The role of 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography in the management of patients with carcinoma of unknown primary.

PURPOSE: Carcinoma of unknown primary is one of the ten most frequent cancers worldwide. Its median survival time is less than 10 months. Detecting primary tumour locations and/or occult metastatic lesions may inform definitive treatment and improve patients' prognosis. We aimed to determine: (1) the sensitivity, specificity and accuracy of (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography; (2) its detection rate of primary tumour locations and occult metastases and (3) factors associated with improved survival times. METHODS: We retrospectively reviewed all cases in the West of Scotland for the period 1 December 2007 to 31 May 2011 that met all our selection criteria: (1) diagnosis of carcinoma of unknown primary; (2) a thorough but negative 'work-up' and (3) (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography report. Statistical methods included frequencies, Kaplan-Meier graphs and log-rank tests to compare survival times. RESULTS: (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography detected primary tumour sites in 19/51 (37.3%) and occult metastases in 28/51 (54.9%) of eligible patients. Its sensitivity, specificity and accuracy were 79.2%, 70.4% and 74.5%, respectively; 20/51 (39.2%) patients died during the study period with a median survival of 8.4 months (range 21.4, SD ± 6.2). The number of metastatic locations was strongly associated with survival (p = 0.002), but detection of a primary tumour site (p = 0.174) or histopathology (p = 0.301) was not. CONCLUSION: (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography detected occult metastatic sites in the majority and a primary cancer location in a substantial minority of patients. Our results were comparable with international literature and may indicate that (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography have an early role to improve the accuracy of cancer staging and to optimise carcinoma of unknown primary management.

The role of imaging in the pre-operative staging and post-operative follow-up of rectal cancer.

Developments in rectal cancer imaging have revolutionised the management of this condition. It has become increasingly important for oncologists and surgeons to have a working insight into radiological assessment in order to make informed clinical decisions. In this context, we discuss the role that imaging plays in the pre-operative staging, post-operative follow-up and therapy of this disease including some novel advances in the field. Rectal cancer outcomes have improved due to modern surgical techniques, namely total mesorectal excision. Meticulous pre-operative assessment remains key. Conventional TNM staging now appears less crucial compared to assessing tumour distance from the potential plane of surgical resection (particularly the circumferential margin bounded by the mesorectal fascia), and this is reliant on high-quality imaging. Those with margin threatening disease can be offered downstaging chemoradiotherapy to facilitate successful resection. Endorectal ultrasound is useful for T staging and CT for detecting metastases. Malignant lymph node identification remains a problem and the use of size and morphological criteria may lead to misdiagnosis. In the post-operative setting, intensive follow-up is associated with improved outcomes but there are many variations in protocols. Most modalities struggle to differentiate tumour from reactive or fibrotic tissue and functional imaging is being investigated as the solution. PET scanning, particularly PET/CT, has been a major recent development. It has superior utility in detecting recurrent disease, including when conventional imaging is negative, detects occult metastases and may significantly enhance our ability to deliver accurate radiotherapy. Imaging has also opened up avenues for guided therapies aimed at ablating liver metastases. Radiofrequency ablation, in particular, is being used successfully and can improve survival of stage four patients.

Colobronchial fistula: a late complication of childhood radiotherapy.

We present the case of a colobronchial fistula in a 41-year-old man who underwent radiotherapy for nephroblastoma as an infant. He attended for barium enema, which demonstrated a fistula between colon and bronchial tree. Following right hemicolectomy and pathological examination of the resected bowel, no active disease process was identified to explain the development of this rare fistula. Radiotherapy was deemed the most probable aetiology. We are unaware of this having been previously described.

Colorectal stenting for colonic obstruction: the indications, complications, effectiveness and outcome--5 year review.

INTRODUCTION: Currently self-expanding metallic stents are being used for palliation and acute decompression of colonic obstruction. The aim of this study is to review our experience of using these metallic stents over a 5-year period. MATERIALS AND METHODS: Case records of 102 patients who had colorectal stenting between 1998 and 2004 were reviewed retrospectively. The indications for colorectal stenting, efficacy of the procedure in relieving the obstruction, complications and clinical outcome were analysed. RESULTS: Ninety-nine patients had malignant disease and in three patients a benign cause of obstruction was demonstrated. All procedures were performed during normal working hours. Stenting was technically successful in 87 patients (85%). A single stent was placed in 80 patients. Seven patients required two stents. Of the successful cases, 67 had stents placed by fluoroscopy alone and 20 by a combined fluoroscopy/endoscopy procedure. Four percent had early complications (within 30 days) which included four perforations. There were late complications (over 30 days) in 9% which included five stent migrations, two blocked stents and one colovesical fistula. Ninety percent (n=76) of the successful patients needed no further radiological or surgical intervention later. Survival ranged from 14 days to 2 years. CONCLUSION: Colorectal stenting when technically successful is an effective procedure for both preoperative and palliative decompression of colonic obstruction.

Accuracy and cost-effectiveness of dynamic contrast-enhanced CT in the characterisation of solitary pulmonary nodules-the SPUtNIk study.

INTRODUCTION: Solitary pulmonary nodules (SPNs) are common on CT. The most cost-effective investigation algorithm is still to be determined. Dynamic contrast-enhanced CT (DCE-CT) is an established diagnostic test not widely available in the UK currently. METHODS AND ANALYSIS: The SPUtNIk study will assess the diagnostic accuracy, clinical utility and cost-effectiveness of DCE-CT, alongside the current CT and 18-flurodeoxyglucose-positron emission tomography) (18FDG-PET)-CT nodule characterisation strategies in the National Health Service (NHS). Image acquisition and data analysis for 18FDG-PET-CT and DCE-CT will follow a standardised protocol with central review of 10% to ensure quality assurance. Decision analytic modelling will assess the likely costs and health outcomes resulting from incorporation of DCE-CT into management strategies for patients with SPNs. ETHICS AND DISSEMINATION: Approval has been granted by the South West Research Ethics Committee. Ethics reference number 12/SW/0206. The results of the trial will be presented at national and international meetings and published in an Health Technology Assessment (HTA) Monograph and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN30784948; Pre-results.

Accuracy of thin section magnetic resonance using phased-array pelvic coil in predicting the T-staging of rectal cancer.

Magnetic resonance (MR) imaging may contribute to staging rectal cancer and inform the decision regarding administration of pre-operative radiotherapy. The accuracy of MR has been debated. The aim of the present study was to determine the accuracy of thin section T2-weighted MR images in rectal cancer patients. MR results were compared with histological assessment of resection specimens. Over a 2-year period, 42 patients were studied. Histological staging was pT2 n = 13, pT3 n = 25 and pT4 n = 4. MR diagnostic accuracy was 74%. MR sensitivity and specificity was 62% and 79% for pT2 lesions, 84% and 59% for pT3 lesions and 50% and 76% for pT4 lesions. Estimation of tumour penetration by thin section MR imaging of rectal cancers using pelvic phased-array coil has moderate diagnostic accuracy. The limitations of MR should be acknowledged when selecting rectal cancer patients for pre-operative radiotherapy.

Vertebral metastases and an equivocal bone scan: value of magnetic resonance imaging.

To assess the value of magnetic resonance imaging (MRI) in the investigation of patients with suspected but nonproven vertebral metastases 45 consecutive patients referred in a 6 month period with known primary malignancy and back pain in whom an isotope bone scan was reported as equivocal were studied. All patients had abnormal isotope uptake localized to the spine. Twelve patients were shown to have bony metastases on plain X-ray. In the remainder, where X-rays showed normal or benign appearance, MRI of the spine was offered. Twenty-four patients underwent MRI examination which showed vertebral metastases in 11 cases. Magnetic resonance imaging is shown to be a useful, noninvasive, complementary investigation for evaluation of patients known to have malignant disease and suspected of having vertebral metastases on bone scintigraphy.

A prospective study of six methods for detection of hepatic colorectal metastases.

Many techniques are available for the identification of patients with hepatic colorectal metastases. The accuracy and clinical relevance of transabdominal ultrasound (US), computed tomography (CT), static scintigraphy, dynamic scintigraphy (HPI), intraoperative ultrasound (IOUS) and manual palpation, in the detection of intrahepatic colorectal metastases were assessed in 73 consecutive patients presenting with colorectal carcinoma; 39 were male and 34 female with a mean age of 68 years (range 43-90 years). In 33 patients either intraoperative ultrasound or palpation were omitted owing to emergency presentation (n = 14) or subsequent non-operative management (n = 19). All six investigations were completed in 40 patients. Computed tomography and hepatic perfusion scintigraphy (HPI) were the most sensitive, detecting over 90% of lesions, the others identifying approximately 80% of lesions, Specificity in all methods, apart from dynamic scintigraphy, was over 80%. Contrast-enhanced CT would appear to remain the most accurate method available. However, if the prognostic ability of HPI is confirmed on subsequent follow-up, the accuracy of HPI will rise with time, whereas that of CT will fall. Intraoperative ultrasonography took time to perform and did not alter the management of any patient within the study. We suggest that its use is limited to those patients in whom resection is contemplated, where the vascular anatomical detail provided may be invaluable.

Technical report: evacuating proctography--a simplified technique.

We describe a prospective study of 63 patients with proctological symptoms, comparing the radiological findings when performing evaluating proctography in both the sitting and left lateral positions. We found that although the left lateral method was slightly less sensitive, the abnormalities missed represented only minor early changes and were of no clinical significance. We conclude that the technique we have described could be adopted easily as a screening procedure for patients with unexplained anorectal symptoms.

Perineal herniation.

In a retrospective study of 800 evacuating proctograms, 37 patients were found to have a varying degree of perineal herniation. The radiological and surgical correlation of this interesting abnormality was discussed.

Late focal pancreatic metastasis of renal cell carcinoma.

Metastatic carcinoma to the pancreas is uncommon. Pancreatic metastasis from a renal cell carcinoma is exceptional, but may occur many years after the initial diagnosis and treatment of the primary tumor. Presentation of our patient mimicked a head of the pancreas carcinoma so well that it was only after the resectional phase of a Whipple operation that the diagnosis of metastatic renal carcinoma was made 18 years after left nephrectomy. The patient is alive and well 18 months after surgery, having gained weight.

Pethidine-augmented white cell scintigraphy in inflammatory bowel disease.

Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scintigraphy is invaluable for assessing the presence and extent of disease activity in patients with inflammatory bowel disease. Interpretation of images can be compromised by physiological excretion of tracer into the bowel via the biliary tree. This study assesses the effect of intravenous pethidine administered with the labelled white cells in an attempt to reduce the enterohepatic circulation of the tracer. Ninety-one subjects with proven or suspected inflammatory bowel disease were included in this study, all of whom underwent 99mTc-HMPAO white cell scintigraphy. The control group of 50 subjects underwent the standard protocol for this study performed in our department. The other 41 subjects received an intravenous injection of 0.3 mg/kg of pethidine at the same time as re-injection of the labelled white cells. Images were graded using a five-point scale at both 1 and 2.5 h and categorised as positive, negative or non-diagnostic. Each scan was also assessed for the presence of a visible gall-bladder. The pethidine group had significantly fewer non-diagnostic scans than the control group (P=0.003), and significantly (P=0.001) more studies in which the gall-bladder was visualised. It is concluded that the use of pethidine appears to reduce biliary excretion of tracer during 99mTc-HMPAO white cell scintigraphy. This may allow the delayed images, and early images with low-grade tracer uptake in the bowel, to be interpreted with greater confidence and thereby reduce the number of scans classified as non-diagnostic.

Videoproctography in selecting patients with constipation for colectomy.

The results of colectomy for constipation based only on evidence of delayed colonic markers have been disappointing. The operation may fail because these patients are unable to evacuate the rectum owing to outlet obstruction. In the present study, we have used a combination of videoproctography and transit marker studies in an attempt to predict patients who will have a favorable outcome after colectomy by excluding patients with outlet obstruction. Videoproctography was performed in 228 patients referred for consideration of surgery for constipation. Only 111 (38 percent) had a normal proctogram with complete evacuation of liquid barium. Of these 111 patients, 21 (19 percent) had delayed colonic marker studies. Colectomy and ileorectal anastomosis were performed in 18 of these 21 patients; two years later, 16 were symptom free, with a median daily bowel frequency of four (range, two to six). The remaining two patients failed to respond to surgery. These data suggest that true idiopathic, slow-transit constipation is uncommon, but, when identified on the basis of delayed markers and the ability to expel liquid on proctography, an excellent result can be anticipated from colectomy and ileorectal anastomosis.

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis.

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography.

A prospective randomized study of abdominal rectopexy with and without sigmoidectomy in rectal prolapse.

Eighteen patients with full-thickness prolapse of the rectum were randomized to rectopexy alone (group 1) or with sigmoidectomy (group 2). Three months postoperatively, seven patients in group 1 and two in group 2 complained of severe constipation. One patient in group 1 and three patients in group 2 remained incontinent. The results of colonic marker studies showed a significant increase in the number of markers at day 5 for those in group 1 (preoperative, 7.7 +/- 2.6; postoperative, 14.6 +/- 2.2; t test, p less than 00.1) but no significant increase in group 2 (preoperative, 4.6 +/- 2.2; postoperative 6.8 +/- 2.3; t test, p less than 0.01). No significant changes or differences between the groups were seen in the anorectal angle on videoproctogram. The results of anorectal physiologic studies done postoperatively showed no differences between the groups in maximum resting pressure, sphincter length or saline solution infusion test; however, the patients in group 1 had a significantly greater rectal compliance (group 1, 0.24 +/- 0.02 millimeters mercury per milliliter; group 2, 0.1 +/- 0.02 millimeters mercury per milliliter; p less than 00.1). This may occur because the redundant loop of sigmoid colon causes hold-up of intestinal content and kinking at the junction between the sigmoid colon and the rectum.