The usefulness of 18F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with 18F-FDG PET/CT

Purpose

This study aimed at demonstrating the feasibility of retrospectively fused ¹⁸F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image.

Methods

We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion.

Results

FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT.

Conclusions

In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.     

Apparent diffusion coefficient as a prognostic biomarker of upper urinary tract cancer: a preliminary report

Objectives

To investigate the role of apparent diffusion coefficient (ADC) as a biomarker reflecting the aggressiveness of upper urinary tract urothelial cell carcinoma (UUT-UCC).

Methods

Thirty-four consecutive patients treated with nephroureterectomy for non-metastatic disease were prospectively enrolled in this study. ADC was compared with clinicopathological variables including Ki-67 labelling index (LI) and cancer-specific survival (CSS).

Results

The overall 3-year CSS rate was 82 % (median follow-up, 36 months). ADC was significantly lower in grade 3 disease than in grades 1–2 disease (P?=?0.011) and significantly and inversely correlated with Ki-67 LI (ρ?=??0.59, P?=?0.0002). Low ADCs (<1.10?×?10^?3 mm²/s) were significantly associated with shorter CSS (P?=?0.039). Multivariate analysis of preoperative variables identified ADC and MRI-based clinical T stage as independent indicators of shorter CSS; the patients were stratified into high-risk (8 patients with low ADC and at least clinical T3) and low-risk (26 patients with high ADC or not more than clinical T2) groups with 3-year CSS rates of 43 % and 93 % (P?=?0.0003).

Conclusions

Our preliminary data suggest the potential role of ADC as a quantitative biomarker reflecting the aggressiveness of UUT-UCC. ADC might be useful for preoperative risk stratification of UUT-UCC patients.

Key Points

? Diffusion-weighted MRI offers new information about the aggressiveness of urinary tract cancers. ? The apparent diffusion coefficient acts as a quantitative biomarker for upper urinary tract cancers. ? ADC inversely correlates with immunohistochemical and histological grading of UUT-UCC. ? ADC offers a prognosis for UUT-UCC patients treated with nephroureterectomy.     

Attenuation of chronic thermotolerance by KNK437, a benzylidene lactam compound,enhances thermal radiosensitization in mild temperature hyperthermia combined with low dose-rate irradiation

Purpose: We investigated whether the attenuation of chronic thermotolerance by KNK437, a heat shock protein inhibitor, can modify the effect of thermal radiosensitization in mild temperature hyperthermia (MTH) combined with low dose-rate irradiation (LDRI).

Materials and methods: The human lung adenocarcinoma cell line A549 was simultaneously exposed to LDRI with MTH at 41°C and KNK437 at a dose of 100 μM. Cell survival was estimated by a clonogenic assay. Cell cycle change during treatment was analyzed by flow cytometry. Expression levels of the heat shock proteins hsp72, hsp27 and heat shock factor 1 (HSF-1) were measured by Western blotting.

Results: KNK437 inhibited the expression of inducible hsp72 and hsp27, but produced no change in the mobility shift of HSF-1. The cytotoxicity of LDRI was enhanced by MTH. The survival curve for LDRI + MTH revealed no development of chronic thermotolerance up to 48 h. Simultaneous LDRI and KNK437 treatment also resulted in enhanced cell killing. The radiosensitizing effect of KNK437 was enhanced by simultaneous exposure of the cells to MTH. Flow cytometry analysis of cell cycle progression demonstrated marked G2 arrest and mild G1 arrest with LDRI alone, but mild G1 arrest with MTH alone, and mild G2-M, S-phase accumulation with KNK437 alone. The marked G2 arrest caused by LDRI was partially suppressed by the addition of MTH, and was also suppressed by KNK437 treatment.

Conclusions: Exposure of A549 cells to KNK437 caused inhibition of hsp72 and hsp27 expression. The addition of KNK437 increased not only thermosensitivity to MTH, but also radiosensitivity to LDRI. KNK437 also enhanced the MTH-induced radiosensitization under these experimental conditions.     

Correction to: Indications for fertility preservation not included in the 2017 Japan Society of Clinical Oncology Guideline for Fertility Preservation in Pediatric,Adolescent, and Young Adult Patients treated with gonadal toxicity,including benign diseases

International Journal of Clinical Oncology -     

A case of intravascular large B-cell lymphoma mimicking erythema nodosum: the importance of multiple skin biopsies

BACKGROUND: Intravascular lymphoma is a rare disease characterized by the proliferation of neoplastic monuclear cells within the lumens of small blood vessels. The neoplastic cells are usually of B-cell origin, and rarely of T-cell or histiocytic origin. Although this clinicopathological entity of lymphoma has not been listed in general pathological classifications such as REAL classification or the Working Formulation, it is recently in the WHO classification scheme, which is essentially an updated REAL scheme, and the EORTC classification scheme. METHODS: In this report, a 62-year-old woman with intravascular large B-cell lymphoma was observed by clinical, histopathological, immunohistochemical and molecular methods. RESULTS: A 62-year-old woman presented with large erythematous macules on the bilateral thighs and lower legs. The lesions were accompanied with hard, tender, intradermal or subcutaneous nodules mimicking erythema nodosum. Histopathological examination in the first biopsy revealed non-specific panniculitis compatible with erythema nodosum. The second biopsy revealed emboli of atypical lymphocytes within many of the dilated and proliferated vessels in the deep dermis and subcutaneous tissue. These cells were positive for L-26 and kappa light chain, and negative for lambda light chain, factor VIII-related antigen, CD30, CD34, CD68 and UCHL-1. These findings confirmed the diagnosis of intravascular large B-cell lymphoma. A laboratory examination showed a high level of LDH and abnormal cells in the bone marrow. An MRI of the brain and computed tomographic (CT) scans of the chest and abdomen revealed no evidence of malignancy. Before the treatment, the size of the nodules decreased spontaneously by about 50% in one month and significantly in two months. Although combination chemotherapy, which consisted of CHOP, brought her partial remission, she experienced neurological symptoms 6 months after the initial treatment and died of brain metastasis 9 months after the treatment. CONCLUSIONS: This is a unique case for two following reasons: 1) the first biopsy revealed non-specific findings compatible with erythema nodosum; and 2) before the treatment, the nodules regressed spontaneously. Dermatologists should take multiple skin biopsies for EN lesions with the non-specific histopathological findings not to refute the existence of this disease.     

Digital gangrene associated with idiopathic hypereosinophilia: treatment with allogeneic cultured dermal substitute (CDS)

In the present case study, the patient was a 65-year-old man who suddenly developed purpuric and necrotic lesions with severe pain in his fingers and toes. Laboratory investigations revealed marked eosinophilia (77.9%), but there was no evidence to support a diagnosis of parasitic infections, allergic disease, neoplasm or connective tissue disorder. The histopathological findings did not show any distinct vasculitis, but there were obliterative changes of the arterioles. The digital gangrene gradually progressed and was unresponsive to corticosteroid therapy. The patient eventually underwent amputation of the distal phalanges. We applied allogeneic cultured dermal substitute (CDS) to the skin defect. The allogeneic CDS was prepared by culturing fibroblasts on a two-layered sponge of hyaluronic acid and atelo-collagen. This CDS is able to release a number of cytokines including VEGF. The present case had a good clinical result.