Contralateral axillary sentinel lymph node drainage in breast cancer: Controversies and management according to the literature. A case report. / Drenaje del ganglio centinela a axila contralateral en cáncer de mama: controversias y manejo según la literatura. A propósito de un caso.

Lymphoscintigraphy in breast cancer usually shows lymphatic drainage to the ipsilateral axilla. Drainage to extraaxillary or contralateral axillary regions is rare and there is still controversy about its management. Due to the significant clinical impact of an accurate staging, a literature research is made based on a case of a patient with recurrence of left breast cancer with contralateral axillary sentinel lymph node detection, without evidence of lymphatic drainage to other locations.

Breslow thickness and (18)F-FDG PET-CT result in initial staging of cutaneous melanoma: Can a cut-off point be established?

AIM: To establish a Breslow Thickness (BT) cut-off point for indication of PET-CT of cutaneous melanoma in early stages and evaluate its prognostic value. MATERIAL AND METHODS: Retrospective analysis of 347 PET-CT studies with diagnosis of melanoma, of which 108 were performed for initial staging. Thirty-one patients were excluded, and a final sample of 77 patients remained. A ROC curve analysis was performed to establish an optimal cut-off point. A survival analysis was performed, considering death assignable to melanoma as the main event, for the evaluation of its prognostic value. RESULTS: Forty-seven (61.04%) of all 77 patients selected were men, and 11 (14.29%) had a positive PET-CT result. Mean age was 65.17±15.00 years. The median BT in patients with a negative PET-CT result was 2.75 mm (IQR 1.83-4.50) and in the positive group 6.25 mm (IQR 5.40-7.50) (P=.0013). In the ROC curve analysis (AUC 0.804, SE 0.054), an optimal value of 5 mm BT with the following values was obtained: sensitivity 90.91%, specificity 78.79%, negative predictive value (NPV) 98.1%, positive predictive value (PPV) 41.7%, diagnostic OR 37.1, and accuracy 80.52%. Mean follow-up was 18.66±14,35 months, detecting 2/53 (3.77%) deaths in the BT<5 mm group, and 7/24 (29.17%) in the BT≥5 mm group. Survival curves between both groups were significantly different (P=.0013). CONCLUSIONS: A 5 mm cut-off point correctly distinguishes those patients with positive PET-CT from those with negative results in the early stages of cutaneous melanoma; therefore it could be included in initial staging of this subgroup of patients.

Effects of the relationship between 65Zn and blood cells. A dynamic and morphological study.

We have studied the dynamic pathway of 65Zn and its autoradiographic location in blood cells, even at the ultra-structural level. We have found evidence that tends to confirm the old biochemical postulates about the capacity of this isotope to displace iron in the haemoglobin molecule. Recently, the bibliography has demonstrated that 57Co is also able to perform this displacement, but unlike 65Zn it does not invalidate the Redox function of the molecule. In the case of 65Zn, the mentioned displacement invalidates this function because the radionuclide can only use valence 2. We have also contributed evidence of erythrocytes destruction by the spleen after the incorporation of 65Zn, as well as the clearly marked degradation of haematic pigments inside the spleen.

Pancreatic involvement detected with (18)F-FDG PET/CT in disseminated sarcoidosis.

La sarcoidosis is a granulomatous disease of unknown etiology. It may mimic malignancy and may affect multiple organs, with a variable clinical course. Pancreatic involvement is very rare. We present the case of a 78-year-old woman with systemic sarcoidosis whose (18)F-FDG PET/CT scan showed a pancreatic lesion and multiple lymphatic (thoracic and non-thoracic) and visceral lesions. The abnormal (18)F-FDG uptake in the pancreas was limited to the tail. A second (18)F-FDG PET/CT study performed 4 months and 3 weeks after the first PET/CT, following corticosteroid therapy during three and a half months, evidenced partial regression of the disease, with persistent (18)F-FDG pathological uptake in the pancreatic lesion.

[Early response to treatment with Glivec detected with 18F-FDG PET in a patient with gastrointestinal stromal tumor]. / PET 18F-FDG en la detección temprana de la respuesta al tratamiento con Glivec en paciente con tumor del estroma gastrointestinal.

We present the case of a male patient with gastrointestinal stromal tumor (GIST) in whom we conducted two (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) studies, the first one prior to beginning the treatment with Glivec and the second after one month of treatment. The first (18)F-FDG PET scan detected multiple FDG avid foci in distal esophagus, liver and in an interaortocava lymph node. The second (18)F-FDG PET showed very good response to therapy, with an almost complete disease remission. After 23 months of follow-up, the early response to treatment detected by (18)F-FDG PET was confirmed. The utility of (18)F-FDG PET in the evaluation of response to treatment in GIST is discussed and compared with CT.

[Diagnostic accuracy of 18F-FDG PET in residual or recurrent differentiated thyroid carcinoma with high thyroglobulin and negative 131-I whole-body scan]. / Eficacia diagnóstica de la PET 18F-FDG en el cáncer diferenciado de tiroides residual o recurrente con tiroglobulina elevada y rastreo con 131-I negativo.

INTRODUCTION: 18F-FDG PET has demonstrated its usefulness in detecting recurrences of differentiated thyroid cancer (DTC) with high thyroglobulin (Tg) levels and negative 131I whole-body scan (WBS); however, the number of patients analyzed is low and different studies report disparate results. OBJECTIVE: To estimate the diagnostic accuracy of 18F-FDG PET in this subgroup of patients. MATERIALS AND METHODS: Fifty eight patients (64 18F-FDG PET studies) with histologically proven DTC treated with total thyroidectomy followed by at least one session of 131I therapy for the ablation of thyroid remnants were retrospectively analyzed. Results were verified by pathology, clinical follow-up, response to treatment, or by comparison with conventional diagnostic methods. Sensitivity (Se), specificity (Sp), likelihood ratios (LR), diagnostic accuracy (DA), positive and negative predictive values (PPV, NPV), and Tg levels were calculated for patients with positive and negative 18F-FDG PET results. RESULTS: Twenty seven studies were true positives, 1 false positive, 25 true negatives, and 11 false negatives. Se was 71 %, Sp 96 %, PPV 96.4 %; NPV 69.4 %, DA 81.3 %, positive LR 17.75, and negative LR 0.3. The mean Tg level was 202.34 ng/ml in patients with positive 18F-FDG PET and 40.94 ng/ml in those with negative 18F-FDG PET; the difference between the two groups (161.4 ng/ml) was significant at p <0.05. CONCLUSIONS: 18F-FDG PET is a useful for detecting residual or recurrent DTC in patients with elevated Tg and negative 131I WBS.

[Meta-analysis of the diagnostic performance of 18F-FDG PET in renal cell carcinoma]. / Meta-análisis sobre el rendimiento diagnóstico de la tomografía por emisión de positrones con 18F-FDG en el carcinoma de células renales.

AIM: Renal cell carcinoma is the most frequent solid kidney tumor. At present, PET is not the imaging test of choice, the helical CT being the best method to assess these patients. The aim of the study was to perform a meta-analysis of the literature to evaluate the performance and accuracy of 18F-FDG PET in the detection of primary disease, recurrence and metastasis of renal cell carcinoma. MATERIALS AND METHODS: A systematic search was done of the available literature in primary and secondary databases published until October 2004 indexed in MEDLINE and CANCERLIT. Exclusion/inclusion criteria were applied. Their quality was evaluated using the Flynn criteria and joint estimators of sensitivity (S), specificity (Sp), likelihood ratios (LR), diagnostic odds ratio (DOR) and summary ROC (SROC) curve were obtained. The presence of the threshold effect was evaluated and the summary ROC (SROC) curve was calculated. RESULTS: Seven out of 46 studies fulfilled the inclusion criteria and were analyzed. Three studies evaluated the use of 18F-FDG PET in the differential diagnosis of renal masses. Two studies analyzed restaging and two analyzed the role of 18F-FDG PET in the detection of metastatic disease. All the selected studies were classified according to Flynn's criteria. We found the highest S in restaging with S 0.87 (95 % CI, 0.75-0.95) and in metastases detection with S 0.72 (95 % CI, 0.56-0.85) as well as the high Sp in differential diagnosis of renal masses. CONCLUSIONS: The results of this meta-analysis suggest that 18F-FDG PET can be useful in restaging and detection of metastatic disease, based on its acceptable S and Sp. However, the performance of 18F-FDG PET in the detection of primary disease is limited, but this may improve with the new PET/CT systems.

[Impact of FDG-PET in therapeutic management of patients with suspected recurrence of head and neck cancer]. / Impacto de la PET-FDG sobre el manejo terapéutico de pacientes con sospecha de recurrencia tumoral por cánceres de cabeza y cuello.

OBJECTIVE: This study aims to evaluate the impact of Positron Emission Tomography on therapeutic decisions in patients with suspicion of recurrence of head and neck cancers. MATERIAL AND METHODS: The diagnostic and therapeutic impact of FDG-PET was evaluated in 59 of 60 studies performed in a sample of 54 patients. The impact was graded on five levels (high, moderate, low, no impact and negative impact) following the Hicks et al. classification modified by us. RESULTS: The FDG-PET impact was high in 28 studies (47.46 %), moderate in 7 (11.86 %), low in 20 (33.90 %), no impact in 3 (5.09 %) and finally negative impact in 1 study (1.69 %). CONCLUSIONS: FDG-PET is useful in the management of patients in 59.32 % of the studies with indeterminate physical examination and conventional imaging tests. This paper supplies new data since we did not find any studies showing statistical results on therapeutic impact of FDG-PET in head and neck cancers in a systematic review of the literature made by our group.

[Recurrent signet-ring cell gastric carcinoma evidenced by FDG-PET]. / Recurrencia de un carcinoma gástrico de células en anillo de sello demostrada por PET-FDG.

OBJECTIVE: To present the case report of a patient with undifferentiated and diffuse signet-ring cell gastric carcinoma in which FDG-PET evidenced recurrent disease. MATERIALS AND METHODS: The patient was diagnosed of a stage III gastric carcinoma in 1994 and was treated with a subtotal gastrectomy. In February 2003, recurrent disease was detected in mediastinal and left supraclavicular lymph nodes. The patient was treated with chemotherapy and radiotherapy, reaching a complete response. After 6 months free of disease, he presented an elevation of the tumor markers with negative results in conventional imaging methods (upper digestive endoscopy, bone scintigraphy, and CT). An FDG-PET scan was performed to rule out recurrent disease. RESULTS: FDG-PET detected pathologic findings suggestive of malignant disease in right supraclavicular and mediastinal lymph nodes. These findings were confirmed by clinical follow-up and with another CT scan performed 4 months later. CONCLUSIONS: In this case report we stress the importance of early recurrence by FDG-PET in a non-intestinal gastric carcinoma. This is of interest given the greater difficulty to detect mucous secreting and/or producing carcinomas with the PET-FDG.

[Impact of positron emission tomography with FDG-PET in treatment of patients with suspected recurrent ovarian cancer]. / Impacto de la tomografía por emisión de positrones mediante 18-Fluoro-2-Desoxi-D-Glucosa (PET-FDG) en el manejo terapéutico de pacientes con recurrencia secundaria a cáncer de ovario.

AIM: Recurrent ovarian cancer is a major problem and an accurate diagnosis can often change patients' management. This study aimed to assess the impact on management of FDG-PET in recurrent ovarian cancer. MATERIAL AND METHODS: Forty-three patients in whom FDG-PET scan was performed due to suspected recurrent ovarian cancer were included. FDG-PET results were confirmed by histopathology and clinical follow-up of at least 12 months. To assess impact on management the treatment plan based on conventional imaging methods was compared with the treatment plan based on inclusion of PET findings, classifying FDG-PET impact on management as high, medium, low or no impact. Management changes, when present, were classified as intermodality or intramodality. RESULTS: FDG-PET had a high impact on therapeutic management in 28 patients (65.1 %), medium impact in 2 patients (4.6 %), low impact in 9 patients (20.9 %), and no impact in 4 patients (9.3 %). FDG-PET induced an intermodality change in management in 27 patients (62,8 %); intramodality changes were induced in 3 patients (7 %). Finally, it produced no treatment changes in 13 patients (30.2 %). CONCLUSION: FDG-PET supplied additional information when compared to conventional diagnostic procedures and allowed adequate management changes in most patients.

[Positron emission tomography in a patient with Von Recklinghausen disease and left dorsal neurofibrosarcoma]. / PET-FDG en paciente con enfermedad de Von Recklinghausen y neurofibrosarcoma dorsal izquierdo.

The development of neurofibrosarcomas in patients with Von Recklinghausen disease is a rare complication that can appear in the daily clinical practice. We report a clinical case with Von Recklinghausen disease and recurrence of a left dorsal neurofibrosarcoma diagnosed by Positron Emission Tomography with fluorine-18-fluoro-deoxyD-glucose (FDG-PET). We believe this work is important due to the relatively uncommon clinical presentation and the discussion on the utility of 18-FDG PET and other conventional imaging methods in the diagnosis of this entity.

Patient surface radiation doses at two PET imaging facilities.

To develop a practical means of auditing the procedures and to optimize the administered radionuclide activity, patient surface radiation doses following the administration of 18FDG for PET imaging have been measured at breast and gonad locations at two PET facilities. Patient dosimetry was performed using LiF TLD-100 chips placed near the breasts and gonads for 2 h following tracer injection. Standard uptake values from the image-reconstruction algorithms of one PET camera were investigated in regions of interest in tomograms of the myocardium and liver with the aim of validating dosimetry at breasts. Mean doses measured on the patient's skin ranged between 3.3 and 6.1 microGy MBq(-1) at the gonads and between 3.9 and 6.4 microGy MBq(-1) at the breasts, noticeably lower than the calculations reported in the literature. These values show good concordance with the injected activities, although they are not proportional. The proportion of injected activity actually contributing to image production seems to decrease gradually as the injected activity increases. Conversely, for a given injected activity, breast and gonadal doses were found to be lower than the values expected from the numerical calculations reported in the literature, showing increasing discrepancies when the injected activity increased. Doses measured at the right breast were consistently higher than for the left, which is indicative of greater radiotracer absorption by the liver compared to the average absorption in the body.

Early diagnosis of recurrent breast cancer with FDG-PET in patients with progressive elevation of serum tumor markers.

BACKGROUND: The aim of this work is to assess the diagnostic value of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG), in the early detection of tumour recurrence in already treated breast cancer patients in apparent complete remission and with a progressive elevation of tumour markers CEA and/or CA 15.3 without any other clinical or instrumental signs of relapses. METHODS: The author studied 45 women (mean age 58+/-12, range 35-80 years) with histological diagnosis of breast cancer who underwent a tumour marker-guided whole body FDG-PET. All patients were in remission, without any other clinical or instrumental signs of relapses, except for the progressive elevation of CA 15.3 and/or CEA, tested during the follow-up. FDG-PET results were controlled by pathology when histological sampling was possible, by other conventional imaging modalities (US, X-rays, CT, MRI) and/or by clinical follow-up up to 12 months at least. RESULTS: FDG-PET findings were evaluated in 38 patients: 27 resulted positive. Among these 27 PET positive patients 24 were true positive and 3 false positive. Tumour marker guided FDG-PET was also able to discover 3 unknown neoplasms not visualized by other modalities. PET revealed 54 sites of intense focal FDG uptake. The anatomical distribution of these sites was 19 skeleton, 18 lymph node basins, 5 liver, 5 pelvic region, 1 lung, 1 pericardium, 1 pleura, 1 contralateral breast, 2 peritoneum and 1 thyroid bed. Forty-eight of these 54 sites of FDG accumulation were confirmed to be metastases. FDG-PET resulted negative in 11 patients and only in 2 of them the other diagnostic modalities were able to discover metastatic lesions; we had 9 true negative and 2 false positive RESULTS. On the basis of our investigation the performances of tumour marker guided FDG-PET per patient are as follows: sensitivity 92% (24/26), specificity 75% (9/12), positive predictive value 89% (24/27), negative predictive value 82% (9/11), accuracy 87% (33/38). CONCLUSIONS: This study demonstrated the clinical utility of tumour marker-guided PET in the follow-up of breast cancer patients. This diagnostic approach allowed to modify the clinical management in those patients in whom a tumor relapse or unexpected primary neoplasm was discovered.

[Neuroimaging in epilepsy. Advances in SPECT and PET in epilepsy]. / Neuroimagen en epilepsia. Avances en SPECT y PET en epilepsia.

INTRODUCTION: The incorporation of neuroimaging techniques into the protocol for localization of epileptogenous foci has considerably reduced the need for use of intracranial electrodes. DEVELOPMENT: SPECT and PET are most useful in cases of epilepsy with no cerebral morphological anomalies, in which there are therefore no changes which shown on MR. Cerebral SPECT with perfused tracers, such as 99mTc-HMPAO, 123I-MP or 99mTc-ECD, permit the study of patients during interictal and perictal phases. In the latter case, although the procedure is complex, one may observe an increase in cerebral blood flow in the epileptogenous focus in 90% of the patients. PET with FDG allows interictal study of patients, and shows reduced metabolism in the epileptogenic region. By comparison with video-EEG there are S = 84% and SP = 86% in temporal lobe epilepsy. The diagnostic efficiency of these two techniques is rather less in the localization of extratemporal foci and in multifocal epilepsies, although it is always better than with other diagnostic techniques. They have also been shown to be useful in the prognosis of functional recovery after surgery. CONCLUSION: The possibility of studying neuroreceptors may be of great use in the investigation of the etiopathogenesis of epilepsy, and thus lead to improvement in the clinical and therapeutic management of patients. With SPECT, 123I-Iomacenil and 123I-lododexetimide are used. With PET and 11C-Carfentanyl opiate receptors have been studied. With 11C-Fluomacenil one may study the cerebral distribution of the benzodiazepine receptors.

[PET-FDG in thyroid cancer with high thyroglobulin levels and negative 131-I scan. A case report]. / La PET-FDG en el cáncer de tiroides ante niveles altos de tiroglobulina y rastro 131-I negativo. A Propósito de un caso.

The value of whole body PET-FDG in the evaluation of metastases has been demonstrated in a wide variety of tumors. In this report, we present the case of a patient with antecedent of papillary thyroid carcinoma, who was operated twelve years ago, and submitted to an ablative dose of residual thyroid tissue through 131I, being the levels of thyroglobulin normals. After twelve years of evolution, the patient refers bag pain and respiratory trouble, appearing in the CT image suspicious of metastases in right pulmonary base. The levels of thyroglobulin were shown increased, being the 131I scan negative. A whole body PET-FDG study was performed in order to exclude metastases of his malignant process, showed multiple high FDG uptake focus in brain, cerebellum, neck, chest, lymphatic nodes and bone, suggestive of dedifferentiated disease These findings were confirmed subsequently in the clinic evolution. Therefore, whole-body PET-FDG is a complementary diagnostic technique for study patients with CDT (Thyroid Differentiated Carcinoma) with 131I scan negative and rising thyroglobulin levels.

[The role of PET-FDG in questionable diagnosis of relapse in the presence of radionecrosis of brain tumors]. / Papel de la PET-FDG ante la duda diagnóstica de recidiva frente a radionecrosis en tumores cerebrales.

INTRODUCTION: Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN). PATIENTS AND METHODS: In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis. RESULTS: In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases. CONCLUSIONS: Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.