodes that simultaneously deliver current and saline have been developed, but the addition of saline also results in an irregular ablation zone. Our aim was to study the distribution of saline during RF ablation.MethodsFour patients were treated: 3 with liver metastases and 1 with hepatocellular carcinoma (HCC). Two different perfusion electrodes were used: a high-perfusion-rate, straight electrode (Berchtold, Germany) and a low-perfusion-rate, expandable electrode (RITA Medical Systems, USA). The saline perfusate was doped with non-ionic contrast medium to render it visible on CT and the electrical conductivity was measured. CT scans were obtained of each electrode position prior to ablation and repeated after ablation. Contrast-enhanced CT was performed 18–24 hr later to demonstrate the ablation zone. All treatments were carried out according to the manufacturer’s recommended protocol.ResultsThe addition of a small quantity of non-ionic contrast did not alter the electrical conductivity of the saline. Contrast-doped saline extravasated beyond the tumor in all 3 patients with metastases but was limited in the patient with HCC. In some areas where saline had extravasated there was reduced enhancement on contrast-enhanced CT consistent with tissue ablation. One patient treated with the high-perfusion-rate system sustained a jejunal perforation requiring surgery.ConclusionSaline can extravasate beyond the tumor and with the high-perfusion-rate system this resulted in an undesirable extension of the ablation zone and a complication.

Prospective study comparing multislice CT colonography with colonoscopy in the detection of colorectal cancer and polyps.

AbstractPURPOSE: Multislice CT colonography is an alternative to colonoscopy. The purpose of this study was to compare multislice CT colonography with colonoscopy in the detection of colorectal polyps and cancers. METHODS: Between June 2000 and December 2001, 45 males and 35 females (median age, 68 (29–83) years) with symptoms of colorectal disease were studied prospectively. All patients underwent multislice CT colonography and colonoscopy, and the findings were compared. RESULTS: Colonoscopy was incomplete in 18 (22 percent) patients because of obstructing lesions or technical difficulty, and multislice CT colonography was unsuccessful in 4 (5 percent) because of fecal residue. Colonoscopy was normal in 26 patients and detected 29 colorectal cancers and 33 polyps in 35 patients, diverticulosis in 16 patients, and colitis in 3 patients. Multislice CT colonography identified 28 of 29 colorectal cancers with one false negative and one false positive (sensitivity, 97 percent; specificity, 98 percent; positive predictive value, 96 percent; negative predictive value, 98 percent). Multislice CT colonography identified all 12 polyps measuring ≥10 mm in diameter (sensitivity, 100 percent), 5 of 6 measuring 6 to 9 mm in diameter (sensitivity, 83 percent), 8 of 15 polyps ≤5 mm (sensitivity, 53 percent), and false-positive for 8 polyps. The overall sensitivity was 74 percent and specificity 96 percent. The positive predictive value for polyps was 88 percent, and the negative predictive value was 90 percent. Multislice CT colonography also detected 5 of 16 patients with diverticulosis (sensitivity, 31 percent; specificity, 98 percent) and colitis in 2 of 3 patients (sensitivity, 67 percent; specificity, 100 percent). In ten (13 percent) patients, extracolonic findings on multislice CT colonography altered management and included five patients with colorectal liver metastases. In 15 (19 percent) patients, there were incidental findings that did not demand further investigation. CONCLUSIONS: The results from this study indicate that the efficacy of multislice CT colonography in the detection of colorectal cancers and polyps ≥6 mm is similar to colonoscopy. Multislice CT colonography allows clinical staging of colorectal cancers, outlines the whole length of the colon in obstructing carcinoma when colonoscopy fails, and can identify extracolonic causes of abdominal symptoms.