Investigations on the donor limb after harvest of lymphatic vessels for lymphedema surgery.

OBJECTIVE: Microsurgical lymphatic vessel transplantation is one of the well-established therapies for lymphedema. Lymphatic vessels are harvested from a healthy thigh and transplanted into lymphedematous limbs to create a lymphatic bypass. Its benefit on lymphatic drainage has already been proven. However, to the best of our knowledge, the effect on the lymphatic function of the donor site has not yet been studied. Our aim was to evaluate the long-term postoperative lymphatic function in the donor site by clinical and scintigraphic examinations and a patient questionnaire. METHODS: A consecutive series of 25 women (mean age, 57.2 years) who had undergone follow-up after lymph vessel transplantation to treat secondary lymphedema of the arm comprised the study group. Lymphatic vessel function of the donor site was evaluated by circumferential measurements of the limb and, in nine cases, by lymphatic scintigraphy. Additionally, a questionnaire was used to assess the patients' pre- and postoperative complaints for the donor limb and quality of life. Separately, the medical records of 100 patients who had undergone lymphatic harvest and been followed up were reviewed for documented signs of lymphatic function of the donor limb. RESULTS: The lymphatic grafts were harvested from the thigh (left, n = 9; right, n = 16) and transplanted to bridge the region of lymphatic obstruction in the axilla. The mean follow-up period was 4.5 years after surgery. None of the patients had shown significant changes in the circumference of the donor limb or pathologic findings via lymphatic scintigraphy. None of the patients had reported any impairment in the donor leg or showed symptoms of postoperative lymphedema or erysipelas. CONCLUSIONS: Our results have shown that harvesting lymphatic vessels from the thigh for lymphatic vessel transplantation is possible without significant donor site morbidity.

Impact of MRI-based Segmentation Artifacts on Amyloid- and FDG-PET Quantitation.

INTRODUCTION: Magnet resonance image (MRI)-based segmentations are widely used for clinical brain research, especially in conjunction with positron-emission-tomography (PET). Although artifacts due to segmentation errors arise commonly, the impact of these artifacts on PET quantitation has not yet been investigated systematically. Therefore, the aim of this study was to assess the effect of segmentation errors on [(18)F]-AV45 and [(18)F]-FDG PET quantitation, with and without correction for partial volume effects (PVE). MATERIAL AND METHODS: 119 subjects with both [(18)F]-AV45, and [(18)F]-FDG PET as well as T1-weighted MRI at baseline and at two-year follow-up were selected from the ADNI cohort, and their MRI brain images were segmented using PMOD 3.5. MRIs with segmentation artifacts were masked with the corresponding [(18)F]-FDG PET standard-uptake-value (SUV) images to elucidate and quantify the impact of artifacts on PET analyses for six defined volumes-of-interest (VOI). Artifact volumes were calculated for each VOI, together with error-[%] and root-mean-square-errors (RMSE) in uncorrected and PVE corrected SUV results for the two PET tracers. We also assessed the bias in longitudinal PET data. RESULTS: Artifacts occurred most frequently in the parietal cortex VOI. For [(18)F]-AV45 and [(18)F]-FDG PET, the percentage-errors were dependent on artifact volumes. PVEC SUVs were consequently more distorted than were their uncorrected counterparts. In static and longitudinal assessment, a small subgroup of subjects with large artifacts (≥1500 voxels; ≙5.06 cm³) accounted for much of the PET quantitation bias. CONCLUSION: Large segmentation artifacts need to be detected and resolved as they considerably bias PET quantitation, especially when PVEC is applied to PET data.

Primary lymphedema of the lower limb: the clinical utility of single photon emission computed tomography/CT.

OBJECTIVE: The aim of this prospective study was to determine whether the additional use of the single photon emission computed tomography/CT (SPECT/CT) technique improves the diagnostic value of planar lymphoscintigraphy in patients presenting with primary lymph edema of the lower limb. MATERIALS AND METHODS: For a defined period of three years (April 2011-April 2014) a total of 34 consecutive patients (28 females; age range, 27-83 years) presenting with swelling of the leg(s) suspicious of (uni- or bilateral, proximal or distal) primary lymphedema were prospectively examined by planar lymphoscintigraphy (lower limbs, n = 67) and the tomographic SPECT/CT technique (anatomical sides, n = 65). RESULTS: In comparison to pathological planar scintigraphic findings, the addition of SPECT/CT provided relevant additional information regarding the presence of dermal backflow (86%), the anatomical extent of lymphatic disorders (64%), the presence or absence of lymph nodes (46%), and the visualization of lymph vessels (4%). CONCLUSION: As an adjunct to planar lymphoscintigraphy, SPECT/CT specifies the anatomical correlation of lymphatic disorders and thus improves assessment of the extent of pathology due to the particular advantages of tomographic separation of overlapping sources. The interpretation of scintigraphic data benefits not only in baseline diagnosis, but also in physiotherapeutical and microsurgical treatments of primary lymphedema.

Lymphedema of the upper limb: evaluation of the functional outcome by dynamic imaging of lymph kinetics after autologous lymph vessel transplantation.

PURPOSE: The aim of this study was to evaluate by lymphoscintigraphy the functional outcome after autologous lymph vessel transplantation (Tx) of the upper limb. METHODS: One hundred seventy-seven patients (172 female, 5 male; median age, 56 years; range, 12-84 years) presenting with Tx situs in an upper limb were included. For correlation of scintigraphic data versus reduction of volume (RV) surplus measurements, we examined at 4 different time points as follows: preoperatively (T0), within 2 weeks after Tx (T1), 6 to 12 months after Tx (T2), and 32 to 38 months after Tx (T3). An additional long-term follow-up after at least 8 years (T4) was available in some cases. RESULTS: The maximum individual postoperative observation period was 19 years. In 169 of 177 cases, lymphedema had been caused by treatment of breast cancer (mastectomy, n = 103/169; breast preserving, n = 66/169) and/or radiation therapy (n = 130/177), but 2 patients presented with primary lymphedema. The remaining 6 cases of lymphatic disorders were caused by treatment of malignant melanoma, Hodgkin lymphoma, axillary Ewing sarcoma, non-Hodgkin lymphoma, hemangioma, or abscess removal.At T1, the mean RV of the affected limb was 73%, and the mean improvement of transport index (TI) was 28%. At T2, the RV was 64% and the TI was 23%, and at T3, the RV was 63% and the TI was 25%. Long-term follow-up after at least 8 years (T4: range, 9-19.2; mean, 14.1 years) was available in 19 of 177 patients, in whom persistent improvement in the scintigraphic data (25% decrease in TI) was confirmed by a mean clinical RV of 68%. The mean overall correlation was by a factor of 2.64. CONCLUSIONS: Our findings in this large set of patients undergoing autologous lymph vessel Tx to an upper limb confirm that this microsurgical technique significantly and persistently improves lymph drainage in patients with lymphedema. The findings of lymphoscintigraphy correlated well with volume measurements at long-term follow-up.

MR lymphangiography at 3.0 T: correlation with lymphoscintigraphy.

PURPOSE: To prospectively compare findings of magnetic resonance (MR) lymphangiography with those of lymphoscintigraphy, evaluate the pattern and delay of lymphatic drainage, compare typical findings, and investigate discrepancies between the techniques. MATERIALS AND METHODS: This prospective study was performed according to the Declaration of Helsinki and was approved by the local ethics committee. Thirty consecutive patients with uni- or bilateral lymphedema and lymph vessel transplants of the lower extremities were examined with 3.0-T fat-saturated three-dimensional gradient-echo MR after gadopentetate dimeglumine injection. Results of all examinations were correlated with corresponding results of lymphoscintigraphy examinations. Results of both techniques were separately reviewed in consensus by a radiologist and a nuclear physician, who rated delay and pattern of drainage, number of enhancing levels, and quality of conspicuity of the depiction of lymph nodes and lymph vessels. Sensitivity and specificity were calculated by using combined results of both techniques and clinical presentation findings as reference standard. Correlation was calculated with weighted k coefficients. RESULTS: Weak lymphatic drainage at lymphoscintigraphy correlated with lymphangiectasia at MR lymphangiography (13 of 33 affected extremities). Lymph vessels were clearly visualized with MR lymphangiography (five of 24 affected extremities), while they were not detectable with lymphoscintigraphy. Depiction of inguinal lymph nodes was clearer with lymphoscintigraphy (five of 60 extremities). Correlation of both techniques was excellent for delay (κ=0.93) and pattern (κ=0.84) of drainage, good for depiction of lymph nodes (κ=0.67) and number of enhancing levels (κ=0.77), and moderate for depiction of lymph vessels (κ=0.50). Sensitivity and specificity for delay and pattern of drainage were concordant, whereas MR lymphangiography showed a higher sensitivity for lymph vessel abnormalities (100% vs 79%) and lower specificity for lymph node abnormalities (78% vs 100%). CONCLUSION: Imaging findings of MR lymphangiography and lymphoscintigraphy show a clear concordance. With lymphoscintigraphy, better visualization of inguinal lymph nodes was achieved, whereas with MR lymphangiography, better depiction of lymph vessels and morphologic features of lymph vessel abnormalities were achieved.

PET/CT in malignant melanoma: contrast-enhanced CT versus plain low-dose CT.

PURPOSE: The aim of this study was to evaluate the diagnostic value of contrast-enhanced CT (CECT) versus non-enhanced low-dose CT (NECT) in the staging of advanced malignant melanoma with (18)F-fluordeoxyglucose (FDG) positron emission tomography (PET)/CT. METHODS: In total, 50 (18)F-FDG PET/CT examinations were performed in 50 patients with metastasized melanoma. For attenuation correction, whole-body NECT was performed followed by diagnostic CECT with contrast agent. For the whole-body PET, (18)F-FDG was applied. Criteria for evaluation were signs of vital tumour tissue (extent of lesions, contrast enhancement, maximum standardized uptake value >2.5). Findings suspicious for melanoma were considered lesions. NECT, CECT and (18)F-FDG PET were evaluated separately, followed by combined analysis of PET/NECT and PET/CECT. Findings were verified histologically and/or by follow-up (>6 months). RESULTS: Overall, 232 lesions were analysed, and 151 proved to be metastases. The sensitivity of NECT, CECT, PET, PET/NECT and PET/CECT was 62, 85, 90, 97 and 100%, and specificity was 52, 63, 88, 93 and 93%, respectively. Compared to CECT, NECT obtained additional false-negative results: lymph node (n = 19) and liver/spleen metastases (n = 9). Misinterpreted physiological structures mainly caused additional false-positive findings (n = 17). In combined analysis of PET/NECT, six false-positive [other tumours (n = 2), inflammatory lymph nodes (n = 2), inflammatory lung lesion (n = 1), blood vessel (n = 1)] and five false-negative findings [liver (n = 3), spleen (n = 1), lymph node metastases (n = 1)] remained. On PET/CECT, six false-positive [inflammatory lymph nodes (n = 3), other tumours (n = 2), inflammatory lung lesion (n = 1)] and no false-negative findings occurred. However, additional false findings on PET/NECT (6 of 232) did not change staging compared to PET/CECT. CONCLUSION: Our results indicate that it is justified to perform PET/NECT instead of PET/CECT for melanoma staging.

Tc-99m sestamibi single photon emission computed tomography for guiding percutaneous coronary intervention in patients with multivessel disease: a comparison with quantitative coronary angiography and fractional flow reserve.

To evaluate the accuracy of myocardial perfusion SPECT (MPI) in the detection and allocation of vessel specific perfusion defects (PD) using standard distribution territories in a routine clinical procedure of patients with multivessel disease (MVD). Combined quantitative coronary angiography and fractional flow reserve (QCA/FFR) measurements were used as invasive reference standard. 216 vessels in 72 MVD patients (67 +/- 10 years, 28 female) were investigated using MPI and QCA. FFR of 93 vessels with intermediate stenoses was determined. MPI detected significant stenoses according to QCA/FFR findings with a sensitivity of 85%. However, vessel-based evaluation using standard myocardial distribution territories delivered a sensitivity of only 62% (28 MPI+ out of 45 (QCA/FFR)+ findings), with specificity, PPV and NPV of 90, 62 and 90%. 7/17 false positive and 7/17 false negative findings (41%) could be attributed to incorrect allocation of reversible PD to their respective coronary arteries. 6/17 (35%) perfusion territories were classified as false negative when additional fixed PD were present. MPI had reasonable sensitivity for the detection of significant coronary artery disease in patients with multivessel disease. However, sensitivity decreased markedly, when the significance of each individual stenosis was evaluated using standard myocardial supplying territories. In this setting, 41% of false negative and false positive MPI findings resulted from incorrect allocation of reversible perfusion defects to their determining supplying vessel.

[Intraoperative labeling of sentinel lymph nodes with a combination of vital dye and radionuclide tracer--results in sentinel lymph node-positive patients]. / Intraoperative Markierung von Sentinel-Lymphknoten bei kombinierter Anwendung von Vitalfärbung und Radiotracer--Ergebnisse bei Sentinel-Lymphknoten-positiven Patienten.

BACKGROUND: Sentinel lymph node biopsy enhances the accuracy of tumor staging in patients with malignant melanoma and can help select candidates for regional lymphadenectomy. There are two techniques for identifying the sentinel lymph node: intradermal injection of a radionuclide tracer or of a blue dye. We evaluated both methods to determine how they can be best utilized to locate a sentinel lymph node. PATIENTS AND METHODS: In a retrospective study, 323 patients with melanoma (tumor thickness > or = 0.75 mm) who underwent sentinel lymph node biopsy after both radionuclide and blue dye injection were evaluated. The labeling of lymph nodes showing micrometastasis by histopathological examination was determined. RESULTS: 63 patients showed sentinel lymph nodes with micrometastasis. All of these nodes (100 %) were labeled with radionuclide tracer, but only 90 % with blue dye. In 5 patients, only radionuclide labeling identified the histopathologically-positive lymph node. In 36 patients, several sentinel lymph nodes were identified, with the histopathologically-positive nodes usually showing a higher radioactive signal intensity than the negative ones. CONCLUSION: Since in some patients histopathologically-positive lymph nodes are only labeled by radionuclide tracer, radionuclide labeling is indispensable for locating sentinel lymph nodes. In contrast, labeling with blue dye represents a supplementary method, which can simplify the recognition of the sentinel lymph node during surgery.

Sentinel node mapping in patients with malignant melanoma using melanoma Tc-99m colloidal rhenium sulfide.

PURPOSE: The aim of the study was to localize the sentinel lymph node using lymphoscintigraphy aided by Tc-99m colloidal rhenium sulfide. MATERIALS AND METHODS: Thirty consecutive patients with histologically proved melanoma, but no clinical evidence of metastases, were examined before operation by injecting 20 to 40 MBq (0.5 to 1.1 mCi) Tc-99m colloidal rhenium sulfide with a mean particle size of 100 nm (range, 50 to 200 nm) intradermally around the lesion. Lymphoscintigraphy was performed immediately after injection. In addition, blue dye was injected before operation. A hand-held gamma probe guided the sentinel node biopsy. RESULTS: Lymphoscintigraphy revealed hot spots in all patients. During surgery, the sentinel node was identified in all 30 patients. The number of sentinel nodes per patient ranged from 1 to 4 (mean, 1.9). Histologic examination confirmed the metastatic involvement of the sentinel lymph node in 11 of 30 patients. The sentinel lymph node-positive rate was 22.4%, which was comparable to findings using Tc-99m-labeled nanocolloids. CONCLUSION: The findings indicate that Tc-99m-bound colloidal rhenium sulfide is suitable for sentinel node mapping.

Dynamic lymph flow imaging in patients with oedema of the lower limb for evaluation of the functional outcome after autologous lymph vessel transplantation: an 8-year follow-up study.

The purpose of this study was to monitor the functional outcome of microsurgical intervention on lymph drainage by means of non-invasive, readily available lymphoscintigraphy. Eight patients with primary or secondary lymphoedema of the lower limb were investigated before and for 8 years after autologous lymph vessel transplantation. For scintigraphy, technetium-99m labelled nanocolloid was subcutaneously injected into the first interdigital space of the affected limb. Sequential images were acquired up to 6 h p.i.; for semiquantitative evaluation a numerical transport index was established by assigning scores of up to 9 on each of five criteria: lymphatic transport kinetics, distribution pattern of the radiopharmaceutical, time to appearance of lymph nodes, visualisation of lymph nodes and visualisation of lymph vessels/grafts. Ti values <10 were considered normal. In all eight patients, lymphatic function significantly (P

Post-therapeutic lymphedema: scintigraphy before and after autologous lymph vessel transplantation: 8 years of long-term follow-up.

The function of lymphatic vessel grafts was proved in 12 patients with lymphedema of the upper extremity by visual and semiquantitative evaluation of a preoperative baseline study and scintigraphic follow-up data for a period of 8 years after microsurgical treatment. The transplantation site was an upper extremity. In 11 of 12 patients, lymphatic function improved after autologous lymphatic vessel transplantation compared with preoperative findings. This could be verified by a statistically significant decrease of the transport index ( < 0.01), clear demonstration of lymph nodes, and a less diffuse distribution pattern of the Tc-99m-labeled nanocolloids. In three patients, the vessel graft could be detected by scintigraphy. Lymphoscintigraphy combined with semiquantitative evaluation of lymphatic transport kinetics has been shown to be an easy and reliable method to assess lymphatic function before and after autologous lymph vessel transplantation.

[Can supplemental imaging with SPECT technique improve the diagnostic value of preoperative Tc-99m-MIBI scintigraphy in primary hyperparathyroidism?]. / Kann durch den zusätzlichen Einsatz der SPECT-Technik die diagnostische Aussage der präoperativen Tc-99m-MIBI-Szintigraphie beim primären Hyperparathyreoidismus verbessert werden?

BACKGROUND: The focus of this retrospective study was to evaluate if the additional use of SPECT improves the diagnostic value of the preoperative Tc-99m-sestamibi scintigraphy combined with sonography in patients presenting with primary hyperparathyroidism. PATIENTS AND METHODS: 62 patients (43 female, 19 male) were examined by visual analysis of planar Tc-99m-sestamibi scintigraphy, SPECT and ultrasound. 14/62 were suffering from superimposed thyroid disease, 22/62 patients underwent previous neck surgery. 12/62 presented with recurrent hyperthyroidism, in 8/62 cases dystopic parathyroid tissue had been localized. For statistic evaluation these imaging modalities were correlated with the histopathological examinations of the surgical specimens for single use as well as combined use for all patients (group 1) and for the subgroups "histologically confirmed adenoma" (group 2), hyperplastic disease (group 3) "recurrency and/or dystopic parathyroid tissue" (group 4) and "patients presenting with thyroid nodules and/or previous neck surgery" (group 5), respectively. RESULTS: For single use planar scintigraphy showed the highest sensitivity (72%) followed by SPECT (67%) and ultrasound (58%). The combination of planar imaging with ultrasound achieved 83% whereas the combined use of all three modalities increased the sensitivity up to a maximum of 85%. The combined use of the imaging modalities leads to the following results: The histologically proven parathyroid adenomas (group 2) could be detected by planar scintigraphy and sonography with a sensitivity of 87%, for group 3 the combined use of all three modalities reached 69% sensitivity. Group 4 achieved the highest sensitivity (69%) by means of planar scintigraphy and SPECT, whereas group 5 reached 82% by means of planar scintigraphy and ultrasound. CONCLUSION: Planar Tc-99m-sestamibi scintigraphy combined with ultrasound is superior regarding to sensitivity and to the costs for the noninvasive preoperative detection in patients presenting with primary hyperparathyroidism. Due to economic reasons the additional use of SPECT might be limited to patients presenting with recurrent hyperparathyroidism or atypically located parathyroid tissue.

Cardiac sympathetic dysinnervation in Type 2 diabetes mellitus with and without ECG-based cardiac autonomic neuropathy.

To evaluate the presence and extent of global and regional distributions of cardiac sympathetic dysinnervation in Type 2 diabetes mellitus I-123-metaiodobenzylguanidine (I-123-MIBG) scintigraphy was applied to 15 Type 2 (noninsulin-dependent) diabetic patients with ECG-based cardiac autonomic neuropathy (> or = two of five age-related cardiac reflex tests abnormal) and 15 clinically comparable Type 2 diabetic patients without ECG-based cardiac autonomic neuropathy. Myocardial perfusion abnormalities were excluded by 99 m-Tc-methoxyisobutylisonitrile (99 m-MIBI) scintigraphy. Both in Type 2 diabetic patients with and without, ECG-based autonomic neuropathy, only one patient (7%) was found to have a normal homogeneous uptake of I-123-MIBG compared to 14 patients (93%) with a reduced I-123-MIBG uptake. The uptake of I-123-MIBG in the posterior myocardium of diabetic patients was smaller than in the anterior, lateral, and septal myocardium (P< .001, P< .001, P< .001, respectively). Diabetic patients with ECG-based cardiac autonomic neuropathy demonstrated a more pronounced reduction of the posterior I-123-MIBG myocardial uptake than diabetic patients without (P< .01). The mean global and the anterior, lateral, septal, and apical myocardial I-123-MIBG uptake was comparable between the two groups. The uptake of the posterior myocardial region correlated with all indices of heart rate variation at rest and during deep breathing. A correlation between global or regional myocardial I-123-MIBG uptake and QT interval was not observed. The study demonstrates that cardiac sympathetic dysinnervation is common in Type 2 diabetes mellitus both with and without ECG-based cardiac autonomic neuropathy. In Type 2 diabetes mellitus, the posterior myocardium is predominantly affected and the extent of dysinnervation is more pronounced in the presence of ECG-based cardiac autonomic neuropathy.