Evaluation of Imaging Findings in Patients with Pretransplant and Posttransplant Tertiary Hyperparathyroidism.

OBJECTIVES: Tertiary hyperparathyroidism, characterized by autonomous overproduction of parathyroid hormone, can be seen in patients with long-standing secondary hyperparathyroidism (pretransplant) or after renal transplant (posttransplant). Parathyroid scintigraphy and ultrasonography are the most commonly used imaging procedures for the preoperative localization of abnormal parathyroid glands. We aimed to evaluate imaging findings in pretransplant and posttransplant tertiary hyperparathyroidism. MATERIALS AND METHODS: This study included 32 patients with pretransplant tertiary hyperparathyroidism and 20 patients with posttransplant tertiary hyperparathyroidism. On parathyroid scintigraphy with technetium-99m sestamibi, early-phase and latephase images were acquired. Images were evaluated for the presence and the number of active foci and the degree of uptake on the late-phase image. The existence of an autonomous gland was based on latephase retention and was scored from 0 to 2 (retention score). On ultrasonography, the criteria threshold for autonomy was the maximum length of the largest gland ≥10 mm (ultrasonography score). RESULTS: On parathyroid scintigraphy, the most commonly observed pattern in the pretransplant group was positivity in ≥3 glands, and in the posttransplant group the most commonly observed pattern was positivity in 1 to 2 glands. In pretransplant and posttransplant groups, the criteria threshold for the presence of an autonomous parathyroid gland on parathyroid scintigraphy (grade 2 retention) was met in 26 (81%) and 9 (45%) patients and on ultrasonography in 25 (78%) and 10 (50%) patients, respectively. In the whole group of patients (n = 52), correlation existed between ultrasonography score and retention score. Glandular weight was correlated with both retention score and ultrasonography score. CONCLUSIONS: Higher numbers of detectable glands and the presence of parathyroid autonomy were more common in the pretransplant group. This might be explained by parathyroid gland involution after transplant. The results may also suggest that factors other than autonomy are responsible for posttransplant tertiary hyperparathyroidism.

Comparison of parathyroid scintigraphy findings in pediatric and adult patients with secondary hyperparathyroidism.

OBJECTIVES: Secondary hyperparathyroidism (sHPT) is a compensatory complication of chronic kidney disease. The aim of this study was to compare PS findings in pediatric and adult patients with sHPT. METHODS: This study included 50 pediatric and 50 adult patients with sHPT. Parathyroid scintigraphy was performed with Tc-99m sestamibi. After radiopharmaceutical injection, early-phase (15 min) and late-phase (60-90 min) images were acquired. Planar images were interpreted visually for the presence / number of active foci compatible with a parathyroid lesion, the presence and degree of uptake in skeletal structures, and the degree of thyroid sestamibi uptake. Parathyroid surgery was performed in 21 pediatric and 28 adult patients. RESULTS: Serum PTH and ALP values were significantly higher in pediatric than in adult patients ( P < 0.05 for each). In operated patients, on a lesion-based analysis, the sensitivity of PS in pediatric and adult patients were 40% and 71%, respectively. A nonlocalizing scan was observed in 24% of pediatric patients. Pediatric patients had a higher incidence of reduced thyroid sestamibi uptake (42% versus 2%). Skeletal sestamibi uptake was detected in 40% of pediatric and 30% of adult patients and the degree of uptake was higher in pediatric patients. CONCLUSIONS: The results revealed more significant changes in the biochemical profile of pediatric compared with adult patients with sHPT. The sensitivity of PS was lower, and the likelihood of a nonlocalizing scan was higher in pediatric patients. The results may also suggest more severe skeletal findings in pediatric patients. Reduced thyroid sestamibi uptake in children needs further evaluation.

The efficacy of low and high dose 99mTc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism / La eficacia de los protocolos de dosis baja y alta de 99mTc-MIBI para la identificación intraoperatoria de las glándulas paratiroides hiperplásicas en el hiperparatiroidismo secundario

Objective: The aim of this study was to compare the efficacy of low- and high-dose 99mTc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands via gamma probe in secondary hyperparathyroidism. Material and Methods: This retrospective study was conducted using a prospective database of 59 patients who had undergone radioguided subtotal parathyroidectomy between 2004-2012. The patients were tudied in 2 groups. Group 1 (n = 31) received 37 MBq 99mTc-MIBI intravenously in the surgical room approximately 10 min before the beginning of the intervention and surgery was performed under gamma probe guidance. Group 2 (n = 28) received 555 MBq 99mTc- MIBI intravenously 2 h before surgery, which was also performed under gamma probe guidance. Intraoperative gamma probe findings, laboratory findings, and histopathological findings were evaluated together. Results: Using acceptance of the histopathological findings as gold standard, sensitivity and specificity of intraoperative gamma probe for identifying hyperplastic parathyroid glands was 98% and 100%, respectively, in both groups. Conclusions: In the light of these findings, it is concluded that the low-dose 99mTc-MIBI protocol might be preferable for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism patients because it was observed to be as effective as the high-dose 99mTc-MIBI protocol. Furthermore, the low-dose protocol does not have the disadvantages that are associated with the highdose protocol (AU)

Objetivo: El objetivo de este estudio fue comparar la eficacia de los protocolos de dosis baja y alta de 99mTc-MIBI para la identificación intraoperatoria de las glándulas paratiroides hiperplásicas usando sonda gamma en pacientes con hiperparatiroidismo secundario.Material y métodos: Este estudio retrospectivo se llevó a cabo utilizando una base de datos prospectiva de 59 pacientes que habían sido sometidos a paratiroidectomía subtotal radioguiada entre 2004-2012. Los pacientes fueron examinados en 2 grupos. El grupo 1 (n = 31) recibió 37 MBq de 99mTc-MIBI por vía intravenosa en el quirófano aproximadamente 10 min antes del comienzo de la intervención y la cirugía se realizó guiada por la sonda gamma. El grupo 2 (n = 28) recibió 555 MBq de 99mTc-MIBI vía intravenosa 2 horas antes de la cirugía, la cirugía también se realizó guiada por la sonda gamma. Los hallazgos de sonda gamma intraoperatoria, los hallazgos de laboratorio y los hallazgos histopatológicos de todos los pacientes fueron evaluados juntos. Resultados: Aceptando los hallazgos histopatológicos como el estándar de oro, la sensibilidad y la especi- ficidad de la sonda gamma intraoperatoria para identificar las glándulas paratiroides hiperplásicas fue 98 y 100%, respectivamente, en los 2 grupos. Conclusiones: A la vista de estos resultados, se concluye que el protocolo de dosis baja de 99mTc-MIBI puede ser preferible para la identificación intraoperatoria de las glándulas paratiroideas hiperplásicas en pacientes con hiperparatiroidismo secundario, porque se observó que era tan eficaz como el protocolo de dosis alta de 99mTc-MIBI. Además, el protocolo de dosis baja no tiene las desventajas que se asocian con el protocolo de dosis alta (AU)

Evaluation of the effects of recipient/donor gender on early/late postoperative renal graft functions by renal scintigraphy.

OBJECTIVES: We discuss the effects of recipient/donor gender on renal allograft functions using scintigraphic parameters obtained 3 days after renal transplant and 1 year after transplant. MATERIALS AND METHODS: This retrospective study included 76 renal allograft recipients (group one, 38 males; group two, 38 females). Patients underwent scintigraphic imaging with Tc-99m DTPA on postoperative day 3 and 1 year after transplant. We used the Hilson perfusion index, maximum renal activity/background activity, ratio of renal activity at 20 minutes to renal activity at 3 minutes, time-to-peak activity, and glomerular filtration rate to measure quantitative parameters. RESULTS: On postoperative day 3, the Hilson perfusion index, maximum renal activity/background activity, the ratio of renal activity at 20 minutes to renal activity at 3 minutes, time-to-peak activity, and glomerular filtration rate values for male/female recipients were similar (P = .65, P = .77, P = .38, P = .10, P = .99). The gender of donors was compared with the above-mentioned scintigraphic parameters of the recipients, and no statistically significant differences were found (P = .24, P = .25, P = .44, P = .29, P = .13). At 1-year follow-up, values obtained from group 1 and group 2 recipients were similar. After 1 year, chronic rejection developed in 15.7% of group 1 recipients and in 10.5% of group 2 recipients; acute rejection developed in 21% of group 1 recipients and in 23.6% of group 2 recipients. There were no statistically significant differences between the occurrence of acute rejection and the gender of recipients or donors (P = 1.00, P = .45). CONCLUSIONS: We observed no statistically significant differences between renal graft functions and gender of the recipients/donors during the early/late posttransplant period.

The efficacy of low and high dose (99m)Tc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism.

OBJECTIVE: The aim of this study was to compare the efficacy of low- and high-dose (99m)Tc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands via gamma probe in secondary hyperparathyroidism. MATERIAL AND METHODS: This retrospective study was conducted using a prospective database of 59 patients who had undergone radioguided subtotal parathyroidectomy between 2004-2012. The patients were studied in 2 groups. Group 1 (n=31) received 37 MBq (99m)Tc-MIBI intravenously in the surgical room approximately 10 min before the beginning of the intervention and surgery was performed under gamma probe guidance. Group 2 (n=28) received 555 MBq (99m)Tc- MIBI intravenously 2h before surgery, which was also performed under gamma probe guidance. Intraoperative gamma probe findings, laboratory findings, and histopathological findings were evaluated together. RESULTS: Using acceptance of the histopathological findings as gold standard, sensitivity and specificity of intraoperative gamma probe for identifying hyperplastic parathyroid glands was 98% and 100%, respectively, in both groups. CONCLUSIONS: In the light of these findings, it is concluded that the low-dose (99m)Tc-MIBI protocol might be preferable for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism patients because it was observed to be as effective as the high-dose (99m)Tc-MIBI protocol. Furthermore, the low-dose protocol does not have the disadvantages that are associated with the high-dose protocol.

Diagnostic significance of the hepatic parenchymal retention index as determined by hepatobiliary scintigraphy in liver transplant recipients.

OBJECTIVES: The aim of this study was to evaluate the usefulness of the hepatic parenchymal retention index in the early diagnosis of parenchymal complications in liver transplant recipients as determined by hepatobiliary scintigraphy. MATERIALS AND METHODS: This retrospective study reviewed 100 liver transplant recipients who had undergone orthotopic liver transplant. In all cases, hepatobiliary scintigraphy images recorded 7 to 10 days posttransplant were quantitatively reinterpreted according to hepatic parenchymal retention index. The hepatocyte extraction fraction value was also calculated. Scintigraphic findings as well as clinical, laboratory, and biopsy results were assessed. RESULTS: Quantitative analysis showed normal hepatocyte extraction fraction value in all subjects. However, significant differences in hepatic parenchymal retention index were observed. Thus, subjects were divided into 3 groups: group 1 (n=75), normal; group 2 (n=15), severely elevated; group 3 (n=10), mildly-to-moderately elevated hepatic parenchymal retention index. Evaluation of histopathological, clinical, and laboratory findings showed normal grafts in all group 1 recipients, acute rejection in all group 2 recipients, and hepatocyte damage/intrahepatic cholestasis in all group 3 recipients. CONCLUSIONS: Based on these findings, we determined that hepatocyte extraction fraction value was not useful, whereas hepatic parenchymal retention index was beneficial for early and accurate diagnosis of parenchymal complications in liver transplant recipients.

Comparison of standardized uptake values obtained from two- and three-dimensional modes of fluorine-18 fluorodeoxyglucose PET-CT in oncological cases.

PURPOSE: We investigated the usability of standardized uptake values (SUV) obtained from both two- and three-dimensional (2D and 3D) positron-emission tomography and computed tomography (PET-CT) imaging, and compared the images obtained from these techniques in terms of image quality, lesion detectability, and the presence of artifacts. MATERIALS AND METHODS: Image data from 100 patients, who had undergone two PET imagings obtained in 2D and 3D mode after a low dose CT, were evaluated prospectively. Subjective analysis of 2D and 3D images was performed by two readers evaluating the following criteria: overall image quality, detectability of each identified lesion, and the presence of artifacts. The lesions recognized by the readers were also analyzed quantitatively by measuring SUV values. RESULTS: There was a significant difference between the SUVs obtained in 2D and 3D modes. Regardless if the first scan was performed in 2D or 3D mode, the values obtained from 3D imaging were significantly lower than those obtained from 2D imaging (mean SUV(max) was 10.48±7.57 for 2D, and 9.66±6.93 for 3D, P < 0.001). Visual analysis did not reveal significant differences regarding lesion detectability between two modes. CONCLUSION: In oncological PET-CT applications, SUV values are significantly lower in 3D compared with 2D mode. Thus when serial scanning is needed to evaluate response to therapy in the same patient, the imaging modality should be taken into account and performed with the same method to avoid misinterpretation. Additionally, 3D PET-CT imaging can be used instead of 2D PET-CT due to its shorter scanning time without loss of lesion detectability.

Restaging of colorectal cancer and PET/CT.

Positron Emission Tomography/Computerized Tomography (PET/CT) is an important assessment method in restaging of oncology patients. Its ability to detect the metabolic/functional changes in patients with colorectal cancer during the early stages, in which morphological changes cannot be documented, is significantly superior to other imaging modalities.

Comparison of efficacy of Tc-99m HIG and Tc-99m nanocolloid on sentinel lymph node mapping in patients with breast cancer.

BACKGROUND AND AIM: This study compared the effectiveness of Tc-99m human polyclonal immunoglobulin (HIG) and Tc-99m nanocolloid at detecting sentinel lymph nodes (SLNs) with lymphoscintigraphy and an intraoperative gamma-probe (IGP) in patients with early breast cancer. METHODS: The study group consisted of 50 women; 25 patients each were given Tc-99m HIG or Tc-99m nanocolloid for lymphoscintigraphy. Then, intraoperative SLN localization with IGP was performed. The results of IGP, lymphoscintigraphy, blue dye injected just before surgery, and pathology were compared. RESULTS: In the Tc-99m HIG group, one patient had tumours in both breasts. In two patients, we could not detect SLNs with lymphoscintigraphy, although they were detected with IGP and blue dye. We found SLNs for all tumours with IGP. With the intraoperative blue dye, SLNs were identified for 25 tumours; for one tumour, no SLN was detected with blue dye. In the histopathological examination, 13 tumours showed metastasis in the SLN and in 11 of these 13, there were also metastases in the axilla. One patient had a skip metastasis. In the Tc-99m nanocolloid group, SLNs were identified in 24 patients with lymphoscintigraphy. IGP found SLNs in 24 patients. The blue dye detected SLNs in all patients. On histopathological examination, 10 patients had metastasis in the SLN and there were also metastases in the axilla in all of these patients. CONCLUSION: Tc-99m HIG can be used in SLN detection with preoperative lymphoscintigraphy and IGP in early-stage breast cancer patients.

Tear clearance measurement in patients with dry eye syndrome using quantitative lacrimal scintigraphy.

OBJECTIVE: The aim of this study was to evaluate the tear clearance in patients with dry eye syndrome using quantitative lacrimal scintigraphy. MATERIALS AND METHODS: We investigated 21 patients (42 eyes; 18 women, 3 men; mean age, 63.19 +/- 13.33 years) with dry eye syndrome. Additionally, for the sake of comparison, 12 normal subjects of the same age group (24 eyes; 10 women, 2 men; mean age, 68.25 +/- 2.63 years) were included. Lacrimal scintigraphy, Schirmer-1 test, BUT, and rose bengal ocular surface vital staining were performed in these cases. RESULTS: According to the results of lacrimal scintigraphy, the mean value of T 1/2 was 4.16 +/- 1.22 minutes and the mean value of RI was 14.15% +/- 2.30% in normal subjects. However, in patients with dry eye syndrome, these values were 20.59 +/- 1.97 minutes and 55.64% +/- 6.90%, respectively. Consistent with the results of ophthalmologic tests, the mean Schirmer-1 value was 12.46 +/- 2.10 mm, the mean value of BUT was 14.36 +/- 3.40 seconds, and the mean staining value of the rose bengal was 1.98 +/- 0.80 in normal subjects, whereas these values were 1.36 +/- 0.49 mm, 5.46 +/- 1.33 seconds, 6.62 +/- 0.86, respectively, in patients with dry eye syndrome. When we compared the results of lacrimal scintigraphy and the results of ophthalmologic tests, an inverse correlation was noted between both the T1/2 and RI values and both the Schirmer-1 and BUT values in all subjects (p < 0.001). However, there was a greater positive correlation between the rose bengal ocular surface staining value and both the T1/2 and RI values in all cases (p < 0.001). CONCLUSION: In the current study, it was concluded that although the lacrimal drainage system was normal, tear clearance was significantly delayed in dry eye patients. With this study, we have shown that quantitative lacrimal scintigraphy, which is an objective, practical, and noninvasive method, appears to be useful for the assessment of the tear clearance in patients with dry eye syndrome.

The efficacy of 99mTc-HIG for sentinel lymph node mapping in breast cancer patients.

OBJECTIVE: To evaluate the efficacy of Tc-HIG on SLN identification in patients with early-stage breast cancer. MATERIALS AND METHODS: Seventeen women (18 tumours) with early-stage breast cancer were included. On the day of the operation, 111 MBq Tc-HIG was injected around the tumour or biopsy scar in all patients. Subsequently, dynamic lymphoscintigraphic images were taken for 30 min. After this, static images were recorded at 15-20 min intervals until the SLN was visualized. Patients were taken to the operating room 2-4 h after radiopharmaceutical injection. Before the incision, 5 ml of isosulfan blue dye solution was injected peritumourally in all subjects. Aided by blue dye and gamma probe SLN detection was done during the operation. RESULTS: In 17/18 tumours, SLN was detected with Tc-HIG lymphoscintigraphy. The mean visualization time for axillary SLNs was 49.94+/-11.25 min and for internal mammary SLNs was 52.50+/-10.60 min. In 15 of the tumours, only one SLN was detected in the axillary region. However, in two tumours, SLNs were found in both axillary and internal mammary regions. With blue dye mapping, axillary SLNs were found in 17/18 tumours. With the application of intraoperative gamma probe, all axillary and internal mammary SLNs were detected in 18 tumours. CONCLUSION: We conclude that Tc-HIG may be a suitable agent for SLN detection by lymphoscintigraphy and intraoperative gamma probe application in early-stage breast cancer patients.

Utility of Tc-99m human polyclonal immunoglobulin G scintigraphy for assessing the efficacy of yttrium-90 silicate therapy in rheumatoid knee synovitis.

PURPOSE: The aim of this study was to determine the utility of Tc-99m human polyclonal immunoglobulin G (HIG) scintigraphy for evaluating the efficacy of yttrium-90 (Y-90) silicate therapy in rheumatoid knee synovitis. MATERIALS AND METHODS: Fifteen patients (13 women, 2 men; mean age, 53.5 +/- 8.4 years) with rheumatoid arthritis had radionuclide synovectomy using 185 MBq (5 mCi) Y-90 silicate to evaluate 24 knee joints with chronic persistent synovitis. Radiologic and clinical evaluations and Tc-99m HIG scans were performed in each patient before radionuclide synovectomy. Each patient was reassessed 3, 6, 9, and 12 months after therapy using clinical examination and Tc-99m HIG scintigraphy. RESULTS: In 14 of 24 knee joints (4 Larsen stage I, 10 Larsen stage II) that had excellent or good clinical responses to Y-90 silicate therapy, the Tc-99m HIG index values 3 months after treatment were significantly lower than the pretreatment index values (P < 0.001). In 13 of these 14 joints, these low index values and clinical results remained constant throughout the 1 year of follow-up. One patient (1 of the 14 knee joints) experienced severe pain and swelling as a result of recurrent arthritis at 9 months, and the Tc-99m HIG index value increased at 9 months and remained high 12 months after therapy. In 10 of 24 knee joints (4 Larsen stage II, 6 Larsen stage III) that had a fair or poor clinical response, Tc-99m HIG index values were statistically similar before and after radionuclide therapy. CONCLUSIONS: Quantitative Tc-99m HIG scintigraphy is a valuable method for assessing the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.