Biomedical subjects
Publications and source records attributed to I R Francis.
A case of metastatic transitional cell carcinoma (TCC) to the ovaries in a patient with prior grade I TCC of the bladder, which morphologically resembled a primary ovarian malignancy on computed tomography (CT), is described. Other tumors whose ovarian metastases can resemble primary ovarian tumors are also listed.
Fourteen patients with refractory advanced neuroblastoma were treated with 131-I-metaiodobenzylguanidine (131-I-MIBG); all had evidence of progressive disease or recurrent disease following combination chemotherapy. One patient without gross evidence of disease, following surgical resection of recurrent neuroblastoma before therapy with 131-I-MIBG, remains healthy without regrowth of tumor 3.5 years later. Two other patients had minor responses, and one had a mixed response. Two patients remain alive 1,212 and 1,926 days following the initial 131-I-MIBG treatment; the remaining 12 patients died of progressive disease. Moderate myelosuppression was the most notable toxicity observed; mild nausea and vomiting and transient mild liver enzyme elevation were also encountered. Treatment with 131-I-MIBG produced antineoplastic activity in patients with neuroblastoma and was well tolerated. To evaluate dose escalation, alternative dosage schedules, and alternative MIBG-radioconjugates, additional trials of radiolabeled MIBG are indicated.
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Fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging provides images with highly T2-weighted contrast in substantially reduced imaging times. In a prospective evaluation, fast SE T2-weighted imaging of the pelvis was compared with conventional SE T2-weighted imaging in 30 consecutive patients in whom pelvic pathologic conditions were suspected. Three reviewers independently analyzed the images for (a) overall image quality, (b) pelvic organ definition, (c) conspicuity of pelvic fluid, and (d) conspicuity of pelvic pathologic conditions. Fast SE images were rated superior to conventional SE T2-weighted images in 60% (54 of 90) of the case reviews for overall image quality, in 69% (62 of 90) for pelvic organ definition, in 63% (57 of 90) for conspicuity of pelvic fluid, and in 68% (43 of 63) for conspicuity of pelvic pathologic conditions. The fast SE examinations were typically three to four times faster than conventional SE T2-weighted examinations. No pathologic findings seen on conventional SE T2-weighted images were undetected on fast SE images. Fast SE images may replace conventional SE T2-weighted images in MR imaging of the pelvis.
PURPOSE: This study was undertaken to evaluate the tumor targeting, toxicity, and therapeutic potential of the anti-B-cell-reactive monoclonal antibody MB-1 (anti-CD37) labeled with iodine 131 given in a nonmarrow ablative dose range in B-cell lymphoma patients who relapsed after chemotherapy. PATIENTS AND METHODS: Twelve patients with MB-1-reactive tumors were infused first with 40 mg of trace-labeled (3 to 7 mCi) MB-1. Ten patients who had no serious toxicity postinfusion and who had successful tumor imaging on serial gamma scans then received at least one 40-mg radioimmunotherapy (RIT) dose (25 to 161 mCi). Tracer estimates of delivered whole-body dose (WBD) were used in prescribing a millicurie RIT dose for seven patients. RESULTS: Eleven patients had positive tumor imaging after a tracer dose, including patients with bulky tumors and/or large tumor burdens (> or = 1 kg) +/- splenomegaly. However, overall sensitivity for the detection of known tumor sites was only 39%. In six of eight patients with dose-assessable tumors, the radiation dose to at least one tumor was 1.1 to 3.1 times higher than to any normal organ, excluding the spleen for a 40-mg tracer dose. Tracer-dose toxicities included reversible glossal edema in one patient, grade 3 hepatic transaminasemia in another, and early drops in both circulating B and T cells (with decreases in B cells more pronounced) in nearly all patients. RIT toxicity was primarily myelosuppression (especially thrombocytopenia), which had a delayed onset and protracted recovery (without significant recovery until at least 2 months post-RIT). Grade 3 myelosuppression in two of two patients who were treated at a tracer-projected 50-cGy WBD level (133 and 149 mCi) precluded further planned RIT dose escalation. Less myelosuppression was generally observed in patients who were treated at < or = 40-cGy WBD levels. Antimouse antibodies developed in two patients. Six patients had tumor responses post-RIT. Four had responses that lasted more than 1 month (2 to 6 months), which included one complete response, one partial response, one minor response, and one mixed response. Responses seemed to occur more frequently in imaged tumors than in nonimaged tumors. The most durable response occurred in a patient who had the best antibody targeting to tumor. CONCLUSIONS: Although 131I-MB-1 has limited diagnostic value, it can produce tumor responses at nonmarrow ablative RIT doses. Further studies that focus on improving tumor targeting with this or other B-cell-reactive radiolabeled antibodies and on ameliorating the myelosuppression associated with the RIT-dosing approach used in this trial are warranted.
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CT examinations of 25 patients with proved primary or metastatic duodenal neoplasms were retrospectively reviewed to determine if morphologic features seen on CT scans could be used to predict the benign or malignant nature of these neoplasms and to assess the effectiveness of using CT findings to predict tumor resectability. We studied 19 malignant and six benign tumors. Histologic proof was obtained by means of surgery in 20 patients and by endoscopic biopsy in five. CT features of tumor morphology were assessed in the 22 cases in which a duodenal tumor was seen on CT. These features included central necrosis, ulceration or excavation, and the location of the tumor with respect to the bowel wall. The specific morphologic features used to predict that a tumor was malignant included the presence of an exophytic or intramural mass, central necrosis, and ulceration. The only criterion used to predict that a tumor was benign was that the mass be entirely intraluminal. Whenever vascular encasement, invasion of contiguous organs other than the head of the pancreas, distant lymphadenopathy, or metastases were present, the tumor was predicted to be unresectable for cure. With the exception of three benign smooth muscle tumors, all tumors with one or more CT morphologic features indicative of a malignant neoplasm were malignant (n = 16). Three of four intraluminal masses were benign. In three cases of polypoid tumors smaller than 2 cm, a duodenal tumor was not seen on CT. Whenever extraduodenal disease was found (15 cases), the neoplasms were malignant. In the 22 cases in which a tumor was detected on CT, the sensitivity of using the presence of one or more morphologic features associated with a malignant neoplasm as a predictor was 94%; the specificity was 50%, and the accuracy was 82%. If the presence of any morphologic feature indicative of a malignant neoplasm was combined with the presence of any finding of extraduodenal disease, CT was 100% sensitive and 86% accurate for predicting that the tumor was malignant. CT appears to be reliable for predicting duodenal tumor resectability. On the basis of CT findings, 10 tumors were correctly predicted as being unresectable for cure, and 12 were predicted as being resectable; no surgery was performed in the remaining three cases. In conclusion, evaluation of the morphologic features of duodenal neoplasms is a sensitive, but nonspecific, method for predicting that a tumor is malignant.(ABSTRACT TRUNCATED AT 400 WORDS)
Thrombosis of a portion of the portal venous system can be directly imaged by contrast-enhanced CT as a low-attenuation lesion within the involved portal venous segment with or without expansion of the vessel or enhancement at the margin of the thrombus. Collateral venous pathways are often evident, which provide supporting evidence of the occlusion. Alterations in portal venous blood flow lead to metabolic disturbances in the liver and to abnormalities in parenchymal enhancement during dynamic CT scanning, and these changes are manifested as abnormalities in hepatic parenchymal density. The detection of portal venous thrombosis or occlusion, collateral veins, or abnormal liver enhancement should initiate a search for the diseases that cause these abnormalities.
OBJECTIVE: Patients on continuous ambulatory peritoneal dialysis are frequently referred for radiologic evaluation of complications related to the dialysis. We studied the value of CT peritoneography in evaluating these complications. CT peritoneography is a technique in which CT scans are obtained after dialysis fluid containing iodinated contrast material is infused into the peritoneal cavity through the dialysis catheter. MATERIALS AND METHODS: Sixty consecutive CT studies performed on 48 patients during a 5-year period were retrospectively analyzed. In each case (with two exceptions), the patient had clinical findings suggesting a complication related to peritoneal dialysis. Each study was reviewed for evidence of dialysate leaks, hernias, unopacified fluid collections, and peritoneal adhesions. The patients' medical records also were reviewed to determine the resulting therapy and outcome. RESULTS: Twenty-nine dialysate leaks were detected on 25 examinations: 15 were along the catheter tunnel, 10 were at the site of a previous surgical incision, two were at a previous catheter site, and two were from an undetermined site (catheter tunnel suspected in both cases). Loculated, unopacified peritoneal fluid collections were present on seven examinations. Adhesions limiting dialysate distribution were shown on five examinations. Five abdominal wall hernias and two inguinal hernias were detected. Overall, at least one abnormality related to continuous ambulatory peritoneal dialysis was shown on 40 (67%) of 60 studies. In 29 (73%) of these cases, clinical management was changed. CONCLUSION: CT peritoneography is useful for evaluating complications commonly encountered in patients on continuous ambulatory peritoneal dialysis.
Knowledge of the appearance and location of the normal fascial structures surrounding the kidneys and the bladder is the key to proper CT analysis of extraperitoneal fluid collections. Recent studies have shown that the renal fascia and the perirenal space are more complex than previously recognized. An extracapsular renal hematoma, confined against the kidney by the posterior renorenal septum within the perirenal space, can entirely simulate a subcapsular hematoma. Pancreatitis fluid can dissect between the discrete layers that constitute the posterior renal fascia, allowing fluid in the anterior pararenal space to extend posterior to the kidney without directly involving the posterior pararenal space. The umbilicovesical fascia separates the small perivesical space from the potential large reservoir of the prevesical space in the extraperitoneal portion of the pelvis. Fluid in the prevesical space can communicate directly with the retroperitoneal spaces surrounding the kidney. In addition to compartmental localization, CT features of the fluid itself or the presence of ancillary findings such as aortic aneurysm, enlarged pancreas, renal mass, or hydronephrosis will frequently indicate the cause and the extent of most extraperitoneal fluid collections.
Pheochromocytomas are potentially curable causes of hypertension. These tumors are currently located by functional imaging with meta-iodobenzylguanidine (MIBG), usually labeled with 131I, or anatomic imaging (computed tomography, magnetic resonance). Hydroxyephedrine (HED) is a newly developed radiotracer that concentrates in adrenergic nerve terminals. When HED is labeled with 11C, its distribution can be mapped in vivo using PET. The purposes of this investigation were to characterize the uptake of 11C-HED in pheochromocytoma and to determine the feasibility and advantages of utilizing this compound as a tumor imaging agent. Ten patients with known or suspected pheochromocytoma were studied. Each patient underwent PET scanning with 11C-HED and conventional scintigraphy with MIBG. Pheochromocytomas were localized by PET scanning in 9 of the 10 patients. Image quality was excellent and superior to that obtained from planar and tomographic MIBG studies. The uptake of 11C-HED into pheochromocytomas was rapid; tumors were evident within 5 min following intravenous injection. All lesions within the field of view that were identified by MIBG scintigraphy were readily apparent. PET scanning with 11C-HED localizes pheochromocytoma using a specifically designed radiotracer and advanced imaging technology. The method has promise for locating the more elusive tumors.
The dosimetry for two, similarly sized tumours in a lymphoma patient being treated with non-bone marrow ablative, monoclonal antibody therapy is reported. The 45-year-old man was infused with 2.48 GBq (67 mCi) of 131I-labelled MB-1. Prior to therapy, a time series of diagnostic conjugate-view images and a radionuclide transmission scan were obtained and processed to obtain time-activity curves. Starting 2 days after the therapeutic infusion of radioactivity, a second conjugate-view time series was obtained. At that time, a quantitative single-photon emission tomography (SPET) acquisition was also carried out. Pre- and post-therapy X-ray computed tomography scans demonstrated a percentage reduction in volume for the right tumour which was 3.8 times that for the left tumour. In contrast, diagnostic conjugate views by themselves estimated the absorbed dose to be the same for the two tumours. Addition of therapy conjugate-view data increased the right-over-left ratio but only to 1.22. Normalizing either time-activity series by the intra-therapy SPET results increased the ratio to greater than 1.5. We assume here that a differential dose is correct according to the differential tumour shirnkage. One can further assume that the largest ratio corresponds most certainly to the most accurate dosimetric method. Other assumptions are possible. While additional study is essential, data from this patient suggest that the preferred dosimetric method is intra-therapy SPET normalization of either time series.
There are few data in the literature on the abdominal manifestations of sarcoidosis at computed tomography (CT). To determine whether differences in nodal distribution and appearance can be reliably used to distinguish between sarcoidosis and non-Hodgkin lymphoma (NHL), the authors retrospectively reviewed the abdominal and pelvic CT scans of 16 patients with biopsy-proved sarcoidosis and 20 patients with biopsy-proved NHL. Eleven of the 16 patients with sarcoidosis had abdominal and/or pelvic lymphadenopathy, which was common at all nodal sites except for the retrocrural and pelvic locations. There was a statistically significant lower frequency of retrocrual adenopathy in sarcoidosis than in NHL. Mean nodal size was significantly greater in NHL. Nodes tended to be confluent in NHL and discrete in sarcoidosis. Hepatomegaly was seen in six of the 16 patients (38%) with sarcoidosis and splenomegaly was present in nine of 15 (60%). CT depicted hepatic lesions in only three of eight patients (38%) with biopsy-proved hepatic involvement. Splenic lesions were seen at CT in five of the 15 patients (33%). The authors believe that the overlap in nodal appearance and distribution poses a limitation for use of these criteria in accurate disease characterization.
The accuracies of magnetic resonance (MR) imaging and computed tomography (CT) in determining tumor classification and assessing mediastinal node metastases were compared in a prospective cooperative study of 170 patients with non-small cell bronchogenic carcinoma. The sensitivity of CT in distinguishing T3-T4 tumors from T0-T2 tumors was 63%; specificity was 84%. These values for MR imaging were not significantly different (56% and 80%). With receiver operating characteristic (ROC) analysis, no difference existed between the accuracies of CT and MR imaging in diagnosis of bronchial involvement or chest wall invasion, but MR imaging was significantly more accurate than CT (P = .047) in diagnosis of mediastinal invasion. Lymph node sampling was performed in 155 patients (642 node stations). Cancerous nodes were found in 14% of stations in 21% of patients. There was no significant difference between the accuracies of CT and MR imaging in detecting mediastinal node metastases (N2 or N3); the sensitivities were 52% and 48%, respectively, and specificities were 69% and 64%. ROC analysis also showed no difference between CT and MR imaging.
To determine the clinical feasibility and applicability of phosphorus-31 magnetic resonance (MR) spectroscopy and to assess its potential for characterization of human hepatic tissue, one-dimensional chemical shift imaging (CSI) was performed in 37 patients with various malignant hepatic neoplasms (30 metastases from a variety of primary tumors and seven hepatocellular carcinomas) and seven healthy volunteers. Tumors were grouped according to the percentage of the analyzed section that was occupied by tumor: less than 50% (group A) or more than 50% (group B). In group B, all phosphomonoester/beta-adenosine triphosphate ratios were significantly higher than normal (P less than .001). Hepatocellular carcinomas and metastases from various primary neoplasms could not be differentiated on the basis of spectral characteristics and metabolite ratios. Limitations of one-dimensional surface coil CSI prevented separation of spectra of small tumors and tumors deep within the liver parenchyma from spectra of normal liver parenchyma.
Acute pancreatitis is an unusual but recognized complication of percutaneous aspiration biopsy of the pancreas. As the pancreatic tail is located anterior to the left adrenal gland, percutaneous biopsy of a left adrenal mass via the anterior approach may result in needle passage through the tail of the pancreas with subsequent potential development of pancreatitis. To evaluate this risk, we retrospectively reviewed 48 CT-directed percutaneous aspiration biopsies of left adrenal masses done between 1984 and 1989 at two institutions. Positioning of the patient, the course of the needle, the number of needle passes, and the size of the needle were analyzed. Thirty-three (69%) of 48 biopsies of a left adrenal mass were performed by using the anterior approach. The pancreas was traversed by one or more needles in 32 of 33 cases. Biopsies were performed with 20- to 22-gauge needles, and the number of needle passes varied widely. The medical records of the 33 patients in whom the anterior approach was used also were reviewed for complications. Acute pancreatitis, which required 11-13 days of hospitalization, developed in two patients (6%). None of the other 31 patients suffered a complication. We conclude that the pancreatic tail is routinely traversed by the biopsy needle when biopsy of a left adrenal mass is done via the anterior approach and that severe acute pancreatitis can occur as a result.
CT scans have been recommended for examination of patients at risk for recurrent transitional cell carcinoma after cystectomy. For CT to be useful in this regard, the location and type of recurrences must be known, so that appropriate scans can be made. Therefore, we retrospectively studied CT scans in 27 postcystectomy patients with recurrent transitional cell carcinoma of the bladder to identify the type and location of the recurrent disease. Recurrence was documented by biopsy in 18 patients and by progression of disease shown on serial CT scans in nine patients. All 27 patients had pelvic CT, and 23 had concomitant abdominal CT. Tumor recurred at the cystectomy site in 10 (37%) of 27 patients, pelvic adenopathy was present in 18 (67%) of 27 patients, and retroperitoneal adenopathy was present in 13 (57%) of 23 patients. Tumor recurrence at the cystectomy site was associated with pelvic adenopathy in seven of 10 patients, and the cystectomy site was the solitary site of disease in the remaining three patients. Conversely, in 11 of 18 patients with pelvic adenopathy no recurrence was seen at the cystectomy site. Combined retroperitoneal and pelvic adenopathy was identified in 11 of 23 patients, but two patients had retroperitoneal lymphadenopathy as their only site of recurrence. Hepatic metastases were seen in seven (30%) of 23 patients; six of these seven patients had metastases elsewhere. In four of five patients in whom underestimation of recurrent disease occurred, the deep pelvis and/or deep perineal space were involved. Our results show that the pelvis is the most common site for recurrence. Cystectomy site or retroperitoneal nodal recurrences are usually accompanied by pelvic adenopathy, but the converse is not as common. Our findings of deep perineal and isolated abdominal recurrences indicate that proper protocol for CT follow-up of the postcystectomy patient should include abdominal scans and scans through the perineum.
Pneumoperitoneum detected on plain radiographs following blunt abdominal trauma is nearly pathognomonic of bowel perforation and usually mandates exploratory laparotomy. To determine the significance of computed tomography (CT)-detected pneumoperitoneum, we reviewed the clinical records and imaging studies of all trauma patients in our hospital over a seven-year period whose abdominal CT scans showed free intraperitoneal gas. Patients who had penetrating injuries or peritoneal lavage prior to CT were excluded. Of the 18 patients who met these inclusion criteria, surgically confirmed bowel injury was found in only four (22%). In the remaining 14 patients, no evidence of gastrointestinal perforation was found by exploratory laparotomy (2 patients), diagnostic peritoneal lavage (4 patients), GI studies and clinical follow-up (6 patients), or clinical follow-up alone (5 patients). Seven patients had a pneumothorax as a possible cause for pneumoperitoneum. Two additional patients were on mechanical ventilation. Unlike pneumoperitoneum seen on plain film, CT-detected pneumoperitoneum is not pathognomonic of bowel perforation. While laparotomy is not mandatory in the non-surgically explored patient, close clinical observation is essential, and additional diagnostic tests such as peritoneal lavage or radiographic contrast studies can be beneficial to confirm the absence of intestinal injury.