Objective: The purpose of the study was to evaluate the qualitative and semi- quantitative effects of using different low- dose computed tomography (CT) matrix sizes for attenuation correction of PET images. Methods: Co-registered 2-[F18]- fluoro-2-deoxy-D-glucose (FDG)-PET and CT images were acquired using a combined PET/CT scanner according to a standardized protocol. PET/CT reconstruction was repeated using default reconstruction protocols with different matrix sizes for low dose CT (512,768 and 1024) in 25 patients. The resulting images were analyzed qualitatively “image quality” and semi-quantitatively using “mean SUV & Signal to Noise Ratio (SNR)”. Results: No significant difference in the resulting attenuated corrected images reconstructed with the different matrix sizes either qualitatively or semi- quantitatively. Conclusion: The matrix size of the low dose CT used in the attenuation correction of PET images does not affect the image quality or semi-quantitative parameters.

Objectives: To assess efficiency of low dose 131Iin thyroid remnant ablation of patients with differentiated thyroid cancer after surgical treatment. Material and Methods: 88 patients with differentiated thyroid cancer, (age 20-75 years) tumor stage T1 to T3, with disease confined to the thyroid or cervical lymph nodes. All patients were treated with 131I after total thyroidectomy and pathologic lymph node resection, if present. A randomized double-armed prospective trial comparing low-dose [1110MBq (30mCi)] and high-dose [3700 MBq (100mCi)] radioiodine ablation.39 patients received low dose and 49 patients received high dose. Six months after the administration of radioiodine, measurements of TG, anti-TG antibodies together with neck ultrasound exam and 131Iwhole-body scan were performed. The success rate of ablation is determined by negative whole body 131I scan, negative neck ultrasonography and serum thyroglobulin level less than 2 ng/mL. Results: Successful ablation reported in 23 out of 39 cases (58.9 %) in the group receiving low-dose radioiodine [1110MBq] versus 37 out of 49 cases (75.5 %) in the group receiving the high dose [2960-3700 MBq] (P value= 0.098). A second follow up was performed one year after the ablative dose for the cases who had successive ablation from both groups. In the low dose group, only 12 out of 23 patients (52%) were available, all of them didn't show any disease recurrence, versus 17 cases out of 37 in the high dose group, 16/17 patients didn't had recurrence, while in one case there was a recurrent disease at the thyroid bed. Conclusion: From this ongoing data, non-significant higher success thyroid remnant ablation was recorded for high compared to low radioiodine doses.

Objectives: To evaluate the diagnostic performance of 18F-Flurodeoxyglucose positron emission tomography/ computed tomography in comparison to contrast enhanced computed tomography alone in the detection of peritoneal metastases after initial treatment of malignant ovarian tumors. Patients and Methods: The study prospectively recruited 111 patients with clinical suspicion of ovarian tumor recurrence. Each patient underwent 18FFDG PET/CT and Ce-CT scans in the same day. Study-based analyses for a total of 136 scans were evaluated. Studies were read independently by one experienced nuclear medicine physician and one experienced radiologist. A four-point score (score 0= definitely benign, score 1 = probably benign, score 2= probably malignant and score 3= definitely malignant) used to assess the presence or absence of peritoneal metastases. The final diagnosis of peritoneal disease status was made on the basis of subsequent follow-up by 18F-FDG PET/CT, conventional imaging (CT/MRI) or histopathology whenever possible. Results: Of the 136 studies evaluated, 75 (55%) studies had peritoneal disease and 61 (45%) studies were free based on final diagnosis.18F-FDG PET/CT & Ce-CT had sensitivity, specificity and accuracy of 96% vs 69%, 100% vs 85%, and 98% vs 76%; respectively. 18F-FDG PET/CT was significantly more sensitive, specific and accurate compared to Ce-CT with P-values of 0.0001, 0.004 and 0.0001; respectively. Conclusions: 18F-FDG PET/CT is superior to Ce-CT in the diagnosis of peritoneal metastases in patients with malignant ovarian tumors.

Objectives: To evaluate the diagnostic performance of 18F-flurodeoxyglucose positron emission tomography/ computed tomography in patients with suspected biochemical ovarian tumor recurrence in comparison to contrast enhanced CT. Patients and Methods: A total of 64 18FFDG PET/CT studies for patients with biochemical suspicious ovarian tumor recurrence were evaluated. Each patient underwent 18F-FDG PET/CT and Ce-CT scans in the same day. Studies were read independently by one experienced nuclear medicine physician and one experienced radiologist. A four-point score (score 0 = definitely benign, score 1 = probably benign, score 2 = probably malignant and score 3 = definitely malignant) used to assess the presence or absence of recurrence (local, regional or distant). The final diagnosis of tumor status was made on the basis of subsequent followup by 18F-FDG PET/CT, conventional imaging (CT/MRI) or histopathology whenever possible. Results: Of the 64 studies evaluated, 61 (95%) studies had tumor recurrence and 3 (5%) studies were free based on final diagnosis. 18F-FDG PET/CT & Ce-CT had sensitivity 97% vs. 87%, specificity 100% vs. 33%, and accuracy of ( 97% vs. 84% ) respectively. 18F-FDG PET/CT was significantly more sensitive and more accurate compared to Ce-CT with P-value of 0.07 and 0.02; respectively with no statistical significant difference in accuracy.Conclusions: 18FFDG PET/CT is more accurate than Ce- CT in the diagnosis of ovarian tumor recurrence in patients with elevated tumor marker.

Background: Thyroglobulin is commonly used to monitor patients with differentiated cancer thyroid. It has also become an excellent biological marker for tumor persistence or recurrence.Aim of study: To study the relation between the level of baseline serum thyroglobulin (TG) and thyroid remnant ablation outcome using radioactive iodine-131 (RAI-131) in patients with differentiated thyroid cancer after surgical treatment. Methods: A prospective study involved 64 patients (age 20-77 years) with differentiated thyroid cancer, referred for post-surgical 131I ablation. All patients performed baseline serum TG, anti-TG-Ab's under TSH stimulation as well as neck ultrasonography, before receiving RAI-131ablation dose 1110 - 3700 MBq (30 -100 mCi). Follow-up was performed 6-8 months later. Successful ablation was determined by negative whole body 131I scan, negative neck ultrasonography and stimulated serum thyroglobulin level less than 2 ng/mL. Results: Successful ablation was reported in 38 out of 64 cases (59.4 %). Baseline serum thyroglobulin level was significantly predictive of ablation outcome. ROC analysis showed AUC (area under curve) of 0.66 (CI: 0.53 - 0.78; P = 0.03). A cutoff value of 4.4 ng/ml showed sensitivity of 79 % and specificity of 68% in predicting ablation outcome. Patients were divided into high (n = 32) and low (n = 32) baseline TG groups using this cut-off point. Successful ablation significantly higher in low TG group (25/32 vs. 13/32; P = 0.002). There was no significant difference between the two groups regarding their clinical and pathological data. Conclusion: Baseline serum thyroglobulin is associated with ablation outcome. Serum TG> 4.4 is linked to significantly higher rates of unsuccessful ablation.

Our aim was to retrospectively assess the diagnostic performance from combined positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) for the detection of bone marrow invasion of the mandible or maxilla in patients with oral cavity squamous cell carcinoma (OCSCC). A total of 114 patients with OCSCC, arising from or abutting the upper or lower alveolar ridge, underwent staging PET/CT and MRI studies before surgery. The possibility of bone marrow invasion on PET/CT and MRI was graded retrospectively on a 5-point score. Histopathology was taken as the reference standard. Sensitivity, specificity, predictive values and likelihood ratios were calculated. Clinical factors affecting the performance, like tumor origin and dentate status were also explored. PET/CT was found to be more specific than MRI (83% vs. 61%, respectively, p=0.0015) but less sensitive (78% vs. 97%, respectively, p=0.0391). Dentate status and tumor origin affected the diagnostic performance of PET/CT. In patients with positive MRI, sensitivity and specificity of PET/CT were 78% and 100% in dentate patients with alveolar ridge tumors, 75% and 80% in dentate patient with buccal tumors, 90% and 33% in edentulous patients with alveolar ridge tumors and 0% and 63% for edentulous patients with buccal tumors, respectively. PET/CT is more specific than MRI and can be used to complement the role of MRI. A negative MRI result can confidently exclude the presence of bone marrow invasion, while in patients with positive MRI findings, a negative PET/CT may be useful to rule out bone marrow invasion in dentate patients.

OBJECTIVES: We sought to determine potential prognostic value of total lesion glycolysis (TLG) calculated from combined positron emission tomography/computed tomography (PET/CT) in patients with oral cavity squamous cell carcinoma (OSCC). MATERIALS AND METHODS: We prospectively studied 126 patients with OSCC who underwent PET/CT before definitive treatment by radical surgery. The metabolic tumor volume (MTV) was calculated for the primary tumor according to an absolute standardized uptake value (SUV) of 3. TLG was calculated as MTV × the average SUV. The nodal SUVmax was also recorded. The median value of SUVmax and TLG were used to divide the patients into two categories (high and low). Patients were followed up until death or for at least 24 months from their surgery. Disease-free (DFS) and disease-specific survivals (DSS) were the main outcome measures. RESULTS: The median TLG of the primary tumor ((T)TLG) was 71.4, and the median nodal SUVmax ((N)SUV) was 7.5. Patients with high (T)TLG (≥ median) had a 2-year DFS of 52% whereas the DFS was 74% for those with a low (T)TLG (P=0.007); the 2-year-DSS rates were 53% vs. 84%, respectively (P0.001). Similarly, patients with high (N)SUVmax (≥ median) had a 2-year DFS of 42% vs. 70% for patients with a low (N)SUVmax (P=0.001); the 2-year-DSS rates were 39% vs. 78%, respectively (P0.001). In multivariate analyses, (T)TLG, (N)SUVmax, and pathological nodal status were independent prognostic factors for the 2-year DSS. A 3-point prognostic scoring system was formulated based on the presence or absence of the independent factors. Patients with positive neck nodes, high (N)SUVmax, and high (T)TLG (score 3) had a 32-fold higher risk of cancer death compared with those lacking such risk factors (2-year-DSS=26% vs. 97%, P0.001). CONCLUSION: Primary tumor TLG is an independent prognostic factor for cancer control and survival in patients with OSCC. A prognostic scoring system that includes primary tumor TLG, nodal SUVmax, and pathological neck status may be useful for risk stratification in this group of patients.

Purpose To investigate the prognostic significance of standardized uptake value (SUV) of metastatic neck lymph nodes measured on FDG PET/CT in patients with stage IV oro/hypopharyngeal cancers treated by definitive chemoradiotherapy (CCRT). Methods Retrospective analysis of 65 patients with clinically N+ stage IV SCC of the oro/hypopharyngeal squamous cell carcinoma (SCC) who underwent FDG PET/CT scans for primary staging. Follow-up continued till death or at least 24 months from the start of treatment. The primary study endpoint was neck control (NC). The log-rank test and Cox proportional hazard analysis were used to identify significant prognostic factors. Results The 3-year NC rate was 53%. In univariate analysis, N3 status and nodal SUV ≥ 9.8 were significantly associated with reduced NC. In multivariable analyses, nodal SUV retained its independent prognostic significance as a predictor of NC. Lymph node stage was an independent predictor of disease specific survival (DSS). A prognostic scoring system was constructed as follows: score 0 = N0-N2 and nodal SUV 9.8; score 1 = N3 or nodal SUV ≥ 9.8; and score 2 = N3 and nodal SUV ≥ 9.8. Patients with a score of 2 showed the worst NC (hazard ratio [HR], 95% confidence interval [CI]= 10.5, 3.3-33.1; P 0.001) and the lowest DSS (HR, 95% CI = 6.4, 2.2-18.7; P = 0.001). Conclusion The combination of high nodal SUV and N3 neck disease identifies a subgroup of high-risk stage IV oro/hypopharyngeal SCC patients. Further prospective studies are warranted to validate this finding.

This commentary addresses strengths and weaknesses of the clinical trial study protocol designed by Liu et al., in particular with regard of the methodology, taking into consideration the commentary article "Assessing surgical methods for treatment of cubital tunnel syndrome - which is the best?" Our commentary emphasizes the importance of adjustment for known prognostic covariates, such as duration of symptoms and advanced age that have been negatively correlated with outcomes in previous studies. Subgroup analysis for the treatment groups of interest, namely moderate and severe cubital tunnel syndrome, which have previously shown conflicting differences in efficacy of surgical options is highly recommended. Intention-to-treat analysis is a preferable approach for the evaluation of primary outcome measures to lessen the bias. Use of well-validated composite outcome measure is strongly encouraged.

Background: Seroma formation after breast surgery could result in significant morbidity and subsequent delay to commence the adjuvant therapy. A prospective randomized study was done to assess the effect of obliterating the axillary dead space by sutures with Flap fixation after Breast cancer surgery either by Modified Radical Mastectomy (MRM) or Conservative Breast Surgery (CBS) prospectively. In addition, Factors predicting the formation of seroma were analyzed and reported. Methods: A total of 164 patients diagnosed as Breast cancer, they were randomized to have the post mastectomy dead space obliterated (intervention group) or standard wound closure (control group) following either MRM or CBS. Those had immediate reconstruction were excluded from the study. Drains were routinely left in place until the preceding 48-hour output was 30 milliliters/day. The duration of the drains left in place and the incidence of seroma formation were reported. A multivariate analysis for the potential factors associated with seroma formation was done. Results: Fifty -eight (n=58) patients were assigned to the treatment group and 106 (n=106) to the control group. MRM was performed on 105 patients (64%) and CBS on 59 (36%). Ten of the 58 patients (17.2%) in the intervention group developed a seroma in comparison to 33 of the 106 control patients (31.1%) (P=0.03). There was a significant reduction in the duration of suction drain in situ with obliteration of the dead space (P=0.001). No statistically significant differences were observed between intervention and control groups with respect to patient and pathological parameters or the incidence of other wound complications. Multivariate analysis revealed that Significant risk factors for seroma formation were Diabetes Mellitus (DM) (P=0.01), neoadjuvant CTH (P=0.019), number of retrieved L node (P=0.019), and dead space obliteration (P=0.04). Conclusion: On multivariate analysis, the most significant factors affecting seroma formation were DM, neoadjuvant CTH, number of retrieved L node and Dead Space Obliteration. Dead Space Obliteration following breast cancer surgery is a simple technique that reduces the time of suction tubal drainage, and incidence of seroma formation.