Temporary Reactive Response of Axillary Lymph Nodes to COVID-19 Vaccination on 18F-rhPSMA-7.3 PET/CT in Patients with Prostate Cancer.

Vaccine-associated lymphadenopathy (VAL) is a common finding on 18F-FDG PET/CT examinations after coronavirus disease 2019 (COVID-19) vaccination. However, data regarding VAL on 18F-rhPSMA-7.3-ligand PET are currently lacking. This study assesses the prevalence, temporal response to vaccination, and characteristics of VAL. Methods: Two hundred thirty-three consecutive vaccinated and 41 unvaccinated patients with confirmed prostate cancer who underwent 18F-rhPSMA-7.3 PET/CT were retrospectively analyzed. Size and uptake of the axillary lymph nodes were measured. Ratios of SUVmax of ipsilateral to contralateral axillary lymph node (SUVratio) were determined. The characteristics of SUVratio in respect to the duration of PSMA avidity in the axillary lymph node after COVID-19 vaccination was analyzed. Results: The prevalence of VAL on 18F-rhPSMA-7.3 PET was 45%. Up to a period of 8 wk after the last COVID-19 vaccination, SUVratio was positive (2.05 ± 0.17). Thereafter, SUVratio dropped significantly (1.35 ± 0.09) and approached the value of unvaccinated group (1.1 ± 0.2). SUVratio of metastatic axillary lymph nodes was very high (>11) and can be easily detected visually or semiquantitatively. In 3 patients, we observed suspected development and consecutively confirmed involving metastasis of axillary lymph node with SUVratio between 4.0 to 6.6. Correlation between SUVratio and lymph node size (r = 0.93, P < 0.0001) and lymph node size and duration after vaccine (r = -0.88, P < 0.0008) was found. Conclusion: Increased uptake of the PSMA ligand 18F-rhPSMA-7.3 by axillary lymph nodes is common after COVID-19 vaccination and can persist for 8 wk. This finding should be considered in the interpretation of 18F-rhPSMA-7.3 PET/CT examinations.

Retooling a Blood-Based Biomarker: Phase I Assessment of the High-Affinity CA19-9 Antibody HuMab-5B1 for Immuno-PET Imaging of Pancreatic Cancer.

PURPOSE: In patients with cancer who have an abnormal biomarker finding, the source of the biomarker in the bloodstream must be located for confirmation of diagnosis, staging, and therapy planning. We evaluated if immuno-PET with the radiolabeled high-affinity antibody HuMab-5B1 (MVT-2163), binding to the cancer antigen CA19-9, can identify the source of elevated biomarkers in patients with pancreatic cancer. PATIENTS AND METHODS: In this phase I dose-escalating study, 12 patients with CA19-9-positive metastatic malignancies were injected with MVT-2163. Within 7 days, all patients underwent a total of four whole-body PET/CT scans. A diagnostic CT scan was performed prior to injection of MVT-2163 to correlate findings on MVT-2163 PET/CT. RESULTS: Immuno-PET with MVT-2163 was safe and visualized known primary tumors and metastases with high contrast. In addition, radiotracer uptake was not only observed in metastases known from conventional CT, but also seen in subcentimeter lymph nodes located in typical metastatic sites of pancreatic cancer, which were not abnormal on routine clinical imaging studies. A significant fraction of the patients demonstrated very high and, over time, increased uptake of MVT-2163 in tumor tissue, suggesting that HuMab-5B1 labeled with beta-emitting radioisotopes may have the potential to deliver therapeutic doses of radiation to cancer cells. CONCLUSIONS: Our study shows that the tumor antigen CA19-9 secreted to the circulation can be used for sensitive detection of primary tumors and metastatic disease by immuno-PET. This significantly broadens the number of molecular targets that can be used for PET imaging and offers new opportunities for noninvasive characterization of tumors in patients.

Phase I Trial of Well-Differentiated Neuroendocrine Tumors (NETs) with Radiolabeled Somatostatin Antagonist 177Lu-Satoreotide Tetraxetan.

PURPOSE: Radiolabeled somatostatin receptor 2 (SSTR2) antagonists have shown higher tumor uptake and tumor-to-organ ratios than somatostatin agonists in preclinical models of neuroendocrine tumors (NETs). We performed a phase I study to evaluate the safety and efficacy of SSTR2 antagonist 177Lu-satoreotide tetraxetan. PATIENTS AND METHODS: Twenty patients with advanced SSTR2-positive NETs were treated with 177Lu-satoreotide tetraxetan. Patients first underwent a dosimetry study with 177Lu-satoreotide tetraxetan to determine the therapeutic activity that could be safely administered. This activity was split into two equal cycles to be delivered 3 months apart. The maximum activity was 7.4 GBq per cycle. RESULTS: Of 20 patients with NETs (one lung, seven small bowel, nine pancreatic, one gastric, one rectal, one kidney; mean prior treatments: three), six received one cycle of 177Lu- satoreotide tetraxetan and 14 received two cycles. Hematologic toxicity after cycle 1 was mild-moderate and reversed before cycle 2. However, grade 4 hematologic toxicity occurred in four of seven (57%) patients after cycle 2 of 177Lu-satoreotide tetraxetan. The study was suspended, and the protocol modified to limit the cumulative absorbed bone marrow dose to 1 Gy and to reduce prescribed activity for cycle 2 by 50%. The best overall response rate was 45% [5% complete response (1/20), 40% partial response (8/20)]; with 40% stable disease (8/20) and 15% progression of disease (3/20). Median progression-free survival (PFS) was 21.0 months (95% CI, 13.6-NR). CONCLUSIONS: In this trial of heavily treated NETs, preliminary data are promising for the use of 177Lu-satoreotide tetraxetan. Additional studies are ongoing to determine optimal therapeutic dose/schedule.

Cerenkov Luminescence Imaging for Radiation Dose Calculation of a 9°Y-Labeled Gastrin-Releasing Peptide Receptor Antagonist.

UNLABELLED: (90)Y has been used to label various new therapeutic radiopharmaceuticals. However, measuring the radiation dose delivered by (90)Y is challenging because of the absence of suitable γ emissions and its low abundance of positron emissions. For the treatment of prostate cancer, radiolabeled gastrin-releasing peptide receptor (GRPr) antagonists have yielded promising results in mouse models. In this study, we evaluated whether Cerenkov luminescence imaging (CLI) could be used to determine radiation doses of a (90)Y-labeled GRPr antagonist in nude mice. METHODS: Mice bearing subcutaneous prostate cancer xenografts were injected with 0.74-18.5 MBq of the (90)Y-labeled GRPr antagonist DOTA-AR and underwent in vivo and ex vivo CLI at 1-48 h after injection. After imaging, animals were sacrificed, their tumors and organs were harvested, and the activity concentration was measured by liquid scintillation counting. In a second set of experiments, Cerenkov photon counts for tumor and kidney on in vivo CLI were converted to activity concentrations using conversion factors determined from the first set of experiments. RESULTS: (90)Y-DOTA-AR concentration in the 3 tumor models ranged from 0.5% to 4.8% of the injected activity per gram at 1 h after injection and decreased to 0.05%-0.15 injected activity per gram by 48 h after injection. A positive correlation was found between tumor activity concentrations and in vivo CLI signal (r(2) = 0.94). A similar correlation was found for the renal activity concentration and in vivo Cerenkov luminescence (r(2) = 0.98). Other organs were not distinctly visualized on the in vivo images, but ex vivo CLI was also correlated with the radioactivity concentration (r(2) = 0.35-0.94). Using the time-activity curves from the second experiment, we calculated radiation doses to tumor and kidney of 0.33 ± 0.12 (range, 0.21-0.66) and 0.06 ± 0.01 (range, 0.05-0.08) Gy/MBq, respectively. CONCLUSION: CLI is a promising, low-cost modality to measure individual radiation doses of (90)Y-labeled compounds noninvasively. The use of Cerenkov imaging is expected to facilitate the development and comparison of (90)Y-labeled compounds for targeted radiotherapy.

Inadvertent intra-arterial injection of (123)I-MIBG in a patient with metastatic pheochromocytoma.

We present an interesting image of the inadvertent arterial injection of I-MIBG (metaiodobenzylguanidine) in a 36-year-old man with hereditary, metastatic pheochromocytoma, who underwent a diagnostic whole-body scan for the evaluation of extent of disease before possible I-MIBG therapy. During the tracer injection in the left antecubital area, the patient experienced tingling and skin redness in the left forearm and hand.

Hybrid imaging of peripheral skeletal disease by SPECT/high-resolution flat-panel CT.

UNLABELLED: The aim of this study was to determine the impact of high-resolution cone-beam CT with flat-panel detectors on the interpretation of bone SPECT in diseases of the peripheral skeleton. METHODS: Forty-one consecutive patients with peripheral skeletal disease were examined with a SPECT/high-resolution CT system providing isotropic voxels of 0.33 × 0.33 × 0.33 mm. High-resolution images were retrospectively analyzed by 2 readers and compared with low-resolution images obtained by filtering the high-resolution images to a lower resolution. RESULTS: SPECT/high-resolution CT demonstrated higher diagnostic confidence scores (1.98 ± 0.27 vs. 1.3 ± 0.45, P < 0.01) and better interobserver agreement (κ = 0.5 vs. 0.2) than SPECT/low-resolution CT. The diagnosis made by SPECT/high-resolution CT was in agreement with the final clinical diagnosis in 95% (reader 1) and 90% (reader 2) of the cases, as compared with 59% (reader 1) and 60% (reader 2) of the cases for SPECT/low-resolution CT (P < 0.01). CONCLUSION: High-resolution flat-panel CT has the potential to significantly improve SPECT/CT imaging in diseases of the peripheral skeleton.

Early recurrence of pancreatic cancer after resection and during adjuvant chemotherapy.

BACKGROUND/AIM: Adjuvant chemotherapy for 6 months is the current standard of care after potentially curative resection of pancreatic cancer and yields an overall survival of 15-20 months. Early tumor recurrence before or during adjuvant chemotherapy has not been evaluated so far. These patients may not benefit from adjuvant treatment. PATIENTS AND METHODS: Thirty-five patients with resection of ductal pancreatic carcinoma and adjuvant chemotherapy with gemcitabine were analyzed between 2005 and 2007. All patients had a computed tomography (CT) scan before and during adjuvant chemotherapy after 2-3 months, 12/35 patients had a histologically confirmed R1 resection. Recurrence of pancreatic cancer was determined by CT scan and the clinical course. RESULTS: Median survival of 35 patients with resected pancreatic cancer was 19.7 months, and the 2-year survival was 44%. Thirteen (37%) of the 35 patients analyzed with a CT scan showed tumor recurrence during adjuvant chemotherapy. Overall survival of patients with tumor recurrence was 9.3 months with a 2-year survival rate of 13%, whereas median overall survival of patients without early relapse was 26.3 months (P<0.001). Local recurrence of pancreatic cancer occurred in 38% (5/13); 46% (6/13) of patients developed distant metastasis, and 38% (5/13) developed lymph node metastasis. Early tumor recurrence during or adjuvant chemotherapy did not correlate with R status (R1 vs R0, P=0.69), whereas histologically confirmed lymph node invasion (pN0 vs pN1) and grading showed a statistically significant correlation with early relapse (P<0.05). CONCLUSION: A significant fraction of patients with resected pancreatic cancer have early relapse during adjuvant chemotherapy, especially those with lymph node metastasis. Radiologic examinations prior to and during adjuvant chemotherapy will help to identify patients with tumor recurrence who are unlikely to benefit from adjuvant treatment and will need individualized palliative chemotherapy.

Immunohistological localization of BMP-2, BMP-7, and their receptors in knee joints with focal cartilage lesions.

INTRODUCTION: Although it is well known that BMP-2 and BMP-7 play significant roles in cartilage metabolism, data about intra-articular expression and localization of these proteins and their receptors in humans are rare. METHODS: Biopsies of synovia and debrided cartilage were taken in patients undergoing autologous chondrocyte implantation. Expression of BMP-2, BMP-7, and their receptors BMPR-1A, BMPR-1B and BMPR-2 were semiquantitatively evaluated by immunohistological staining. RESULTS: BMP-7 was equally highly expressed in all cartilage and synovial biopsies. Increased levels of BMPR-1A, but not of BMPR-1B, and BMPR-2, were found in all synovial and 47% of all cartilage samples (P = 0.002). BMP-2 was positively scored in 47% of all cartilage and 40% of all synovial specimens. Defect size, KOSS, Henderson or Kellgren-Lawrence score did not statistically significant correlate with the expression of the analyzed proteins or Mankin and Pritzker scores. Duration of symptoms and localization of lesions were associated with KOSS (P < 0.02), but there was no influence of these parameters on protein expression. CONCLUSIONS: BMP-2, BMP-7, and BMPR-1A were expressed in cartilage and synovia of knees with focal cartilage lesions. Although defect localization and duration of symptoms decisively influence KOSS, there was no associated alteration of protein expression observed.

Treatment of various secondary lymphedemas by microsurgical lymph vessel transplantation.

Chronic lymphedema is a debilitating complication of cancer diagnosis and therapy and poses many challenges for health care professionals. It remains a poorly understood condition that has the potential to occur after any intervention affecting lymph node drainage mechanism. Microsurgical lymph vessel transplantation is increasingly recognized as a promising method for bypassing the obstructed lymph pathways and promoting long-term reduction of edema in the affected limb. A detailed review of 14 patients with postoperative lymphedema treated with autologous lymph vessel transplantation between October 2005 and November 2009 was performed. In this report, the authors gave an account of their experience in utilizing this operative method to alleviate secondary lymphedema including upper limb, lower limb, genital, and facial edemas. Lymph vessel transplantation enhanced lymphatic drainage in patients with secondary lymphedema. In the upper and lower extremities, three patients had completed symptomatic recovery and another nine patients achieved reasonable reduction of lymphedema, four of these needed no further lymph drainage or compression garments and the remaining maintained their improvement with further decongestive therapy with or without compression garments. The patients with facial and genital edemas also experienced significant symptomatic improvement. The authors were able to establish long-term patency of the lymph vessel anastomosis by magnetic resonance lymphangiography.

Risk of graft fracture after dorso-ventral thoraco-lumbar spondylodesis: is there a correlation with graft size?

STUDY DESIGN: Retrospective clinical study in patients with dorso-ventral thoraco-lumbar spondylodesis. OBJECTIVE: To investigate whether the ratio between graft cross sectional area and the surface area of the adjacent endplates has any effect on the midterm stability of the spondylodesis. Dorso-ventral spondylodesis in the region of the thoraco-lumbar spine is one of the most frequent operations in orthopaedic surgery. Anterior stabilization with autologous iliac crest graft currently is a standard approach in many hospitals. Although numerous recommendations are given how to perform this technique, no clinical advice is available with regard to minimum graft size. METHODS: Sixty-four-slice CT-scans were obtained from 82 patients 4-12 months after posterior spondylodesis with anterior implantation of iliac crest graft and stabilization with an internal fixator. The scans were analyzed using image analysis software. First, the cross sectional area of the graft was calculated and then the surface area of the adjacent endplates. The ratio between graft cross sectional area and endplate surface area was then calculated from these two values. The grafts were then evaluated in sagittal reconstruction for signs of fracture. RESULTS: The probability for graft fracture in autologous tricortical grafts was >0.1% (p < 0.001) if the graft cross sectional area exceeded 23.9% of the surface area of the adjacent endplates. Patients with lower ratio values had a higher fracture risk and below a value of 10% all grafts fractured. CONCLUSION: The relationship between graft cross sectional area and adjacent endplate area has an important effect on graft midterm stability in ventral spondylodesis of the thoraco-lumbar spine. In our opinion, the risk of graft fractures in dorso-ventral spondylodesis can be reduced by implantation of an appropriately sized graft without any additional procedures or instrumentation.

Assessment of the lymphatic system in patients with diffuse lymphangiomatosis by magnetic resonance imaging.

OBJECTIVE: To assess the lymphatic system in patients with diffuse lymphangiomatosis by magnetic resonance imaging. MATERIALS AND METHODS: 15 patients with diffuse lymphangiomatosis were examined by magnetic resonance imaging. Three locations were examined: first, the lower leg and foot region; second, the upper leg and the knee region; and third, the pelvic with retroperitoneal and abdominal region. For magnetic resonance lymphangiography a T1-weighted 3D spoiled gradient-echo and a T2-weighted 3D-TSE sequence was used. RESULTS: The size of the genital lymphangiomas, which were revealed in all patients, varied between 5 and 83 mm. In 47% of the patients lymphangiomas were detected at the level of the lower legs, and in 87% of the patients at the level of the upper leg and retroperitoneum. Furthermore, lymphangiomas were seen in the inguinal and pelvic region in 100% and intraabdominally in 40% of the patients. The lymphangiomas extended into the abdominal wall in 93% of the examined patients. A chylous pleural effusion was revealed in 20% and a chylous ascites in 13% of patients. 93% of patients suffered due to the diffuse lymphangiomatous pathologies from a lymphedema of the lower extremities, while a generalized lymphedema of the trunk was found in 87% of the patients. CONCLUSION: Magnetic resonance imaging is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic system in patients with diffuse lymphangiomatosis. Since the localization and extension of the lymphangiomas are important prognostic factors, it is crucial to perform a safe radiologic evaluation with a high resolution for the patient's therapeutic planning.

Diffuse lymphangiomatosis with genital involvement--evaluation with magnetic resonance lymphangiography.

OBJECTIVE: To assess, for the first time, the morphology of the lymphatic system in patients with diffuse lymphangiomatosis and genital involvement by magnetic resonance lymphangiography (MRL). MATERIALS AND METHODS: Ten patients with diffuse lymphangiomatosis and genital involvement were examined by MRL. Three locations were examined: first, the lower leg and foot region; second, the upper leg and the knee region; and third, the pelvic with retroperitoneal region. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MRL, a T1-weighted 3D-spoiled gradient-echo and a T2-weighted 3D-TSE sequence were used. RESULTS: The size of the genital lymphangiomas, which were revealed in all patients, varied between 6 and 85 mm. In 60% of the patients, lymphangiomas were additionally detected at the level of the lower legs, and in 70% patients at the level of the upper leg. Furthermore, lymphangiomas were seen in the inguinal and retroperitoneal regions in 80%, and in the pelvic region and anterior abdominal wall in 90% of the patients examined. The genital lymphangiomas feeding lymphatic vessels were detected in 80% of the patients in the anterior abdominal wall and in 90% of the patients in the inguinal and pelvic regions; 90% of the patients suffered consecutively from a lymphedema of the lower extremities. All patients suffered from recurrent infections in the genital region; 80% of the patients repeatedly experienced genital lymphorrhea due to lympho-cutaneous fistulas and lymphcysts. CONCLUSION: MRL is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic circulation in patients with diffuse lymphangiomatosis and genital involvement. Because the site and extent of the lymphangiomas with their feeding lymphatic vessels are important prognostic factors, performing radiologic evaluation with a high resolution is crucial for the therapeutic planning of patients.

MR imaging of the lymphatic system in patients with lipedema and lipo-lymphedema.

OBJECTIVE: To assess for the first time the morphology of the lymphatic system in patients with lipedema and lipo-lymphedema of the lower extremities by MR lymphangiography. MATERIALS AND METHODS: 26 lower extremities in 13 consecutive patients (5 lipedema, 8 lipo-lymphedema) were examined by MR lymphangiography. 18 mL of gadoteridol and 1 mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously in the forefoot. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography, a 3D-spoiled gradient-echo sequence was used. For evaluation of the lymphedema a heavily T2-weighted 3D-TSE sequence was performed. RESULTS: In all 16 lower extremities (100%) with lipo-lymphedema, high signal intensity areas in the epifascial region could be detected on the 3D-TSE sequence. In the 16 examined lower extremities with lipo-lymphedema, 8 lower legs and 3 upper legs demonstrated enlarged lymphatic vessels up to a diameter of 3 mm. In two lower legs with lipo-lymphedema, an area of dermal back-flow was seen, indicating lymphatic outflow obstruction. In the 10 examined lower extremities with clinically pure lipedema, 4 lower legs and 2 upper legs demonstrated enlarged lymphatic vessels up to a diameter of 2 mm, indicating a subclinical status of lymphedema. In all examined extremities, the inguinal lymph nodes demonstrated a contrast material enhancement in the first image acquisition 15 min after injection. CONCLUSION: MR lymphangiography is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic circulation in patients with lipedema and lipo-lymphedema of the lower extremities. If the extent of lymphatic involvement is unclear at the initial clinical examination or requires a better definition for optimal therapeutic planning, MR lymphangiography is able to identify the anatomic and physiological derangements and to establish an objective baseline.

Posttraumatic edema of the lower extremities: evaluation of the lymphatic vessels with magnetic resonance lymphangiography.

OBJECTIVE: To assess for the first time the morphology of the lymphatic system in patients with posttraumatic edema of the lower extremities by magnetic resonance (MR) imaging using the interstitial lymphangiography technique MATERIALS AND METHODS: Six patients with posttraumatic edema in eight of their 12 lower extremities were examined by MR lymphangiography. Eighteen mL of gadoteridol and one mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography, a 3D-spoiled gradient-echo sequence was used. RESULTS: In five of the eight (63%) traumatized lower extremities, enlarged lymphatic vessels were detected, with the largest diameter measuring 5 mm. Additionally, a fast lymphatic outflow was observed in seven of the eight (88%) traumatized legs with enhancement of the inguinal lymph nodes already in the first image acquisition 15 minutes after contrast material injection. In two of the eight (25%) traumatized lower extremities, an extensive network of collateral lymphatic vessels was detected at the level of the calf. In both extremities, lymphatic collateralization involved not only the epifascial but also the subfascial lymphatic system. In one patient, who sustained a trauma of the left lower leg with tibial fracture, a small aneurysmatic widening of 7 mm could be detected at the middle level of the calf. CONCLUSION: MR lymphangiography is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic circulation in patients with posttraumatic edema of the lower extremities. If the extent of lymphatic damage is unclear at the initial clinical examination or requires a better definition for optimal therapeutic planning, MR lymphangiography is able to identify the anatomic and physiological derangements and to establish an objective baseline.

MR lymphangiography for the assessment of the lymphatic system in patients undergoing microsurgical reconstructions of lymphatic vessels.

OBJECTIVE: To assess the morphology of the lymphatic system pre- and postoperatively in patients undergoing microsurgical reconstructions of the lymphatic vessels. MATERIALS AND METHODS: 8 lower extremities in 4 consecutive patients with secondary unilateral lymphedema of the lower extremities were examined by MR lymphangiography. 18 mL of gadoteridol and 1 mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously into the dorsal aspect of each foot at the region of the four interdigital webs and medial to the first proximal phalanx. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography a 3D-spoiled gradient-echo sequence was used. For evaluation of the lymphedema a heavily T2-weighted 3D-TSE sequence was performed. RESULTS: In 2 patients the 3D-TSE sequence demonstrated a decrease of the epifascial lymphedema in the postoperative acquisitions, whereby MR lymphangiography displayed an improvement of dermal-back areas and collateral lymphatic vessels. In one patient the epifascial lymphedema of the lower extremity decreased, whereas the diameter of the lymphatic vessels showed a constant diameter of 2 mm. In one patient with a lymphocutaneous fistula at the level of the right groin, the feeding lymphatic vessels and contrast media extravasation could clearly be visualized. The 3D-TSE sequence demonstrated an epi- as well as subfascial lymphedema of the right leg. CONCLUSION: MR lymphangiography is a safe and accurate diagnostic imaging method for the pre- and postoperative evaluation of the lymphatic circulation in patients undergoing microlymphatic surgery. Due to the minimal-invasiveness and lack of radiation, diagnostic follow-up MR lymphangiography examinations can be performed routinely and with no risk for the patient.

Interstitial MR lymphangiography - a diagnostic imaging method for the evaluation of patients with clinically advanced stages of lymphedema.

BACKGROUND: To assess the feasibility of interstitial magnetic resonance lymphangiography with intracutaneous injection of a commercially available, non-ionic, extracellular paramagnetic contrast agent, to visualize lymphatic vessels in patients with clinically advanced stages of primary lymphedema. METHODS: Sixteen lower extremities in 8 patients with clinically advanced stages of primary lymphedema were examined with magnetic resonance lymphangiography. A 18 mL of gadodiamide and 2 mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously into the dorsal aspect of both feet. For MRL, a 3D spoiled gradient-echo sequence (Volumetric Interpolated Breathold Examination, VIBE) was performed. RESULTS: The beaded appearance of lymphatic vessels extending from the injection site was detected in all 16 lower extremities (100%). In 10 lower extremities (63%), lymphatic vessels of the upper leg could be visualized. A contrast enhancement was observed in 10/16 inguinal lymph node groups (63%). In 12 lower extremities (75%) collateral vessels with dermal back-flow areas between lymphatic vessels were seen. CONCLUSION: Magnetic resonance lymphangiography is safe, technically feasible, and assists the clinician in the therapeutic planning of patients with clinically advanced stages of primary lymphedema by imaging the pathologically modified lymphatic vessels and accompanying complications non-invasively.

Quantitative and semiquantitative evaluation of erythropoietin-induced bone marrow signal changes in lumbar spine MRI in patients with tumor anemia.

BACKGROUND: The topic of this article is the quantitative and semiquantitative assessment of bone marrow signal alteration in magnetic resonance imaging (MRI) of the lumbar spine in patients with tumor anemia during therapy with epoietin beta or placebo. PATIENTS AND METHODS: We examined 32 patients with head or neck cancer (16 epoietin beta, 16 placebo) during radiotherapy in a double-blind multicenter trial. During radiotherapy, the patients underwent epoietin beta therapy for 7-9 weeks. Lumbar spine measurements using T1-w SE, OPP and Turbo- STIR were taken prior to the first epoietin beta or placebo therapy, after the acquired hemoglobin level had been reached, and after the final radiotherapy. The semiquantitative assessment was made blinded by 2 independent radiologists. RESULTS: We found significant differences between both groups. The first MRI showed normal marrow signals. The second MRI revealed a quantified decrease in bone marrow signal in T1-w SE (p < 0.018) and an increase in OPP (p < 0.01) and Turbo-TIR (p < 0.048) sequences. At the third MR imaging, quantified relative marrow signals returned to baseline level in all sequences. Semiquantitative assessment confirmed these results. CONCLUSION: In both analyses, lumbar spine MRI demonstrates significant bone marrow changes in T1-w SE, OPP and Turbo-STIR sequences during epoietin beta therapy.

Magnetic resonance imaging of lymphatic vessels without image subtraction: a practicable imaging method for routine clinical practice?

OBJECTIVE: To assess the feasibility of a time-efficient, high-resolution magnetic resonance lymphangiography (HR MRL) protocol without image subtraction for the detection of lymphatic vessels in patients with primary and secondary lymphedema. METHODS: Three consecutive patients with lymphedema of the lower extremities (2 primary bilateral, 1 secondary unilateral) underwent HR MRL without image subtraction. An amount of 9 mL of gadodiamide and 1 mL of mepivacaine hydrochloride 1% were subdivided into 5 portions and injected intracutaneously into the dorsal aspect of each foot outside the scanner before image acquisition. Magnetic resonance imaging was performed with a 1.5-T system equipped with high-performance gradients. For HR MRL, a 3-dimensional, spoiled gradient-echo sequence (Volumetric Interpolated Breath-hold Examination) was used. The extent and distribution of the lymphedema was evaluated using a heavily T2-weighted, 3-dimensional turbo-spin echo sequence. RESULTS: The HR MRL bilaterally detected the inguinal lymph nodes and the lymphatic vessels in the lower and upper leg in the 2 patients with primary lymphedema. In the patient with left-sided secondary lymphedema, the inguinal lymph nodes and the lymphatic vessels in the lower and upper leg were depicted on the right side. The diameter of the displayed lymphatic vessels varied between 1 and 5 mm. Three-dimensional, maximum-intensity projection images of different angles of view provided detailed outlining of the lymphatic vessels and differentiation from veins, which showed a lower signal intensity. CONCLUSION: The HR MRL without image subtraction is safe, technically feasible, and has the potential to become a diagnostic imaging tool in daily clinical practice because of its time efficiency.

MRI and (18)FDG-PET in the assessment of bone marrow infiltration of the spine in cancer patients.

The aim of this study was to evaluate the diagnostic value of MRI and (18)FDG-PET in bone marrow infiltration of the spine due to metastases of solid tumours and lymphoma in cancer patients. In 35 cancer patients (solid tumours n = 26, lymphoma n = 9) MRI of the spine and (18)FDG-PET were reviewed and the detectability of metastases, infiltration of the spine, extent of disease, and therapeutic implications were compared. In 8/35 cases (23%) imaging technique showed concordantly no bone marrow infiltration. In 19/35 patients (54%), both MRI and (18)FDG-PET revealed bone marrow infiltration of the axial skeleton. In 12/19 patients (63%), MRI showed more extensive disease which lead to subsequent therapy. The imaging findings of MRI and (18)FDG-PET were discordant in 8/35 cases (23%). (18)FDG-PET was false positive in two patients. In six patients, (18)FDG-PET failed to detect bone metastases and bone marrow infiltration of the spine, which was detected by MRI and proven by clinical follow-up with subsequent therapy in two cases. MRI is more sensitive and specific than (18)FDG-PET detecting bone marrow metastases and infiltration of the spine and has a great impact in staging cancer patients.