Ronald J. Rosenberg

Preoperative lymphoscintigraphy during lymphatic mapping for breast cancer : Improved sentinel node imaging using subareolar injection of technetium 99m sulfur colloid

BACKGROUND Preoperative lymphoscintigraphy has been recommended to confirm the successful uptake and direction of migration of radiotracer into sentinel nodes during lymphatic mapping for breast cancer. In addition, preoperative lymphatic mapping may provide a visually useful aid to the relative location of sentinel nodes within a nodal basin. One common method of breast lymphoscintigraphy involves injections of unfiltered technetium 99m sulfur colloid (Tc-99m-SC) directly into parenchymal tissues surrounding a tumor or biopsy cavity (IP injection). Because of the many imaging failures and prolonged imaging times of IP lymphoscintigraphy, the procedure has fallen into disfavor by oncologic surgeons. The purpose of this study is to document the increased success rate of preoperative breast lymphoscintigraphy using a new anatomic site of injection, the subareolar lymphatic plexus (SA injection). STUDY DESIGN In the 12 months between December 1, 1998, and December 29, 1999, 42 women with stage I and II breast cancer underwent preoperative lymphoscintigraphy by either the IP (n = 12, December 1998 to May 1999) or SA (n = 30, May 1999 to December 1999) route of injection. Both groups were injected with 1 mCi (37 MBq) of unfiltered Tc-99m-SC followed immediately by external gamma-camera imaging. The success rate for preoperative sentinel node imaging and the total imaging time were recorded in both groups. RESULTS The success rate of identifying a sentinel node by SA lymphoscintigraphy was 90% (n = 27 of 30 patients), compared with 50% (n = 6 of 12 patients) for IP lymphoscintigraphy (p = 0.009). The imaging time in the SA injection group was 34 +/- 16 minutes, which was 59% shorter than the imaging time in the IP injection group of 82 +/- 48 minutes (p < 0.001). No uptake into internal mammary nodes was seen in either group. CONCLUSIONS Moving the site of injection ofunfiltered Tc-99m-SC to the subareolar lymphatic plexus (SA injection) increased the success rate of preoperative lymphoscintigraphy to 90%, compared with 50% using IP injections. Preoperative SA lymphoscintigraphy resulted in the rapid visualization of axillary sentinel nodes within 30 minutes of SA injection, enabling a visual determination of the approximate number of sentinel nodes and their relative locations within the axilla. We conclude SA injection of unfiltered Tc-99m-SC is superior to IP injections when performing preoperative breast lymphoscintigraphy and is a visually useful aid to lymphatic mapping for breast cancer.

Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.

OBJECTIVE The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding. SUBJECTS AND METHODS Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location. RESULTS Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative. CONCLUSION Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.

Asymmetric tongue muscle uptake of F-18 FDG: Possible marker for cranial nerve XII paralysis

A 58-year-old woman, with nonsmall cell carcinoma, had multiple metastasis on 2-F-18 FDG positron emission tomography imaging. The right hemitongue had increased activity as compared with the left. This was not the result of the presence of a metastasis to the tongue, as shown by a negative computed tomography scan of the region and failure to demonstrate a lesion over a period of weeks. Uptake was likely related to right hemiglossal muscle activity. This was made more apparent by decreased uptake on the opposite side of the tongue (up to the midline) as a result of left cranial nerve XII paralysis.

Diagnosing osteomyelitis in Gaucher's disease. Observations on two cases.

Bone scans in two patients with Gauchers disease were reported as consistent with Gauchers-associated osseous crises. A bone-radiogallium subtraction study was also initially negative in each individual (although it later became positive in one). At surgery both patients were seen to have osteomyelitis. These two cases point out the difficulty in attempting to diagnose osteomyelitis in the presence of Gauchers bone disease. A possible role for MRI in such instances was mentioned. Also noted was clinical reluctance to accept a diagnosis of osteomyelitis (positive bone-radiogallium subtraction study) in an afebrile Gauchers patient.

FDG-positron emission tomographic imaging in carcinoma of the breast: interference by massive sarcoidosis.

A 44-year-old woman was examined for a mass in the right breast. Stereotactic biopsy noted invasive lobular carcinoma with ductal and mucinous features. Whole-body positron emission tomographic (PET) imaging with F-18 fluorodeoxyglucose (FDG) showed massive accumulation in the thorax and abdomen. This was not consistent with the clinical impression of limited disease. The patient reported a visit to an emergency room 3 years earlier, because of iritis and uveitis of the left eye, consistent with sarcoidosis. Biopsy of retroperitoneal lymph nodes revealed findings of sarcoidosis, without the presence of a breast tumor.

Ureteral leak after renal transplantation.

In the course of radionuclide dynamic studies in 187 consecutive patients who had renal transplants, leakage from a ureter was identified in five cases (an incidence of less than 3%). Demonstrated patterns fell into three classes: 1) perirenal collection (n = 2), 2) peribladder activity (n = 2), and 3) downward dissection (n = 1 case). The sensitivity and specificity of the radionuclide study for detecting ureteral escape of urine after renal transplantation is unknown. However, this study suggests that both indices may be high.

Dual radionuclide subtraction imaging of the spleen

Dual radionuclide subtraction imaging of the spleen using 67Ga citrate and 99mTc is useful in further delineating lesions that are identified on either a routine radiogallium survey or on a conventional sulfur colloid liver-spleen image. Better anatomic localization of left subphrenic abscesses may be obtained. Differentiation of tumors and abscesses from less serious lesions such as cysts, infarcts, and hematomas is possible. We have found this technique to be generally applicable to any organ that can be selectively imaged using a technetium radiopharmaceutical, including the liver, bones, and kidneys. In addition, we are currently evaluating thallium-pertechnetate subtraction imaging in the evaluation of parathyroid adenomata.

Radionuclide study of functional resolution of unilateral renal vein thrombosis.

The diagnosis of unilateral renal vein thrombosis was established in a 50-year-old woman. A functional evaluation, by means of Tc-99m DTPA, was performed almost immediately, and at intervals up to nearly eight months later. Functional return of the involved kidney could be documented by plotting the ratio of affected kidney/total kidney activity. Conservative therapy was accompanied by a return of function of the kidney to 45% of total renal activity.

Photopenic to Avid Radiogallium Transition after Rupture of the Marrow Cavity in Acute Femoral Osteomyelitis

A 4-year-old boy had markedly reduced Ga-67 uptake in a painful left leg when compared with the right. A repeat study 9 days later showed an intense accumulation of nuclide in the lower left femur and surrounding area. Increased intramedullary pressure probably precluded Initial Ga-67 delivery into the site of infection, and subsequent release of this pressure permitted accumulation.

Incidental Finding of Intense Thyroid Radiogallium Activity During Febrile Illness

Two elderly adults presented with fever of undetermined origin. Radiogallium imaging showed intense concentration in the thyroid, without abnormal localization elsewhere. In the first case, a repeat radiogallium study performed three weeks later was within normal limits. The patient had 0% uptake of radioiodide, and no demonstrable iodine within the thyroid. This probably represented thyroiditis. In the second case, an elevated T4(RIA) and borderline elevated T3 resin uptake suggested the “dumping phase” of thyroiditis. The two cases indicate that “benign” diseases of the thyroid can be associated with diffuse radiogallium concentration in the gland.