A simplified method to estimate Diphyllobothrium spp. infection in salmonids.

Some fish parasites constitute severe management problems as they may cause mortality of their fish host or are important zoonoses of humans. Parasite assessments are therefore critical to keep track of infections. If conventional sampling techniques can be simplified, parasite assessments might be easier to obtain, less time-consuming and more extensive. In this study, we compare the assessed number of Diphyllobothrium spp. cysts (CYST) with the counted number of Diphyllobothrium spp. plerocercoid larvae recovered using a conventional digestive technique (LARV). The aim was to determine the potential of using CYST as a simplified methodology for assessing Diphyllobothrium spp. infection in salmonids. In total, 365 brown trout and 424 Arctic charr were sampled from nine lakes in subarctic Norway. Strong correlation, significant linear relationship and large amount of explained variation were found between log10 CYST and log10 LARV in both fish species. The method had a slight, but not significant tendency to work better in charr compared to trout. In addition, absolute difference between CYST and LARV increased at parasite intensities >100 indicating that the method has reduced functionality when estimating parasite intensity in heavily infected salmonid populations. However, overall, using this simplified and less time-consuming methodology, a good indication of Diphyllobothrium spp. intensity, abundance and prevalence was obtained. We suggest that this method provides a sound proxy of the Diphyllobothrium spp. burden and have the potential to be used in parasite assessment during fish monitoring and fisheries management surveys, particularly if the time and resources for detailed parasite studies are not available.

Effects of fish species composition on Diphyllobothrium spp. infections in brown trout - is three-spined stickleback a key species?

Subarctic populations of brown trout (Salmo trutta) are often heavily infected with cestodes of the genus Diphyllobothrium, assumedly because of their piscivorous behaviour. This study explores possible associations between availability of fish prey and Diphyllobothrium spp. infections in lacustrine trout populations. Trout in (i) allopatry (group T); (ii) sympatry with Arctic charr (Salvelinus alpinus) (group TC); and (iii) sympatry with charr and three-spined stickleback (Gasterosteus aculeatus) (group TCS) were contrasted. Mean abundance and intensity of Diphyllobothrium spp. were higher in group TCS compared to groups TC and T. Prevalence, however, was similarly higher in groups TCS and TC compared to group T. Zero-altered negative binomial modelling identified the lowest probability of infection in group T and similar probabilities of infection in groups TC and TCS, whereas the highest intensity was predicted in group TCS. The most infected trout were from the group co-occurring with stickleback (TCS), possibly due to a higher availability of fish prey. In conclusion, our study demonstrates elevated Diphyllobothrium spp. infections in lacustrine trout populations where fish prey are available and suggests that highly available and easily caught stickleback prey may play a key role in the transmission of Diphyllobothrium spp. parasite larvae.

Epidermal response of rainbow trout to Ichthyobodo necator: immunohistochemical and gene expression studies indicate a Th1-/Th2-like switch.

Infections with the parasitic flagellate Ichthyobodo necator (Henneguy, 1883) cause severe skin and gill disease in rainbow trout Oncorhynchus mykiss (Walbaum, 1792) juveniles. The epidermal disturbances including hyperplasia and mucous cell exhaustion caused by parasitization are known, but no details on specific cellular and humoral reactions have been presented. By applying gene expression methods and immunohistochemical techniques, further details of immune processes in the affected skin can be presented. A population of I. necator was established in the laboratory and used to induce an experimental infection of juvenile rainbow trout. The course of infection was followed by sampling for parasite enumeration, immunohistochemistry (IHC) and quantitative PCR (qPCR) on days 0, 5, 9 and 14 post-infection. IHC showed a significant increase in the occurrence of IgM-positive cells in the skin of the infected fish, whereas IgT-positive cells were eliminated and the number of CD8-positive cells declined. qPCR studies supported the IHC findings showing a significant increase in IgM and a decrease in the CD8 gene expression. In addition, genes encoding innate immune genes such as lysozyme, SAA and cathelicidin 2 were up-regulated. Expression of cytokines (IL-1ß, IL-4/13A, IL-6, IL-8, IL-10), the cell marker CD4 and the transcription factor GATA3 showed a significant increase after infection. Cytokine profiling including up-regulation of IL-4/13A and IL-10 genes and transcription factor GATA3 connected to the proliferation of IgM producing lymphocytes suggests a partial shift towards a Th2 response associated with the I. necator infection.

Intraoperative modality of treatment for peritoneal carcinomatosis: use of hyperthermic interperitoneal chemoperfusion.

The use of hyperthermia as an adjunct to chemotherapy in the treatment of peritoneal carcinomatosis is a promising technique for patients who otherwise have a poor prognosis for survival. We, herein, report an overview and description of our technique for the safe conduct of this treatment. Included in these data are a total of 71 patients who underwent an intraoperative treatment with Mitomycin C at temperatures of 41-42 degrees C for a 90- to 120-min time period. The treatment protocol, perfusion system description, technical considerations, and potential complications are also included. The prognosis for intraabdominal carcinomatosis is poor with conventional treatments and modalities. We believe that the use of this technique offers a very positive clinical alternative for patients undergoing treatment for laparoscopic palliation of malignant ascites and/or surgical debulking for intraoperative treatment and prevention of metastasis.

Prospective evaluation of office-based parotid ultrasound.

BACKGROUND: Differentiation of parotid neoplasms from extraparotid upper cervical lesions is difficult by physical examination. The purpose of this report is to identify the role of office-based parotid ultrasound (US) in the evaluation of periauricular masses. METHODS: A prospective database including the results of physical examination, office-based US, and the corresponding pathology was reviewed. Soft-tissue US was performed with a 7.5-mHz parallel probe with biplanar imaging. RESULTS: Thirty-eight patients were evaluated over a 28-month period (mean age. 45 years; range, 23-78 years). US demonstrated a mass within the substance of the parotid (n = 23, 61%), outside the parotid (n = 11, 29%), or diffuse parotitis (n = 4, 10%). Intraparotid masses were preauricular (n = 14), postauricular (n = 5), or upper cervical (n = 4) and were solid (n = 22) or cystic (n = 1). Patients with solid intraparotid masses underwent superficial (n = 20) or total parotidectomy (n = 2). Benign (n = 19) and malignant (n = 3) solid parotid nodules had similar US features of hypoechogenicity with posterior enhancement. Indistinct margins were noted in 3 of 3 malignant lesions as well as 15 of 19 benign nodules (P = .9). Extraparotid masses were confirmed to be nodal disease on the basis of observation with resolution (n = 3), fine-needle aspiration (n = 6), or surgical removal (n = 2) (mean follow-up, 6 months). CONCLUSIONS: Surgical office-based parotid US can delineate the location of periauricular mass lesions relative to the parotid gland. Benign and malignant lesions have a similar sonographic appearance.

Gene therapy for head and neck cancers.

Despite advances in surgery, radiotherapy, and chemotherapy, survival of patients with squamous cell carcinoma of the head and neck has not significantly improved over the past 30 years. Locally recurrent or refractory disease is particularly difficult to treat. Repeat surgical resection and/or radiotherapy are often not possible, and long-term results for salvage chemotherapy are poor. Recent advances in gene therapy have been applied to recurrent squamous cell carcinoma of the head and neck. Many of these techniques are now in clinical trials and have shown some efficacy. This article discusses the techniques employed in gene therapy and summarizes the ongoing protocols that are currently being evaluated in clinical trials.

A prospective phase II trial of ONYX-015 adenovirus and chemotherapy in recurrent squamous cell carcinoma of the head and neck (the Baylor experience).

BACKGROUND: The E1-b attenuated adenovirus, ONYX-015 (Onyx Pharmaceuticals, Richmond, CA), has demonstrated antitumoral activity in patients with recurrent squamous cell carcinoma of the head and neck. This study evaluated the effects of intratumoral ONYX-015 injection combined with systemic chemotherapy. METHODS: Inclusion criteria included: (1) recurrent squamous cell carcinoma of the head and neck, not surgically salvageable, (2) target tumor amenable to direct injection, and (3) no prior chemotherapy for recurrent disease. Patients received ONYX-015 (10(10) plaque-forming units) intratumorally for 5 days, cisplatin (80 mg/m2) on day 1, and 5-fluorouracil (800-1000 mg/m2) on days 1-5. This cycle was repeated every 3 weeks. Serial physical examination and computed tomography were used to assess tumor size and treatment response. RESULTS: Fourteen patients were enrolled, and nine patients were evaluable for response at the time of enrollment. The mean age of the evaluable patients was 60.8 years (range, 46-71 years). Mean maximum tumor diameter was 4.8 cm (range, 1.9-10.5 cm). Treatment-related toxicity included nausea (n = 7, 77.8%), vomiting (n = 5, 55.6%), mucositis (n = 5, 55.6%), pain at the injection site (n = 5, 55.6%), constipation (n = 4, 44.4%), and fatigue (n = 4, 44.4%). Locoregional tumor control was obtained in all nine patients (100%) (mean observation time, 157 days). Complete clinical response was seen in three patients (33.3%), partial response was seen in three patients (33.3%), minor response was seen in one patient (11.1%), and two patients (22.2%) had stable disease. Median time to local progression of disease has not been reached (range, 35-356 days). CONCLUSIONS: ONYX-015 adenovirus plus systemic cisplatin and 5-fluorouracil provides antitumor activity and local tumor control in patients with recurrent squamous cell carcinoma of the head and neck. This novel treatment approach offers hope for patients with limited treatment alternatives and provides the foundation for a phase III clinical trial.

Diagnostic evaluation of hepatocellular carcinoma in a cirrhotic liver.

Hepatocellular carcinoma (HCC) is one of the world's most common cancers. It is closely associated with cirrhosis, especially that due to viral hepatitis. The incidences of viral hepatitis and HCC are rising steadily in the United States. When symptomatic, HCC is usually unresectable and associated with a median survival of less than 6 months. Nodular lesions of undetermined malignant potential are often found in cirrhotic, explanted livers. There appears to be a continuum of increasing malignant potential from regenerating nodules to dysplastic nodules and to HCC. Pathologic differentiation of high-grade dysplastic nodules from HCC is often difficult. Early diagnosis offers the best potential for curative intervention. Screening of high-risk patient populations using serum alpha-fetoprotein and ultrasound has been attempted but is hindered by low sensitivity and specificity. The multinodularity and vascular flow anomalies of the cirrhotic liver complicate imaging. However, recent advances in magnetic resonance imaging technology allow for more accurate examination of the liver. We review the current status of hepatic imaging techniques and the results of screening a high-risk population for HCC.

Hepatic imaging with iron oxide magnetic resonance imaging.

The management of hepatic tumors presents a challenging problem. The natural history of primary and metastatic liver lesions portends a poor prognosis. However, surgical resection and newer ablative techniques have had a great impact on cure rates. Unfortunately, the majority of newly diagnosed patients have surgically unresectable disease. Advances in hepatic imaging have improved the preoperative evaluation of malignant lesions and greatly assisted in selecting patients for surgical resection or other interventions. Currently, a number of modalities are available for the evaluation of hepatic tumors. This article provides an overview of some of the modalities currently in use, examines the role of iron oxide magnetic resonance imaging (MRI), and relates experience with its use at Baylor University Medical Center.

Association of an abnormal pancreaticobiliary junction with biliary tract cancers.

Recent international reports have suggested that an abnormal pancreatic and bile duct junction can influence the degree of pancreatic fluid regurgitation, resulting in an increased incidence of biliary tract malignancy. To confirm these reports, we retrospectively examined the anatomic relation at the pancreaticobiliary junction in all patients diagnosed with cholangiocarcinoma or gallbladder cancer at Baylor University Medical Center (BUMC) over a 10-year period. From 1989 to 1998, 82 patients with bile duct cancer were treated at BUMC. Adequate visualization of the pancreaticobiliary junction was accomplished in 29 patients (35%). Among these patients, an abnormal junction, with a common channel length of 8 to >15 mm, was noted in 13 patients (45%). Thus, this study confirms previous reports regarding the high incidence of an abnormal pancreaticobiliary junction in patients with bile duct cancer. A prospective effort to examine this anatomy and the length of the common channel should be encouraged to identify a potential high-risk group.

Laparoscopic cholecystectomy for acalculous gallbladder disease.

Use of laparoscopic cholecystectomy (LC) to treat patients with symptoms due to gallstone disease is well established. However, use of LC for patients with acalculous gallbladder disease remains controversial. In this study, we examined the use of hepatobiliary iminodiacetic acid (HIDA) scans with cholecystokinin (CCK) infusion to identify patients with acalculous gallbladder disease who would benefit from LC. From December 1991 to February 1997, 4480 patients underwent cholecystectomy at Baylor University Medical Center, including 72 patients who underwent LC for acalculous disease following preoperative HIDA scan. We retrospectively analyzed their preoperative symptoms and workup. Follow-up was obtained by telephone questionnaire in 59 of 72 patients (82%). Overall, 48 of 59 patients (82%) reported an excellent outcome following LC. We found no significant difference in outcome in patients who underwent HIDA scan with CCK infusion, regardless of gallbladder ejection fraction or exacerbation of symptoms caused by the infusion. Preoperative symptom complex was also not predictive of postoperative outcome. LC is an effective treatment for patients with acalculous gallbladder disease. A preoperative HIDA scan with CCK infusion does not accurately predict treatment success or failure. Patients with a normal ejection fraction and absence of symptoms from a HIDA scan can still have excellent relief of symptoms after LC.

The effect of surgical office-based thyroid ultrasound on clinical decision making.

An important diagnostic tool for the evaluation of thyroid disease, thyroid ultrasound has recently become available for use in surgical offices. The purpose of this report is to determine the lesional sensitivity of office-based thyroid ultrasound and its impact on clinical decision making. Surgical office-based thyroid ultrasound was performed on 49 consecutive patients who presented with thyroid disease. Indications for sonography included a solitary palpable nodule (n = 32), multiple palpable nodules (n = 3), diffuse enlargement (n = 5), or other hormonal or radiologic abnormalities (n = 9). Thyroid ultrasound demonstrated 104 lesions compared with 38 lesions found on physical examination (P < 0.0001). In the subpopulation who underwent scintigraphy (n = 10), 24 nodules were identified by ultrasound and only 10 nodules were identified by scan (P < 0.01). Overall, office-based thyroid ultrasound impacted the clinical management of 40 patients (80%): in 16 patients, thyroid ultrasound was the only modality that demonstrated a multinodular condition, thus contributing to a decision to avoid surgery; 19 patients had ultrasound-guided fine-needle aspiration of vaguely palpable or nonpalpable lesions; and 5 patients underwent ultrasound-guided cyst aspiration and follow-up. Office-based thyroid ultrasound performed by surgeons is a highly accurate imaging modality that identified significantly more lesions than physical examination or scintigraphy. Clinical management was affected through the identification of a multinodular process or through facilitation of accurate image-guided biopsy.

Galactography in patients with nipple discharge.

Nipple discharge is a common presenting symptom of underlying breast pathology. This study examined the impact of galactography on the evaluation of abnormal nipple discharge. Thirty-five women with spontaneous, unilateral nipple discharge who underwent galactography from 1995 to 1997 were retrospectively studied. Their presenting signs as well as mammographic, galactographic, and pathology findings were evaluated. Nipple discharge was bloody (n = 24), clear (n = 7), or serous (n = 4). A palpable mass was found in 5 patients, and discharge was spontaneous in 29 patients (83%). Mammography was normal in 25 patients (71%). Thirty patients (86%) had an abnormal ductogram that was characterized as a filling defect (n = 20), cutoff sign (n = 5), or ductal dilatation (n = 5). The ductogram demonstrated the location and depth of the lesion in 29 patients (97%). Excision was performed in 27 of 30 patients with an abnormal ductogram: 14 received complete subareolar duct excisions; 12, focused excisions; and 1, excision with a vacuum-assisted biopsy device. Pathology included intraductal papilloma (n = 20) and ductal ectasia (n = 7). Follow-up was completed in 24 patients, including 2 postoperative patients who had persistent discharge on manipulation. In conclusion, galactography is accurate in identifying the location of the ductal abnormality. It allows a focused surgical approach to the pathologic lesion in these patients.

Hepatic tumor imaging using iron oxide MRI: comparison with computed tomography, clinical impact, and cost analysis.

BACKGROUND: The surgical management of hepatic tumors has traditionally relied on preoperative contrast-enhanced computed tomography (CECT) in combination with intraoperative ultrasonography (IOUS). Unfortunately, the ability to detect and characterize hepatic tumors by using CECT is limited, and IOUS frequently reveals additional disease that alters the operative approach. Recent advances in hepatic magnetic resonance imaging (MRI) may improve preoperative tumor detection and characterization; however, little is known about how MRI compares with CECT or about the clinical impact and cost considerations of liver MRI. METHODS: A retrospective chart review was performed to compare iron oxide (Feridex [Fe])-MRI with CECT in the preoperative imaging of hepatic neoplasms, as well as to determine the clinical impact and overall healthcare costs associated with Fe-MRI. RESULTS: Of approximately 1000 patients who underwent abdominal MRI at a single institution during a 20-month period, 57 were identified who underwent Fe-MRI evaluation of the liver. Indications for imaging included suspected metastases (n = 43), an indeterminate hepatic mass (n = 9), or primary hepatic cancer (n = 5). Overall, Fe-MRI identified a total of 157 lesions (mean, 2.75 per patient; range, 0-14). CECT was performed in 50 patients, of whom 35 had primary or metastatic cancer. Fe-MRI identified more lesions than CT (n = 136 vs. 77; P = .016), and the average size of lesion detected by Fe-MRI was significantly smaller than that by CECT (2.5 vs. 3.4 cm; P = .018). Comparison of CECT and Fe-MRI findings with IOUS and pathological specimens showed a significant difference in sensitivity (MRI, 86%; CECT, 58%; P<.001), and IOUS changed the operative approach in only 5% of those imaged with Fe-MRI. Overall, Fe-MRI altered the clinical management in 67% of patients imaged (n = 38 of 57), which corresponded to an overall net cost savings of $108,368 ($1,901 per patient). CONCLUSIONS: Fe-MRI is a powerful imaging technique, with greater hepatic tumor detection sensitivity than CECT. Moreover, it is an economically feasible imaging method that will alter the clinical management in most patients imaged.

Radiation safety with breast sentinel node biopsy.

BACKGROUND: Sentinel lymph node biopsy with Technetium 99m sulfur colloid (Tc99m) is an evolving technique that offers the potential for improved staging of breast cancer with decreased morbidity. However, the use of radioactive materials in the operating room generates significant concern about radiation exposure. The purpose of this study was to evaluate radiation exposure to operating room personnel, pathologist, and equipment from specimens during breast sentinel lymph node biopsy. METHODS: Twenty patients were injected with 0.7 to 1.1 mCi of Tc99m sulfur colloid 1.5 to 3 hours before sentinel lymph node biopsy. A calibrated Geiger counter was used to measure dose rates from the breast injection site before skin incision (n = 20), lumpectomy specimens (n = 8), and sentinel nodes (n = 20) at distances of 3, 30, and 300 cm. This represented exposure to the surgeon's hands, surgeon's torso, and scrub nurse, respectively. Exposure to the pathologist's hands and torso was represented as dose-rate measurements from lumpectomy and nodal specimens. The operative instruments, trash receptacles, suction canisters, pathology slides, and cryostat machines were measured at 3 cm at the conclusion of each procedure. Specimens or equipment emitting radiation doses equal to background levels (0.04 mRem/h) were exempt from special handling and disposal. RESULTS: The highest exposure rate was to the surgeon's hands from the breast injection site before skin incision (34.25 mRem/h). Exposure to the surgeon's torso measured 1.33 mRem/h, and exposure to the scrub nurse's torso measured 0.15 mRem/h from the injection site. Exposure to the pathologist's hands was 18.62 and 0.06 mRem/h from the lumpectomy specimen and sentinel node, respectively. Exposure to the pathologist's torso measured 0.34 and 0.04 mRem/h from the lumpectomy specimen and sentinel node, respectively. One hundred percent of lumpectomy specimens measured above the exempt level. Thirty-two of 46 (70%) sentinel lymph nodes emitted radiation equal to the exempt background level. Seventeen of 20 trash receptacles (85%) and 4 of 12 (33%) suction canisters measured equal to background levels. All operative instruments, pathology slides, and cryostat machines were equal to background levels. CONCLUSIONS: Radiation exposure to operating room personnel, pathologists, and operative equipment during a breast sentinel node biopsy using Tc99m is minimal. A primary surgeon can perform 2,190 hours, a scrub nurse 33,333 hours, and a pathologist 14,705 hours of procedural work before surpassing Occupational Safety and Health Administration limits. Operative instruments, pathology slides, and cryostat machines do not require special handling. All lumpectomy specimens should be stored for decontamination until the dose rate equals background levels. Intraoperative dose-rate monitoring allows selective decontamination of nodal specimens, trash receptacles, and suction canisters, which decreases disposal time and cost.

The role of computed tomography in the diagnosis of acute appendicitis.

BACKGROUND: Routine contrast-enhanced computed tomography (CECT) has been described as an accurate diagnostic imaging modality in patients with acute appendicitis. However, most patients with acute appendicitis can be diagnosed by clinical findings and physical exam alone. The role of CECT in patients suspected of having appendicitis but with equivocal clinical exams remains ill defined. METHODS: One hundred and seven consecutive patients who were thought to have appendicitis but with equivocal clinical findings and/or physical exams were imaged by CECT over a 12-month period. Oral and intravenous contrast-enhanced, spiral abdominal and pelvic images were obtained using 7-mm cuts. CECT images were interpreted by a board-certified radiologist. Main outcome measures included CECT sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in the diagnosis of acute appendicitis, comparing CECT with ultrasound, and determining the impact of CECT on the clinical management of this patient population. RESULTS: A group of 107 patients consisting of 44 males (41%) and 63 females (59%) with a median age of 33 years (range 13 to 89 years) were imaged with CECT to evaluate suspected appendicitis. Of the 107 CECTs performed, 11 false-positive and 3 false-negative readings were identified, resulting in a sensitivity of 92%, specificity of 85%, PPV of 75%, NPV of 95%, and an overall accuracy of 90%. Forty-three patients were imaged with ultrasound and CECT, and CECT had significantly better sensitivity and accuracy (30% versus 92% and 69% versus 88%, P<0.01). With regard to clinical management, 100% (36/36) of patients with appendicitis, and 4.2% (3/71) of patients without appendicitis underwent appendectomy. Therefore, the overall negative appendectomy rate was 7.6% (3/39). CONCLUSIONS: CECT is a useful diagnostic imaging modality for patients suspected of having acute appendicitis but with equivocal clinical findings and/or physical exams. CECT is more sensitive and accurate than ultrasound and is particularly useful in excluding the diagnosis of appendicitis in those without disease.

Cryotherapy for liver tumors.

The curative management of primary and metastatic liver tumors has traditionally relied on surgical resection. Unfortunately, fewer than 10% of newly diagnosed patients have tumors that are considered to be surgically resectable. Limitations that often preclude a safe surgical resection include bilobar or centrally located tumors, insufficient hepatic reserve, cirrhosis, and/or associated comorbid medical conditions. For individuals with unresectable hepatic tumors, the treatment options are few, and the prognosis is uniformly poor. However, cryosurgery is a promising therapeutic alternative for these patients. This rapidly emerging technology allows for image-guided in situ tumor eradication using subzero temperatures, while selectively sparing most normal hepatic tissue. Tumor death occurs by direct cellular freezing and indirectly through vascular thrombosis and tissue anoxia. Accumulating data suggest that cryosurgery is a safe, effective treatment option for patients who would otherwise fair quite poorly, and that it may achieve long-term survival rates similar to those observed with formal surgical resection. This article summarizes the role cryosurgery may play in the management of patients with surgically unresectable primary and metastatic liver tumors.

Correlates of sexual assault in Mexican American and white non-Hispanic adolescent males.

Psychosocial and emotional characteristics were assessed in a nonclinical sample of 1,385 adolescent Mexican American and White non-Hispanic males. Fifty-four males who reported being sexually assaulted one or more times were compared to 1,331 males who reported no history of sexual assault. Sexually assaulted male victims were more emotionally distressed, socially isolated, deviant (e.g., lying & stealing), likely to affiliate with deviant peers, and to come from homes in which there was parental substance use, than males who did not report sexual assault. Significant differences were not found between Mexican American and White non-Hispanic assault victims. Implications of these findings are discussed.

Sentinel lymph node biopsy for melanoma.

BACKGROUND: The most powerful predictor of survival for patients with melanoma is the status of the regional lymph nodes. Sentinel lymph node biopsy may provide improved staging accuracy without the morbidity of elective lymph node dissection (ELND). METHODS: Sixty-eight patients with intermediate thickness melanoma underwent gamma probe guided sentinel node biopsy without ELND and were followed up over a mean of 22 months. RESULTS: A sentinel node was found in all patients. Six patients (9%) had positive sentinel nodes; all underwent complete lymphadenectomy. Two patients (3%) with negative sentinel nodes developed nodal recurrence; 1 of these patients was found to have microscopic disease on reexamination of the sentinel node. Two patients (3%) developed systemic disease. CONCLUSION: Gamma probe guided sentinel node biopsy can be performed with a high rate of technical success. It provides accurate pathological staging with a low incidence of nodal basin failure.