Intraindividual comparison of 68Ga-DOTATATE PET / CT vs 11C-Choline PET / CT in patients with prostate cancer in biochemical relapse: in vivo evaluation of the expression of somatostatin receptors

BACKGROUND AND OBJECTIVES

To prospectively compare the detection rate of ⁶⁸Ga-DOTATATE versus ¹¹C-choline PET/CT in patients with prostate cancer in biochemical relapse, and to evaluate somatostatin receptor expression in vivo to plan targeted therapies (¹⁷⁷Lu-DOTATATE).

MATERIAL AND METHODS

We prospectively analysed 64 patients with biochemical relapse (median PSA: 4.25 ng/mL). A PET/CT was performed with ¹¹C-choline, and another with ⁶⁸Ga-DOTATATE. The SUVmax was measured in all lesions. The correlative images, histopathology and/or clinical and biochemical follow-up were taken as the reference standard.

RESULTS

The overall detection rate per patient was 48.43% for ⁶⁸Ga-DOTATATE and 46.87% for ¹¹C-choline. The results were concordant in 53 cases (82.81%). The maximum SUV of ¹¹C-choline was significantly higher than that of ⁶⁸Ga-DOTATATE for all the concordant lesions (n=130): 6.17 (1.7-15.5) versus 4.38 (1.37-26.7), median (range) for each radiotracer, respectively (p < .0001). The sensitivity and specificity values per patient were the same for both techniques: 0.82 (0.65-0.93) and 0.9 (0.73-0.98), respectively. Although the difference was not significant, the sensitivity was lower in patients with lower PSA levels: 0.63 vs. 0.89; p=.13. A significant correlation was found between the SUVmax of both tracers (r = 0.41, n = 130, p <.0001).

CONCLUSIONS

⁶⁸Ga-DOTATATE PET/CT and ¹¹C-choline PET/CT seem to have a high capacity to detect pathological lesions in the assessment of patients with prostate cancer with biochemical relapse. Further studies are required to test the potential complementary value of these PET/CT techniques, and to evaluate the potential role of ⁸Ga-DOTATATE for planning somostatin receptor-mediated therapies (¹⁷⁷Lu-DOTATATE).

Incidental focal colonic uptake in studies 18F-FDG PET/CT

OBJECTIVES

To assess the frequency of focal colonic uptake as an incidental observation in ¹⁸F-FDG PET/CT studies, and to correlate this finding with histopathological results.

MATERIAL AND METHODS

Out of a total of 3,176 PET/CT studies with ¹⁸F-FDG systematic analysis was carried out on 30 studies in which colonic focal uptake was observed. Patients with known colorectal neoplasia were excluded. The maximum standardised uptake values (SUVm) and the morphological findings provided by the CT were recorded. The studies were reported by a radiologist and a nuclear medicine doctor. The findings were compared with endoscopy and pathology findings.

RESULTS

Of the 30 patients with focal hypermetabolic lesions of the colon (0.94%), 15 were men and 15 were women with ages between 27 and 73 (mean 55 years). The reasons for PET/CT were bronchopulmonary cancer (4), breast cancer (4), tumour of unknown origin (4), melanoma (3), renal carcinoma (3), cervical neoplasia (2), adenocarcinoma of ovary (2), and others (8). Of the 23 colonoscopies performed, 10 patients (43.4%) had malignant lesions, 6 (26.1%) had pre-malignant lesions, and in 7 patients (30.4%) no lesion was identified or was benign. No endoscopy was performed on 7 patients for various reasons (patient refusal to perform the study, advanced oncological disease). An analysis was performed with the SUVm, with no statistically significant differences being found between malignant-premalignant lesions and benign lesions.

CONCLUSIONS

Focal uptake in the colon of ¹⁸F-FDG has clinical relevance, and is mainly associated with morphological lesions in CT. It should be evaluated, as it may be a second tumour or a pre-malignant lesion. It is recommended that all focal uptakes of the colon be evaluated with endoscopy.

(99m)Tc glucarate as a potential radiopharmaceutical agent for assessment of tumor viability: from bench to the bed side

Several radiotracers have been used for assessing cell death, whether by necrosis or apoptosis. ^99mTc glucarate, which has initially been reported to be concentrating/accumulating in myocardial infarction or zones of cerebral injury, has also shown some tumor-seeking properties in a few preliminary studies. Under International Atomic Energy Agency (IAEA)'s coordinated research program, we report here the standardization, quality control, and clinical evaluation (detection, evaluation of response, and comparison with ¹⁸F Fluorodeoxyglucose) of this tracer in well-characterized lung cancer and head neck malignancies in a single-arm prospective observational study. Forty-seven patients (29 inoperable lung carcinoma and 18 head and neck malignancies) were prospectively enrolled and underwent ^99mTc glucarate imaging [whole body planar and single-photon emission computed tomography of the region of interest] 4-5 hours after injection of 20 mCi of the radiopharmaceutical. Excellent ^99mTc glucarate concentration was noted in the target lesion in lung cancer and head and neck malignancies. The sensitivity was found to be better in lung cancer. Avid concentration of tracer was seen in the metastatic sites. During response evaluation, the glucarate concentration correlated well with the clinical and other radiological findings. ^99mTc glucarate showed avid concentration of tracer in the tumor, suggesting it to be a potential tumor imaging agent which can be used for detection and assessment of therapeutic response in malignancy.

The inflammatory response to colloids and crystalloids used for pump priming during cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response frequently occurs after coronary artery bypass surgery and is strongly correlated with the risk of postoperative morbidity and mortality. This study tests the hypothesis that the priming of the extracorporeal circuit with colloid solutions results in less inflammation in patients undergoing cardiac surgery than priming with crystalloid solutions.

METHODS

A prospective, randomized study was designed. Forty-four patients undergoing elective coronary artery bypass grafting were randomly allocated to one of two groups: 22 patients primed with Ringer's lactate (RL) solution and 22 patients primed with gelatin-containing solution during the surgery. Plasma levels of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP) and, complement 4 were measured during the surgical intervention and over the following 48 postoperative hours. Cytokine levels were measured by enzyme-linked assays from plasma samples obtained at specific time points pre- and post-operatively.

RESULTS

In both groups the serum levels of the pro-inflammatory cytokines (IL-6, IL-8, TNF-alpha), CRP, complement 4, and leukocytes increased significantly over the baseline, although no significant differences were observed between the two groups. The operation time, blood loss, need for inotropic support, extubation time, and length of intensive care unit stay did not differ significantly between the two groups.

CONCLUSION

Priming with gelatin vs. RL produces no significant differences in the inflammatory response in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Valor de la cirugía radioguiada con 99mTc-MIBI sensibilizada con dobutamina en el hiperparatiroidismo secundario persistente

99mTc-MIBI is a radiopharmaceutical that has been successfully used for the detection of hyperfunctioning parathyroid glands and for radioguided surgery techniques. We report on the case of a 55 year old woman in hemodialysis, with secondary persistent hyperparathyroidism after total parathyroidectomy. The conventional double-phase 99mTc-MIBI parathyroid scintigraphy was negative. The study was repeated after sensibilization with intravenous low-dose dobutamine showing an area of increased focal uptake in the lower cervical region. With this finding, radioguided 99mTc-MIBI surgery was performed after dobutamine administration, using a hand held gamma probe. The technique was considered successful with the resection of parathyroid cervical tissue which was further confirmed as nodular hyperplasia. We conclude that this methodology has the potential of being a an useful tool for the intraoperative localization of remanent tissue in patients with secondary persistent/recurrent hyperparathyroidism.

Upper aerodigestive tract and lung tumors after liver transplantation

BACKGROUND

The purpose of this study was to analyze the incidence, clinical characteristics, treatment, and outcome of upper aerodigestive (UAD) and lung de novo tumors after ortothopic liver transplantation (OLT).

PATIENTS AND METHODS

Between April 1986 and June 2002, we performed 851 OLT in 753 patients. We excluded pediatric, partial, and hepatorenal transplants and recipients who died within 2 months after OLT. Thus, we analyzed the incidence and outcome of these tumors in 605 patients after OLT.

RESULTS

We found 21 (3.5%) tumors in 20 (3.3%) recipients: 14 were UAD tumors (three in floor of the mouth, two in tonsil, one in tongue, one in pharynx, three in larynx, and four in esophagus) and seven were lung tumors. Nineteen patients were men and one was a woman, with a mean age at transplantation of 47.7+/-8.6 years. Mean time from OLT to tumor diagnosis was 61.7+/-35.1 years. As risk factors, 70% were heavy smokers, 75% were heavy drinkers, and 70% developed acute rejection. The incidence of these tumors was significantly higher in transplanted patients for alcoholic cirrhosis compared to the nonalcoholic cirrhosis (8.1% vs 0.8%; P<.0001). After surgical excision in 65% of patients, 1-, 2-, and 3-year patient survival were 47.6%, 37.0%, and 19.7%, respectively.

CONCLUSION

There is a significantly higher incidence of these tumors in male heavy drinkers and/or smokers who underwent OLT for alcoholic cirrhosis; in spite of aggressive surgical treatment, the prognosis is poor.

Changes in the incidence and severity of recurrent hepatitis C after liver transplantation over 1990-1999

BACKGROUND/AIM

Changes in immunosuppression and other factors may have changed the severity of recurrent hepatitis C during recent years. This study sought to establish the changes in incidence and severity of recurrent hepatitis C, and its association with the changes in acute rejection and induction immunosuppressive therapy between 1990 and 1999.

PATIENTS AND METHODS

Among 213 liver transplants in HCV-infected recipients, 129 grafts were selected for this study: all grafts with severe recurrent hepatitis C (fibrosis 3-4 in Scheuer's score or fibrosing cholestatic hepatitis), and those grafts without severe recurrence with at least 2 years of follow up. Grafts were divided in 5 groups depending on the year of transplantation to compare recurrent hepatitis C-related variables, AR incidence and induction immunosuppression.

RESULTS

Hepatitis-free survival decreased in recent years (p=0.015). The incidence of fibrosing cholestatic hepatitis was higher among 1996-1997 and the 1998-1999 periods (p=0.019). Survival free of severe hepatitis at 1 year follow up was 95% in 1990-1991 and 80% in 1998-1999; however, in the long-term the survival was similar between groups (p=0.933). HCV-related graft survival at 5 years was 93.5% in the 1990-95 period and 82.5% in 1996-99 (p=0.068). Neither AR nor any regimen of induction immunosuppression was associated with changes in the occurrence of recurrent hepatitis C related survival.

CONCLUSIONS

Severity of recurrent hepatitis C and HCV-related graft loss after liver transplantation were higher in the second half of the 1990s; however, there was no association with AR or induction immunosuppression.

[Examination of regional limph nodes in penile carcinoma by 99M Tc-MIBI scintigraphy]

99mTc-MIBI scintigraphy has proven utility as a clinically valuable technique for the diagnosis of various primary and recurrent malignant lesions. We report the case of a 65 year old man with penile squamous cell carcinoma and clinically questionable bilateral inguinal lymph nodes. 99mTc-MIBI scan shows increased focal uptake in both groins and in the right iliac region. The patient underwent penile amputation with bilateral lymphadenectomy. Histopathologic report revealed metastatic lymph nodes in all lymphatic basins seen with 99mTc-MIBI. We conclude that this technique has the potential of supplying clinically relevant information for the diagnosis of regional extension of patients with penile carcinoma.

Predictive value of (99m)Tc sestamibi scintigraphy in the evaluation of doxorubicin based chemotherapy response in patients with advanced breast cancer

Resistance to doxorubicin based chemotherapy is a major therapeutic problem limiting advanced breast cancer treatment. 99mTc hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been reported to be extruded from tumour cells by the P-glycoprotein and multidrug resistance protein encoded by MDR1 and MRP1 genes, respectively. These proteins are involved in the cellular efflux of several chemotherapeutic agents including doxorubicin. The aim of this study was to investigate the clinical value of a standard (99m)Tc-MIBI scintimammography technique in the prediction of response to chemotherapy in advanced breast cancer patients. Fifty-six lesions from 33 female patients with locally advanced (n=27) or recurrent breast cancer (n=6) were included in the study. MIBI scintigraphy was performed 2-8 days prior to chemotherapy (FAC regimen). Images were acquired 10 min and 1 h post-injection of 740-1110 MBq of (99m)Tc-MIBI. Tumour-to-normal background tissue uptake ratios were calculated on each lesion in the early (T/B(e)) and delayed phase of the study (T/B(d)). Both T/B(e) and T/B(d) ratios were significantly higher (P<0.0001) in responders (n=43) than nonresponders (n=13). Diagnostic values of (99m)Tc-MIBI in the prediction of chemotherapy response were evaluated using the arbitrary cut-off values of 1.5 for T/B(e) and 1.4 forT/B(d). Sensitivity, specificity, positive and negative predictive values were 88.4%, 92.3%, 97.4%, 70.6%; and 90.7%, 100.0%, 100.0%, 76.6%, for T/B(e) and T/B(d), respectively. We conclude that (99m)Tc-MIBI scintigraphy may be a clinically valuable tool for guiding chemotherapy in advanced breast cancer patients.

Is (99m)Tc-sestamibi scintimammography complementary to conventional mammography for detecting breast cancer in patients with palpable masses?

The aim of this trial was to evaluate in developing countries from different regions the diagnostic performance of (99m)Tc-sestamibi scintimammography (SM) in palpable breast lesions and to verify the clinical usefulness of a joint evaluation with mammography and SM.

METHODS

From 10 countries, a total of 238 patients with palpable breast masses (n = 245) were included in this prospective multicenter trial. Prone SM was performed 10 min and 60-90 min (157 patients) after injection using an isotime acquisition of 10 min. Mammography was assessed by the same dedicated imaging radiologist according to breast imaging reporting and data system (BI-RADS) categories for malignancy and breast density. Masked SM findings and mammography findings were checked for a correlation with histopathology findings for excisional biopsy samples. Diagnostic values for breast cancer detection were calculated per lesion.

RESULTS

Histopathology revealed 189 cancerous lesions and 56 benign lesions. The sensitivity and specificity of SM were 0.83 and 0.77, respectively. SM diagnostic values did not depend on the incidence of breast cancer in the country of origin or on the timing of imaging (early vs. delayed scans). On mammography, the technique yielded a sensitivity and specificity of 0.85 and 0.66, with 27 mammograms classified as BI-RADS category 1, 33 as category 2, 5 as category 3, 56 as category 4, and 124 as category 5. Thirty-seven lesions were considered to show increased radiologic density. No significant difference was found in SM diagnostic values among different BI-RADS categories or between the groups with low and high breast density. A sensitivity of 96% was calculated when SM and mammography results were combined, with 75% of all false-negative mammography findings classified as true-positive results by SM.

CONCLUSION

SM complements mammography in patients with palpable masses and negative mammography findings.

Posttraumatic hypothermia is neuroprotective in a model of traumatic brain injury complicated by a secondary hypoxic insult

OBJECTIVE

Human traumatic brain injury frequently results in secondary complications, including hypoxia. In previous studies, we have reported that posttraumatic hypothermia is neuroprotective and that secondary hypoxia exacerbates histopathologic outcome after fluid-percussion brain injury. The purpose of this study was to assess the therapeutic effects of mild (33 degrees C) hypothermia after fluid-percussion injury combined with secondary hypoxia. In addition, the importance of the rewarming period on histopathologic outcome was investigated.

DESIGN

Prospective experimental study in rats.

SETTING

Experimental laboratory in a university teaching hospital.

INTERVENTION

Intubated, anesthetized rats underwent normothermic parasagittal fluid-percussion brain injury (1.8-2.1 atmospheres) followed by either 30 mins of normoxia (n = 6) or hypoxic (n = 6) gas levels and by 4 hrs of normothermia (37 degrees C). In hypothermic rats, brain temperature was reduced immediately after the 30-min hypoxic insult and maintained for 4 hrs. After hypothermia, brain temperature was either rapidly (n = 6) or slowly (n = 5) increased to normothermic levels. Rats were killed 3 days after traumatic brain injury, and contusion volumes were quantitatively assessed.

MEASUREMENTS AND MAIN RESULTS

As previously shown, posttraumatic hypoxia significantly increased contusion volume compared with traumatic brain injury-normoxic animals (p <.02). Importantly, although posttraumatic hypothermia followed by rapid rewarming (15 mins) failed to decrease contusion volume, those animals undergoing a slow rewarming period (120 mins) demonstrated significantly (p <.03) reduced contusion volumes, compared with hypoxic normothermic rats.

CONCLUSIONS

These data emphasize the beneficial effects of posttraumatic hypothermia in a traumatic brain injury model complicated by secondary hypoxia and stress the importance of the rewarming period in this therapeutic intervention.

Preoperative evaluation of sentinel lymph node status in melanoma by means of (99m)Tc-MIBI and lymphoscintigraphy: a case report

Previous reports have shown that (99m)Tc-sestamibi (MIBI) could detect clinically occult metastatic melanoma lesions. This article reports on a patient with invasive melanoma of the right heel in whom the sentinel node status was preoperatively evaluated with this tracer. Although regional lymph nodes were clinically negative, (99m)Tc-MIBI scintigraphy showed focal increased tracer uptake in the right groin that corresponded to the location of 2 sentinel nodes visualized by lymphoscintigraphy with (99m)Tc-colloidal rhenium sulfide performed the same day. A gamma-probe was used intraoperatively to guide the excision of the sentinel nodes that were further classified as metastatic by histopathology. This double-technique approach is technically feasible and has the potential of selecting a group of patients who might benefit from a selective complete lymphadenectomy.

Delayed hemorrhagic hypotension exacerbates the hemodynamic and histopathologic consequences of traumatic brain injury in rats

Alterations in cerebral autoregulation and cerebrovascular reactivity after traumatic brain injury (TBI) may increase the susceptibility of the brain to secondary insults, including arterial hypotension. The purpose of this study was to evaluate the consequences of mild hemorrhagic hypotension on hemodynamic and histopathologic outcome after TBI. Intubated, anesthetized male rats were subjected to moderate (1.94 to 2.18 atm) parasagittal fluid-percussion (FP) brain injury. After TBI, animals were exposed to either normotension (group 1: TBI alone, n = 6) or hypotension (group 2: TBI + hypotension, n = 6). Moderate hypotension (60 mm Hg/30 min) was induced 5 minutes after TBI or sham procedures by hemorrhage. Sham-operated controls (group 3, n = 7) underwent an induced hypotensive period, whereas normotensive controls (group 4, n = 4) did not. For measuring regional cerebral blood flow (rCBF), radiolabeled microspheres were injected before, 20 minutes after, and 60 minutes after TBI (n = 23). For quantitative histopathologic evaluation, separate groups of animals were perfusion-fixed 3 days after TBI (n = 22). At 20 minutes after TBI, rCBF was bilaterally reduced by 57% +/- 6% and 48% +/- 11% in cortical and subcortical brain regions, respectively, under normotensive conditions. Compared with normotensive TBI rats, hemodynamic depression was significantly greater with induced hypotension in the histopathologically vulnerable (P1) posterior parietal cortex (P < 0.01). Secondary hypotension also increased contusion area at specific bregma levels compared with normotensive TBI rats (P < 0.05), as well as overall contusion volume (0.96 +/- 0.46 mm(3) vs. 2.02 +/- 0.51 mm(3), mean +/- SD, P < 0.05). These findings demonstrate that mild hemorrhagic hypotension after FP injury worsens local histopathologic outcome, possibly through vascular mechanisms.

The effect of bone morphogenetic protein-7 (BMP-7) on functional recovery, local cerebral glucose utilization and blood flow after transient focal cerebral ischemia in rats

Bone morphogenetic protein-7 (BMP-7) has been shown to enhance dendritic growth and improve functional recovery after experimental stroke. In this study, we examined the effect of BMP-7 on functional recovery, local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCMRglu) following transient middle cerebral artery occlusion. Sprague--Dawley rats (n=29) were anesthetized with halothane/nitrous oxide and received 2-h middle cerebral artery occlusion (MCAo) by poly-L-lysine-coated intraluminal suture. Rectal and cranial temperatures were regulated at 37.0--37.5 degrees C. BMP-7 or vehicle (volume, 25 microl) was administered intracisternally in a blinded fashion at 24 h after MCAo. Neurological status was evaluated during occlusion (60 min) and daily for 2 days after MCAo. In matched animal groups, LCMRglu was measured autoradiographically with [(14)C]2-deoxyglucose (2-DG) and LCBF with [(14)C]iodoantipyrine 48 h after MCAo. Four animals groups were studied: LCMRglu series (BMP-7, n=7; vehicle, n=8); LCBF series (BMP-7, n=6; vehicle, n=8). Average three-dimensional image data sets were constructed for each group and were compared by pixel-based statistical methods. Rectal and cranial temperatures, mean blood pressure, plasma glucose and blood gases were similar among groups. BMP-7 significantly improved the total neurological score compared to vehicle at 48 h after MCAo (7.3+/-0.4 vs. 9.0+/-0.2, respectively; P<0.0003). Compared to vehicle-rats, BMP-7 enhanced glucose utilization in the basal ganglia ipsilateral to stroke and improved LCBF in ipsilateral subthalamus, but decreased LCBF and LCMRglu in contralateral cortical regions.

Adult respiratory distress syndrome occurring in two patients undergoing cytoreductive surgery plus perioperative intraperitoneal chemotherapy: case reports and a review of the literature

Cytoreductive surgery and perioperative intraperitoneal chemotherapy with mitomycin C and 5-fluorouracil may be considered as an accepted treatment for appendiceal malignancy with mucinous peritoneal carcinomatosis or for pseudomyxoma peritonei. This aggressive approach has been successfully utilized in approximately 500 patients with an acceptable mortality (1.5%) and morbidity (27%). Although pulmonary complications are frequently recorded, life-endangering acute respiratory failure in the absence of pulmonary infection or an obvious source of systemic sepsis has not been previously described. An extensive clinical review of two patients who had a clinical course compatible with acute respiratory distress syndrome without obvious cause except for the cytoreductive surgery and perioperative intraperitoneal chemotherapy itself was undertaken. These two patients developed gradually increasing respiratory distress in the postoperative period. No bacterial or fungal infections of lungs or intra-abdominal sites or sepsis were discovered. These two patients were unusual in that they had extensive cytoreduction, maximal heat with the mitomycin C chemotherapy, and perfusion of both the abdominal cavity and the right pleural space. Reoperation in both patients failed to show a septic source within the abdomen for progressive adult respiratory distress syndrome. We conclude that aggressive cytoreductive surgery plus perioperative intraperitoneal and intrapleural chemotherapy was associated with life-endangering respiratory failure in two patients. No other cause for this condition was evident from an exhaustive review of the clinical course of these two patients. It is possible that this aggressive approach to appendix malignancy with carcinomatosis is sufficiently traumatic to be considered a cause of adult respiratory distress syndrome.

Chronic metabolic sequelae of traumatic brain injury: prolonged suppression of somatosensory activation

Injuries to the brain acutely disrupt normal metabolic function and may deactivate functional circuits. It is unknown whether these metabolic abnormalities improve over time. We used 2-deoxyglucose (2-DG) autoradiographic image-averaging to assess local cerebral glucose utilization (lCMR(Glc)) of the rat brain 2 mo after moderate (1.7-2.1 atm) fluid-percussion traumatic brain injury (FPI). Four animal groups (n = 5 each) were studied: sham-injured rats with and without stimulation of the vibrissae-barrel field ipsilateral to injury; and animals with prior FPI, with or without this stimulation. In sham-injured rats, resting lCMR(Glc) was normal, and vibrissae stimulation produced right-sided metabolic activation of the ventrolateral thalamic and somatosensory-cortical projection areas. In rats with prior injury, lCMR(Glc) contralateral to injury was normal, but lCMR(Glc) of the ipsilateral forebrain was depressed by approximately 38-45% compared with shams. Whisker stimulation in rats with prior trauma failed to induce metabolic activation of either cortex or thalamus. Image-mapping of histological material obtained in the same injury model was undertaken to assess the possible influence of injury-induced regional brain atrophy on computed lCMR(Glc); an effect was found only in the lateral cortex at the trauma epicenter. Our results show that, 2 mo after trauma, resting cerebral metabolic perturbations persist, and the whisker-barrel somatosensory circuit shows no signs of functional recovery.

Evaluation of ocular tumors with technetium-99m-MIBI: planar pinhole technique or SPECT?

OBJECTIVE

This study compares 2 imaging protocols, planar pinhole technique (PPHT) and SPECT, for evaluating ocular masses with 99mTc-MIBI.

METHODS

Sixteen patients with ocular lesions were studied. Planar images were acquired 10 min after the injection of 740 MBq 99mTc-MIBI with an LFOV camera fitted with a pinhole collimator (5.0 mm). A SPECT study was performed immediately after the planar study, using a 360 degrees orbit, 64 steps, 20 s/stop, a 128 x 128 matrix, and a low-energy high-resolution (LEHR) collimator. Twelve lesions (9.5-18.0 mm) proved to be malignant: 8 primary tumors (ocular melanoma); 3 local relapses of different tumors of the conjunctiva; and 1 ocular metastasis from breast cancer. The remaining 4 lesions (10.0-16.0 mm) were benign: 1 inflammatory lesion; 1 benign intraocular calcification; and 2 naevi.

RESULTS

SPECT images showed 11 of 12 malignant lesions (91.6%), whereas the planar technique demonstrated only 4 of the 12 lesions (33.3%). One false-positive result, the inflammatory lesion, was visualized by both techniques. The remaining benign lesions were not detected with either method.

CONCLUSION

Technetium-99m-MIBI SPECT is a sensitive technique for detecting malignant ocular tumors. SPECT imaging is a better alternative to planar imaging for ocular tumors.

Management and outcome of liver recipients with post-transplant lymphoproliferative disease

BACKGROUND/AIMS

The possibility of development of post-transplant lymphoproliferative disease by patients receiving immunosuppressive therapy is well known. However, elective treatment and outcome remain controversial. We reviewed the management and outcome of our patients with post-transplant lymphoproliferative disease.

METHODOLOGY

Records of 457 patients who underwent orthotopic liver transplantation from 1986 to 1997 were analyzed. Patients who developed post-transplant lymphoproliferative disease were reviewed retrospectively. Incidence, clinical presentation, risk factors and outcomes were examined with special emphasis on ductopenic rejection and hilum involvement.

RESULTS

Eleven patients developed a post-transplant lymphoproliferative disease (2.4%). These were B-cell non-Hodgkins lymphoma, Epstein-Barr virus-associated in all cases. Five patients (45.5%) received monoclonal antibodies or antithymocyte globulin. Seven patients (63.6%) developed a lymphoproliferative disease before 9 months post-transplant and 4 recipients (36.4%) after 20 months. No late lymphomas regressed after withdrawal from immunosuppression. Six patients (54.5%) were treated with chemotherapy. Eight patients (72.7%) had a tumoral remission. Five patients (45.5%) developed chronic rejection after immunosuppressant discontinuation. Four of them died as a consequence of ductopenic rejection and retransplantation was required in another; 2 died due to graft hilum infiltration. Five patients (45.5%) are alive after a follow-up of 36.5 +/- 32 months (range: 4-77 months).

CONCLUSIONS

Patients with post-transplant lymphoproliferative disease require a close follow-up in order to promptly treat conditions that could lead to death. In our series, these were more closely associated with a failing transplanted organ than with the lymphoma itself.

Induction of tolerance against traumatic brain injury by ischemic preconditioning

We tested the hypothesis that a transient non-lethal ischemic insult lasting 2 min would protect against subsequent moderate traumatic brain injury. Sprague-Dawley rats were randomized into three experimental groups, including sham ischemia procedures and ischemic preconditioning (IPC) followed 48 h later by moderate traumatic brain injury (TBI) provoked by parasagittal fluid percussion injury (1.8-2.1 atm) and IPC followed by 48 h sham TBI. Seven days after the secondary insult, animals were perfusion-fixed for quantitative histopathological analysis. The CA3 necrotic cell count was decreased by 63% in TBI animals that had undergone IPC as compared to TBI animals that underwent sham IPC. TBI animals that had undergone IPC demonstrated significantly smaller contusion volumes than the TBI alone group (6.44 +/- 1.51 vs 1.37 +/- 0.63 mm3, mean +/- s.e.m.) These data indicate that IPC applied 2 days before moderate fluid percussion brain injury increases the brain resistance to traumatic brain damage.

The human cranial remains from Gran Dolina Lower Pleistocene site (Sierra de Atapuerca, Spain)

In this article we study the cranial remains of the late Lower Pleistocene human fossils from Gran Dolina (Sierra de Atapuerca, Spain), assigned to the new species Homo antecessor. The cranial remains belong to at least five individuals, both juveniles and adults. The most outstanding feature is the totally modern human morphology of the very complete face ATD6-69, representing the earliest occurrence of the modern face in the fossil record. The Gran Dolina fossils show in the face a suite of modern human apomorphies not found in earlier hominids nor in contemporary or earlier Homo erectus fossils. There are also traits in the Gran Dolina fossils shared with both Neandertals and modern humans, which reinforce the hypothesis that Neandertals and modern humans form a clade, and that the Gran Dolina fossils are a common ancestor to both lineages.

Scintigraphic evaluation of malignant melanoma lesions with Tc-99m tetrofosmin

Two cases of malignant melanoma (primary and metastatic lesions) imaged with Tc-99m tetrofosmin are reported. One patient showed intense uptake in a primary skin lesion of the thorax, and the other patient had accumulation in skin, cerebellum, breast, and lymph node metastases. Like Tc-99m MIBI, Tc-99m tetrofosmin imaging may be of clinical relevance in the evaluation of suspicious skin lesions and in patients with known cutaneous malignant melanoma in the assessment of recurrent disease during follow-up evaluation.

Posttraumatic cerebral ischemia after fluid percussion brain injury: an autoradiographic and histopathological study in rats

OBJECTIVES

Mild-to-moderate reductions in local cerebral blood flow (ICBF) have been reported to occur in rats after moderate (1.7-2.2 atm) fluid percussion brain injury. The purpose of this study was to determine whether evidence for severe ischemia (i.e., mean ICBF < 0.25 ml/g/min) could be demonstrated after severe brain injury. In addition, patterns of indium-labeled platelet accumulation and histopathological outcome were correlated with the hemodynamic alterations.

METHODS

Sprague-Dawley rats (n = 23), anesthetized with halothane and maintained on a 70:30 mixture of nitrous oxide:oxygen and 0.5% halothane, underwent normothermic (37 degrees C) parasagittal fluid percussion brain injury (2.4-2.6 atm). Indium-111-tropolone-labeled platelets were injected 30 minutes before traumatic brain injury (TBI), while 14C-iodoantipyrine was infused 30 minutes after trauma for ICBF determination. Sham-operated animals (n = 8) underwent similar surgical procedures but were not injured. For histopathological analysis, traumatized rats (n = 5) were perfusion-fixed 3 days after TBI.

RESULTS

In autoradiographic images of indium-labeled platelets, abnormal platelet accumulation that was most pronounced overlying the pial surface was commonly associated with severe reductions in ICBF within underlying cortical regions 30 minutes after TBI. For example, within the lateral parietal cortex, ICBF was significantly reduced from 1.67 +/- 0.11 ml/g per minute (mean +/- standard error of the mean) in sham-operated animals to 0.23 +/- 0.03 ml/g per minute within the traumatized group. In addition to focal severe ischemia, moderate reductions in ICBF were detected throughout the traumatized hemisphere, including the frontal and occipital cortices, hippocampus, thalamus, and striatum. Mild decreases in ICBF were also observed throughout the contralateral cerebral cortex. At 3 days after severe TBI, histopathology demonstrated intracerebral and subarachnoid hemorrhage associated with cerebral contusion and selective neuronal necrosis.

CONCLUSION

These data indicate that multiple cerebrovascular abnormalities, including subarachnoid hemorrhage, focal platelet accumulation, and severe ischemia, are important early events in the pathogenesis of cortical contusion formation after TBI. Injury severity is expected to be a critical factor in determining what therapeutic strategies are attempted in the clinical setting.

Detection of recurrent malignant melanoma with 99mTc-MIBI scintigraphy

Initial reports suggest that 99mTc-methoxyisobutylisonitrile (MIBI) scanning may be of clinical value in staging patients with malignant melanoma. We carried out a study to evaluate the potential of this technique in the detection of recurrent disease. Whole-body 99mTC-MIBI scans were performed in 81 patients with a history of a surgically excised MM: 28 with known recurrent lesions and 53 during follow-up without evidence of disease. Images started 10 min post-injection, using a dose of 740 MBq. Diagnoses were confirmed by cytological/histological examination or at least one conventional imaging modality. Blinded interpretations of the MIBI scans were performed. Whole-body MIBI scanning correctly detected 68 (92%) of 74 metastatic lesions in the following sites: regional lymph nodes (n=23), non-regional lymph nodes (n=10), skin (n=16), brain/cerebellum (n=6), lung (n=8), bone (n=4) and breast (n=1). The technique failed to detect three subcutaneous regressive lesions (< 1 cm), one liver metastasis, one spleen metastasis and a case of multiple small lesions of the duodenal mucous membrane. In 14 patients the procedure detected previously unknown metastatic lesions. These results suggest that 99mTc-MIBI scanning is an effective imaging modality for whole-body screening of metastatic disease in malignant melanoma patients with the potential to influence treatment planning.

99Tc(m)-MIBI scanning of the thyroid gland in patients with markedly decreased pertechnetate uptake

Diffusely reduced 99Tc(m)-pertechnetate uptake is a relatively infrequent but annoying finding that impairs evaluation of the thyroid gland. We studied 32 female patients aged 19-85 years with markedly reduced pertechnetate uptake. The following causes of reduced pertechnetate uptake were recognized: treatment with iodinated pharmaceuticals (n = 15), suppression therapy with T4 (n = 11), subacute thyroiditis (n = 5) and massive tumour replacement (n = 1). 99Tc(m)-MIBI thyroid scintigraphy was performed within 24 h of the pertechnetate study. The results were correlated with neck ultrasound, serum TSH (n = 25) and surgical findings in patients who had been operated on. The technique identified the following conditions: normally sized thyroids (n = 4), diffuse goitres (n = 8), multinodular goitres (n = 17) and solitary thyroid nodules (n = 3). Moreover, substernal goitres were identified in nine patients. This condition was confirmed at surgery in seven patients. Ultrasonography was concordant in 29 of 32 patients in terms of thyroid size and structure, but failed to demonstrate substernal thyroid tissue. Our results suggest that 99Tc(m)-MIBI scintigraphy may contribute to the diagnosis of thyroid pathology and treatment planning in patients with diffusely decreased 99Tc(m)-pertechnetate uptake.

Extracellular release of serotonin following fluid-percussion brain injury in rats

Serotonin has been implicated in the pathobiology of central nervous system trauma. Using microdialysis techniques, we performed measurements of extracellular serotonin release within the traumatized cerebral cortex of rats subjected to moderate fluid-percussion (F-P) brain injury. Twenty-four hours prior to TBI, a F-P interface was positioned parasagitally over the right cerebral cortex. On the second day, fasted rats were anesthetized with 70% nitrous oxide, 1% halothane and 30% oxygen. Under controlled physiological conditions and normothermic brain temperature (37-37.5 degrees C), rats were injured (n = 6) with a F-P pulse ranging from 1.8 to 2.0 atm. Following trauma, brain temperature was maintained for 4 h at 37 degrees C. Sham trauma animals (n = 7) were treated in an identical manner. Brain trauma induced acute elevations in the extracellular levels of serotonin (p < 0.01, ANOVA) compared to sham-operated controls. For example, serotonin levels increased from 18.85 +/- 7.12 pm/mL (mean +/- SD) in baseline samples to 65.78 +/- 11.36 in the first 10 min after trauma. The levels of serotonin remained significantly higher than control for the first 90-min sampling period. In parallel to the increase in serotonin levels after TBI, a significant 71.1% decrease (i.e., 182.29 +/- 30.08 vs 52.75 +/- 16.92) in extracellular 5-hydroxyindoleacetic acid (5-HIAA) levels was observed during the first 10 min after TBI. These data indicate that TBI is followed by a prompt increase in the extracellular levels of serotonin in cortical regions adjacent to the impact site. These neurochemical findings indicate that serotonin may play a significant role in the pathophysiology of TBI.

Scintigraphic detection of invasive cutaneous malignant melanoma with Tc-99m MIBI

Malignant melanoma is a relatively uncommon cancer of increasing incidence. The authors report on two cases of malignant melanoma lesions (primary and lymph node metastasis) imaged with Tc-99m MIBI. One patient revealed intense accumulation of the radiotracer in a primary skin lesion of the thorax, whereas the other patient showed increased Tc-99m MIBI uptake in a lymph node metastasis of the neck. Tc-99m MIBI imaging could be helpful in the evaluation of patients with suspicious skin lesions and in patients with known cutaneous malignant melanoma, in the investigation of lymph nodal invasion, local recurrence, and metastatic spread.

Posttreatment with intravenous basic fibroblast growth factor reduces histopathological damage following fluid-percussion brain injury in rats

The purpose of this study was to determine whether treatment with intravenous basic fibroblast growth factor (bFGF) would protect histopathologically in a rat model of traumatic brain injury (TBI). Twenty-four hours prior to TBI, the fluid-percussion interface was positioned parasagittally over the right cerebral cortex. On the second day, fasted rats were anesthetized with 70% nitrous oxide, 1% halothane, and 30% oxygen. Under controlled physiological conditions and normothermic brain temperature (37-37.5 degrees C), rats were injured with a fluid-percussion pulse ranging from 1.6 to 1.9 atm. Rats were randomized into two groups where either bFGF (45 micrograms/kg/h) in vehicle (n = 7) or vehicle alone (n = 7) was infused intravenously for 3 h, beginning 30 min after TBI. Three days later, brains were perfusion-fixed for histopathological assessment and quantitative analysis of contusion volume and numbers of necrotic cortical neurons. In vehicle-treated animals, necrotic neurons were observed throughout the lateral cerebral cortex remote from the impact site. In addition, an intracerebral contusion was present in all rats at the gray-white interface underlying the injured cortical areas. Posttraumatic administration of bFGF significantly reduced the numbers of damaged cortical neuron profiles at several coronal levels and reduced the total number of damaged neurons (696 +/- 148 vs. 1,248 +/- 198, means +/- SEM), p < 0.05, ANOVA). In addition, contusion ares at several coronal levels as well as total contusion volume was significantly reduced (1.13 +/- 0.39 mm(3) vs. 3.18 +/- 0.81 mm(3), p < 0.05). These data demonstrate neuroprotection with intravenous bFGF infusion in the posttraumatic setting.