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Background The value of positron emission tomography/computed tomography (PET/CT) in the staging and assessment of treatment response in marginal zone lymphoma (MZL) lymphomas remains controversial. We investigated radiologic characteristics of subcutaneous MZL as imaged on PET/CT scans. Patients and Methods From the records of a single medical center, for the years 2008 and 2017, we identified subcutaneous lesions in PET/CT scans of patients with histopathologically confirmed MZL in sites other than subcutaneous tissue. Results Of 571 scans of 178 patients, subcutaneous lesions were found in 20 (11%). Lesions were located in soft tissue structures, mainly along the lateral aspects of the buttocks, thighs and lower and upper back areas, the flank, and the shoulders. Median lengths of the long and short axes of the lesions were 2.0 (range, 1.1-6.0) cm and 0.8 (range, 0.3-2.0) cm, respectively. Median standardized maximum uptake value was 2.3 (range, 0.9-7.6). In 12 patients (60%), MZL was diagnosed at an early stage; 15 (75%) had lymph node involvement and 10 (50%) extranodal involvement. One had spleen and 2 had cutaneous involvement; none had gastric findings. Conclusion The findings of this study support the usefulness of PET/CT in the detection of subcutaneous MZL as well as in staging and treatment decisions.

Objective To determine the safety and outcome following standard-dose ibritumomab tiuxetan followed by BEAM high-dose chemotherapy and autologous stem cell transplantation (ASCT) in patients with chemo-refractory aggressive non-Hodgkin's lymphoma. Patients and Methods The study included 23 patients, median age 55 years (range, 35–66) with chemo-refractory lymphoma, either primary refractory (n = 11) or in refractory relapse (n = 12). Rituximab 250 mg/m 2 followed by ibritumomab tiuxetan 0.4 mCi/kg were given on day −14 and high-dose BEAM chemotherapy started on day −6. Results All patients engrafted. Twenty-one patients are evaluable for response; 11 achieved CR, 9 achieved PR, 5 of whom converted to CR with additional radiation therapy (overall CR rate 76%). With a median follow-up of 17 months (range, 4–27) 16 patients are alive and 12 are progression-free. The estimated 2-year overall and progression-free survival are 67% (95% CI, 46–87%) and 52% (95% CI, 31–72%), respectively. The day-100 rate of treatment-related mortality was 9% (95% CI, 2–33%) and the 2-year cumulative incidence of relapse was 31% (95% CI, 17–57%). Extensive prior therapy (>3 lines), high LDH and IPI score at ASCT, bulky disease, and progression during last chemotherapy were risk factors for reduced survival. Conclusion Ibritumomab tiuxetan–BEAM and ASCT is relatively safe and may improve outcome in patients with refractory lymphoma. Although excess nonrelapse mortality can not be ruled out, relapse rate was relatively low, resulting in improved outcome. Standard-risk patients with chemo-sensitive disease may also benefit from ibritumomab tiuxetan–BEAM and ASCT. This hypothesis merits further study in larger-scale prospective randomized studies.

Allogeneic SCT is an effective therapy for lymphoma. Reduced-intensity conditioning (RIC) reduces non-relapse mortality (NRM) associated with myeloablative conditioning but relapse rates are high when performed in active disease. This study was designed to explore the safety and outcome of ibritumomab tiuxetan (Zevalin) combined with RIC in patients with advanced lymphoma. The study included 12 patients, median age 54 years (37-62), with a median of four prior treatments (2-6) and active disease documented on PET-CT. Zevalin 0.4 mCi/kg was given on day -14 and fludarabine combined with BU (n=6) or melphalan (n=6) was started on day -6. GVHD prevention was tapered 3 months after SCT to augment the graft-versus-lymphoma effect. All patients engrafted, a median of 14 days after SCT. Eighty-three percent achieved CR/PR. With a median follow-up of 21 months (12-37), 2-year PFS is 33%. Only three patients relapsed; cumulative incidence 25%. NRM was 42%, predominantly due to acute GVHD. Zevalin-RIC is feasible with consistent engraftment, acceptable organ toxicity, but high rates of acute GVHD. The low incidence of relapse suggests augmented anti-lymphoma effect. Zevalin-RIC merits further study. Better results may be achieved in patients earlier in disease course and with longer duration of immune-suppression.

We showed that differences in learning capacity between DBA and C57Bl/6 mice correlates with differences in slow afterhyperpolarization amplitude in hippocampal CA1 pyramid neurons. In DBA mice learning capacity is lower, but the amplitude of slow afterhyperpolarizations higher than in C57Bl/6 mice.

Authors from Israel have investigated the use of dynamic renal scans in young female patients with acute pyelonephritis, combined with indirect radionuclide cystography. They found that using these techniques may avoid up to half of the delayed voiding cysto-urethrograms, preventing the related inconvenience and cost. OBJECTIVE To review our experience using dynamic 99mTc-diethylenetriamine penta-acetic acid renal scintigraphy combined with indirect radionuclide cystography (IRC) in the acute phase of pyelonephritis, as a possible alternative to the conventional imaging, as investigating acute pyelonephritis usually includes imaging the upper urinary tract during the acute phase, to exclude obstruction, and delayed voiding cysto-urethrography (VCUG) when underlying vesico-ureteric reflux (VUR) is suspected. PATIENTS AND METHODS Between 1997 and 1999, 47 young women (median age 22 years, range 18–37) were hospitalized for acute pyelonephritis. The combined study was used during the acute phase of the disease, usually within 24 h of hospitalization. The principle of IRC is based on the reappearance of radioactivity in the ureters or kidneys after previously detecting renal clearance of an intravenously injected radioisotope. The increase in radioactivity over the ureters or kidneys indicates VUR. The subsequent follow-up included VCUG, after recovery and at least 6 weeks after discharge. RESULTS Overall, 47 patients had early IRC studies; obstruction of the urinary tract during the acute phase of the disease was excluded in all. In 13 (28%) of the patients early IRC studies showed VUR involving 21 upper tract units. The renal parenchymal scan was impaired in 17 (36%) patients, and six of these 17 also had detectable concomitant reflux on IRC. Overall, 24 IRC studies (51%) were considered positive, showing VUR, renal parenchymal pathology or both; 23 (49%) were normal. Follow-up VCUG was used in 32 patients (68%); only three (9%) detected VUR. All of the patients with VUR on follow-up VCUG had also had an abnormal early IRC study, showing either reflux (two) or findings suggestive of pathological renal parenchyma (one). CONCLUSIONS In addition to the well-established role of renal scintigraphy in excluding obstruction of the collecting system, early IRC is characterized by high sensitivity and accurate negative predictive value for detecting VUR. It can therefore be used to screen adults presenting with acute pyelonephritis for the presence of VUR. Patients with an abnormal IRC require follow-up VCUG after complete recovery, while those with a negative study may be managed expectantly, with no further radiological evaluation. This proposed strategy may avoid up to half of the delayed VCUG studies, preclude the related inconvenience, and substantially reduce the costs.

Squamous cell carcinoma (SCC) is the most common cancer of the head and neck (HNC). Advanced HNC warrants extensive ablative and reconstructive procedures, significantly altering locoregional anatomy, while radiation treatment further adds to the distortion. Anatomic imaging is therefore often inconclusive in suspected recurrent HNC. Functional imaging with fluorodeoxyglucose-positron emission tomography (FDG-PET) has been reported contributory in the evaluation of patients with SCC. While most reports are from dedicated PET systems, full ring PET is of limited availability and gamma-PET may offer a suitable compromise. The therapeutic impact of gamma-PET in patients with suspected recurrent HNC was retrospectively evaluated. Seventeen patients were evaluated. All had undergone surgery for HNC, 16 also received radiotherapy. gamma-PET scans were compared to anatomic imaging, histopathology and clinical follow-up. The impact of the FDG-PET scan on patient management was then evaluated. Eleven positive findings were confirmed. Two false positives were due to radiation changes, a recognized pitfall. There were no false negatives. Overall accuracy of the 18F-FDG gamma-PET scans was 88% with considerable effect on patient management. Gamma-PET with FDG appears valuable in the evaluation of suspected recurrent HNC, and may provide a suitable alternative when dedicated PET is unavailable.

The therapeutic approach to recurrent well-differentiated thyroid cancer is based on the detection of active disease. While a measured increase of thyroglobulin level in an ablated patient is highly suggestive of recurrence, localization of the tumour is necessary for adequate treatment planning. A whole body scan with 131I yields false negative results in the presence of non-iodophyllic foci of disease. Hypermetabolic foci of differentiated thyroid carcinoma can be detected by gamma PET with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG). This study retrospectively evaluated the therapeutic impact of the 18F-FDG scan in patients with suspected recurrent thyroid carcinoma in whom the iodine scan was negative. Twenty patients (five male, 15 female) aged 19-77 years, were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels and/or palpable neck findings. All whole body iodine scans obtained with diagnostic doses (74-148 MBq (2-4 mCi) of 131I), were reported normal, i.e., no iodophyllic foci were detected. Whole body gamma positron emission tomography (PET) imaging was performed in fasting patients following i.v. administration of 370 MBq (10 mCi) 18F-FDG, with a strict 1 h immobilization post-injection. Gamma PET results were validated either by anatomical imaging, repeat iodine scanning after administration of a therapeutic dose (at least 3,700 MBq (100 mCi) of 131I) or surgery. The impact of the FDG scan on patient management was evaluated by the referring physicians. Positive gamma PET results confirmed the presence of active disease in 14/15 patients. One false positive finding (fibrosis) and one false negative (carcinoid) were reported. Localization of hypermetabolic foci supported treatment decisions in 10 patients, and significantly altered therapeutic management in six others. Treatment was withheld in four patients with negative findings. The clinical impact of the scan in this patient group is similar to that reported in the literature and justifies its future implementation.

6538 Background: High-dose chemotherapy and autologous SCT have an established role in the treatment of patients with first chemo-sensitive relapse of aggressive lymphoma. However, autologous SCT has only limited success when performed in refractory or progressive stage of the disease and the expected 1-year progression-free survival (PFS) in this setting is < 20%. Methods: This study was designed to explore the safety and outcome following inclusion of ibritumomab tiuxetan (IT) in the conditioning regimen given prior to autologous SCT. Patients were eligible for this study only if they had refractory lymphoma and a positive PET-CT prior to SCT. The primary end-point was 1-year PFS. Rituximab 250 mg/m2 followed by IT 0.4 mCi/kg were given on day -14. Chemotherapy according to standard BEAM was started on day -6. Results: The study included 20 pts, median age 55 years (range, 35–66). Histology was diffuse large cell (n=14), transformed follicular (n=5) and mantle cell lymphoma (n=1). Patients had active lymphoma at SCT, either primary refractory (n=11) or refractory relapse (n=9) and 12 had bulky disease at SCT. The median number of prior therapies was 3 (range, 1–6). There were no early infusion reactions associated with IT. Fourteen patients achieved CR, 4 achieved PR and 2 died early after SCT. With a median follow-up of 9 months (range, 1–20), 14 patients are alive and 6 have died with an estimated 1-year survival of 58% (95% C.I., 31–85). All surviving patients are progression-free. Only 2 patients relapsed with a 1-year cumulative incidence of only 14% (5–51). Two patients died of multi-organ toxicities and 2 of late occurring infections. These rates of non-relapse mortality are expected in heavily pretreated patients with refractory lymphoma and there was no additional toxicity related to IT. Conclusions: The inclusion of IT in the conditioning regimens given prior to autologous SCT may reduce the risk of relapse following autologous SCT and improve the poor outcome of patients with refractory lymphoma given SCT with standard conditioning regimens. This observation merits further study in larger comparative trials. No significant financial relationships to disclose.