Incremental diagnostic value and impact on patient management of somatostatin receptor scintigraphy with indium-111-pentetreotide in gastroenteropancreatic neuroendocrine tumors.

OBJECTIVE: To evaluate the efficacy of somatostatin analog scintigraphy with indium-111-pentetreotide and its overall impact on management in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET). SUBJECTS AND METHODS: Twenty-two consecutive patients with a proven or clinically suspected GEP-NET with or without proven metastases were imaged at 24 and 48 h after injection of (111)In-pentetreotide. The scintigraphic findings were compared with results from conventional imaging methods. The final diagnosis was based on histopathological and surgical findings and complementary radiology. RESULTS: Somatostatin receptor-positive lesions were found in 20 of the patients, whereas conventional methods were positive in 18 patients. Additionally, 13 new tumor sites were discovered by somatostatin receptor scintigraphy in 5 patients (liver: 6; chest: 2; bone: 1; abdomen: 4). The surgical therapeutic strategy was changed in 7 patients (32%). CONCLUSIONS: Our data reinforced that scintigraphy with (111)In-pentetreotide represents the imaging modality of choice in the initial evaluation of GEP-NET. It is highly accurate and can identify clinically unsuspected lesions and optimize the overall staging. It also guides optimal therapy choice and most importantly identifies patients with inoperable or metastatic disease who might be candidates for high-dose targeted therapy.

Evaluation of the gamma probe guided sentinel lymph node biopsy and the blue dye technique in the management of breast cancer.

The aim of this study was to evaluate the efficacy of lymphoscintigraphy, gamma probe guided sentinel lymph node biopsy (GP-SLNB) in the management of breast cancer and study the follow-up results. Fifty two patients (mean age 47.28+/-9.7; range 23-69yr) with operable breast carcinoma and clinically negative axilla were studied. Scintigraphy for the detection of SLN was performed 2-4h before surgery by injecting technetium-99m labeled nanocolloid intradermally in the peritumoral region. First lymph node (LN) to appear on the scan was labeled as SLN and by using the GP was marked on the skin. Blue dye was also injected in all patients intraoperatively and hot and/or blue LN were studied in the axilla using the GP. The SLN was identified in 50 patients (96% success rate) while in 2 patients SLN was not visualized on imaging. The blue dye successfully localized SLN in 45/52 (87%) of the cases. Of the 52 patients, 16 had axillary lymph node dissection (ALND), including 14 SLNB positive for lymph node metastases cases and the two cases in which no SLN was imaged. In the remaining 36/52 cases SLN were negative for metastases and patients on the follow-up remained disease free (NPV 100% for a follow-up period of 12-36 months). The success rate, sensitivity, negative predictive value, and accuracy were 96%, 93%, 100%, and 98% using the GP-SLNB, 87%, 80%, 100%, and 93% using blue dye, and 98%, 100%, 100%, and 98% using combined methods, respectively. In conclusion, lymphoscintigraphy, GP-SLNB has a higher success rate and sensitivity versus the dye technique and when combined with the blue dye technique its sensitivity increases to 100%. We found a high negative predictive value for SLNB and the recurrence rate in these negative SLNB was comparable to the ALND.

Minimally invasive radionuclide-guided parathyroidectomy using 99mTc-sestamibi in patients with primary hyperparathyroidism: a single-institution experience.

OBJECTIVE: To evaluate the efficacy and usefulness of (99m)Tc-sestamibi scintigraphy and gamma probe localization of parathyroid glands in patients with primary hyperparathyroidism and establish radio-guided minimally invasive parathyroidectomy at Hussain Makki Al Jumma Center for Specialized Surgery, Kuwait. SUBJECTS AND METHODS: Twelve patients with primary hyperparathyroidism (mean age: 48 +/- 14 years; median age: 46 years; age range: 29-68 years) were evaluated. The diagnosis of hyperparathyroidism was established by elevated serum calcium and parathyroid hormone levels. All patients had a well-defined parathyroid lesion on previous standard (99m)Tc-sestamibi scintigraphy with or without ultrasound study. All had a normal thyroid gland, no history of familial hyperparathyroidism or multiple endocrine neoplasia nor any history of previous neck irradiation. On the day of surgery, patients were injected with 740 MBq (20 mCi) of (99m)Tc -sestamibi followed by a half-hour-delayed single standard pinhole view of the neck. A skin marker was placed on the basis of maximum count intensity during gamma probe localization. Patients were then sent for radio-guided minimally invasive parathyroidectomy. RESULTS: The preoperative localization of the affected gland was successful in all cases using a gamma probe and (99m)Tc -sestamibi scintigraphy. The pathological parathyroid tissue was localized and successfully removed with the gamma probe. The histopathological diagnosis was parathyroid adenoma in 11 cases and hyperplasia in the remaining one. All patients remained disease and symptom free at 12-month follow-up. CONCLUSIONS: Our initial experience with intraoperative use of a gamma probe to carry out minimally invasive parathyroidectomy was a useful, easy and safe procedure for treating patients with primary hyperparathyroidism.

Tc-99m-methoxy isobutyl isonitrile scintimammography: imaging postexcision biopsy for residual and multifocal breast tumor.

OBJECTIVES: The interpretation of mammogram in a postsurgical breast can be extremely complex and difficult because masses, calcifications, and architectural distortion can mimic cancer. Scintimammography has been proposed because it is not affected by these morphological changes and can potentially be used in patients after excision biopsy to assess any residual tumor, other foci of disease (multifocal disease). MATERIALS AND METHODS: The population comprised of 21 patients (mean age: 47.80 years, median age: 50 years, and age range: 26-77 years) evaluated for suspected residual breast cancer after excision biopsy. All patients received a 740-1000 MBq bolus IV injection of Tc-99m-methoxy isobutyl isonitrile (MIBI) preferably in pedal vein. At 5-10 min after injection, planar images were obtained in prone lateral and supine anterior positions using dual head gamma camera. MIBI uptake was scored as follows: 1 - as normal uptake (compared with contralateral side), 2 - focal low-intense uptake (equivocal), and 3 - focal high-intense uptake (positive). All patients had histopathology for tissue diagnosis. RESULTS: Of the 21 patients evaluated, scintimammography planar was found true positive in 13 and true negative in six. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 92.85, 85.71, 92.85, 85.71, and 90.47%, respectively (P<0.001). Scintimammography detected 2/2 multifocal disease. CONCLUSION: In patients after excision biopsy, scintimammography with Tc-99m-MIBI is valuable in assessing residual or multifocal disease. Scintimammography has high positive predictive value and may influence planning further management.

Role of serial quantitative gallium-67 tumor uptake in assessing response rates for chemotherapy in lymphoma patients.

PURPOSE: To evaluate in serial gallium-67 scans (GS) the role of semiquantitative tumor-to-background (Tm/Bg) and tumor-to-liver ratios in assessing response rates to chemotherapy, in Hodgkin's disease and non-Hodgkin's lymphoma. MATERIALS AND METHODS: Twenty-seven consecutive patients (15 Hodgkin's disease and 12 non-Hodgkin's lymphoma patients) with an average age of 30 (range, 5-60) years underwent GS at prechemotherapy, early chemotherapy (after first cycle), and postchemotherapy. Average tumor, background, and liver region of interest counts obtained and Tm/Bg, tumor-to-liver, and liver region to background ratios were derived for each patient on serial GS. All patients were assessed by visual and quantitative GS and followed up clinically for more than 7 years. RESULTS: At early visual GS, 70% (19 of 27) of the patients showed rapid response, 15% (four of 27) showed delayed response (negative at post-GS), and 15% showed no response. Mean early-GS Tm/Bg ratio of disease-free patients (1+/-0.04) was significantly different from relapsed (1.4+/-0.2) (P<0.025) and progressive disease (1.8+/-0.7) patients. A significant difference was noted (P<0.01) in serial paired comparisons of Tm/Bg ratios between pretherapy and early-therapy scans in relapsed patients, whereas progressive disease patients showed no significant change during the same time. At early-GS, 15 patients showed quantitative rapid response (Tm/Bg ratio 1.04), nine patients showed quantitative delayed response (Tm/Bg ratio >1.04 with significant serial change between pretherapy and early-therapy GS), and three patients showed quantitative no response (Tm/Bg ratio >1.04 with nonsignificant serial change between pretherapy and posttherapy GS). CONCLUSION: Quantitative GS is an effective tool in the detection of early response to chemotherapy. Quantitative response rates after the first cycle can more reliably identify patients who are most likely to be disease-free or relapse after first-line therapy or those that will show no response to therapy as compared with visual analysis alone.

The value of quantitative uptake of (99m)Tc-MDP and (99m)Tc-HMPAO white blood cells in detecting osteomyelitis in violated peripheral bones.

UNLABELLED: Our objective in this study was to evaluate whether measurement of quantitative uptake of (99m)Tc-methylene diphosphate (MDP) and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO) white blood cells (WBCs) is useful in detecting osteomyelitis in peripheral bony lesions. METHODS: Twenty-four patients (12 men and 12 women; age range, 25-72 y) were referred for imaging because of clinically suspected osteomyelitis. They had a traumatic fracture (n = 10), knee prosthesis (n = 5), hip prosthesis (n = 2), diabetic foot (n = 4), or chronic osteomyelitis (n = 3). Three-phase bone scanning and (99m)Tc-HMPAO WBC studies were performed on all patients within the same week. Regions of interest were drawn over the abnormal bony sites and the contralateral normal sites, and the abnormal-to-normal uptake ratios (A/N ratios) were obtained for both studies. RESULTS: All patients had abnormal findings on 3-phase bone scanning, whereas 17 (71%) had abnormal findings on (99m)Tc-HMPAO WBC studies, of which 15 were confirmed to be true-positive. In those 15 patients, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 3.0 +/- 1.6 (range, 1.3-6.2) and 1.8 +/- 0.3 (range, 1.4-2.2), respectively. In the other 9 patients, whose scan results were clinically confirmed to be true-negative, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 2.1 +/- 1.2 and 1.2 +/- 0.2, respectively. In the group with a (99m)Tc-MDP A/N ratio greater than 2 (n = 15), 87% (13/15) had a high (99m)Tc-HMPAO WBC A/N ratio (>1.5), including 2 that were false-positive. In the remaining 2 patients, one with chronic osteomyelitis and the other with a recent hip prosthesis, (99m)Tc-HMPAO WBC ratios were normal. In the group with a bone A/N ratio of less than 2 (n = 9), only 4 patients (44%) were true-positive for acute osteomyelitis. CONCLUSION: (99m)Tc-MDP bone scanning alone, with an A/N ratio of more than 2, is useful in detecting osteomyelitis in violated bone except in the case of a recent hip prosthesis or chronic osteomyelitis.