Outcomes of Radioembolization in Patients with Chemorefractory Colorectal Cancer Liver Metastasis: a Single-Center Experience.

PURPOSE: We aimed to evaluate the efficacy and outcomes of radioembolization with Yttrium-90 (Y-90) microspheres in patients with unresectable and chemorefractory colorectal cancer liver metastasis (CRCLM). METHODS: This single-center study included 43 patients (34 male, 9 female) who underwent radioembolization with Y-90 for unresectable, chemorefractory CRCLM between September 2008 and July 2014. Overall survival (OS), liver progression-free survival (LPFS), overall response rate (ORR), local disease control rate (LDCR), and relations of these parameters with patient disease characteristics were evaluated. OS and LPFS rates were compared according to microspheres. Survival rates were calculated with Kaplan-Meier method, and potential prognostic variables were evaluated on univariate analyses. RESULTS: Post-procedural median OS was 12.8 months. LPFS was 5.6 months. ORR was 33%, LDCR was 67% on 3rd month follow-up. Low tumor burden (< 25%) was associated with higher median OS after radioembolization (< 25 vs > 25-50% p < 0.0001 and < 25 vs > 50% p = 0.005). Patients with left colon tumors exhibited significantly longer median OS after metastasis than right colon tumors (p = 0.046). Extrahepatic disease and synchronicity showed poorer survival parameters; however, the difference was not significant (p = 0.1 and p = 0.3, respectively). In subgroup analyses, the distribution of patient number and characteristics showed heterogeneity as number of patients with low tumor burden was higher in resin Y-90 group. Resin Y-90 group exhibited significantly higher median OS and LPFS compared to glass Y-90 group (16.5 vs. 7 months, p = 0.001; 6.73 vs. 3.38 months, p = 0.023, respectively). CONCLUSION: Radioembolization is a safe local-regional treatment option in chemorefractory, inoperable CRCLM. Radioembolization at earlier stages may lead to more favorable results especially with lower tumor burden patients.

Comparison of 800 and 3700 MBq iodine-131 for the postoperative ablation of thyroid remnant in patients with low-risk differentiated thyroid cancer.

INTRODUCTION: The initial treatment of differentiated thyroid cancer is thyroidectomy, followed by remnant ablation with iodine-131 (I-131) in some patients. However, controversy exists concerning the appropriate radioiodine dose. The aim of the study is to compare the success rate of low and high activities of I-131 for postoperative remnant ablation. PATIENTS AND METHODS: A total of 108 nonmetastatic low-risk patients (mean age: 46, 85% women) with papillary and follicular carcinoma had I-131 ablation for the postoperative thyroid remnant. Fifty-three patients received a low dose (L) (800 MBq) and 55 patients received a high dose (H) (3700 MBq) of I-131. After total thyroidectomy, thyroid bed I-131 uptake (RAIU) and neck ultrasonography (USG) were performed to determine the remnant volume and the iodine avidity, which were used to calculate the dose delivered to the remnant tissue. The success rate of I-131 ablation was assessed with four different criteria based on serum thyroglobulin (Tg) and USG with and without the utilization of I-131 diagnostic whole-body scintigraphy (DxWBS). Ablation was considered to be successful if patients fulfilled all of the following criteria. (a) Strict criteria based on three tests: (i) USG negative, (ii) no tracer uptake or less than twice the background activity in the thyroid bed on DxWBS and/or up to 0.2% RAIU, and (iii) Tg < 0.2 ng/ml; (b) lax criteria based on three tests: (i) USG negative, (ii) no tracer uptake or less than twice the background activity in the thyroid bed on DxWBS and/or ≤ 0.2% RAIU, and (iii) Tg < 2 ng/ml; (c) strict criteria based on two tests: (i) USG negative and (ii) Tg < 0.2 ng/ml; (d) lax criteria based on two test: (i) USG negative and (ii) Tg < 2 ng/ml. RESULTS: When three tests were used to define successful ablation, in group L, 32 out of 53 (60%) and 43 out of 53 (81%) patients were successfully treated versus 35 out of 55 (64%) and 42 out of 55 (76%) for group H on the basis of strict and lax criteria, respectively (P=NS). The differences were not statistically significant between the two groups when only two tests were used to define ablation success (62 vs. 69% with strict and 89 vs. 87% with lax criteria, respectively). CONCLUSION: Our findings suggest that remnant thyroid tissue in patients with low-risk, well-differentiated thyroid cancer after total thyroidectomy can be ablated with 800 MBq of I-131. The success rate is not different from that obtained with 3700 MBq I-131.

Computerized scar detection on renal cortical scintigraphy images.

OBJECTIVE: Renal cortical scintigraphy is a well-established functional imaging technique for visual analysis of radiopharmaceutical tracer distribution. However, the visual evaluation is subjective, causing interobserver variability, especially in a quantifiable number of scars. The purpose of this study was to develop new computerized methods in renal cortical scintigraphy image interpretation, particularly addressing activity distribution and cortex continuity (scars). METHODS: The proposed methods involve preprocessing stages of model-based automatic kidney segmentation using active-shape model and image normalization (transforming each kidney image into a standardized image vector). For our previous computer-aided diagnosis scheme, two new image-based features [localized activity drop and principal component analysis (PCA)] were defined. Their performance was evaluated and compared with our previous scheme by using free-response receiver operating characteristic that is in terms of sensitivity (true-positive fraction) and the mean number of false positives (FPs) per image. RESULTS: Clinical tests were conducted in 297 patients (231 normal and 66 abnormal). The PCA-based image feature presented the best scar detection performance, followed by the localized activity drop feature. Both schemes were found to be superior to our previous computer-aided diagnosis scheme. In the PCA-based scheme, for sensitivity of 0.90 (76/84), the mean number of FPs was measured as 4.52 (1343/297). For another setting with reduced sensitivity of 0.79 (66/84), the mean number of FPs improved to 1.21 (360/297). Finally, a decision fusion scheme using 'majority voting' was also proposed, the sensitivity and mean number of FPs of which were measured as 0.83 (70/84) and 1.90 (563/297), respectively. CONCLUSION: The proposed methods have potential to provide effective second-reader information to nuclear medicine specialists in finding scar regions. Possible ways to improve the FP rate were also proposed.

Radioembolization for the treatment of unresectable liver cancer: initial experience at a single center.

PURPOSE: Radioembolization with yttrium-90 microsphere (Y-90) therapy with SIR-Spheres (Sirtex Medical, Lane Cove, Australia) was approved by the Turkish Ministry of Health in April 2008. In this study, we present the preliminary experience at a tertiary care center with early follow-up results of Y-90 therapy, as well as a review of the related literature. MATERIALS AND METHODS: Complete evaluation for radioembolization was performed in 10 patients (8 males, 2 females; mean age, 52.3 years) during an 8-month period at a single center, of which 9 were actually treated with SIR-Spheres(R). All patients underwent meticulous pre- and post-procedural imaging studies to document the therapy response. RESULTS; In order to isolate the target hepatic arterial circulation, following branches were embolized as they were considered as potential gastrointestinal shunts: the gastroduodenal artery (n = 5), right gastric artery (n = 1), and supraduodenal artery (n = 1). Radioembolization therapy could not be performed only in one patient because of a hepatogastric shunt of unknown origin. No significant hepatopulmonary shunting was identified (maximum, 9% shunting). The body surface area method was used to calculate the Y-90 dose in all patients (mean dose, 1.24 GBq). All patients had at least partial response of the targeted liver lesions, according to RECIST (Response Evaluation Criteria in Solid Tumors). CONCLUSION: In comparison to chemoembolization, radioembolization has less systemic toxicity and can be performed as an outpatient procedure, which makes it more attractive to both patients and physicians. From our limited experience, the radioembolization procedure is a promising first-line treatment in unresectable liver cancer; randomized controlled multi-center studies, however, are needed.

Normal parathyroid hormone levels in a diabetic patient with parathyroid adenoma.

OBJECTIVE: The incidence of diabetes mellitus in patients with primary hyperparathyroidism and, conversely, primary hyperparathyroidism in diabetic patients are approximately threefold higher than the respective expected prevalence in the general populace. The diagnosis is straightforward when the patient presents hypercalcemia and inappropriately elevated serum parathyroid hormone (PTH) levels. We report a case of parathyroid adenoma in a diabetic patient with persistent hypercalcemia and normal PTH levels. PATIENT: A 50-year-old female patient who was referred to our outpatient clinic presented with persistent hypercalcemia (serum Ca levels between 10.5 and 11 mg/dl) with a normal serum intact PTH level of 46.1 pg/ml. Her blood pressure was 120/80 mmHg, and she was being treated with antihypertensive therapy. Her HbA1c was 7.2%, and her triglycerides were in the normal range. A bone densitometry exam revealed osteopenia of radius -1.39, femoral neck -1.39, and the total hip -1.04. A neck ultrasound revealed a mass of 13 mm next to the inferior and posterior of the right thyroid lobe. A dual phase Tc-99m-sestamibi scan revealed an area of increased uptake in the same region, which is indicative of a parathyroid adenoma. The parathyroid adenoma was removed, which resulted in the achievement of normocalcemia. CONCLUSION: Diabetic patients should be evaluated for hyperparathyroidism as associated hypertension can complicate the course of the disease. These patients should be evaluated for primary hyperparathyroidism when they exhibit persistent hypercalcemia and when clinical suspicion is aroused even if the serum PTH levels are within the normal range.