Şakir Berkarda

99mTc-MIBI SPET in non-small cell lung cancer in relationship with Pgp and prognosis

Abstract Higher technetium-99m methoxyisobutylisonitrile (MIBI) uptake in non-small cell lung cancer (NSCLC) has been reported to be associated with a positive response to chemotherapy. It has previously been found that in tumour cells, P-glycoprotein (Pgp) expression is of importance for tracer uptake. However, some studies have indicated that Pgp expression does not play an important role in 99mTc-MIBI uptake in NSCLC; indeed, a negative correlation between 99mTc-MIBI uptake and Pgp expression has been reported. Against the background of conflicting results, our aim was to evaluate the relationship between 99mTc-MIBI uptake, prognosis and Pgp expression in NSCLC. A total of 37 patients with NSCLC underwent 99mTc-MIBI single-photon emission tomography (SPET) before chemotherapy. In 19 patients both Pgp and p53 expression, and in two patients only p53 expression (due to the limited biopsy material), were measured with immunohistochemical staining. 99mTc-MIBI uptake was significantly higher in responders than in non-responders: 3.09±1.14 vs 2.24±0.88 (P<0.03) and 3.09±1.08 vs 2.37±1.06 (P<0.05) for the early ratio (ER) and the delayed ratio (DR), respectively. The wash-out rate (WR) of responders was not significantly different from that of non-responders. We found no significant differences in ER, DR and WR among the groups positive or negative for Pgp and p53 status. There was a significant positive correlation between the survival rate and both ER and DR: r=0.49 (P=0.003) and r=0.40 (P=0.018), respectively. Patients with ER and DR values above 3 showed significantly longer survival than those with values below 3: 14.7±8.5 months vs 7.3±5.1 months (P<0.009) and 13.2±8.4 months vs 7.4±5.3 months (P<0.04) for ER and DR, respectively. However, interestingly, and in contrast to expectations, patients with a Pgp score of +2 showed significantly longer survival (12.9±6.7 months) than those with Pgp scores of +1 (4.4±3.0 months) or – (negative) (3.8±2.2 months) (P<0.009 and P<0.02, respectively). Our results suggest that in NSCLC, patients with higher 99mTc-MIBI uptake tend to show a positive response to chemotherapy, and patients with ER and DR values above 3 have a significantly better prognosis. We also found that Pgp expression seems to play only a minor role in 99mTc-MIBI uptake. Our finding that patients with ER and DR values above 3 have a better prognosis needs to be confirmed in larger series of patients.

Salivary function in patients with chronic renal failure undergoing hemodialysis

Purpose: The aim of this study was to evaluate the changes in salivary gland function in patients with chronic renal failure (CRF) undergoing hemodialysis.Methods: The group consisted of 23 patients with CRF (13 female, 10 male; mean age: 40±13 yr) and 14 healthy control subjects (mean age: 40±13 yr). All underwent dynamic salivary gland scintigraphy with gustatory stimulation. After intravenous administration of99mTc pertechnetate, first, perfusion images at 2 seconds per frame were acquired for 1 minute, then dynamic images at 1 minute per frame were acquired for 45 minutes. At 30 minutes after injection, 10 ml lemon juice was given for 15 minutes as a gustatory stimulus. We obtained time-activity curves derived from regions of interest centered over the four major salivary glands. The following functional indices were calculated for each gland: the time of maximum radioactivity (Tmax) for the prestimulated period, the time of minimum radioactivity (Tmin), as an indicator of velocity of secretion after stimulation, and the Lem E5% value as an indicator of the secretion function.Results: When the patients with CRF undergoing hemodialysis were compared to the controls, there were statistically significant differences in Tmax, Tmin and Lem E5% values for bilateral parotid glands, and Tmin values for bilateral submandibular glands (p<0.05), there were no statistically significant differences in Tmax and Lem E5% values for bilateral submandibular glands. There were also significant differences in Tmax and Lem E5% values for bilateral parotid glands between mild oral problems and severe oral problems in patients with CRF (undergoing hemodialysis).Conclusion: In this study, prolonged Tmax and Tmin values, and decreased Lem E5% values for parotid glands and prolonged Tmin values for submandibular glands on salivary scintigraphy pointed out decreased parenchymatous and excretory function in patients with CRF undergoing hemodialysis.

The relationship between 99mTc-HMPAO brain SPECT and the scores of real life rating scale in autistic children

Childhood autism is a developmental disability of unknown origin with probable multiple etiologies. The purpose of this study was to compare the changes of regional cerebral blood flow (rCBF) in autistic and non-autistic controls, and to determine the relationship between rCBF on 99mTc-hexamethylpropylene amine oxime (HMPAO) brain SPECT and the scores of the Ritvo-Freeman Real Life Rating Scale (RLRS), IQ levels, and age of autistic children. Eighteen autistic children (four girls, 14 boys; mean age: 6.13 +/- 1.99 years) and 11 non-autistic controls (five girls, six boys, mean age: 6.5 +/- 3.39 years) were examined using 99mTc-HMPAO brain SPECT. All the children satisfying DSM-IV criteria for autistic disorder were taken into evaluation, and scored by the Ritvo-Freeman RLRS. IQ levels of these children were determined by Goodenough IQ test. Six cortical regions of interest (ROIs; frontal (F), parietal (P), frontotemporal (FT), temporal (T), temporo-occipital (TO), and occipital (O)) were obtained on transaxial slices for count data acquisition. The ratio of average counts in each ROI to whole-slice counts for the autistic children was correlated with the scores of Ritvo-Freeman RLRS. Hypoperfusion in rCBF in autistic children compared with the control group were identified in bilateral F, FT, T, and TO regions. We found no relationship between rCBF on 99mTc-HMPAO brain SPECT and the scores of the Ritvo-Freeman RLRS. There was a relationship between bilateral F regions perfusion on 99mTc-HMPAO brain SPECT and the age of autistic children. There was also a negative correlation between IQ levels and the scores of sensory responses, social relationship to people, and sensory-motor responses. Our results suggest that 99mTc-HMPAO brain SPECT is helpful to locate the perfusion abnormalities but no correlation is found between rCBF on 99mTc-HMPAO brain SPECT and the scores of Ritvo-Freeman RLRS.

Assessment of tissue viability after frostbite injury by technetium-99m-sestamibi scintigraphy in an experimental rabbit model

Abstract. Frostbite causes injury to the tissue by direct ice-crystal formation at the cellular level with cellular dehydration and microvascular occlusion. Muscle that initially appears viable on reperfusion may subsequently become necrotic because of microcirculatory collapse. Since muscle is a sensitive tissue in frostbite injury, we used technetium-99m-sestamibi limb scintigraphy to assess tissue viability in an experimental rabbit model. Twelve rabbits were used for this investigation. The right hind limb of the rabbits was immersed to the ankle joint in a container filled with 90% ethanol at –25°C for 10 min. Frostbitten limbs were allowed to thaw in air at room temperature. Imaging and pathological examination of the affected limbs were performed 2 h, 24 h, 48 h and 72 h after freezing. In 2-h images, initial hypoperfusion was seen that corresponded to circulatory collapse. In 24-h images, there was hyperperfusion (so-called period of temporary reperfusion), corresponding to circulatory restoration. In 48-h images, a second hypoperfusion corresponded to viable but ischaemic tissue. In 72-h images, there was non-perfusion of the limb that correlated with the pathologically determined diagnosis of necrosis. All scintigraphic patterns correlated with pathological findings. We suggest that these scintigraphic patterns in soft tissue may be helpful in distinguishing between frank infarction and reversible ischemia and therefore may be useful in selecting early therapeutic or surgical interventions to salvage bone and soft tissue. Further studies are needed to show the usefulness of 99mTc sestamibi scintigraphy in clinical frostbite cases.

Evaluation of dysthymic disorder with technetium-99 m hexamethylpropylene amine oxime brain single-photon emission tomography

Abstract. Dysthymic disorder is a chronic disorder characterised by the presence of a depressed mood and is classified as a distinct category in DSM-IV, separately from major depression. Although brain imaging studies have been performed in major depressive disease, there have to date been no reports of such studies in dysthymic disorder. In this study 36 patients with dysthymic disorder were compared with 16 normal subjects using technetium-99m hexamethylpropylene amine oxime brain single-photon emission tomography. A relative blood flow ratio was calculated for each region of interest using the average tissue activity in the region divided by activity in the cerebellum. There were significant differences in the bilateral inferior frontal, bilateral parietal, right superior frontal and left posterior temporal regions in the patients with dysthymic disorder compared with the healthy controls. These findings support the hypothesis that the biological bases for dysthymic disorder and major depression are similar. Recognition of these regional abnormalities may have clinical utility in both the diagnosis and the treatment of dysthymic disorder. Further studies are needed to confirm our results and to assess the influence of treatment in patients with dysthymic disorder.

Thallium-201 SPECT in advanced non-small cell lung cancer: In relation with chemotherapeutic response, survival, distant metastasis and p53 status

Purpose: The aim of this study was to evaluate the relationship between201Tl tumor uptake, chemotherapeutic response, metastasis, p53 status and survival in non-small cell lung cancer (NSCLC).Methods: A total of 23 patients underwent201Tl SPECT. In 9 patients, 2nd201Tl SPECT study were performed 1 week after the 3rd cycle of chemotherapy (ChT), and early (ER) and delayed (DR) tumor/normal lung ratios and retention indices (RI) were obtained. In 15 patients p53 status was assayed with immuno-histochemical staining. The patients were divided into subgroups after the 3rd cycle of ChT; responders [R(+) (n=10)] and non-responders [R(−) (n=13)], distant metastasis [(M1) n=11] and [(M0) n=12], and mutant p53 status [p(+) n=7, p53(−) n=8].Results: The differences for ER, DR and RI values between all of the subgroups were not statistically significant. ER and DR of responders decreased significantly after ChT; from to 2.46 to 1.36 (p=0.04) and 2.29 to 1.53 (p=0.04), respectively. In the non-responder group, both ER and DR slightly increased after ChT (p>0.05).Conclusion: Our results suggest that in NSCLC, there was a weak correlation between higher201Tl ratios and positive response to chemotherapy, absence of distant metastasis, and p53(−) status. Significant201Tl uptake decrease after chemotherapy indicates that delayed201Tl uptake can be used in evaluating the chemotherapeutic response.

Diffuse uptake of Tc-99m tin colloid in extramedullary hematopoiesis of the lungs.

Tc-99m tin colloid scintigraphy was performed in a 58-year-old man with myelofibrosis to search for extramedullary hematopoiesis (EMH). He had a 14-year history of myelofibrosis, and splenectomy was performed 4 years earlier. He was hospitalized because of a thoracic mass and pulmonary symptoms.