Transarterial Yttrium-90 Radioembolization in Intrahepatic Cholangiocarcinoma Patients: Outcome Assessment Applying a Prognostic Score.

Radioembolization (RE) is a viable therapy option in patients with intrahepatic cholangiocarcinoma (ICC). This study delineates a prognostic score regarding overall survival (OS) after RE using routine pre-therapeutic parameters. A retrospective analysis of 39 patients (median age, 61 [range, 32−82] years; 26 females, 13 males) with ICC and 42 RE procedures was conducted. Cox regression for OS included age, ECOG, hepatic and extrahepatic tumor burden, thrombosis of the portal vein, ascites, laboratory parameters and dose reduction due to hepatopulmonary shunt. Median OS after RE was 8.0 months. Using univariable Cox, ECOG ≥ 1 (hazard ratio [HR], 3.8), AST/ALT quotient (HR, 1.86), high GGT (HR, 1.002), high CA19-9 (HR, 1.00) and dose reduction of 40% (HR, 3.8) predicted shorter OS (each p < 0.05). High albumin predicted longer OS (HR, 0.927; p = 0.045). Multivariable Cox confirmed GGT ≥ 750 [U/L] (HR, 7.84; p < 0.001), ECOG > 1 (HR, 3.76; p = 0.021), albumin ≤ 41.1 [g/L] (HR, 3.02; p = 0.006) as a three-point pre-therapeutic prognostic score. More specifically, median OS decreased from 15.3 months (0 risk factors) to 7.6 months (1 factor) or 1.8 months (≥2 factors; p < 0.001). The proposed score may aid in improved pre-therapeutic patient identification with (un-)favorable OS after RE and facilitate the balance between potential life prolongation and overaggressive patient selection.

Selective Internal Radiation Therapy in Breast Cancer Liver Metastases: Outcome Assessment Applying a Prognostic Score.

Selective internal radiation therapy (SIRT) is a therapy option in patients with breast cancer liver metastasis (BCLM). This analysis aimed at identifying a prognostic score regarding overall survival (OS) after SIRT using routine pretherapeutic parameters. Retrospective analysis of 38 patients (age, 59 (39-84) years) with BCLM and 42 SIRT procedures. Cox regression for OS included clinical factors (age, ECOG and prior treatments), laboratory parameters, hepatic tumor load and dose reduction due to hepatopulmonary shunt. Elevated baseline ALT and/or AST was present if CTCAE grade ≥ 2 was fulfilled (>3 times the upper limit of normal). Median OS after SIRT was 6.4 months. In univariable Cox, ECOG ≥ 1 (hazard ratio (HR), 3.8), presence of elevated baseline ALT/AST (HR, 3.8), prior liver surgery (HR, 10.2), and dose reduction of 40% (HR, 8.1) predicted shorter OS (each p < 0.05). Multivariable Cox confirmed ECOG ≥ 1 (HR, 2.34; p = 0.012) and elevated baseline ALT/AST (HR, 4.16; p < 0.001). Combining both factors, median OS decreased from 19.2 months (0 risk factors; n = 14 procedures) to 5.9 months (1 factor; n = 20) or 2.2 months (2 factors; n = 8; p < 0.001). The proposed score may facilitate pretherapeutic identification of patients with unfavorable OS after SIRT. This may help to balance potential life prolongation with the hazards of invasive treatment and hospitalization.

Image Quality Assessment for Low-Dose-CT in Hybrid SPECT/CT Imaging.

OBJECTIVES: Low-dose-computed tomography (LD-CT) is used in nuclear medicine hybrid imaging (e.g., SPECT/CT) for attenuation correction of emission data and anatomical correlation of findings. However, there are currently no standards for image quality (e. g., detectability) comparable to those for diagnostic CT. Therefore, the aim of this explorative study was to evaluate retrospective LDCT data in terms of CT image quality and detectability of anatomical structures. METHODS: Two readers blindly scored abdominal LD-CT images (n = 40 patients) in terms of detectability (n = 20 structures/patient), image quality, and readers' confidence in scoring the image quality for a clinically hybrid imaging protocol. Results were analysed by ANOVA to identify factors (e. g., anatomical structures) that influenced performance scores. The inter-rater agreement was evaluated by determining the chance-corrected Cohen's Kappa coefficient. RESULTS: Image noise was acceptable for anatomical correlation in 96.1 % of the readings with an almost perfect inter-rater agreement (KBP = 0.85). A detectability of at least 80 % was observed in 13/20 (KBP ≥ 0.7) and 90 % in 9/20 (KBP ≥ 0.85) of the structures analysed by both readers. The confidence of both readers in scoring image quality was at least sufficient in 98.8 % of the examined patients (KBP = 0.95). CONCLUSION: Although LD-CT protocols commonly used in hybrid imaging have a poor image quality not suitable for primary CT diagnostics, they enable detection of a variety of anatomical structures. LDCT can therefore also be referenced in the associated reports for anatomical correlation of findings from SPECT imaging.

Individualized risk assessment in neuroblastoma: does the tumoral metabolic activity on 123I-MIBG SPECT predict the outcome?

PURPOSE: Risk-adapted treatment in children with neuroblastoma (NB) is based on clinical and genetic factors. This study evaluated the metabolic tumour volume (MTV) and its asphericity (ASP) in pretherapeutic 123I-MIBG SPECT for individualized image-based prediction of outcome. METHODS: This retrospective study included 23 children (11 girls, 12 boys; median age 1.8 years, range 0.3-6.8 years) with newly diagnosed NB consecutively examined with pretherapeutic 123I-MIBG SPECT. Primary tumour MTV and ASP were defined using semiautomatic thresholds. Cox regression analysis, receiver operating characteristic analysis (cut-off determination) and Kaplan-Meier analysis with the log-rank test for event-free survival (EFS) were performed for ASP, MTV, laboratory parameters (including urinary homovanillic acid-to-creatinine ratio, HVA/C), and clinical (age, stage) and genetic factors. Predictive accuracy of the optimal multifactorial model was determined in terms of Harrell's C and likelihood ratio χ 2. RESULTS: Median follow-up was 36 months (range 7-107 months; eight patients showed disease progression/relapse, four patients died). The only significant predictors of EFS in the univariate Cox regression analysis were ASP (p = 0.029; hazard ratio, HR, 1.032 for a one unit increase), MTV (p = 0.038; HR 1.012) and MYCN amplification status (p = 0.047; HR 4.67). The mean EFS in patients with high ASP (>32.0%) and low ASP were 21 and 88 months, respectively (p = 0.013), and in those with high MTV (>46.7 ml) and low MTV were 22 and 87 months, respectively (p = 0.023). A combined risk model of either high ASP and high HVA/C or high MTV and high HVA/C best predicted EFS. CONCLUSIONS: In this exploratory study, pretherapeutic image-derived and laboratory markers of tumoral metabolic activity in NB (ASP, MTV, urinary HVA/C) allowed the identification of children with a high and low risk of progression/relapse under current therapy.

Detection of obstructive uropathy and assessment of differential renal function using two functional magnetic resonance urography tools. A comparison with diuretic renal scintigraphy in infants and children.

AIM: After detection of obstructive uropathy (OU), the indication for or against surgery is primarily based on the differential renal function (DRF). This is to compare functional magnetic resonance urography (fMRU) with dynamic renal scintigraphy (DRS) to assess OU and DRF in infants and children. PATIENTS, METHODS: Retrospective analysis in 30 patients (female: 16; male: 14; median age: 5.5 years [0.2-16.5]), divided into subgroup A (age: 0-2 years; n = 16) and B (> 2-17 years; n = 14). fMRU was assessed by measuring renal transit time (RTT) and volumetric DRF with CHOP fMRU tool (CT) and ImageJ MRU plug-in (IJ). OU detection by fMRU was compared with DRS (standard of reference) using areas under the curves (AUC) in ROC analyses. Concordant DRF was assumed if absolute deviation between fMRU and DRS was ≤ 5 %. RESULTS: DRS confirmed fixed OU in 4/31 kidneys (12.9 %) in subgroup A. AUC of CT was 0.94 compared with 0.93 by IJ. Subgroup B showed fixed OU in 1/21 kidneys (4.8 %) with AUCs of 0.98 each. RTT measured neither by CT nor by IJ in confirmed fixed OU was < 1200 s - resulting in negative predictive values of 1.0 each. In subgroup A, DRF was concordant in 81.3 % of the kidneys for CT and DRS compared with 75.0 % for IJ and DRS. In subgroup B, CT and DRS were concordant in 91.7 %, and IJ and DRS in 45.8 % of the kidneys. CONCLUSION: fMRU accurately excluded fixed OU in infants and children, independent from the software used for quantification. However, assessment of DRF with fMRU deviated from DRS especially in infants who may profit most from early intervention. Thus, fMRU cannot fully replace DRS as primary functional examination. If, for clinical reasons, fMRU is performed in first place and it cannot exclude fixed OU, it should be followed by DRS for validation and DRF quantification.

Y90 Radioembolization in chemo-refractory metastastic, liver dominant colorectal cancer patients: outcome assessment applying a predictive scoring system.

BACKGROUND: In treatment-refractory liver dominant metastatic colorectal cancer, the role of liver directed therapies still is unclear. We sought to determine a prognostic score for Y90 radioembolization in these patients. METHODS: We analyzed 106 patients with refractory liver dominant mCRC who had undergone a total of 178 Y90 radioembolizations with resin microspheres was collected. Potential factors influencing survival were analyzed using a Cox regression. The Log rank test served to establish prognostic factors and to form a clinical score for outcome prediction after Y90 radioembolization. RESULTS: Median survival of all patients was 6.7 months. Neither age nor prior surgical or systemic therapy nor metastatic spread had an effect on survival. In contrast, hepatic tumor load, Karnofsky index as well as CEA and CA19-9 serums level had a significant influence (p < 0.001, p = 0.037, p = 0.023 and p < 0.001, respectively). These three factors formed a score with 1 point each for tumor load >20 %, CEA >130 ng/ml or CA19-9 > 200U/ml and Karnofsky index <80 %. Patients with a score of 0 and 1 displayed a median OS of 10.4 months. Patients with a score of 2 and 3 demonstrated a median OS of 5.1 months only (p < 0.001). CONCLUSION: Overaggressive patient selection for Y90 radioembolization of liver dominant chemorefractory mCRC is of questionable benefit. A scoring system comprising hepatic tumor load, CEA and CA19-9 serum levels and Karnofsky index (TuCK-score) may support an improved patient selection. In our cohort of liver only versus liver dominant disease, extrahepatic lung or lymphatic metastases did not significantly alter the prognosis.

Comparative evaluation of SUV, tumor-to-blood standard uptake ratio (SUR), and dual time point measurements for assessment of the metabolic uptake rate in FDG PET.

BACKGROUND: We have demonstrated recently that the tumor-to-blood standard uptake ratio (SUR) is superior to tumor standardized uptake value (SUV) as a surrogate of the metabolic uptake rate K m of fluorodeoxyglucose (FDG), overcoming several of the known shortcomings of the SUV approach: excellent linear correlation of SUR and K m from Patlak analysis was found using dynamic imaging of liver metastases. However, due to the perfectly standardized uptake period used for SUR determination and the comparatively short uptake period, these results are not automatically valid and applicable for clinical whole-body examinations in which the uptake periods (T) are distinctly longer and can vary considerably. Therefore, the aim of this work was to investigate the correlation between SUR derived from clinical static whole-body scans and K m-surrogate derived from dual time point (DTP) measurements. METHODS: DTP (18)F-FDG PET/CT was performed in 90 consecutive patients with histologically proven non-small cell lung cancer (NSCLC). In the PET images, the primary tumor was delineated with an adaptive threshold method. For determination of the blood SUV, an aorta region of interest (ROI) was delineated manually in the attenuation CT and transferred to the PET image. Blood SUV was computed as the mean value of the aorta ROI. SUR values were computed as ratio of tumor SUV and blood SUV. SUR values from the early time point of each DTP measurement were scan time corrected to 75 min postinjection (SURtc). As surrogate of K m, we used the SUR(T) slope, K slope, derived from DTP measurements since it is proportional to the latter under the given circumstances. The correlation of SUV and SURtc with K slope was investigated. The prognostic value of SUV, SURtc, and K slope for overall survival (OS) and progression-free survival (PFS) was investigated with univariate Cox regression in a homogeneous subgroup (N=31) treated with primary chemoradiation. RESULTS: Correlation analysis revealed for both, SUV and SURtc, a clear linear correlation with K slope (P<0.001). Correlation SUR vs. K slope was considerably stronger than correlation SUV vs. K slope (R (2)=0.92 and R (2)=0.69, respectively, P<0.001). Univariate Cox regression revealed SURtc and K slope as significant prognostic factors for PFS (hazard ratio (HR) =3.4/ P=0.017 and HR =4.3/ P=0.020, respectively). For SUV, no significant effect was found. None of the investigated parameters was prognostic for OS. CONCLUSIONS: Scan-time-corrected SUR is a significantly better surrogate of tumor FDG metabolism in clinical whole-body PET compared to SUV. The very high linear correlation of SUR and DTP-derived K slope (which is proportional to actual K m) implies that for histologically proven malignant lesions, FDG-DTP does not provide added value in comparison to the SUR approach in NSCLC.

Hybrid SPECT/CT for the assessment of a painful hip after uncemented total hip arthroplasty.

BACKGROUND: The diagnosis of hip pain after total hip replacement (THR) represents a highly challenging question that is of increasing concern to orthopedic surgeons. This retrospective study assesses bone scintigraphy with Hybrid SPECT/CT for the diagnosis of painful THR in a selected cohort of patients. METHODS: Bone SPECT/CT datasets of 23 patients (mean age 68.9 years) with a painful hip after THR were evaluated. Selection of the patients required an inconclusive radiograph, normal serum levels of inflammatory parameters (CRP and ESR) or a negative aspiration of the hip joint prior to the examination. The standard of reference was established by an interdisciplinary adjudication-panel using all imaging data and clinical follow-up data (>12 month). Pathological and physiological uptake patterns were defined and applied. RESULTS: The cause of pain in this study group could be determined in 18 out of 23 cases. Reasons were aseptic loosening (n = 5), spine-related (n = 5), heterotopic ossification (n = 5), neuronal (n = 1), septic loosening (n = 1) and periprosthetic stress fracture (n = 1). In (n = 5) cases the cause of hip pain could not be identified. SPECT/CT imaging correctly identified the cause of pain in (n = 13) cases, in which the integrated CT-information led to the correct diagnosis in (n = 4) cases, mainly through superior anatomic correlation. Loosening was correctly assessed in all cases with a definite diagnosis. CONCLUSIONS: SPECT/CT of THA reliably detects or rules out loosening and provides valuable information about heterotopic ossifications. Furthermore differential diagnoses may be detected with a whole-body scan and mechanical or osseous failure is covered by CT-imaging. SPECT/CT holds great potential for imaging-based assessment of painful prostheses.

Quantitative assessment of the asphericity of pretherapeutic FDG uptake as an independent predictor of outcome in NSCLC.

BACKGROUND: The aim of the present study was to evaluate the predictive value of a novel quantitative measure for the spatial heterogeneity of FDG uptake, the asphericity (ASP) in patients with non-small cell lung cancer (NSCLC). METHODS: FDG-PET/CT had been performed in 60 patients (15 women, 45 men; median age, 65.5 years) with newly diagnosed NSCLC prior to therapy. The FDG-PET image of the primary tumor was segmented using the ROVER 3D segmentation tool based on thresholding at the volume-reproducing intensity threshold after subtraction of local background. ASP was defined as the relative deviation of the tumor's shape from a sphere. Univariate and multivariate Cox regression as well as Kaplan-Meier (KM) analysis and log-rank test with respect to overall (OAS) and progression-free survival (PFS) were performed for clinical variables, SUVmax/mean, metabolically active tumor volume (MTV), total lesion glycolysis (TLG), ASP and "solidity", another measure of shape irregularity. RESULTS: ASP, solidity and "primary surgical treatment" were significant independent predictors of PFS in multivariate Cox regression with binarized parameters (HR, 3.66; p<0.001, HR, 2.11; p=0.05 and HR, 2.09; p=0.05), ASP and "primary surgical treatment" of OAS (HR, 3.19; p=0.02 and HR, 3.78; p=0.01, respectively). None of the other semi-quantitative PET parameters showed significant predictive value with respect to OAS or PFS. Kaplan-Meier analysis revealed a probability of 2-year PFS of 52% in patients with low ASP compared to 12% in patients with high ASP (p<0.001). Furthermore, it showed a higher OAS rate in the case of low versus high ASP (1-year-OAS, 91% vs. 67%: p=0.02). CONCLUSIONS: The novel parameter asphericity of pretherapeutic FDG uptake seems to provide better prognostic value for PFS and OAS in NCSLC compared to SUV, metabolic tumor volume, total lesion glycolysis and solidity.

Assessment of tumor size reduction improves outcome prediction of positron emission tomography/computed tomography after chemotherapy in advanced-stage Hodgkin lymphoma.

PURPOSE: Positron emission tomography (PET) after chemotherapy can guide consolidating radiotherapy in advanced-stage Hodgkin lymphoma (HL). This analysis aims to improve outcome prediction by integrating additional criteria derived by computed tomography (CT). PATIENTS AND METHODS: The analysis set consisted of 739 patients with residues≥2.5 cm after chemotherapy from a total of 2,126 patients treated in the HD15 trial (HD15 for advanced stage Hodgkin's disease: Quality assurance protocol for reduction of toxicity and the prognostic relevance of fluorodeoxyglucose-positron-emission tomography [FDG-PET] in the first-line treatment of advanced-stage Hodgkin's disease) performed by the German Hodgkin Study Group. A central panel performed image analysis and interpretation of CT scans before and after chemotherapy as well as PET scans after chemotherapy. Prognosis was evaluated by using progression-free survival (PFS); groups were compared with the log-rank test. Potential prognostic factors were investigated by using receiver operating characteristic analysis and logistic regression. RESULTS: In all, 548 (74%) of 739 patients had PET-negative residues after chemotherapy; these patients did not receive additional radiotherapy and showed a 4-year PFS of 91.5%. The 191 PET-positive patients (26%) receiving additional radiotherapy had a 4-year PFS of 86.1% (P=.022). CT alone did not allow further separation of patients in partial remission by risk of recurrence (P=.9). In the subgroup of the 54 PET-positive patients with a relative reduction of less than 40%, the risk of progression or relapse within the first year was 23.1% compared with 5.3% for patients with a larger reduction (difference, 17.9%; 95% CI, 5.8% to 30%). CONCLUSION: Patients with HL who have PET-positive residual disease after chemotherapy and poor tumor shrinkage are at high risk of progression or relapse.

SUV-measurements and patient-specific corrections in pediatric Hodgkin-lymphoma: is there a benefit for PPV in early response assessment by FDG-PET?

BACKGROUND: To evaluate the influence of different SUV-measurements and patient-specific corrections thereof on the positive predictive value (PPV) of FDG-PET in pediatric Hodgkin lymphoma (pHL) using SUV-based response assessment. METHODS: PET-datasets of 33 children [female, n = 13, male, n = 20; range of age, 8.0-17.8 (mean, 15.0) years; follow-up, 44.5-83.3 (mean 63.0) months] with HL were analyzed retrospectively. PET-scans were obtained baseline (PET1) and after two cycles of chemotherapy (PET2). Within the leading lesion maximal SUV (SUVmax) and mean SUVs were generated by using isocontur-thresholds for different volumes of interest: Absolute, SUV2.5; relative to SUVmax, SUVmean40% to SUVmean70%. Generated SUVs were adjusted to body weight (SUV) and corrected for body surface area (SUV_BSA), patient's blood glucose and a combination thereof. The decrease in SUV or respective derivates thereof between PET1 and PET2 (ΔSUV) was assessed for response prediction using receiver operating characteristics (ROC)-analysis. RESULTS: Three patients had recurrence of disease. ROC-analysis showed the most accurate differentiation of responders and non-responders for ΔSUVmax_BSA [AUC, 0.97; P = 0.0026; sensitivity, 100%; specificity, 93.3%; PPV, 60.0%; negative predictive value (NPV), 100%; accuracy, 93.3%]. However, comparable results were obtained for conventional ΔSUVmax-determination (AUC, 0.96; P = 0.0112; sensitivity, 100%; specificity, 90.0%; PPV, 50.0%; NPV, 100%; accuracy, 90.9%). Threshold-based approaches were less effective or technically not performable in all patients. CONCLUSIONS: At early response assessment by FDG-PET, patient-specific correction of ΔSUVmax by BSA improves PPV without impairment of excellent NPV in pHL. However, it is not statistically superior to simple ΔSUVmax-analyses. Larger cohorts are needed to investigate this observation.

Effectiveness of repeat angiographic assessment in patients designated for radioembolization using yttrium-90 microspheres with initial extrahepatic accumulation of technitium-99m macroaggregated albumin: a single center's experience.

PURPOSE: To evaluate the efficacy of a workflow consisting of repeat assessment in patients planned for yttrium-90 ((90)Y) radioembolization in case of nontarget visceral technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) accumulation despite initial prophylactic coil embolization of nonhepatic arteries. MATERIALS AND METHODS: In 341 patients with primary and secondary liver cancer, pretreatment hepatic angiograms, as well as single-photon emission computed tomography coregistered with magnetic resonance imaging scans, were obtained. Extrahepatic tracer deposition was identified in 33 patients (9.7%) necessitating repeat assessment. Images were reviewed to correlate the site of MAA accumulation with causative gastrointestinal vessels, and repeat angiograms served as reference standard. RESULTS: At repeat angiography, the source of extrahepatic flow was identified and eliminated in 31 of 33 patients (93.9%). In 20 patients (60.6%), successful embolization of nontarget vessels was achieved, in 13 patients (39.4%), MAA was administered more distally. Afterward, extrahepatic MAA deposition was eliminated in 30 patients (90.9%). CONCLUSION: The algorithm of repeat assessment in case of extrahepatic MAA accumulation has proven highly effective to eliminate extrahepatic shunting, thus decreasing the risk of postradioembolization complications due to inadvertent visceral microsphere deposition.

Assessment of histological response of paediatric bone sarcomas using FDG PET in comparison to morphological volume measurement and standardized MRI parameters.

PURPOSE: The objective of this study was to evaluate positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI) parameters for the assessment of histological response in paediatric bone sarcoma patients. METHODS: FDG PET and local MRI were performed in 27 paediatric sarcoma patients [Ewing sarcoma family of tumours (EWS), n = 16; osteosarcoma (OS), n = 11] prior to and after neoadjuvant chemotherapy before local tumour resection. Several parameters for assessment of response of the primary tumour to therapy by FDG PET and MRI were evaluated and compared with histopathological regression of the resected tumour as defined by Salzer-Kuntschik. RESULTS: FDG PET significantly discriminated responders from non-responders using the standardized uptake value (SUV) reduction and the absolute post-therapeutic SUV (SUV2) in the entire patient population (SUV, p = 0.005; SUV2, p = 0.011) as well as in the subgroup of OS patients (SUV, p = 0.009; SUV2, p = 0.028), but not in the EWS subgroup. The volume reduction measured by MRI/CT did not significantly discriminate responders from non-responders either in the entire population (p = 0.170) or in both subgroups (EWS, p = 0.950; OS, p = 1.000). The other MRI parameters alone or in combination were unreliable and did not improve the results. Comparing diagnostic parameters of FDG PET and local MRI, metabolic imaging showed high superiority in the subgroup of OS patients, while similar results were observed in the population of EWS. CONCLUSION: FDG PET appears to be a useful tool for non-invasive response assessment in the group of OS patients and is superior to MRI. In EWS patients, however, neither FDG PET nor volumetry or standardized MRI criteria enabled a reliable response assessment to be made after neoadjuvant treatment.

Early and late therapy response assessment with [18F]fluorodeoxyglucose positron emission tomography in pediatric Hodgkin's lymphoma: analysis of a prospective multicenter trial.

PURPOSE: In adult Hodgkin's lymphoma (HL) risk stratification after early therapy response assessment with [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) seems to allow tailoring therapy with less toxicity for patients with adequate metabolic response. This study delivers the first prospective data on the potential of FDG-PET for response assessment in pediatric HL. PATIENTS AND METHODS: FDG-PET was performed in 40 pediatric HL patients before polychemotherapy (PET-1), after two cycles of polychemotherapy (PET-2), and after completion of polychemotherapy (PET-3). Mean follow-up was 46 months (range, 26 to 72 months). RESULTS: At early and late response assessment, the proportion of PET-negative patients was significantly higher compared with those patients with negative findings in conventional imaging methods (CIMs; PET-2, 26 of 40 v CIM-2, one of 40; P < .001; PET-3, 21 of 29 v CIM-3, four of 29; P < .001). Sensitivity and negative predictive value were 100% for early and late therapy response assessment by PET. Both patients suffering a relapse during follow-up were identified by PET-2/3, whereas one of these patients was not detected by CIM-3. PET was superior to CIMs with regard to specificity in early and late therapy response assessment (68% v 3%, and 78% v 11%, respectively; both P < .001). Specificity of early therapy response assessment by PET was improved to 97% by quantitative analysis of maximal standardized uptake value reduction using a cutoff value of 58%. CONCLUSION: Pediatric HL patients with a negative PET in response assessment have an excellent prognosis while PET-positive patients have an increased risk for relapse.

Hepatocellular carcinoma and liver cirrhosis: assessment of the liver function after Yttrium-90 radioembolization with resin microspheres or after CT-guided high-dose-rate brachytherapy.

PURPOSE: To identify changes of liver function after single-fraction irradiation or yttrium-90 radioembolization ((90)Y-RE) of hepatocellular carcinoma associated with liver cirrhosis on the basis of laboratory data. METHODS AND MATERIALS: 24 patients with primary liver carcinoma and liver cirrhosis classified Child-Pugh A or B were treated either by image-guided high-dose-rate brachytherapy (HDR-BT) (12 patients) or by (90)Y-RE (12 patients). The following laboratory parameters were assessed 1 day before and 3 days, 6 weeks and 3 months after the intervention: total bilirubin and gamma-glutamyl transpeptidase (GGTP) as parameters of detoxification function, albumin and cholinesterase (ChE) as direct synthesis parameters, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AP) as indicators of liver tissue damage. Preinterventional values were taken as baseline, following values were calculated as percentage changes from the baseline value. Statistical analysis was performed using the Wilcoxon-matched pairs test, comparing postinterventional with preinterventional values. Differences were considered statistically significant with a p value <0.05. RESULTS: In all patients the median bilirubin, ALT, AP and albumin values remained within normal limits at any time of follow-up. AST levels in the RE group and GGTP in both groups have been already elevated over a normal range before the intervention, and in both groups both parameters showed a slight increase after interventions. ChE activity was lowered already in the baseline values and showed a further decrease 3 days after BT as well as 3 days and 6 weeks after RE, with final reconstitution to baseline values. All liver function test parameters showed mild changes shortly after radiation therapy but floating laboratory values recovering within 12 weeks to baseline values. Radiation or RE-induced liver disease was recorded in no patient. CONCLUSIONS: Liver function parameters show only mild changes shortly after intervention with recovery within 6-12 weeks to baseline values.

Use of positron emission tomography for staging, preoperative response assessment and posttherapeutic evaluation in children with Wilms tumour.

PURPOSE: To evaluate FDG-PET for staging, grading, preoperative response assessment and posttherapeutic evaluation in children with Wilms tumour (WT). METHODS: In this study, 23 FDG-PET examinations in 12 paediatric patients (female, n = 5; male, n = 7; age, 1-19 years) with WT (primary, n = 9; relapsed, n = 3) were analysed. All patients were examined with conventional imaging methods (CIM) according to the SIOP2001/GPOH trial protocol. Additionally, FDG-PET/PET-CT was performed for staging (n = 12), preoperative response assessment (n = 6) and posttherapeutic evaluation (n = 5). Imaging results of FDG-PET and CIM were analysed regarding the accuracy in tumour visualisation, impact on therapeutic management and preoperative response assessment, with clinical follow-up and histopathology as the standard of reference. RESULTS: FDG-PET and CIM showed concordant results for staging of primary WT, whereas FDG-PET was superior in 1/3 cases with recurrent WT. Concerning histological differentiation, one case with anaplastic WT had an standard uptake value (SUV) of 12.3, which was remarkably higher than the average SUV in the eight cases with intermediate risk histology. No parameter analysed for PET or CIM was reliably predictive for histological regression or clinical outcome. After completion of therapy, FDG-PET was superior to CIM in 2/5 cases in detecting residual disease with therapeutic relevance. CONCLUSION: FDG-PET does not provide additional information to the traditional imaging work-up for staging WT patients, preoperative response assessment and clinical outcome. FDG-PET was advantageous in ruling out residual disease after completion of first line treatment and in pretherapeutic staging of relapse patients. Furthermore, there seems to be a good correlation of initial SUV and histological differentiation.