A different perspective on PET/CT before treatment in patients with Hodgkin lymphoma: importance of volumetric and dissemination parameters.

The aim of this study is to investigate the role of the combination of volumetric and dissemination parameters obtained from pretreatment 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in predicting the interim response and progression status in patients with Hodgkin lymphoma (HL). Pretreatment PET/CT images of HL patients were analyzed with LIFEx software, and volumes of interest (VOIs) were drawn with a fixed SUV 4.0 threshold. MTV, SUVmax, and TLG values were obtained from each VOI. Total MTV (tMTV) was calculated by summing the MTV values in all VOIs, and similarly, total TLG (tTLG) was obtained by summing the TLG values. The distance between the centers of the lesions was noted as Dmax, and the distance between the outermost voxels of the lesions as DmaxVox. tMTV/DmaxVox was calculated by dividing the tMTV value by the DmaxVox value, and tTLG/DmaxVox was calculated by dividing the tTLG value by the DmaxVox value. The correlation of pretreatment PET parameters with response groups (complete/poor) and relapse/progression status (stable/progressive) was statistically evaluated. A total of 52 patients were included in the study. Bulky disease, tMTV, tTLG, and tMTV/DmaxVox values were found to be significantly higher in the poor response group. tMTV > 190.60 ml was found to be the only prognostic factor predicting interim PET response. The tMTV/DmaxVox and tTLG/DmaxVox showed statistically significant differences between the groups with and without progression. tMTV/DmaxVox > 7.70 was found to be the only prognostic factor in predicting relapse/progression. The evaluation of tumor burden and dissemination together in 18F-FDG PET/CT before treatment in patients with HL can help us to predict the results of the patients.

Intra and peritumoral PET radiomics analysis to predict the pathological response in breast cancer patients receiving neoadjuvant chemotherapy.

OBJECTIVE: The aim of our study was to evaluate the contribution of 18Fluorine-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) radiomic data obtained from both the tumoral and peritumoral area in predicting pathological complete response (pCR) in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy (NAC). METHODS: Female patients with a diagnosis of invasive ductal carcinoma who received NAC were evaluated retrospectively. The volume of interest (VOI) of the primary tumor (VOI-T) was manually segmented, then a voxel-thick VOI was added around VOI-T to define the peritumoral area (VOI-PT). Morphological, intensity-based, histogram and texture parameters were obtained from VOIs. The patients were divided into two groups as pCR and non-complete pathological response (npCR). A "radiomic model" was created with only radiomic features, and a "patho-radiomic model" was created using radiomic features and immunohistochemical data. RESULTS: Of the 66 patients included in the study, 21 were in the pCR group. The only statistically significant feature from the primary tumor among patients with pCR and npCR was Morphological_Compacity-T (AUC: 0.666). Between response groups, a significant difference was detected in 2 morphological, 1 intensity, 4 texture features from VOI-PT; no correlation was found between Morphological_Compacity-PT and NGTDM_contrast-PT. The obtained radiomic model's sensitivity and accuracy values were calculated as 61.9% and 75.8%, respectively (AUC: 0.786). When HER2 status was added, sensitivity and accuracy values of the patho-radiomic model increased to 85.7% and 81.8%, respectively (AUC: 0.903). CONCLUSIONS: Evaluation of PET peritumoral radiomic features together with the primary tumor, rather than just the primary tumor, provides a better prediction of the pCR to NAC in patients with breast cancer.

Investigation of the role of the NO-cGMP pathway on YC-1 and DEA/NO effects on thoracic aorta smooth muscle responses in a rat preeclampsia model.

The present study was designed to investigate the effects of YC-1, a nitric oxide (NO)-independent soluble guanylate cyclase (sGC) activator, and DEA/NO, a NO donor, on smooth muscle responses in the preeclampsia model with suramin-treated rats and on the levels of cyclic guanosine monophosphate (cGMP) of thoracic aorta rings isolated from term-pregnant rats. Rats of 2 groups, control group and suramin group, were given intraperitoneal injection of saline or suramin, respectively. Suramin injection caused increased blood pressure, protein in urine, and fetal growth retardation. Thoracic aorta rings were exposed to contractile and relaxant agents. KCl contraction and papaverine relaxation responses were similar. Relaxation responses of YC-1 and DEA/NO decreased in suramin group. In both groups in the presence of ODQ, a sGC inhibitor, the relaxation responses of YC-1 and DEA/NO decreased. The cGMP content was determined by radioimmunoassay technique. The content of cGMP in the suramin group decreased. In the presence of YC-1 and DEA/NO in both groups, cGMP content increased, but in ODQ-added groups, there was a significant decrease. We conclude that in preeclampsia, the decrease of relaxation responses and the decrease of cGMP content could be due to the reduction in stimulation of sGC and the decrease in cGMP levels.

Predicting pathological response and overall survival in locally advanced gastric cancer patients undergoing neoadjuvant chemotherapy: the role of PET/computed tomography.

BACKGROUND: Gastric cancer is the second leading cause of cancer-related deaths, with a 5-year survival rate of about 20-25%. The ability to predict pathological response (PR) to neoadjuvant chemotherapy (NACT); hence, overall survival (OS) probability of patients can allow the clinician to individualize treatment strategies. We investigated the role of F-18 fluorodeoxyglucose PET-computed tomography (F-18 FDG PET/CT) in predicting histopathologic response and prognosis in locally advanced gastric cancer (LAGC) patients undergoing NACT. METHODS: F-18FDG PET/CT images taken before and after NACT, adenocarcinoma histopathology and operation pyesis reports of 43 LAGC patients were analyzed. Maximum (SUVmax) and mean (SUVmean) standardized uptake values, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of lesions were measured before and after NACT. Changes in percentage were calculated for ΔSUVmax%, ΔSUVmean%, ΔMTV%, ΔTLG%, and cutoff values were determined by receiver operating characteristic curve analysis. NACT response in pathology pyesis was determined according to the College of American Pathologists classification. PR and OS were analyzed with Kaplan-Meier and Cox proportional hazards regression models based on cutoffs found with PET measurements. RESULTS: Cutoffs were ΔSUVmax = 33.31%, ΔSUVmean = 42.96%, ΔMTV = 30.38%, and ΔTLG = 28.14%, and all patients showed significance in PR and OS based on these cutoffs (all P < 0.01). PET/CT findings before and after NACT (ΔMTV > 30.38%, ΔTLG > 28.14%) predicted PR with 100% sensitivity and specificity. Multivariate analysis showed ΔSUVmean as an independent risk factor predicting OS (hazard ratio 0.348, 95% confidence interval 2.91-22.3, P = 0.03). CONCLUSIONS: Metabolic parameters obtained with F-18 FDG PET/CT scanning before and after NACT in LAGC patients can accurately predict PR and OS.

Intrathyroidal Parathyroid Adenomas in Primary Hyperparathyroidism: Clinical and Imaging Findings.

Objectives: Primary hyperparathyroidism (PHPT) is a common endocrine disease. Ectopic adenomas may cause a failed surgery which results in persistence or recurrence. Intrathyroidal parathyroid adenoma (ITPA) is a rare reason for PHPT and site of ectopia. Herein, we aimed to investigate the clinical and imaging features of patients with ITPAs and the effectiveness of radiological tools for localization at a tertiary reference center. Methods: The files of 708 consecutive patients who underwent parathyroidectomy for PHPT in our department between January 2007 and December 2021 were investigated retrospectively. PHPT patients with ITPA were included in the study. Patients with missing data were excluded from the study. Clinicopathological features of the patients and radiological evaluation findings were investigated. Results: Twenty-eight (28/708: 3.9%) patients were included in the study. The complete intrathyroidal gland and subcapsular parathyroid gland were observed in 8 (1.1%) and 20 (2.8%) patients, respectively. The ultrasound and parathyroid scintigraphy revealed the accurate localization of ITPA in 25 (89.3%) and 18 (64.3%) patients, respectively. Additional imaging modalities were applied for 10 patients in which conventional localization studies were discordant or inconclusive. ITPAs were most commonly found in the lower gland (n=20) localization. All patients had a successful parathyroidectomy and neither persistence nor recurrence was occurred in the study group. Conclusion: The ITPAs are rare in PHPT. The ultrasound has a high diagnostic rate in experienced hands. The second-line imaging methods may be favorable in the presence of negative or discordant scans. The pre-operative localization studies can detect the ITPAs in most patients, so blind thyroidectomy should be avoided.

Comparison of the volumetric and radiomics findings of 18F-FDG PET/CT images with immunohistochemical prognostic factors in local/locally advanced breast cancer.

OBJECTIVE: The aim of this study was to determine the change in volumetric and radiomics parameters of fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) imaging in local/locally advanced cancer patients according to immunohistochemical findings. PATIENTS AND METHODS: A total of 72 patients who were diagnosed with local/locally advanced breast cancer and then examined by F-FDG PET/CT for staging were included in this study. Immunohistochemical prognostic factors [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2), p53 mutation, Ki-67 proliferation index] and histological grades were determined. Standardized uptake value (SUV)-based, volume-based, and radiomics findings were obtained from F-FDG PET/CT images. RESULTS: In cases of ER and PR negativity, Her-2 positivity, presence of the p53 mutation, and Ki-67 index of at least 20% patients, total volumetric parameters were significantly higher in paired comparisons. The results of the ER-negative group were significantly higher than those of ER-positive patients in GLRLM_GLNU, GLRLM_RLNU, GLZLM_GLNU, and GLZLM_ZLNU comparisons. In grade 3 patients, mean SUV, maximum SUV, and GLRLM_LRHGE values were higher than those of grade 2 patients. SUV and volumetric parameters were significantly higher in patients with Ki-67 index of at least 20% than those with less than 20%. Maximum SUV, breast tumor lesion glycolysis values, and entropy in nuclear polymorphism in the 3+ patient group were found to be higher compared with the 2+ patient group. Moreover, patients with mitosis 3+ had significantly higher breast metabolic tumor volume, breast tumor lesion glycolysis, and kurtosis values than the 1+ group. CONCLUSION: ER negativity, triple negativity, high tumor grade, and high nuclear polymorphism were associated with tumor heterogeneity. With respect to ER negativity, PR negativity, high tumor grade, high mitosis number, high Ki-67 index, Her-2 positivity, and the presence of p53 mutation, an increased tumor load were observed. In addition to immunohistochemical parameters, the use of radiomics data is believed to contribute to breast cancer management.

The effect of sildenafil on the altered thoracic aorta smooth muscle responses in rat pre-eclampsia model.

The pathophysiology of pre-eclampsia is still unknown thus effective primary prevention is not possible at the stage. The present study was conducted to research the smooth muscle responses in the pre-eclampsia model with suramin treated rats and the effect of phosphodiesterase-5 (PDE5) inhibitor on these responses. Rats of three groups; control, suramin and suramin+sildenafil were given intraperitoneal injections of saline, suramin or sildenafil citrate. Suramin injections caused increased blood pressure, protein in urine and caused fetal growth retardation. The use of sildenafil citrate straightened significantly both blood pressure and average fetus weight, but did not reach to control values. At the end of pregnancy, thoracic aorta rings were exposed to contractile and relaxant agents. KCl contraction responses, sodium nitroprusside and papaverine relaxation responses were similar in three groups. Contraction responses of phenylephrine, increased significantly in suramin group. Relaxation responses of acethylcholine and bradykinin decreased in suramin group. The use of sildenafil citrate partially straightened both relaxation and contraction responses, but did not reach to control values. In all groups in the presence of L-nitromonomethylarginine (L-NAME), 1H-(1, 2, 4) oxadiazole (4, 3-a) guinoxalin-1-one (ODQ) and indomethacin decreased the relaxation responses of acetylcholine and bradykinin. The cyclic guanosine monophosphate (cGMP) content of thoracic aorta tissue was determined by radioimmunoassay technique. The content of cGMP in suramin group decreased and use of sildenafil citrate increased the cGMP content but did not reach to control values. We conclude that in pre-eclampsia, the increase of contraction responses, the decrease of relaxation responses and the decrease of cGMP content can depend on insufficiency about synthesis or release of relaxant factors which was released from the vessel endothelium. The results in this study show that in pre-eclampsia; PDE5 inhibitors enhance endothelial function and may be used for protection. Further studies are needed to clear the efficiency and safety of PDE5 inhibitors.

Validity of the CA125 level in the differential diagnosis of pulmonary tuberculosis.

The aim of the current study was to determine the possible crucial role of cancer antigen 125 (CA125) in the diagnosis of pulmonary tuberculosis (PTB). The CA125 levels of study and control groups were statistically compared. In a total of 146 patients that were included in the current study, 30 had active PTB, 37 inactive PTB, 28 community-acquired pneumonia (CAP), 25 pleural or pulmonary malignancies, and 13 patients exacerbation of chronic obstructive pulmonary disease. The mean CA125 levels in PTB, inactive PTB, CAP, and pleural-pulmonary malignancies were 118.46 +/- 248.41, 40.80 +/- 50.95, 47.76 +/- 60.76, and 57.77 +/- 65.59, respectively. For active-inactive discrimination of PTB, with a cut-off level of >35 U/ml, the sensitivity, specificity, positive predictive value, and negative predictive value of CA125 were 63, 59, 56, and 67%, respectively. Increased CA125 levels were detected in active PTB in the current results. The current results also show that high level CA125 should be reconsidered in the prediagnosis and/or discrimination of active and inactive PTB patients.

Diagnostic importance of 18F-FDG PET/CT parameters and total lesion glycolysis in differentiating between benign and malignant adrenal lesions.

PURPOSE: Benign adrenal lesions are prevalent in oncologic imaging and make metastatic disease diagnoses difficult. This study evaluates the diagnostic importance of metabolic, volumetric, and metabolovolumetric parameters measured by fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT in differentiating between benign and malignant adrenal lesions in cancer patients. PATIENTS AND METHODS: In this retrospective study, we evaluated F-FDG PET/CT parameters of adrenal lesions of follow-up cancer patients referred to our clinic between January 2012 and November 2016. The diagnosis of adrenal malignant lesions was made on the basis of interval growth or reduction after chemotherapy. Patient demographics, analysis of metabolic parameters such as maximum standard uptake value (SUVmax), tumor SUVmax/liver SUVmean ratio (T/LR), morphologic parameters such as size, Hounsfield Units, and computed tomography (CT) volume, and metabolovolumetric parameters such as metabolic tumor volume and total lesion glycolysis (TLG) of adrenal lesions were calculated. PET/CT parameters were assessed using the Mann-Whitney U-test and receiving operating characteristic analysis. RESULTS: In total, 186 adrenal lesions in 163 cancer patients (108 men/54 women; mean±SD age: 64±10.9 years) were subjected to F-FDG PET/CT for tumor evaluation. SUVmax values (mean±SD) were 2.8±0.8 and 10.6±6; TLG were 10.8±9.2 and 124.4±347.9; and T/LR were 1±0.3 and 4.1±2.6 in benign and malignant adrenal lesions, respectively. On the basis of the area under the curve, adrenal lesion SUVmax and T/LR had similar highest diagnostic performance for predicting malignant lesions (area under the curve: 0.993 and 0.991, respectively, P<0.001). Multivariate logistic regression analysis showed that T/LR, adrenal lesion SUVmax, and Hounsfield Units were independent predictive factors for malignancy rather than TLG. CONCLUSION: Irrespective of whether TLG was statistically highly significant for differentiating benign from malignant adrenal lesions, it did not reach the expected performance with a low negative predictive value. This may be because of the malignant but small and benign but large lesions on metabolovolumetric calculation.

Relaxant effects of beta-adrenoceptor agonist formoterol and BRL 37344 on bovine iris sphincter and ciliary muscle.

We investigated the relaxant effect of beta2-adrenoceptor agonist formoterol and beta3-adrenoceptor agonist BRL 37344 on bovine iris sphincter and ciliary muscle and measured cAMP and cGMP levels. Iris sphincter (n = 16) and ciliary muscle (n = 16) strips were mounted in organ baths and tested for changes in isometric tension in response to formoterol and BRL 37344. Their relaxant effects on serotonin-induced contractions in the presence or absence of metoprolol, ICI 118.551 and SR 59230A (beta1-, beta2-, beta3-adrenoceptor antagonist, respectively) were investigated. Their effects on cAMP and cGMP levels in iris sphincter (n = 12) and ciliary muscle (n = 12) were evaluated. Formoterol (10(-11)-10(-5) M) and BRL 37344 (10(-10)-10(-5) M) decreased the serotonine-induced contractions in a concentration-dependent manner. Emax values of formoterol were significantly higher than those of BRL 37344 in iris sphincter and ciliary muscle, with no significant change in pD2 values. The relaxation responses by formoterol and BRL 37344 were antagonized with ICI 118.551 (10(-6) M) and SR 59230A (10(-6) M). cAMP levels of formoterol- and BRL 37344-treated tissues were significantly higher than those of the control tissues. cGMP levels of BRL 37344-treated tissues were significantly higher than those of control tissues, but this effect of BRL 37344 was less significant than its effect on cAMP levels. beta-adrenoceptor relaxation responses in bovine iris sphincter and ciliary muscle are mediated by a mixed population of beta2- and beta3-adrenoceptor subtypes, with a predominant contribution of cAMP. Potency of formoterol and BRL 37344 was similar, but efficacy of formoterol was better than BRL 37344.

Evaluation of the cell death pathway and apoptosis-stunning effect relationship after low- and high-dose I-131 administrations in rat thyroid tissue.

OBJECTIVES: This study had two aims; (1) to describe the cell death pathway (apoptosis or necrosis) induced by a low and high dose of radioiodine (I-131) in rat thyroid tissue in in vivo conditions and (2) to determine the role of apoptosis in the development of "stunning effect" in the thyroid tissue with low and high doses of I-131 application. DESIGN: The experimental group consisted of 18 rats; low and high I- 131 doses with a 1-week interval were administered to this group. At first, low doses were injected intraperitoneally (i.p.) (net injected dose was 51.54 +/- 8.6 microCi). After 1 week of the low-dose injection, high doses were also injected (net injected dose was 934.9 +/- 211.8 microCi). Thyroidal I-131 uptakes for both low- and high-dose applications were calculated by using a gamma camera after 24 hours of injections. Immediately after the uptake calculation, thyroid tissues were resected. A control group of 10 rats was also included in the study; in this group, I-131 was not administered. Thyroid tissues of this group rats were also resected. DNA was extracted from thyroid tissues, and damage was examined with the "DNA ladder by agaroz gel electrophoresis." RESULTS: Thyroidal I-131 uptakes were calculated as 11.3% +/- 3.6% and 9.8% +/- 5.3% at the 24th hour after low- and high-dose I-131 applications, respectively. When the low- and high-dose uptake values were compared for each rat; a significant relationship was not found between thyroidal uptakes and injected low and high doses of I-131. When the chromosome images were examined, there was healthy DNA appearance in 1 rat; in 4 rats, only necrotic hyperfragmentations were observed; in 9 rats, both apoptotic specific fragmentations and necrotic hyperfragmentations were observed; and in 4 rats, apoptosis, necrosis, and healthy DNA appearances were seen together. In none of the rats, specific fragmentations concordant only with apoptosis was found. When the thyroidal uptake alterations were taken into consideration, significant difference was not found between first and second uptake calculations (p = 0.28). No significant relationship was also observed between thyroidal uptake alterations and apoptosis-necrosis-healthy DNA findings. Additionally, when we take into consideration the DNA results of only 13 of the rats that had reduced thyroidal uptake, a significant relationship could also not be observed between reduced uptake and apoptotic, necrotic, or healthy tissue findings. Interestingly, apoptotic and necrotic tissue or only necrotic, tissue findings were observed in the other 5 rats which had increased thyroidal uptake. CONCLUSIONS: Following I-131 administration, two types of cell death--both apoptosis and necrosis findings--have been observed in most of the rats. We think that the decreased uptake values are because of the probable stunning effect in thyroid tissue. We also investigated whether the stunning effect is related to apoptosis. According to our results, it can be concluded that the stunning effect is not related to tissue damage, cell decrease, or cell death. Alternatively, we think that this can be related to a radiation-induced reduction of iodine uptake/metabolism or a modified iodine transport mechanism. For further in vivo studies, this experimental model using normal rat thyroid tissue may be useful in investigating the cell death pathways induced by I-131 and its probable roles in the development of the stunning phenomenon.

Preoperative localization of parathyroid adenomas with technetium-99m methoxyisobutylisonitrile imaging: relationship with P-glycoprotein expression, oxyphilic cell content, and tumoral tissue volume.

UNLABELLED: In addition to tumor size, it has been suggested that P-glycoprotein (P-gp) expression and/or oxyphilic cell content in parathyroid adenomas has an important influence on the results of technetium 99m methoxyisobutylisonitrile (Tc-99m MIBI) parathyroid imaging. AIM: In this study, we compared the results of MIBI parathyroid imaging and immunohistochemical analysis (IHA) of P-gp expression, oxyphilic cell content, and tumoral tissue volume in parathyroid adenomas. We also evaluated the relationship between MIBI and ultrasound (US) results, operation findings, serum biochemical values. MATERIALS AND METHODS: Forty (40) patients (36 female and 4 male; mean age, 53.2 +/- 8.16 years) with hyperparathyroidism who had undergone surgery were included in this study. Preoperatively, "double phase" parathyroid scintigraphy with Tc-99m MIBI (including imaging of the neck and mediastinum) was performed in all patients. Thirty-two (32) of the patients had also neck US. Serum parathormon (PTH), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels were measured preoperatively. In resected parathyroid tissues, P-gp expression and percentage of oxyphilic cell content were analyzed with IHA in 34 patients. RESULTS: Three (3) of the resected parathyroid tissues were hyperplastic parathyroid tissue, whereas 31 of the tissues were parathyroid adenoma (mean volume, 1.99 +/- 1.93 mL). In Tc-99m MIBI parathyroid scintigraphy, 70% of the parathyroid adenoma/hyperplastic parathyroid tissue was detected in correct localization; at US, this rate was 46.8%. According to the resected parathyroid tissue localization at surgery, sensitivity, accuracy, positive predictive value, and prevalence in scintigraphy were 82.3%, 70%, 82.3%, and 85%, respectively. Those were 60%, 46.8%, 68.2%, and 78.1% for US, respectively. No significant correlation and no concordance was found between MIBI and US results (kappa, -0.103, r = -0.11; p: 0.53). Interestingly, significant correlation was found between tumoral volume and ALP level (r = 0.42; p = 0.010) and between PTH and ALP levels (r = 0.72; p < 0.001). Significant correlation was also found between patient age and tumoral volume (r =-0.37; p = 0.02) and between PTH and serum Ca levels (r = 0.32; p = 0.04). In 23 of 34 patients in whom histopathological examination was done MIBI was positive and in 13 of these patients (56.5%), P-gp expression was positive. When the histopathological results and MIBI results were compared, there was no significant correlation and concordance between P-gp expression (kappa = 0.09, r = 0.10; p = 0.54), oxyphilic cell content (r = -0.17; p = 0.33), and tumoral tissue volume (r = -0.14; p = 0.38). In 12 of 19 patients (63%) who had parathyroid tissue < 1 mL and in 15 of 24 patients (62.5%) who had oxyphilic cell content < 10%, lesions were also detected correctly with MIBI scintigraphy. CONCLUSIONS: Present study results suggest that MIBI scintigraphy was clearly superior to US as a diagnostic tool. However, P-gp expression, oxyphilic cell content, and tumoral volume may have not a main effect on MIBI parathyroid scintigraphy results in parathyroid adenoma.

Evaluation of the p53 tumor suppressor gene mutation in normal rat salivary gland tissue after radioiodine application: an experimental study.

In this experimental study, investigators explored p53 tumor suppressor gene mutation induced by low and high doses of iodine-131 sodium iodide (I-131) in salivary gland tissue in rats. Group 1 consisted of 10 rats; low and high I-131 doses were applied at a 1-wk interval. First,low doses of I-131 were injected. (The net injected dose was 47.5-/+9.2 microCi.) After 1 wk, high doses of I-131 were also injected. (The net injected dose was 1007.2-/+53 microCi.) Group 2 consisted of 5 rats, and only a low I-131 dose was applied. (The net injected dose was 52.7-/+5.5 microCi.) The Control Group consisted of 5 rats that did not receive I-131. Thyroidal I-131 uptakes were calculated for Groups 1 and 2 with the use of a gamma camera after 24 h of injections. Immediately after uptake was calculated, salivary glands were resected in all groups and DNA was extracted for genotyping. Genomic DNA of the p53 gene exon 5 was examined by polymerase chain reaction single-strand conformational polymorphism. In Group 1, thyroidal I-131 uptakes were calculated as 12.45%-/+4.14% and 9.66%-/+6.73% after low-dose and high-dose I-131 applications, respectively. In Group 2, thyroidal I-131 uptake was calculated as 13.12%-/+3.04%. In Group 1, p53 gene abnormality was seen in the salivary gland of only 1 of the rats. Double- and single-strand gene profiles showed that both alleles of this rat have a mutated single-strand conformational polymorphism profile of point mutation in the p53 gene exon 5. This rat received the highest low dose and the second highest total dose of I-131; its thyroidal uptakes were the second highest. In the other rats in Group 1, and in Group 2 and the Control Group, p53 gene abnormalities were not observed. In Groups 1 and 2, a significant relationship could not be discerned between thyroidal uptake of I-131 and p53 gene mutation in the salivary gland. No significant relationship was observed between thyroidal uptake alterations and p53 gene mutations in salivary glands in Group 1. A point mutation in the p53 gene exon 5 that was seen in only 1 of the rats in Group 1 seems related to the high-dose application of I-131, although coincidental occurrences could not be excluded. We believe that this topic is open to additional in vivo studies.

Is Very High Thyroid Stimulating Hormone Level Required in Differentiated Thyroid Cancer for Ablation Success?

OBJECTIVE: Remnant ablation with radioactive iodine (I-131) is a successful form of treatment that aims to destroy the remaining residual tissue and/or metastatic tissue after total thyroidectomy in differentiated thyroid cancer (DTC) patients. High level of thyroid stimulating hormone (TSH) (≥30 mIU/L) is recommended for success of ablation treatment. In this retrospective study, our aim was to investigate whether the TSH levels at the time of ablation effect the success of radioactive iodine remnant ablation. METHODS: Patients who were diagnosed with DTC, treated with bilateral total/near total thyroidectomy and who were referred for I-131 remnant ablation were included in this study. Patients with undetectable TSH-stimulated serum thyroglobulin (Tg) level, normal physical examination, negative results on whole body scan with I-131, and no evidence of neck lymph node metastasis on ultrasound were defined as disease-free. The correlation between TSH level at the time of ablation and ablation success was assessed. RESULTS: Two hundred sixty one consecutive patients were included in the present study. Mean TSH level was 19.47±6 mIU/L in the 34 patients with TSH <30 mIU/L, while mean TSH level was 73.65±27 mIU/L in the 227 patients with TSH ≥30 mIU/L during I-131 remnant ablation. Ablation was unsuccessful in only one patient with TSH <30 mIU/L who had lung metastasis. Ablation was unsuccessful in 5.1% of patients with TSH ≥30 mIU/L. The effect of TSH level was not significant on ablation success (p=0.472). CONCLUSION: In conclusion, we think that a high TSH serum level alone is not a factor for the success of ablation. Age, presence of metastasis, extent of residual thyroid mass should also be considered. Especially, in the presence of metastatic tissue, obtaining adequate increase in TSH level is not always possible. The success of ablation at lower levels of TSH elevations may be sufficient for patients, and long-term hypothyroidism may not be required.

Morphologic and Metabolic Comparison of Treatment Responsiveness with 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography According to Lung Cancer Type.

OBJECTIVE: The aim of the present study was to evaluate the response to treatment by histopathologic type in patients with lung cancer and under follow-up with 18F-fluoro-2deoxy-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT) imaging by using Response Evaluation Criteria in Solid Tumors (RECIST) and European Organisation for Research and Treatment of Cancer (EORTC) criteria that evaluate morphologic and metabolic parameters. METHODS: On two separate (pre- and post-treatment) 18F-FDG PET/CT images, the longest dimension of primary tumor as well as of secondary lesions were measured and sum of these two measurements was recorded as the total dimension in 40 patients. PET parameters such as standardized uptake value (SUVmax), metabolic volume and total lesion glycolysis (TLG) were also recorded for these target lesions on two separate 18F-FDG PET/CT images. The percent (%) change was calculated for all these parameters. Morphologic evaluation was based on RECIST 1.1 and the metabolic evaluation was based on EORTC. RESULTS: When evaluated before and after treatment, in spite of the statistically significant change (p<0.05) in SUVmax, the change was not significant in TLG, in the longest total size and in the longest size (p>0.05). In histopathologic typing, when we compare the post-treatment phase change with the treatment responses of RECIST 1.1 and EORTC criteria; for RECIST 1.1 in squamous cell lung cancer group, progression was observed in sixteen patients (57%), stability in seven patients (25%), partial response in five patients (18%); and for EORTC progression was detected in four patients (14%), stability in thirteen patients (47%), partial response in eleven patients (39%), in 12 of these patients an increase in stage (43%), in 4 of them a decrease in stage (14%), and in 12 of them stability in stage (43%) were determined. But in adenocancer patients (n=7), for RECIST 1.1, progression was determined in four patients (57%), stability in two patients (29%), partial response in one patient (14%); for EORTC, progression in one patient (14%), stability in four patients (57%), partial response in two patients (29%) were observed and in these patients, an increase in stage was detected in 3 of them (43%), while 4 of them remained stable. According to histopathologic diagnosis, between squamous cell cancer and adenocancer cases, no significant difference was determined in terms of SUVmax (p>0.05). Post-treatment SUVmax was significantly different in primary tumor but was not significantly different in nodal involvement and metastatic lesions for squamous cell carcinoma patients as compared to the pre-treatment SUVmax measurements. Similarly, there was no significant difference between primary tumor and nodal involvement for adenocarcinoma patients. CONCLUSION: Whether metabolic or morphologic changes are more accurate in evaluating treatment response in lung cancer remains unknown, and there is no gold standard diagnostic method on this issue yet. The most reliable results can only be achieved by survival curve parameters. However, we believe SUVmax seems to provide more easy and practical data for the evaluation of treatment response.

The Diagnostic Value of the Correlation between Serum Anti-p53 Antibody and Positron Emission Tomography Parameters in Lung Cancer.

OBJECTIVE: Mutations in the p53 gene are the most commonly observed genetic abnormalities in malignancies. The purpose of this study was to assess the diagnostic value of serum anti-p53 antibody (Ab) along with the correlation between serum anti-p53 Ab level and quantitative positron emission tomography (PET) parameters such as maximum standardized uptake value (SUVmax), SUVave, metabolic tumor volume, total lesion glycolysis (TLG) and tumor size. METHODS: Serum anti-p53 Ab level was studied in three groups. Patients who underwent 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) imaging for staging of previously diagnosed lung cancer constituted the first group, while patients who underwent 18F-FDG PET/CT imaging for evaluation of suspicious pulmonary nodules detected on thorax CT and did not show pathologic FDG accumulation (NAPN=pulmonary nodule with non avid-FDG) were enrolled in the second group. The third group consisted of healthy volunteers. RESULTS: Twenty-eight patients with lung cancer (median age: 62.5, range: 39-77years), 28 patients with NAPN (median age: 65, range: 33-79 years), and 24 healthy volunteers (median age: 62, range: 44-74 years) were enrolled in the study. The serum anti-p53 Ab level was low in healthy volunteers while it was higher in both lung cancer patients and NAPN patients (p<0.05). When serum anti-p53 Ab level and PET parameters were evaluated, there was no significant correlation between serum anti-p53 Ab level and SUVmax, SUVave, TLG, tumor volume and tumor size of patients with lung cancer (p>0.05). Besides, there was no significant difference between serum anti-p53 Ab level and lesion size of NAPN patients (p>0.05). CONCLUSION: It was determined that serum anti-p53 Ab levels are not significantly correlated with PET parameters, and that serum anti-p53 Ab levels increase in any benign or malignant lung parenchyma pathology as compared to healthy volunteers. These results indicate that this Ab cannot be used as a predictor of malignancy in a lung lesion.

Dobutamine stress tetrofosmin SPECT; evaluation of short rest-stress protocol and head to head comparison with MIBI in detection of coronary artery disease.

OBJECTIVE: The purpose of the present study was to evaluate the feasibility and diagnostic accuracy of same day short rest-dobutamine stress Tetrofosmin (TF) SPECT imaging protocol and to compare TF SPECT results with MIBI SPECT in the same subjects who were unable to perform treadmill exercise or were unsuitable for pharmacological vasodilator stress. METHODS: The study group consisted of 19 patients (2 female and 17 male, with a mean age of 53.8 +/- 7.9 yrs) in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). MIBI SPECT imaging was performed first. TF SPECT images were obtained one week after MIBI imaging. Immediately after the rest SPECT imaging in both of the MIBI and TF studies, patients underwent dobutamine stress tests. Rest-stress radiotracer doses and dobutamine doses were the same for both TF and MIBI studies. While 60 min waiting periods were applied for MIBI study, only 30 min waiting periods were applied for TF study after the rest and stress injections. Images were evaluated by visual and quantitative analysis. RESULTS: Dobutamine stress parameters were similar for both studies. Although in TF study, the time between radiopharmaceutical injection and imaging was shorter than in MIBI study, there was no significant difference between heart-to-liver (H/Li) and heart-to-lung (H/Lu) ratios. According to CA results, diagnostic accuracy was similar for TF and MIBI. While sensitivity, specificity and accuracy for TF study were calculated as 82%, 84% and 82%, respectively, the corresponding values for MIBI were 82%, 88% and 84%, respectively. This clinical study has shown comparable diagnostic performance for the detection of CAD between MIBI and TF. Good correlation was found between segmental analysis for both studies. CONCLUSION: MIBI and TF showed similar perfusion defects and good segmental correlation during dobutamine stress with the same quality images. Both radiopharmaceuticals may be acceptable with this imaging protocol. Besides this, TF study showed better reversibility degree (55%) in a shorter time when compared to MIBI study (25%) in perfusion defects (especially in segments with severely decreased perfusion or no uptake).

Usefulness of measuring the gastric emptying time in a case of brittle diabetes.

Gastric emptying time measurement by radionuclide study, although quite informative, is rarely remembered in clinical practice. We presented a patient with brittle diabetes who had multiple emergency admissions due to hypoglycemia under routinely prescribed insulin therapy. She had severe gastroparesis, which was determined by scintigraphic gastric emptying study (gastric half-emptying time = 260 min for a mixed meal). She had not presented to the emergency service for two years because of only a slight change the timing of her insulin administration time (after meal instead of before meal) in the light of gastric-emptying study.

Dobutamine Tc-99m furifosmin SPECT in detection of coronary artery disease: evaluation of same day, rest-stress protocol.

The purpose of this study was to evaluate the feasibility and diagnostic accuracy of same day rest-stress myocardial perfusion SPECT (MP SPECT) protocol by using technetium-99m (Tc-99m) furifosmin in conjunction with dobutamine stress test in subjects in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). The study group consisted of 25 patients (8 female and 17 male with a mean age of 53.04 +/- 8.56 yrs) unable to perform treadmill exercise or unsuitable for pharmacologic vasodilator stress testing. Ten mCi (370 MBq) of Tc-99m furifosmin was injected intravenously at rest. Sixty min after injection, planar and SPECT images were acquired. One hour later all patients underwent dobutamine stress test. At the peak stress, 20 mCi (740 MBq) of Tc-99m furifosmin was injected. Sixty min after stress dose injection, planar and SPECT images were acquired. Rest-stress planar and SPECT data were evaluated by using visual and quantitative analysis. Heart to adjacent organ (Heart/Lung; H/Lu and Heart/Liver; H/Li) activity ratios were calculated from anterior planar images by using regions of interest (ROI). SPECT data were interpreted by using 20 segment-5 point scoring system from short axis and vertical long axis slices. The results of rest-dobutamine stress Tc-99m furifosmin MP SPECT were compared with CA results. There were statistically significant differences between H/Lu and H/Li ratios at rest and stress conditions. Heart/adjacent organ activity ratios were similar and significant statistical difference could not be found between CA positive and CA normal patients. Sensitivity, specificity and accuracy for Tc-99m furifosmin SPECT study were calculated as 90%, 80% and 84% for left anterior descending (LAD), 87%, 94% and 92% for left circumflex (LCx) and 67%, 86% and 80% for right coronary artery (RCA), respectively. Overall sensitivity, specificity and accuracy were calculated as 83%, 87% and 85%, respectively. According to the results obtained in this study, it may be concluded that same day rest-dobutamine stress Tc-99m furifosmin SPECT protocol is a feasible and accurate technique in the evaluation of CAD, especially in patients unable to perform treadmill exercise or unsuitable for pharmacologic vasodilator stress testing.