Should 18F-FDG PET/CT Be Routinely Performed in the Clinical Staging of Locally Advanced Gastric Adenocarcinoma?

PURPOSE: The aim of this study was to evaluate F-FDG PET/CT compared with conventional imaging techniques in the clinical management of patients with locally advanced gastric cancer (LAGC). METHODS: A prospective study between January 2010 and December 2011 in patients with suspected LAGC was conducted in our hospital. F-FDG PET/CT, contrast-enhanced CT (CECT), endoscopic ultrasound, and laparoscopy were performed in all cases. Standard whole-body F-FDG PET/CT images were obtained centered on the stomach at 1 and 2 hours after injection of 4.0 MBq/kg of F-FDG. Findings were confirmed by histopathology or by imaging follow-up in nonoperable patients. RESULTS: Fifty consecutive patients with confirmed LAGC (20 women, 30 men) with a mean ± SD age of 65.7 ± 12.1 years were included. Using Lauren classification, 24 patients were intestinal subtype, and 26 were diffuse subtype. Thirty-five patients with locoregional lymph node involvement and 22 with distant metastases were confirmed as peritoneal metastases (n = 15), retroperitoneal (n = 2) or mediastinal lymph nodes (n = 1), and liver (n = 3) or bone metastases (n = 1). Patients with signet ring carcinoma showed significantly less F-FDG uptake (P = 0.001). SUVmax correlated with tumor grading (P < 0.05). Standard and delayed F-FDG PET/CT and CECT images identified LAGC in 24, 27, and 28 of 30 patients, respectively. The sensitivity and specificity for F-FDG PET/CT and CECT to detect metastases were 68% and 100% and 64% and 93%, respectively. Contrast-enhanced CT and F-FDG PET/CT diagnosed only 6 of the 15 patients with confirmed peritoneal metastases. The impact in therapeutic management of F-FDG PET/CT and CECT was 24% and 22%, respectively. Kaplan-Meier survival curves for the LGAC showed a significant correlation between SUVmax and overall survival using an SUVmax threshold of less than 3.96 (P = 0.04). CONCLUSIONS: F-FDG PET/CT should be recommended for staging of LAGC; however, F-FDG PET/CT and CECT cannot replace laparoscopy to rule out peritoneal metastases. Delayed F-FDG PET/CT images show an increase of F-FDG uptake in most cases, improving LAGC detection. The grade of F-FDG uptake represents a significant prognostic tool in this series.

Left ventricular function and visual phase analysis with equilibrium radionuclide angiography in patients with biventricular device.

PURPOSE: Cardiac resynchronisation therapy (CRT) is a technique indicated in patients with moderate to severe heart failure and ventricular dyssynchrony. To evaluate left ventricular ejection fraction (LVEF) and synchronisation changes after CRT with a biventricular pacing implant, we used an equilibrium radionuclide angiography (ERNA). METHODS: Fifty patients were studied. An ERNA was made 72 h and 6 months after the implant. Two acquisitions were performed: with the CRT device connected and after disconnecting it. In the follow-up, responders were defined as those who had improved in accordance with various clinical variables. Quantitative changes in LVEF and visual changes in synchronisation (phase analysis) were studied comparing the two studies and also comparing the connected and disconnected modes. RESULTS: At 6 months, 30 patients were defined as responders. LVEF increased significantly at 6 months compared with the 72-h study only in responders. At 72 h, the number of patients showing a decrease in LVEF (p < 0.05) or a synchronisation worsening after disconnecting the device was higher in responders than in nonresponders. At 6 months, 57% of responders had no synchronisation changes between the connected and disconnected modes, suggesting a resynchronisation process. CONCLUSIONS: ERNA permits the study of resynchronisation patients, showing a statistical LVEF improvement at 6 months. Moreover, visual phase analysis permits the study of the mechanism involved in the response, with an important number of responders with no changes between the two modes at 6 months. In the 72-h study, after disconnection of the device, LVEF and resynchronisation worsening can predict patient improvement at 6 months.

Validation and application of the sentinel lymph node concept in malignant vulvar tumours.

PURPOSE: Inguinal lymphadenectomy, unilateral or bilateral, is widely used in cases of vulvar squamous cell carcinoma and melanoma but has a high morbidity. Sentinel lymph node (SLN) biopsy may be used in the management of these patients. The aims of this study were firstly to determine the reliability of SLN biopsy in predicting regional lymph node status and secondly to apply this technique in the routine clinical setting. METHODS: We prospectively studied 70 women with vulvar malignancies. The first 50 cases were of squamous vulvar cancer and were used to validate the SLN technique in this clinical setting (validation group). Once a satisfactory success rate had been achieved in the validation group, the SLN technique was applied to a further 20 patients with vulvar malignancies, i.e. squamous cell carcinoma (n=12) and melanomas (n=8) (application group). Dynamic and static images were acquired after the injection of 74-148 MBq of a colloidal albumin, and continued until SLN identification. Fifteen minutes before surgery, blue dye injection was administered in a similar manner to the radiocolloid. After incision, a hand-held gamma probe was used to find the SLN. In the validation group, dissection of the SLN was always followed by lymphadenectomy. In the application group, this procedure was only performed if the SLN was positive for metastases. For pathological staging, samples were evaluated using haematoxylin and eosin and immunohistochemistry. RESULTS: In the validation group, lymphoscintigraphy allowed SLN detection in 49/50 patients (98%). Blue dye detected the SLN in 40/50 patients (80%). In 16 patients (33%), the SLN showed metastases in the pathology study. All 33 patients with negative SLN had regional lymph nodes negative for metastases (negative predictive value 100%). In the application group, lymphoscintigraphy showed drainage to an SLN in 19 out of 20 patients (95%) and blue dye demonstrated a stained SLN in 17/20 patients (85%). Seven of the 19 SLN-identified nodes (37%) were positive for metastases. CONCLUSION: SLN identification permits the accurate pathological study of regional nodes and could reduce the high morbidity of current surgical treatment in vulvar tumour patients if the technique were to be adopted on a routine clinical basis.

Bilateral Paget disease of the calcaneus diagnosed by conventional bone scintigraphy.

An 85-year-old woman who had an invasive ductal carcinoma of the breast and elevated alkaline phosphatases (420 U/L) was referred for Tc-99m MDP bone scintigraphy for initial evaluation of skeletal metastases. Bone symptoms were limited to chronic pain in both knees. A bone scan revealed pagetoid findings in both calcanei. Feet and toes on plain x-rays of the calcaneus were unremarkable. Findings were stable in the 2-year follow up, excluding other potential diagnosis as extensive metastases or stress fractures.

Role of pre-operative imaging using 99mTc-MIBI and neck ultrasound in patients with secondary hyperparathyroidism who are candidates for subtotal parathyroidectomy.

PURPOSE: The purpose of this study was to assess whether pre-operative (99m)Tc-methoxyisobutylisonitrile (MIBI) scintigraphy and neck ultrasound (US) are of value in improving the outcome of subtotal parathyroidectomy in patients with secondary hyperparathyroidism. METHODS: Forty-eight consecutive haemodialysis patients with severe secondary hyperparathyroidism prospectively underwent "blinded" subtotal parathyroid surgery, with 1-year follow-up to establish cure or relapse of their secondary hyperparathyroidism. Double-phase (99m)Tc-MIBI scintigraphy and neck US were performed pre-operatively in all patients. When the preserved gland showed (99m)Tc-MIBI uptake or an abnormal size on US, it was considered that "(99m)Tc-MIBI advice" and "US advice", respectively, had not been followed. Pre-operative and follow-up parathyroid hormone (PTH) levels were obtained in all patients. All data were evaluated on a patient by patient basis. RESULTS: Four parathyroid glands were identified in each patient at primary surgery, resulting in an operative success rate of 100%. Their weight ranged from 15 to 7,300 mg (mean 1,120+/-900 mg). Nine of the 48 patients (19%) showed a recurrence of their secondary hyperparathyroidism. The recurrence rate was 2% (1/48) and 10% (5/48), respectively, when (99m)Tc-MIBI and US advice was followed. The sensitivity, specificity, NPV and PPV for pre-operative imaging were 72%, 95%, 97% and 80% respectively for (99m)Tc-MIBI, and 55%, 67%, 87% and 28% for US. CONCLUSION: (99m)Tc-MIBI scintigraphy is a reliable non-invasive exploratory tool and its preoperative use results in a significant reduction in the number of recurrences in haemodialysis patients with secondary hyperparathyroidism who are candidates for subtotal parathyroidectomy. The use of neck US did not significantly improve the results obtained with (99m)Tc-MIBI alone.

Clinical relevance of sentinel lymph nodes in the internal mammary chain in breast cancer patients.

PURPOSE: Despite the widespread use of sentinel lymph node (SLN) biopsy in breast cancer patients, some controversy exists about the correct management of extra-axillary nodes, especially those located in the internal mammary chain. The aim of this study was to evaluate the incidence of SLNs in this region, calculate the lymphoscintigraphic and surgical detection rates and evaluate the clinical impact on staging and therapeutic decisions. METHODS: The study involved 383 consecutive women diagnosed with early breast cancer with T1 or T2 tumours. Eight patients had a bilateral tumour, which brought the total to 391 lesions. Lymphoscintigraphy was performed on the day before surgery by injection of (99m)Tc-labelled nanocolloid. The injection site was subdermal (68 patients), peritumoural (107 patients) or intratumoural (216 patients). During surgery a gamma probe was used to guide the surgeon and the SLNs were removed. SLNs were analysed by a conventional pathological study and processed for H&E examination and immunohistochemistry. RESULTS: Lymphoscintigraphy detected at least one SLN in 369 out of the 391 procedures (94.4%). SLNs were found in the axillary chain in 367 cases and in the internal mammary chain in 55. In two of these 55 cases (3.6%), the SLN was the only one detected. There was no drainage to the internal mammary chain in any case of subdermal injection but such drainage was found in 15.9% of cases with peritumoural injection and 17.6% of those with intratumoural injection. Compared with tumours located in the outer quadrants, a higher percentage of tumours located in the inner quadrants showed drainage to the internal mammary chain (p<0.001). A total of 42 SLNs in the internal mammary chain could be removed in 32 patients without appreciable morbidity. In 20 cases both axillary and internal mammary SLNs were negative, in four both were positive, and in five axillary SLNs were positive and internal mammary SLNs were negative. More interestingly, in the remaining patient with both axillary and internal mammary SLNs, the axillary SLN was negative while malignant cells were found in the internal mammary region. In the evaluation of the clinical impact of internal mammary SLN biopsy, we found that staging was modified from pN1a to pN1c in four patients and, more importantly, from pN0 to pN0(i+) in one patient. The change in stage led to a modification of the postoperative treatment plan with respect to radiotherapy and systemic therapy. CONCLUSION: Evaluation of the SLNs in the internal mammary chain provides more accurate staging of breast cancer patients. If internal mammary sampling is not performed, patients can be understaged. This technique can offer a better indication of those patients who will benefit from selective treatment options like radiotherapy to this region or systemic therapy.

Predicting the effect of intravenous calcitriol on parathyroid gland activity using double-phase technetium Tc 99m-sestamibi scintigraphy.

BACKGROUND: Although intravenous calcitriol is useful for decreasing intact parathyroid hormone (iPTH) blood levels in patients with secondary hyperparathyroidism (SHP) undergoing hemodialysis, approximately half these patients remain refractory to this treatment. The current study measures the diagnostic utility of double-phase technetium Tc 99m-sestamibi (MIBI) scintigraphy in predicting the response to calcitriol treatment. METHODS: Sixty hemodialysis patients with SHP with iPTH blood levels between 240 and 600 pg/mL (ng/L) were selected. Initial intravenous calcitriol pulse therapy was 6 microg/wk (for iPTH levels of 400 to 600 pg/mL [ng/L]) or 3 microg/wk (for iPTH levels of 240 to 400 pg/mL [ng/L]). MIBI scintigraphy was performed before the onset of calcitriol therapy and repeated 1 year later. Patients were injected intravenously with 740 MBq of MIBI. Images were obtained at 15 minutes (thyroid phase) and 2 hours (parathyroid phase) after radiotracer administration. Focal areas of increased MIBI uptake were considered pathological parathyroid glands. RESULTS: Forty-eight patients completed the study. After 1 year, iPTH levels had decreased significantly in 95.2% (47 patients), whereas good control (iPTH < 240 pg/mL [ng/L]) was reached in 70.8% (34 patients) and only 4 patients had iPTH levels greater than 400 pg/mL (ng/L; all were patients with 3 MIBI-positive areas at baseline determination). At baseline, there were 30 patients (62.5%) with MIBI positive areas (1, 2, or 3 areas), which decreased to 14 patients (29%) at the end of the study period. No patient showed 4 positive areas at any time. The 18 patients (37.5%) with no MIBI-positive area at baseline remained unchanged. CONCLUSION: MIBI scintigraphy is a reliable exploratory tool in predicting the response to treatment with intravenous calcitriol in hemodialysis patients with SHP.