123Iodine-metaiodobenzylguanidine scintigraphy versus whole-body magnetic resonance imaging with diffusion-weighted imaging in children with high-risk neuroblastoma - pilot study.

BACKGROUND: The prognostic value of the International Society of Paediatric Oncology European Neuroblastoma Research Network (SIOPEN) skeletal score using 123iodine-metaiodobenzylguanidine (MIBG) has been confirmed for people with high-risk neuroblastoma. Whole-body MRI with diffusion-weighted imaging is used increasingly. OBJECTIVE: To compare the original SIOPEN score and its adaption by diffusion-weighted imaging in high-risk stage 4 neuroblastoma and to evaluate any consequences of score differences on overall survival. MATERIALS AND METHODS: This retrospective observational study included pediatric patients who underwent MIBG scintigraphy and whole-body MRI, including diffusion-weighted imaging, between 2010 and 2015. Semi-quantitative skeletal scores for each exam were calculated independently. A difference of two or more points was defined as clinically relevant and counted as M+ (more in diffusion-weighted imaging) or S+ (more in MIBG). In cases of a negative result in one of the studies, residual disease of 1 point was also rated as relevant. We tested correlation and differences on an exam basis and also grouped by different therapeutic conditions. Overall survival was used to evaluate prognostic relevance. RESULTS: Seventeen children with 25 paired examinations were evaluated. Median MIBG scintigraphy score was 0 (interquartile range [IQR] 0-4, range 0-25) vs. a median whole-body MRI score of 1 (IQR 0-5.5, range 0-35) (P=0.018). A relevant difference between whole-body MRI and MIBG scintigraphy was noted in 14 of the 25 paired examinations (M+: n=9; S+: n=5). After treatment, the median survival of cases with M+ was 14 months (IQR 4-59, range 1-74 months), while S+ cases showed a median survival of 49 months (IQR 36-52, range 36-52 months) (P=0.413). CONCLUSION: The SIOPEN scoring system is feasible for whole-body MRI but might result in slightly higher scores, probably because of MRI's superior spatial resolution. Further studies are necessary to validate any impact on prognosis.

Diagnostic value of whole-body MRI in Opsoclonus-myoclonus syndrome: a clinical case series (3 case reports).

BACKGROUND: Opsoclonus-myoclonus syndrome (OMS) is a rare clinical disorder and typically occurs in association with occult neuroblastic tumor in pediatric patients. I-123 metaiodobenzylguanidine (mIBG) scintigraphy is widely adopted as screening procedure in patients with suspected neuroblastic tumor. Also, contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) are involved in the imaging workup, primarily for the assessment of the primary tumor region. However, the diagnostic value of whole-body MRI (WB-MRI) for the detection of occult neuroblastic tumor in pediatric patients presenting with OMS remains unknown. CASE PRESENTATION: We present three cases of patients with OMS, in whom WB-MRI revealed occult neuroblastic tumor masses, whereas scintigraphy was inconclusive: In a 17 months old girl with OMS, WB-MRI revealed a paravertebral mass. After thoracoscopic resection, histopathology revealed a ganglioneuroblastoma. A 13 months old boy presenting with OMS WB-MRI detected a tumor of the left adrenal gland; histopathology demonstrated a ganglioneuroblastoma after adrenalectomy. In a 2 year old boy with OMS, immunoscintigraphy at the time of diagnosis was inconclusive. At the age of 13 years, a WB-MRI was performed due to persistent neurological symptoms, revealing a paravertebral retroperitoneal mass, which was classified as ganglioneuroblastoma. CONCLUSION: In OMS, particularly in the setting of inconclusive scintigraphy, WB-MRI may be considered as a valuable alternative in the early phase of diagnostic work-up.

Nodal Clearance Rate and Long-Term Efficacy of Individualized Sentinel Node-Based Pelvic Intensity Modulated Radiation Therapy for High-Risk Prostate Cancer.

PURPOSE: To assess the efficacy of individual sentinel node (SN)-guided pelvic intensity modulated radiation therapy (IMRT) by determining nodal clearance rate [(n expected nodal involvement - n observed regional recurrences)/n expected nodal involvement] in comparison with surgically staged patients. METHODS AND MATERIALS: Data on 475 high-risk prostate cancer patients were examined. Sixty-one consecutive patients received pelvic SN-based IMRT (5 × 1.8 Gy/wk to 50.4 Gy [pelvic nodes + individual SN] and an integrated boost with 5 × 2.0 Gy/wk to 70.0 Gy to prostate + [base of] seminal vesicles) and neo-/adjuvant long-term androgen deprivation therapy; 414 patients after SN-pelvic lymph node dissection were used to calculate the expected nodal involvement rate for the radiation therapy sample. Biochemical control and overall survival were estimated for the SN-IMRT patients using the Kaplan-Meier method. The expected frequency of nodal involvement in the radiation therapy group was estimated by imputing frequencies of node-positive patients in the surgical sample to the pattern of Gleason, prostate-specific antigen, and T category in the radiation therapy sample. RESULTS: After a median follow-up of 61 months, 5-year OS after SN-guided IMRT reached 84.4%. Biochemical control according to the Phoenix definition was 73.8%. The nodal clearance rate of SN-IMRT reached 94%. Retrospective follow-up evaluation is the main limitation. CONCLUSIONS: Radiation treatment of pelvic nodes individualized by inclusion of SNs is an effective regional treatment modality in high-risk prostate cancer patients. The pattern of relapse indicates that the SN-based target volume concept correctly covers individual pelvic nodes. Thus, this SN-based approach justifies further evaluation, including current dose-escalation strategies to the prostate in a larger prospective series.

Systemic IgG4-related sclerosing disease: spectrum of imaging findings and differential diagnosis.

OBJECTIVE: The purposes of this article are to provide a practical review of the spectrum of imaging findings in patients with systemic IgG4-related sclerosing disease and to address the differential diagnoses. CONCLUSION: IgG4-related sclerosing disease is a systemic disorder that can involve almost any organ. The imaging findings consist of diffuse and focal organ infiltration and encasement by inflammatory and fibrotic tissue. Awareness of the spectrum of imaging findings in IgG4-related disease should prompt further evaluation for systemic manifestations to avoid misdiagnosis.

Expression of the proliferation marker Ki-67 associates with tumour staging and clinical outcome in differentiated thyroid carcinomas.

OBJECTIVE: Although the prognosis of differentiated thyroid carcinoma (DTC) is excellent, with 10-year survival rates of about 90%, about one-third of patients experiences recurrent disease. We aimed to identify novel histological prognostic factors to optimize treatment and follow-up of patients at risks. DESIGN: Retrospective analysis of patients diagnosed from January 1990 to March 2004. SUBJECTS: A total of 93 patients diagnosed with DTC of which 67 with papillary and 26 with follicular histology. MEASUREMENTS: Analysis of immunohistochemical expression of somatostatin receptor (sst) subtypes 1-5, glucose transporter-1 (GLUT-1), receptor tyrosine kinase c-KIT, oestrogen and progesterone receptors, and proliferation marker Ki-67 and correlation with the patients' clinical outcome. RESULTS: DTC showed immunohistochemical expression of GLUT-1, C-KIT and progesterone receptor in a high percentage of cases (range: 57-80%). In contrast, the oestrogen receptor as well as the sst subtypes 1-5 was less frequently detected (range: 15-29%). Mean staining of the proliferation marker Ki-67 was 6% positive cells (range 0-20%). Ki-67 expression was significantly associated with tumour staging (ρ = 0·2076, P = 0·0459), whereas the other histopathological markers were not associated with gender, age, tumour entity, or tumour classification. Tumour staging and expression of Ki-67, oestrogen receptor and sst2, but of none of the other histopathological factors, independently predicted the clinical outcome 5 years after definitive treatment (P < 0·0001, P < 0·0001, P = 0·0004 and P = 0·0206, respectively). CONCLUSIONS: In patients with DTC, Ki-67 expression associates with tumour staging and clinical outcome.

Follow-up of acute osteomyelitis in children: the possible role of PET/CT in selected cases.

BACKGROUND: Magnetic resonance imaging (MRI) and/or scintigraphy are commonly used for follow-up in children after treatment of acute osteomyelitis. Regularly, post-treatment imaging reveals pathological findings even if serum inflammatory parameters and clinical presentation are normal. We analyzed combined positron emission tomography and multislice computed tomography (PET/CT) for this condition. METHODS: Six children received PET/CT after treatment of acute osteomyelitis. Post-treatment MRI had revealed suspicious residual and/or additional findings. All patients had physiological serum infection parameters and no clinical symptoms. RESULTS: Median patient age was 59.5 months (range, 48-156). No increased 18-Fluor-2-deoxy-D-glucose uptake was observed in 3 patients. In 3 patients, there was minimal activity at the site of infection, which, however, did not reach the presumed range of osteomyelitis. All children were taken off antibiotic medication. No clinical symptoms reoccurred in any of them, and repeatedly controlled serum infection parameters were all normal. Median follow-up was 33 months (range, 4-65). CONCLUSIONS: The PET/CT was superior to MRI in distinguishing between infection and reparative activity within the musculoskeletal system in selected children after acute osteomyelitis. The termination of antibiotic treatment for children after acute osteomyelitis seems justified when laboratory parameters as well as clinical presentation are normal, and PET/CT scan is unsuspicious.

Accuracy of parathyroid imaging: a comparison of planar scintigraphy, SPECT, SPECT-CT, and C-11 methionine PET for the detection of parathyroid adenomas and glandular hyperplasia.

PURPOSE: To compare the accuracy of planar scintigraphy, single photon emission computed tomography (SPECT), SPECT-CT, and positron emission tomography (PET) with C-11 methionine for the pre-operative detection of parathyroid adenomas. MATERIALS AND METHODS: We retrospectively evaluated the pre-operative studies of 60 patients with primary (n=56) and secondary (n=4) hyperparathyroidism. In 25/60 patients (Group 1), only planar scans were obtained, and additional SPECT and SPECT-CT were carried out in 35/60 patients (Group 2). PET or PET-CT with C-11 methionine was conducted in 8/60 patients (Group 3). RESULTS: The results of the planar scans (Group 1) were true positive in 19/25 patients and false negative in 6/25 patients (sensitivity per patient, 76%). Histopathology confirmed 27 adenomas and two hyperplasia. Planar imaging identified 20/29 of these pathologies, whereas 9/29 were missed (sensitivity per adenoma, 69%). SPECT (Group 2) results were true positive in 34/35 patients and false negative in only one case (sensitivity per patient, 97%). On a lesion-based analysis, 38 adenomas were identified, and two were missed (sensitivity per adenoma, 95%). The sensitivities of SPECT and SPECT-CT were equal; however, SPECT-CT provided superior topographic information. C-11 methionine PET (Group 3) results were true positive in all eight patients. In one case, surgery confirmed two ipsilateral adenomas, only one of which was identified by PET (sensitivity per patient, 100%; per adenoma, 88.9%). CONCLUSION: SPECT is superior to planar imaging. SPECT-CT has identical sensitivity compared to SPECT alone, but it provides additional topographic information. The sensitivity of PET appears to be even higher compared to SPECT. In the case of negative scintigraphic findings and proven hyperparathyroidism, additional C-11 methionine PET or PET-CT is recommended.

Distribution of prostate sentinel nodes: a SPECT-derived anatomic atlas.

PURPOSE: The randomized Radiation Therapy Oncology Group 94-13 trial revealed that coverage of the pelvic lymph nodes in high-risk prostate cancer confers an advantage (progression-free survival and biochemical failure) in patients with ≥15% risk of lymph node involvement. To facilitate an improved definition of the adjuvant target volume, precise knowledge regarding the location of the relevant lymph nodes is necessary. Therefore, we generated a three-dimensional sentinel lymph node atlas. METHODS AND MATERIALS: In 61 patients with high-risk prostate cancer, a three-dimensional visualization of sentinel lymph nodes was performed using a single photon emission computed tomography system after transrectal intraprostatic injection of 150 to 362 (median 295) mega becquerel (MBq) (99m)Technetium-nanocolloid (1.5-3 h after injection) followed by an anatomic functional image fusion. RESULTS: In all, 324 sentinel nodes in 59 of 61 patients (96.7%) were detected, with 0 to 13 nodes per patient (median 5, mean 5.3). The anatomic distribution of the sentinel nodes was as follows: external iliac 34.3%, internal iliac 17.9%, common iliac 12.7%, sacral 8.6%, perirectal 6.2%, left paraaortic 5.3%, right paraaortic 5.3%, seminal vesicle lymphatic plexus 3.1%, deep inguinal 1.5%, superior rectal 1.2%, internal pudendal 1.2%, perivesical 0.9%, inferior rectal 0.9%, retroaortic 0.3%, superficial inguinal 0.3%, and periprostatic 0.3%. CONCLUSIONS: The distribution of sentinel nodes as detected by single photon emission computed tomography imaging correlates well with the distribution determined by intraoperative gamma probe detection. A lower detection rate of sentinels in close proximity to the bladder and seminal vesicles is probably caused by the radionuclide accumulation in the bladder. In regard to intensity-modulated radiotherapy techniques, the presented anatomic atlas may allow optimized target volume definitions.

Central serotonin transporter levels are associated with stress hormone response and anxiety.

RATIONALE: Negative mood states are characterized by both stress hormone dysregulation and serotonergic dysfunction, reflected by altered thalamic serotonin transporter (5-HTT) levels. However, so far, no study examined the individual association between cortisol response and cerebral in vivo 5-HTT levels in patients suffering from negative mood states. OBJECTIVE: The objective of this cross-sectional study was to assess the interrelation of cortisol response, thalamic 5-HTT levels, and anxiety in healthy subjects and two previously published samples of patients with unipolar major depression (UMD) and obsessive-compulsive disorder (OCD), controlling for age, gender, 5-HTT genotype, smoking, and seasonality. METHODS: Regional 5-HTT levels and cortisol response to dexamethasone-corticotropin (Dex-CRH) challenge were assessed in consecutive samples of medication-free patients suffering from UMD (N = 10) and OCD (N = 10), and 20 healthy volunteers. The intervention used was combined Dex-CRH test and [(11)C]DASB positron emission tomography. The main outcome measures were: 5-HTT binding potential (BP(ND)) in a predefined thalamic ROI, cortisol response defined as the maximum cortisol increase in the combined Dex-CRH-test, and state of anxiety from the state-trait-anxiety inventory. RESULTS: Reduced thalamic 5-HTT BP(ND) was associated with increased cortisol response (r = -0.35, p < 0.05; in patients: r = -0.53, p < 0.01) and with increased state anxiety (r = -0.46, p < 0.01), surviving correction for age, gender, 5-HTT genotype, smoking, and seasonality (p < 0.05). The 5-HTT genotype, on the contrary, was not significantly associated with cortisol response (p = 0.19) or negative mood (p = 0.23). CONCLUSION: The association between stress hormone response, thalamic 5-HTT levels, and anxiety in patients suffering from negative mood states suggests an interaction between two major mechanisms implicated in negative mood states in humans.

PET/CT with 18F-FLT: does it improve the therapeutic management of metastatic germ cell tumors?

UNLABELLED: Because (18)F-FDG PET alone has only limited value in metastatic germ cell tumors (GCTs), we investigated the addition of 3'-deoxy-3'-(18)F-fluorothymidine (FLT) to (18)F-FDG for early response monitoring and prediction of the histology of residual tumor masses in patients with metastatic GCT. METHODS: Eleven patients with metastatic GCT were examined with both (18)F-FDG PET/CT and (18)F-FLT PET/CT before chemotherapy, after the first cycle of chemotherapy (early response), and 3 wk after completion of chemotherapy. In 1 patient with negative (18)F-FLT PET/CT results before chemotherapy, no further (18)F-FLT scanning was performed. PET images were analyzed visually and, using standardized uptake values (SUVs), semiquantitatively. The results were compared with the findings of CT and tumor marker levels and validated by histopathologic examination of resected residual masses, including Ki-67 immunostaining (7 patients), or by clinicoradiologic follow-up for at least 6 mo (4 patients). A responder was defined as a patient showing the presence of necrosis, a complete remission, or a marker-negative partial remission within a minimum progression-free interval of 6 mo. Early treatment response was judged according to the criteria of the European Organization for Research and Treatment of Cancer. RESULTS: Before chemotherapy, reference lesions showed increased (18)F-FDG uptake (mean SUV, 8.8; range, 2.9-15.0) in all patients and moderate (18)F-FLT uptake (mean SUV, 3.7; range, 1.7-9.7) in 10 of 11 patients. After 1 cycle of chemotherapy, mean SUV decreased in responders and nonresponders by 64% and 60%, respectively, for (18)F-FDG (P = 0.8) and by 58% and 48%, respectively, for (18)F-FLT (P = 0.5). After the end of chemotherapy, mean SUV decreased in responders and nonresponders by 85% and 73%, respectively, for (18)F-FDG (P = 0.1) and by 68% and 65%, respectively, for (18)F-FLT (P = 0.8). The results of early and final PET were inconsistent in 6 of 11 patients for (18)F-FDG and in 4 of 10 patients for (18)F-FLT. Both patients with teratoma had false-negative results on both (18)F-FDG and (18)F-FLT. The sensitivity, specificity, positive predictive value, and negative predictive value for detection of viable tumor after 1 cycle of chemotherapy were 60%, 33%, 43%, and 50%, respectively, for (18)F-FDG and 60%, 80%, 75%, and 67%, respectively, for (18)F-FLT PET/CT. The respective values after the end of chemotherapy were 20%, 100%, 100%, and 60% for (18)F-FDG and 0%, 100%, 0%, and 50% for (18)F-FLT PET/CT. CONCLUSION: PET-negative residual masses after chemotherapy of metastatic GCT still require resection, since the low negative predictive value of (18)F-FDG PET for viable tumor cannot be improved by application of (18)F-FLT.

Modified concept for radioisotope-guided sentinel lymph node dissection in prostate cancer.

PURPOSE: To present a modified concept for sentinel lymph node (SLN)-guided pelvic lymph node dissection in prostate cancer. METHODS: A total of 463 patients with histologically proven prostate cancer underwent SLN-guided lymph node dissection. The day before surgery patients received intraprostatic injection of Tc-99 m-labeled nanocolloid (Tc-NC) under transrectal ultrasound guidance. At the time of surgery, the lymph nodes of the obturator fossa were dissected routinely in all patients. After meticulous testing with a handheld gamma probe, all lymphatic tissues in predefined anatomic regions (external iliac, internal iliac, common iliacal and presacral) with Tc-NC uptake were additionally resected. RESULTS: In 146 (12.8%) patients, SLN were located exclusively in the obturator fossa, but 317 patients (87.2%) underwent resection of additional sentinel regions. In 28 (6.1%) patients, 62 lymph node metastases were detected, and 32 (51.6%) of these were located outside the obturator fossa. Eight (28.6%) patients displayed lymph node metastases exclusively outside the obturator fossa and had been resected only because of positive SLN probing. CONCLUSIONS: The obturator fossa comprises the major landing site of lymph node metastases, but more than half of the metastases are located outside this anatomic region. Routine resection of the obturator fossa with additional resection of positive sentinel regions improves staging accuracy compared to resection of the obturator fossa only.

Imaging findings in immunosuppressed patients with Epstein Barr virus-related B cell malignant lymphoma.

OBJECTIVE: The purpose of this study was to describe multimodality imaging findings in immunosuppressed patients with Epstein-Barr virus (EBV)-related malignant lymphoproliferative diseases. CONCLUSION: EBV-related malignant lymphoproliferative diseases share common features with other aggressive lymphomas, including a high degree of extranodal involvement, tumor vascularization, and tumor necrosis. Cognizance of the particular underlying diseases and conditions associated with the development of EBV-related lymphoproliferative diseases and associated imaging results should provide more accurate diagnosis.

Multimodal imaging in functional endocrine pancreatic tumors.

Endocrine pancreatic tumors, also known as pancreatic islet tumors, are rare entities of neuroendocrine origin that are located within the pancreas or in its close proximity. Approximately 50% of these tumors secrete biologically active substances that lead to the development of specific clinical syndromes. Once diagnosis has been established on the basis of clinical and laboratory findings, localization of the source of pathologic hormone secretion is warranted. Endocrine pancreatic tumor imaging comprises anatomical imaging modalities, such as ultrasound, computed tomography (CT) and MRI, as well as functional radiological studies, including arterial calcium stimulation with hepatic venous sampling, and functional nuclear medicine imaging modalities, such as scintigraphy and PET. The recent combination of high-resolution anatomic studies and functional imaging, such as PET/CT and single-photon emission CT/CT, allows excellent diagnostic evaluation of pancreatic islet cell tumors and has, therefore, especially high value. Given that none of these imaging methods are exclusively superior to the others, visualization of pancreatic islet cell tumors often requires the combination of different imaging modalities.

[68Ga]-DOTATOC-PET/CT for meningioma IMRT treatment planning.

PURPOSE: The observation that human meningioma cells strongly express somatostatin receptor (SSTR 2) was the rationale to analyze retrospectively in how far DOTATOC PET/CT is helpful to improve target volume delineation for intensity modulated radiotherapy (IMRT). PATIENTS AND METHODS: In 26 consecutive patients with preferentially skull base meningioma, diagnostic magnetic resonance imaging (MRI) and planning-computed tomography (CT) was complemented with data from [(68)Ga]-DOTA-D Phe(1)-Tyr(3)-Octreotide (DOTATOC)-PET/CT. Image fusion of PET/CT, diagnostic computed tomography, MRI and radiotherapy planning CT as well as target volume delineation was performed with OTP-Masterplan((R)). Initial gross tumor volume (GTV) definition was based on MRI data only and was secondarily complemented with DOTATOC-PET information. Irradiation was performed as EUD based IMRT, using the Hyperion Software package. RESULTS: The integration of the DOTATOC data led to additional information concerning tumor extension in 17 of 26 patients (65%). There were major changes of the clinical target volume (CTV) which modify the PTV in 14 patients, minor changes were realized in 3 patients. Overall the GTV-MRI/CT was larger than the GTV-PET in 10 patients (38%), smaller in 13 patients (50%) and almost the same in 3 patients (12%). Most of the adaptations were performed in close vicinity to bony skull base structures or after complex surgery. Median GTV based on MRI was 18.1 cc, based on PET 25.3 cc and subsequently the CTV was 37.4 cc. Radiation planning and treatment of the DOTATOC-adapted volumes was feasible. CONCLUSION: DOTATOC-PET/CT information may strongly complement patho-anatomical data from MRI and CT in cases with complex meningioma and is thus helpful for improved target volume delineation especially for skull base manifestations and recurrent disease after surgery.

3'-Deoxy-3'-[(18)F]fluorothymidine (FLT) uptake in breast cancer cells as a measure of proliferation after doxorubicin and docetaxel treatment.

INTRODUCTION: The nucleoside analogue [(18)F]fluorothymidine (FLT) has been designed as a marker of cell proliferation that can be imaged in vivo by positron emission tomography. Clinical pilot studies have demonstrated decreasing FLT uptake following antiproliferative chemotherapy of breast cancer. However, the significance of posttreatment FLT uptake has not been evaluated at the cell level. The aim of this study was to investigate whether FLT uptake detects proliferation inhibition induced by docetaxel or doxorubicin treatment in an in vitro breast cancer model. METHODS: Breast cancer cells (MCF-7) were treated with docetaxel or doxorubicin for 24 h at drug doses inducing 25-99% inhibition of clonogenic survival (IC(25) to IC(99)). Cellular FLT uptake was estimated at 4 h and at 1, 3 and 5 days interval from chemotherapy. [(3)H]Thymidine incorporation and S-phase fraction were measured for comparison. Analysis of variance and the Bland-Altman difference plot were employed for statistical analysis. RESULTS: After treatment, FLT uptake was declined in dependence of the proliferation inhibition mediated by both chemotherapeutic agents (all P<.0001). The decrease of FLT was greater after doxorubicin treatment than after the corresponding docetaxel dose. With doxorubicin (IC(99)), FLT accumulation was reduced by 70% as early as 4 h after treatment. FLT uptake was closely correlated to [(3)H]thymidine incorporation and S-phase fraction (r=.84 to .93). CONCLUSIONS: Right after docetaxel or doxorubicin treatment, FLT uptake corresponds to the reduction of tumor cell proliferation induced. [(18)F]FLT appears promising for monitoring chemosensitivity in breast cancer.

[18F]Fluorodeoxyglucose positron emission tomography in nonseminomatous germ cell tumors after chemotherapy: the German multicenter positron emission tomography study group.

PURPOSE: In patients with metastatic nonseminomatous germ cell cancer (NSGCT), residual masses after chemotherapy (CTX) can consist of vital carcinoma, mature teratoma, or necrosis. This prospective trial has evaluated the accuracy of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) for the prediction of histology compared with computed tomography (CT) and serum tumor markers (STM). PATIENTS AND METHODS: A total of 121 patients with stage IIC or III NSGCT scheduled for secondary resection after cisplatin-based CTX were included. FDG-PET was performed after completion of CTX. All results were confirmed by histopathology and correlated to STM and CT. RESULTS: Prediction of tumor viability with FDG-PET was correct in 56%, which did not reach the expected clinically relevant level of 70%, and was not better than the accuracy of CT (55%) or STM (56%). Sensitivity and specificity of FDG-PET were 70% and 48%. The positive predictive values were not significantly different (55%, 61%, and 59% for CT, STM, and PET, respectively). Judging only vital carcinoma as a true malignant finding, the negative predictive value increased to 83% for FDG-PET. CONCLUSION: The presence of vital carcinoma and mature teratoma is common (55%) in residual masses in patients with NSGCT, and CT and STM cannot reliably predict absence of disease. In contrast to prior studies, this prospective trial, which is the only with histologic confirmation in all patients, demonstrated that FDG-PET is unable to give a clear additional clinical benefit to the standard diagnostic procedures, CT and STM, in the prediction of tumor viability in residual masses.

Positron emission tomography has a high negative predictive value for progression or early relapse for patients with residual disease after first-line chemotherapy in advanced-stage Hodgkin lymphoma.

In the HD15 trial of the German Hodgkin Study Group, the negative predictive value (NPV) of positron emission tomography (PET) using [(18)F]-fluorodeoxyglucose in advanced-stage Hodgkin lymphoma (HL) was evaluated. A total of 817 patients were enrolled and randomly assigned to receive BEACOPP-based chemotherapy. After completion of chemotherapy, residual disease measuring more than or equal to 2.5 cm in diameter was assessed by PET in 311 patients. The NPV of PET was defined as the proportion of PET(-) patients without progression, relapse, or irradiation within 12 months after PET review panel. The progression-free survival was 96% for PET(-) patients (95% confidence interval [CI], 94%-99%) and 86% for PET(+) patients (95% CI, 78%-95%, P = .011). The NPV for PET in this analysis was 94% (95% CI, 91%-97%). Thus, consolidation radiotherapy can be omitted in PET(-) patients with residual disease without increasing the risk for progression or early relapse compared with patients in complete remission. The impact of this finding on the overall survival at 5 years must be awaited. Until then, response adapted therapy guided by PET for HL patients seems to be a promising approach that should be further evaluated in clinical trials. This trial is registered at http://isrctn.org study as #ISRCTN32443041.

Marginal zone B-cell non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue type: imaging findings.

OBJECTIVE: The aim of this essay is to describe the imaging features of marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type throughout various organs. CONCLUSION: Awareness of the expected locations of MALT lymphoma combined with knowledge of the incidence and imaging findings leads to accurate diagnosis of lesions suspicious for this disorder and helps to differentiate this disease from other abnormalities.