Biomedical subjects

S Fuertes

Publications and source records attributed to S Fuertes.

6 recordsLinked to original sources

PubMed2004

Can the Wada test evaluate mesial temporal function? A SPECT study.

OBJECTIVE: To assess the value of SPECT during intracarotid amobarbital procedure (IAP) to discriminate which patients performed the test with the hippocampus inactivated and correlate it with the risk of amnesia after anterior temporal lobectomy (ATL). METHODS: The authors studied 40 consecutive patients undergoing ATL for refractory epilepsy. SPECT was performed after IV injection of 99mTc-HMPAO during the IAP (IAP-SPECT). Interictal SPECT and IAP-SPECT were realigned to obtain the perfusion change percentage (PCP), allowing a quantitative measurement. Wechsler Memory Scale Revised (WMS-R) before and during the first year of follow-up was used to assess memory impairment after surgery. RESULTS: A decrease between 10 and 12% of the mean PCP values was observed in the frontal, parietal, and lateral temporal lobes of the injected side and in the contralateral cerebellum. However, no significant PCP changes were observed in the occipital or mesial temporal lobes. Thirty-eight passed the memory evaluation of the IAP and in 6 of those 38 patients a decline in memory was demonstrated 1 year after ATL. However, high preoperative neuropsychological score (in two patients) and IAP asymmetry scores (in other three patients) predicted postoperative memory risk in five of these six patients. Fourteen of the 38 patients (40%) had hypoperfusion of the hippocampus during the IAP-SPECT (i.e., the hippocampus was inactivated) and only 1 of these 14 patients (2.5%) developed memory impairment after temporal lobectomy. On the other hand, 5 of the 24 patients (13%) who had a functional hippocampus on IAP-SPECT developed memory impairment. CONCLUSIONS: The results suggest that the combination of SPECT, intracarotid amobarbital procedure, and neuropsychological testing predicted risk for all patients who had postoperative memory decline, indicating that risk prediction should be based on multiple factors. IAP-SPECT results demonstrated that the hippocampus is not inactivated in over 60% of patients and that the lack of accuracy of the IAP alone in predicting the risk of amnesia is probably related to an insufficient inactivation of the ipsilateral hippocampus during the test.

Adolescent↗

PubMed2003

Double-phase parathyroid 99mTc-Sestamibi scintigraphy in chronic haemodialysis patients: correlation with biochemical markers of parathyroid function.

99mTc-Sestamibi identifies the presence of hyperfunctioning autonomous parathyroid glands in patients with secondary hyperparathyroidism (SHP). The objectives of this study were: (i) to evaluate the interdependence between biochemical markers of SHP and 99mTc-Sestamibi uptake; and (ii) to determine whether 99mTc-Sestamibi uptake could be efficiently predicted by any combination of the former variables. Double-phase parathyroid 99mTc-Sestamibi uptake and total serum calcium, phosphorus, intact parathormone, 25-OH vitamin D and 1,25(OH) vitamin D determinations were performed simultaneously in 74 patients (36 female, 38 male) with SHP. Planar images of the neck and upper thorax were obtained in anterior view, 15 min (early phase) and 120 min (delayed phase) after the injection of 740 MBq of 99mTc-Sestamibi. In each patient, a final parathyroid/thyroid (P/T) activity index was obtained by adding the results of the P/T index of all parathyroid lesions. There was a significant correlation between intact parathormone levels and delayed 99mTc-Sestamibi uptake ( r=0.656; P<0.01). Of all the variables, intact parathormone was the only significant predictor of delayed 99Tc-Sestamibi uptake ( r=0.487; P<0.001). Calcium, phosphorus, vitamin D metabolites, age, gender, time spent on haemodialysis and cause of chronic renal failure displayed no significant correlation with 99mTc-Sestamibi uptake. It can be concluded that 99mTc-Sestamibi uptake is a potential predictor of parathyroid function in SHP patients. Hence, 99mTc-Sestamibi scintigraphy could be useful to assess parathyroid function and in the clinical follow-up of these patients.

Age Factors↗

PubMed2003

Is there a role for (99m)Tc-anti-CEA monoclonal antibody imaging in the diagnosis of recurrent colorectal carcinoma?

AIM: To evaluate the usefulness of immunoscintigraphy with an anti-CEA monoclonal antibody fragment labelled with (99m)Tc for early detection of colorectal recurrence in patients with rising serum CEA levels. METHODS: Fifty-one consecutive patients (27 women, 24 men) with colorectal cancer (mean age 68.9+/-10.2 years) and rising CEA levels (16.2+/-18.2 ng/ml) were prospectively studied. Two immunoscintigraphy studies were performed in 8 patients (n=59). Immunoscintigraphy was performed after i.v. injection of 925 MBq of anti-CEA monoclonal antibody. Planar images of the thorax, abdomen and pelvis, as well as SPECT of the abdomen and pelvis were obtained at 4 and 24 hours after injection. In all cases an abdominal CT scan was previously performed. Findings were validated by histopathological analysis (28 cases) or by imaging and clinical follow-up of at least 6 months following the immunoscintigraphy (31 cases). RESULTS: Forty-one patients did not show recurrence during follow-up. We found 18 cases with confirmed diagnosis of extrahepatic abdominal or pelvic diseases, 11 cases with liver metastases, 9 in the thorax and 2 in the bone. In patients with pelvic and extrahepatic abdominal disease, immunoscintigraphy was positive in 18 cases (14 true positive, 4 false positive). From the 14 true positive only 7 cases had been detected by CT. Immunoscintigraphy was negative in the remaining 41 cases (37 true negative, 4 false negative). Therefore, the sensitivity and specificity for immunoscintigraphy in extrahepatic abdominal and pelvic disease were 78% and 90%, respectively. CT results showed a lower sensitivity of 61% (p<0.05) and specificity of 83%. Liver metastases were detected by CT in 9 cases, but only 2 of these were identified using immunoscintigraphy. CONCLUSION: Scintigraphy with anti-CEA monoclonal antibody fragment labelled with (99m)Tc is superior to CT for the detection of pelvic and extrahepatic abdominal recurrence of colorectal cancer, while CT is more sensitive in the detection of liver and lung metastases. Immunoscintigraphy has a limited usefulness in the detection of distant metastases, but it may be helpful in the diagnosis of suspected colorectal recurrence in patients with non-conclusive CT findings, when FDG-PET is not available.

Aged↗

PubMedDate not supplied

[Fast method of labelling leukocytes with 99mTc HM PAO].

OBJECTIVE: To modify the method of labelling leukocytes with 99mTc HM-PAO by centrifuging 15 minutes at low gravity (g) instead of sedimentation at a variable time (30-90 minutes) to obtain leukocytic rich plasma (LRP). METHODS: The g number recovering the greatest number of leukocytes was determined. The cellular composition of LRP obtained by centrifugation and sedimentation was analyzed. Lastly, labelling results in two groups of patients (p) were compared: one group of 118 p using the traditional sedimentation method (SM) and another of 124 p using the proposed centrifugation alternative (CM). RESULTS: Centrifugation at 5xg produced the greatest recovery of leukocytes (93.1 5.1%). No significant difference was observed in leukocyte recovery in LRP obtained either by centrifugation or by sedimentation. However, red blood cell contamination was greater in centrifugation (12.8 4.9 x 108) than in sedimentation (7.7 3.5 x 108) (p < 0.0001). The comparison of the SM and the CM gave the following results:The number of leukocytes recovered in both methods was similar (73.9 15.1% vs 76.5 12.7%) with approximately the same platelet contamination (8.0 6.2 vs 8.4 6.5%). The number of red blood cell contaminants per leukocyte was 3.0 1.0 for the MS and 5.1 2.6 for the MC (p < 0.001). Labelling yield (LY) was somewhat higher for the CM (57.8 11.9%) than for the SM (50.8 12.6%) as a result of greater red blood cell contamination and superior radiochemical purity of the 99mTc HM-PAO used in the labelling by CM (90,9 5,9%) with regard to the SM (87.9 9.5%). No difference was observed in the scintigraphic images obtained with either of the methods, given the scarce uptake of the radiopharmaceutical by the red blood cells (3-7%) in comparison with the leukocyte uptake (70-90%). CONCLUSION: The proposed MC considerably reduces the labelling time of leukocytes with 99mTc HM-PAO without affecting the quality of scintigraphic images and represents an important labelling alternative of great interest to the Radiopharmacy Units of Nuclear Medicine Services.

Blood Cell Count↗

PubMedDate not supplied

[Usefulness of the sentinel node in the treatment and staging of initial cervix cancer].

OBJECTIVE: The aim of this study was to evaluate the usefulness of intraoperative sentinel node (SN) detection in patients with initial cervix cancer. PATIENTS AND METHODS: Lymphoscintigraphy and intraoperative SN detection was performed in 17 patients with initial cervix cancer who we going to have a radical laparoscopic hysterectomy and pelvic lymphadenectomy. Conization was performed in 4/17. The day before surgery, an injection of 111 MBq 99mtechnetium nanocolloid around the primary tumour and a subsequent lymphoscintigraphy were carried out. Blue dye was injected at the same location intraoperatively. A laparoscopic gamma probe was used to identify SNs. RESULTS: SNs were successfully localized using a combination of radiocolloid and blue dye in 16/17 patients (detection rate 94 %). The detection rate only using blue dye technique decreases to 71 % (12/17) and it reaches an 82 % (14/17) if we avoid the blue dye injection. In 3 cases, there was no migration in lymphoscintigraphy and in one of the three SN could not be detected. Thirty-three SNs were identified (1.9 nodes/patient). The most frequent location was left external iliac nodal group (13 nodes: 39 %). SNs were identified in regions that are not included in usual lymphadenectomy: right parametrium (2 sentinel nodes, one of them in the retrouterine region), and interiliac (2 SNs). In all four patients with previous conization SNs were identified (detection rate 100 %). CONCLUSIONS: The rate of SN detection combining lymphoscintigraphy with gamma probe and blue dye is 82 %. The use of blue dye allows increasing this rate to 94 % in those cases which migration was not seen or when the SN is placed near the injection site. The SN technique offers the possibility to find SNs in regions not included in usual lymphadenectomy.

Adult↗

PubMedDate not supplied

[Psoas abscess as cause of lumbar spine pain detected by scintigraphy with gallium in a patient with suspicion of spondylodiscitis].

A 56 year old man with fever and lumbar pain who underwent an abdominal CT scan that showed lumbar arthrosic changes, although it was not possible to rule out infectious disease in L5/S1. Bone scintigraphy was requested. It showed heterogeneous hyperuptake that did not make it possible to exclude a spondylodiscitis in this site. Scintigraphy with 67Ga-citrate excluded infectious diseases in the lumbar spine column. However, a pathological uptake was observed in the left iliac fossa suggestive of psoas abscess, which was confirmed by ultrasonography, isolating streptococcus viridans.

Citrates↗