Horacio Amaral

The role of PET-CT in patients with incidental gallbladder cancer

INTRODUCTION After a cholecystectomy, incidental gallbladder cancer (IGC) requires accurate imaging studies to determine the actual extent of the disease to properly tailor subsequent treatment. The aim of this study was to evaluate the utility of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)FDG PET-CT) to provide optimal pre-treatment staging in patients with IGC. MATERIAL AND METHODS Between January 2006 and August 2008, all patients with IGC and at least muscular layer invasion were studied with (18)FDG PET-CT. The examination was considered positive when the standardized uptake values (SUV) were >/=2.5. In all instances patients were offered to undergo definitive exploration and possible radical resection. RESULTS The series included 32 patients, 26 women and 6 men, with a median age of 57 years (range 30-81 years). The examination was performed at a median time of 6 weeks after cholecystectomy (range 2-52 weeks). (18)FDG PET-CT was negative in 13 patients and positive in 19 patients: 9 with localized potentially resectable disease (PRD) and in 10 with disseminated disease. Of the 13 patients with negative PET-CT, 9 refused surgery and 4 underwent formal exploration: 3 patients were resected with no disease identified in the final pathology report (FPR) and 1 was not resected as a result of peritoneal carcinomatosis. Of the 9 with PRD, 4 patients refused reoperation and 5 underwent exploration: 3 were resected with residual disease noted in the FPR and 2 did not undergo resection because of dissemination. Two patients with disseminated disease were reoperated and in both instances disseminated disease was confirmed. The median survival for the entire group was 20.3 months (range 1.6-32.9 months). The median survival for those patients with negative PET-CT was 13.5 months (range 5.6-32.9 months), 6.2 months (range 1.6-18.7 months) for localized potentially resectable disease and 4.9 months (range 2-14.1 months) for disseminated disease (P < 0.003). CONCLUSIONS For patients presenting with stage T1b or greater IGC, the use of (18)FDG PET-CT will help reduce the number of patients undergoing non-therapeutic re-exploration and may help to determine the likely prognosis. (18)FDG PET-CT might be a useful tool for the selection of patients for potentially curative treatment.

Cold-hot mismatch between Tc-99m HMPAO-labeled leukocytes and Tc-99m ciprofloxacin in axial skeleton infections: a report of three cases.

Radiolabeled leukocyte scintigraphy is a well-established technique for the diagnosis of inflammation and infection with a typical presentation of a hot spot within the abnormal areas. However, in some cases of osteomyelitis of the axial skeleton, a cold defect pattern has been described. Tc-99m ciprofloxacin is a new agent claimed to be specific for imaging sites containing viable bacteria. In this report, we present three cases of proved bacterial infection of the axial skeleton with a mismatch pattern between Tc-99m ciprofloxin and tagged leukocytes. Although Tc-99m-labeled leukocyte scanning showed a cold defect, probably caused by bone marrow replacement, the Tc-99m ciprofloxacin consecutively revealed a hot spot at the site of infection. These data suggest that Tc-99m ciprofloxacin should be a better agent than radiolabeled leukocytes for detecting osteomyelitis of the axial skeleton.

Anal and rectal syphilis on F-18 FDG PET/CT.

A 59-year-old man was referred for F-18 fluorodeoxyglucose (FDG) PT/CT to characterize pulmonary nodules. Although the lung lesions were negative, an unsuspected increased FDG uptake was detected in the distal rectum, anus, and regional lymphadenopathy. On physical examination a nonpurulent maculopapular exanthema, mainly on the chest, was identified. Anorectal examination and colonoscopy were negative; however the patient recognized a risky sexual behavior. Lymphadenopathy was not palpable. HIV antibody test was negative. Rapid plasma reagin and chromatographic immunoassay (SmarTest) were positive for syphilis. The patient was treated with benzylpenicillin with complete remission of the skin lesions. A new RPR test after therapy was negative.

Thyroid metastases from gallbladder cancer.

BackgroundGallbladder cancer is an aggressive malignancy and radical resection is the only curative therapy available. Metastatic disease in the thyroid is rarely seen; however, different studies have confirmed that the most common primary tumor source is the kidney.Case ReportThyroid metastases from tumors originating in the gastrointestinal tract have been reported. We report a patient with gallbladder cancer (T2N1M0) treated with radical resection and postoperative chemoradiation who developed thyroid metastases.

Detection efficacy of [18F]PSMA-1007 PET/CT in 251 Patients with biochemical recurrence after radical prostatectomy

Prostate-specific membrane antigen (PSMA)–targeted PET imaging recently emerged as a new method for the staging and restaging of prostate cancer. Most published studies investigated the diagnostic potential of 68Ga-labeled PSMA agents that are excreted renally. 18F-PSMA-1007 is a novel PSMA ligand that has excellent preclinical characteristics and that is only minimally excreted by the urinary tract, a potential advantage for pelvic imaging. The aim of this study was to investigate the diagnostic efficacy of 18F-PSMA-1007 for biochemical recurrence (BCR) after radical prostatectomy. Methods: From 3 academic centers, 251 patients with BCR after radical prostatectomy were evaluated in a retrospective analysis. Patients who had received second-line androgen deprivation therapy (ADT) or chemotherapy were excluded, but prior first-line ADT exposure was allowed. The median prostate-specific antigen (PSA) level was 1.2 ng/mL (range, 0.2–228 ng/mL). All patients underwent PSMA PET/CT at 92 ± 26 min after injection of 301 ± 46 MBq of 18F-PSMA-1007. The rate of detection of presumed recurrence sites was correlated with the PSA level and original primary Gleason score. A comparison to a subset of patients treated previously with ADT was undertaken. Results: Of the 251 patients, 204 (81.3%) had evidence of recurrence on 18F-PSMA-1007 PET/CT. The detection rates were 94.0% (79/84), 90.9% (50/55), 74.5% (35/47), and 61.5% (40/65) for PSA levels of greater than or equal to 2, 1 to less than 2, 0.5 to less than 1, and 0.2 to less than 0.5 ng/mL, respectively. 18F-PSMA-1007 PET/CT revealed local recurrence in 24.7% of patients (n = 62). Lymph node metastases were present in the pelvis in 40.6% of patients (n = 102), in the retroperitoneum in 19.5% of patients (n = 49), and in supradiaphragmatic locations in 12.0% of patients (n = 30). Bone and visceral metastases were detected in 40.2% of patients (n = 101) and in 3.6% of patients (n = 9), respectively. In tumors with higher Gleason scores (≤7 vs. ≥8), detection efficacy trended higher (76.3% vs. 86.7%) but was not statistically significant (P = 0.32). However, detection efficacy was higher in patients who had received ADT (91.7% vs. 78.0%) within 6 mo before imaging (P = 0.0179). Conclusion: 18F-PSMA-1007 PET/CT offers high detection rates for BCR after radical prostatectomy that are comparable to or better than those published for 68Ga-labeled PSMA ligands.

Melanoma primario del esófago tratado con esofagectomía: Casos clínicos

Esophageal melanomas correspond to 0.1 to 0.2% of esophageal tumors. We report two patients with the disease. The first patient is a 51 year-old woman pre-sentingwith dysphagia and weight loss. An upper gastrointestinal endoscopy showed a polypoid ulcerated lesion in the middle third of the esophagus. The pathological study ofthe biopsy disclosed a malignant melanoma. The patient was subjected to an esophagectomy with a satisfactory postoperative evolution. Four months later, liver metastases were detected and the patient died eleven months after the operation. The second patient is a 59 year-old mole that consulted by dysphagia. An endoscopy showed a pigmented esophageal lesion whose pathological diagnosis was a malignant melanoma. The patient was subjected to an esophagectomy and sixteen months after surgery there was no evidence of relapse.

Carcinoma hepatocelular variedad fibrolamelar metastásico en menores de 20 años. Reporte de 2 casos tratados con intención curativa y revisión de la literatura

Fibrolamellar hepatocellular carcinoma (FLC) is a rare histologicvariant of hepatocellular carcinoma that appears most commonly in teenagers and young adults.The diagnosis is often made incidentally and surgical resection is the only curative treatment.Here we report two cases of incidental FLC involving a 19 year-old male, initially diagnosed withscreening abdominal ultrasound, and a 14 year-old female that presented with abdominal pain.Diagnostic workup consisted of abdominal PET/CT and MRI Imaging studies and tissue diagnosiswas confirmed with percutaneous liver biopsy. Both patients were treated with radical liverresection/tumor excision. However, tumor recurrence was observed in both during short-termfollow-up. The male patient was treated successfully with surgical treatment however the femalepatient succumbed to pregression of disease (Rev Med Chile 2009; 137: 394-400).(

Effect of captopril in Takayasu's arteritis

Recently Schnaper et al. [1] reported the case of a 10-year-old girl suffering from renovascular hypertension secondary to abdominal-pulmonary Takayasus arteritis. This girl, who has been followed for 5 years, was treated with steroids, cyclophosphamide, captopril and surgery. Jackson et al. [2], Miyamori et al. [31, and Nally et al. [4], using 99mTc-diethylenetriamine-pentaacetic acid (DTPA) renograms, have demonstrated a fall in the glomerular filtration rate (GFR) after the use of captopril in patients with renovascular hypertension. We have investigated the effect of captopril in four children (3 boys, 1 girl), whose ages ranged from 5 to 12 years. Each had Takayasus arteritis and renal ar-

Una nueva modalidad diagnóstica para la detección de tumores neuroendocrinos con 68Ga-DOTATATE PET/CT: Caso clínico

We report a 74-year-old male with liver metastases from a neuroendocrine tumor (NET) of unknown origin. Conventional imaging studies with ultrasound, computed tomography colonoscopy and Positron emission tomography-computed tomography (PET/CT) with 18Fluor odeoxyglucose did not identify the site of origin of the primary tumor. The patient was submitted for a PET/CT scan with a new radiopharmaceuticai, the somatostatin analogue 68Ga-DOTATATE. This new technique demonstrated increased focal uptake at the ileocecal valve. This lesion and other two liver metastases were surgically removed. The histopathology and immunohistochemistry analysis confirmed the diagnosis of NET (carcinoid). This case illustrates the advantages of the PET/CT scan with 68Ga-DOTATATE.