Value of scintigraphy in chronic peritoneal dialysis patients.
BACKGROUND: A variety of factors can adversely impact chronic peritoneal dialysis (CPD) as an effective renal replacement therapy for patients with end-stage renal disease. These factors include peritonitis, poor clearances, loss of ultrafiltration, and a variety of anatomic problems, such as hernias, peritoneal fluid leaks, loculations, and catheter-related problems caused by omental blockage. This study reviews our experience with peritoneal scintigraphy for the evaluation of some of these difficulties. METHODS: From 1991 to 1996, 50 peritoneal scintigraphy scans were obtained in 48 CPD patients. Indications for scintigraphy were evaluated, and the patients were placed into four groups: group I, abdominal wall swelling; group II, inguinal or genital swelling; group III, pleural fluid; and group IV, poor drainage and/or poor ultrafiltration. A peritoneal scintigraphy protocol was established and the radiotracer isotope that was used was 2.0 mCi of 99mtechnetium sulfur colloid placed in two liters of 2.5% dextrose peritoneal dialysis solution. RESULTS: Ten scans were obtained to study abdominal wall swelling, with seven scans demonstrating leaks; six of these episodes improved with low-volume exchanges. Twenty scans were obtained to evaluate inguinal or genital swelling, and 10 of these had scintigraphic evidence for an inguinal hernia leak (9 of these were surgically corrected). One of four scans obtained to evaluate a pleural fluid collection demonstrated a peritoneal-pleural leak that corrected with a temporary discontinuation of CPD. Sixteen scans were obtained to assess poor drainage and/or ultrafiltration. Five of these scans demonstrated peritoneal location, and all of these patients required transfer to hemodialysis. The other 11 scans were normal; four patients underwent omentectomies, allowing three patients to continue with CPD. CONCLUSION: Peritoneal scintigraphy is useful in the evaluation and assessment of CPD patients who develop anatomical problems (such as anterior abdominal, pleural-peritoneal, inguinal, and genital leaks) and problems with ultrafiltration and/or drainage. (+info)
Technical aspects of sentinel node lymphoscintigraphy for breast cancer.
OBJECTIVE: A significant morbidity risk is associated with axillary nodal dissections for breast cancer. Many treatment decisions are based on axillary nodal status. Lymphatic mapping and sentinel node biopsy have been investigated to determine if the histology of the sentinel node reflects the remaining lymph node basin. We describe the technical aspects of sentinel node lymphoscintigraphy for breast cancer. METHODS: Ninety-three patients had lymphoscintigraphy for breast cancer. Patients with palpable lesions had 4 concentric injections around the site and lesions requiring localization had injections made through tubing connected to the localizing wire introducer needle. Immediate static images were acquired and the sentinel node was marked for surgery. Marks were reverified using a handheld gamma probe. RESULTS: Lymph nodes were visualized by lymphoscintigraphy in 87% of cases. Time to visualization of lymph nodes ranged from 1-120 min with a mean of 28 min. An average of 1.5 nodes were visualized. The overall success rate for identifying the sentinel node at time of surgery was 85%. CONCLUSION: We conclude that lymphoscintigraphy for breast cancer is a detailed procedure that requires coordination with radiology and surgery teams to ensure proper identification of sentinel lymph nodes. (+info)
Subareolar versus peritumoral injection for location of the sentinel lymph node.
BACKGROUND: Sentinel lymph node (SLN) biopsy is fast becoming the standard for testing lymph node involvement in many institutions. However, questions remain as to the best method of injection. The authors hypothesized that a subareolar injection of material would drain to the same lymph node as a peritumoral injection, regardless of the location of the tumor. METHODS: To test this theory, 68 patients with 69 operable invasive breast carcinomas and clinically node-negative disease were enrolled in this single-institution Institutional Review Board-approved trial. Patients were injected with 1.0 mCi of technetium-99 sulfur colloid (unfiltered) in the subareolar area of the tumor-bearing breast. Each patient received an injection of 2 to 5 cc of isosulfan blue around the tumor. Radioactive SLNs were identified using a hand-held gamma detector probe. RESULTS: The average age of patients entered into this trial was 55.2 +/- 13.4 years. The average size of the tumors was 1.48 +/- 1.0 cm. Thirty-two percent of the patients had undergone previous excisional breast biopsies. Of the 69 lesions, 62 (89.9%) had SLNs located with the blue dye and 65 (94.2%) with the technetium. In four patients, the SLN was not located with either method. All blue SLNs were also radioactive. All located SLNs were in the axilla. Of the 62 patients in which the SLNs were located with both methods, an average of 1.5 +/- 0.7 SLNs were found per patient, of which 23.2% had metastatic disease. All four patients in which no SLN was located with either method had undergone prior excisional biopsies. CONCLUSIONS: The results of this study suggest that subareolar injection of technetium is as accurate as peritumoral injection of blue dye. Central injection is easy and avoids the necessity for image-guided injection of nonpalpable breast lesions. Finally, subareolar injection of technetium avoids the problem of overlap of the radioactive zone of diffusion of the injection site with the radioactive sentinel lymph node, particularly in medial and upper outer quadrant lesions. (+info)
99mTc-human serum albumin: an effective radiotracer for identifying sentinel lymph nodes in melanoma.
Sentinel lymph node (SLN) biopsy has emerged as a novel approach for identifying patients with melanoma and regional nodal micrometastasis who may benefit from full nodal basin resection. To identify the pattern of tumor lymphatic drainage and the SLN, lymphoscintigraphy has been performed using primarily 99mTc-sulfur colloid (SC). In this study, we compare the efficacy of SLN biopsy using 99mTc-human serum albumin (HSA) with SLN biopsy after SC-based lymphoscintigraphy. METHODS: One hundred and six patients with localized cutaneous melanoma were studied. Lymphoscintigraphy was performed after intradermal injection of HSA in 85 patients and SC in 21 patients. Four patients underwent lymphoscintigraphy twice, once with SC and once with HSA. Dynamic images were acquired for up to 1 h, followed by high-count images of the SLN in various projections so that the most likely site was marked on the skin for biopsy. Intraoperatively, blue dye was injected around the primary site. Twenty-four patients underwent SLN dissection directed by preoperative lymphoscintigraphy and vital blue dye mapping; in the remaining 80 patients, a gamma probe was added intraoperatively to the localization procedure. Two patients underwent mapping with gamma probe alone. RESULTS: Draining lymphatic basins and nodes were identified by lymphoscintigraphy in all patients. The SLN was identified in 95% of patients when both blue dye and intraoperative gamma probe were used. When 99mTc-HSA was used for imaging, 98% of the SLNs ultimately identified were radiolabeled, and 82% were both hot and blue. Of the SLN recovered with SC, all the nodes were radiolabeled; however, there was only 58% hot and blue concordance. Greater numbers of SLNs were removed in the SC group (median 2.0 versus 1.0, P = 0.02); however, the incidence of micrometastasis was statistically similar in both HSA and SC cohorts. In the 4 patients examined with both tracers, SLN mapping was similar. CONCLUSION: Although SC has been the radiotracer of choice for SLN mapping in melanoma, HSA appears to be a suitable alternative, with identical success rates. In fact, the higher concordance between hot and blue nodes using HSA suggests superiority of this tracer for this purpose. (+info)
The effect of dialysate dwell on gastric emptying time in patients on continuous ambulatory peritoneal dialysis.
METHODS AND PATIENTS: We evaluated gastric emptying time (GET) with a technetium (Tc) 99m-sulfur colloid gastric emptying scan in 11 patients on continuous ambulatory peritoneal dialysis (CAPD) (6 males, 5 females) and in 14 controls. We investigated the effect of dialysate dwell on GET by studying the subjects twice: once without dialysate in the abdomen (drained) and once with 2 L of dialysate in the abdomen (full). We also investigated the relationship between body surface area (BSA) and delayed gastric emptying. RESULTS: (1) The mean gastric emptying rate in 120 minutes in patients on CAPD when drained (67.8%+/-13.4%) was not different from that in controls (65.4%+/-8.6%). (2) The mean gastric emptying rate in 120 minutes in patients on CAPD when full was significantly slower than that when drained (55.6%+/-14.6% versus 67.8%+/-13.4%, p < 0.05). In four of the 11 patients (36.4%), gastric emptying was extremely delayed from normal to abnormal range when full. (3) The BSA of patients who had extremely delayed GET from normal to abnormal range was smaller than that of patients who had minimal delayed or unchanged GET when full (1.5+/-0.11 m2 versus 1.74+/-0.22 m2). CONCLUSION: This study showed that patients on CAPD had normal gastric emptying when drained, and that gastric emptying was delayed by dialysate dwell, especially in patients who has less than 1.5 m2 of body surface area. Therefore, we suggest that, based on adequacy, intermittent nocturnal peritoneal dialysis or a small volume of dialysate be considered for patients with small body surface area. (+info)
Validation of the lactose-[13C]ureide breath test for determination of orocecal transit time by scintigraphy.
The breath test using oral administration of a 13C-labeled substrate, lactose-ureide (LU), to measure orocecal transit time (OCTT) was validated against 99mTc-scintigraphy. Although LU is not absorbed in the human small intestine, colonic bacteria readily metabolize LU, producing 13C-labeled CO2. The time at which 13CO2 appears in breath corresponds to the OCTT. METHODS: Twenty-two healthy volunteers ingested a meal labeled with 99mTc and 13C-LU. Scintigraphy was performed over 8 h at time intervals of 10 or 15 min. OCTT with scintigraphy was defined as the time at which at least 10% of the label had entered the colon. Breath samples were obtained every 10-15 min for 10 h and measured by isotope ratio mass spectrometry. OCTT was defined as the time of first significant increase above baseline. The results were compared using correlation and Altman-Bland statistics. RESULTS: OCTT results from scintigraphy (mean OCTT = 283+/-53 min) and breath test (mean OCTT = 292+/-58 min) correlated well (r = 0.94). Altman-Bland statistics showed close agreement between scintigraphy and breath test. No significant difference between male and female subjects was observed. CONCLUSION: The breath test using 13C-LU is a valid alternative to scintigraphy techniques for measuring OCTT. (+info)
Scintigraphic imaging and absorption of a 5-aminosalicylic acid enema in patients with ileorectal anastomosis.
Ileorectal anastomosis (IRA) is a possible surgical treatment for hyperacute and drug-unresponsive forms of ulcerative colitis (UC). UC relapses in the rectal remnant usually are prevented by chronic administration of 5-aminosalicylic acid (5-ASA) in topical formulations. The relationships between intestinal absorption and pattern of luminal spread of 5-ASA enemas are still unknown in patients with IRA. We correlated the absorption of a 5-ASA enema with its spread in the distal bowel of patients with IRA as assessed by 99mTc radioenema imaging. METHODS: Eight patients with UC in remission and previous IRA received a therapeutic 50-mL 5-ASA enema labeled with 99mTc-sulfer colloid. Absorbed 5-ASA and its major metabolite, acetyl 5-ASA, were measured in plasma, and dynamic images of radiolabeled enema were obtained for 6 h. The retrograde ileal spread (RIS) was determined and expressed as percentage of total enema radioactivity. Plasma levels of 5-ASA and acetyl 5-ASA were measured in six healthy volunteers after administration of the same enema volume with no radiolabeling. RESULTS: The mean 5-ASA plasma level was 0.70 microg/mL (range 0.37-0.95 microg/mL) in patients and 0.96 microg/mL (range 0.78-1.16 microg/mL) in healthy volunteers (P = not significant), and the mean acetyl 5-ASA plasma levels were 0.89 microg/mL (range 0.44-1.19 microg/mL) and 0.84 microg/mL (range 0.51-1.02 microg/mL), respectively (P = not significant). Radioenema imaging allows RIS assessment of patients with IRA. The mean value was 8.5% (range 2%-19.3%) of administered radioactivity, which correlated significantly with the total absorption of 5-ASA in the IRA group (P = 0.033, linear correlation test). Rectal wall contractions recognized by dynamic radioenema imaging were defined as a common cause of RIS episodes. CONCLUSION: In IRA patients, 5-ASA plasma levels were similar to those in healthy volunteers after administration in enema. Only part of a 50-mL 5-ASA enema reaches the ileum, and radiolabeled imaging shows the degree and number of these RIS episodes. The absorption of 5-ASA can increase in patients compared with healthy volunteers, in the presence of either occasional but significant ileal spread associated with postural factors and abdominal wall contraction or multiple moderate episodes of radioenema backdiffusion related to rectal wall motility. (+info)
A novel, simple method of functional spleen volume calculation by liver-spleen scan.
Spleen enlargement is commonly associated with portal hypertension from cirrhosis and may cause thrombocytopenia. Thus, accurate assessment of spleen size may be helpful in the clinical evaluation. Spleen length is not a precise estimate of spleen size because of the variation in spleen configuration, and spleen volumes measured by edging techniques can be tedious. We present a new method of measuring the functional spleen volume by liver-spleen scan (LSSs), validation experiments and some clinical data. METHODS: The method involves measurement of the total spleen counts by SPECT and dividing by a representative voxel concentration on a single frame to obtain the organ volume. Validation included phantom studies and clinical evaluation in 443 consecutive patients, including 216 with histologic assessments of chronic liver disease (CLD) and 11 healthy volunteers. RESULTS: A calibration factor determined from phantoms was used to convert the calculated volume (CV) to the "true" volume (V): V = CV (0.956) - 66.5 (r = 0.9991; P < 0.001). The volume calculations were validated in a second group of phantoms (r= 0.981; P < 0.0001). Spleen volumes were expressed as volume (cm3) and as volume per pound ideal body weight (IBW) (cm3/lb) (the conversion factor to convert cm3/lb IBW to cm3/kg IBW is 2.2). Clinical studies of reproducibility included demonstration of a significant (P < 0.0001) linear correlation between volumes calculated from repeat LSSs within 9 mo of the initial LSS in 11 healthy volunteers and 32 patients with CLD: y = 1.02x - 25; r = 0.968. The correlation with spleen volumes from autopsy or splenectomy was significant: y = 0.766x + 57; r = 0.845; P < 0.001. The normal spleen volume in 11 patients was 201 +/- 77 cm3 and 1.43 +/- 0.68 cm3/lb IBW (upper limits of normal: 335 cm3 or 2.5 cm3/lb IBW). In 443 consecutive LSSs over 15 mo, half of the patients had spleen volumes above the upper limits of healthy volunteers, and CLD was present in 90.9% of these patients. In 216 patients with histologically proven liver disease, a progressive increase in the percentage of spleen volumes above the upper limits of normal was noted from no fibrosis (10%) to mild to moderate fibrosis (36.7%) to early cirrhosis (52%) to advanced liver disease (75%). The correlation of spleen volume with platelet count was excellent (r = 0.7635; P < 0.005). CONCLUSION: This novel spleen volume measurement detects serious liver disease and correlates with splenic hyperfunction. (+info)