Enlightening the Immune Mechanism of the Abscopal Effect in a Murine HCC Model and Overcoming the Late Resistance With Anti-PD-L1.

PURPOSE: The establishment of a preclinical model of the abscopal effect on hepatocellular carcinoma (HCC) and evaluation of whether the hypofractionated radiation therapy (RT) multitumor Hepa1-6 mouse HCC model could be used to suppress nonradiated tumor mass was performed in this study. METHODS AND MATERIALS: Hepa1-6 mouse liver cancer cell lines were used to form tumors. Immunogenicity was analyzed using ELISpot and immune cell labeled antibody. Interferon (IFN) ß expression was confirmed through polymerase chain reaction. RESULTS: After investigation, the intratumoral transcription of type Ⅰ IFN increased by 2-fold. The antitumor immune response to Hepa 1-6 cells induced by radiation was increased. Moreover, the influx of activated CD8+ T cells was increased in nonirradiated tumors. The number of dendritic cells and activation status were evaluated by flow cytometry on the second day after irradiation. Flow cytometry revealed a significantly increased dendritic cell population expressing the CD11c molecule in tumor-draining lymph nodes. Furthermore, because irradiation leads to adaptation of immune resistance of tumor cells against RT, we sought to elucidate a potent tool to overcome the resistance and confirm the ability of PD-L1 antibody to survive late RT resistance. CONCLUSIONS: The immunologic mechanism of the abscopal effect was revealed and the application of PD-L1 inhibitor successfully performed as a breakthrough in late RT resistance in the Hepa1-6 tumor model.

Setup uncertainties for inter-fractional head and neck cancer in radiotherapy.

PURPOSE: The aim of this study is to determine the inter-fractional motion of cervical spine in radiotherapy (RT). MATERIALS AND METHODS: Eleven localized head and neck cancer patients who were treated from April 2014 to September 2015 were evaluated. Every patient underwent 3 times of computed tomography (CT) simulation with equivalent setting. Left-right (LR, x) and antero-posterior (AP, z) directional shift of cervical spine were evaluated using 33 number of CT image. In regard to random error, geometric changes were evaluated by 22 data set (compared the first obtained CT to second or third CT) by one-sample T test. Systemic error was evaluated by each patients' data set (11 pairs) by paired T test. RESULTS: The mean random error of LR and AP translational shift of cervical spine were -0.39 ± 3.24 mm and -0.57 ± 0.99 mm respectively. The mean random error of translational change of AP direction showed statistical significance (p = 0.014). The mean random error of x and z rotational shift were -0.07 ± 0.29° and -0.05 ± 0.35°, respectively. The mean systemic error of translational shift of LR and AP direction were -0.64 ± 2.57 mm and -0.33 ± 1.22 mm, respectively. The mean systemic error of rotational shift of x and z were 0.01 ± 0.18° and -0.27 ± 0.33°, respectively. The mean systemic error of rotational changes of z direction showed statistical difference (p = 0.022). CONCLUSIONS: We have to be aware of the inter-fractional motion of cervical spine in head and neck RT and give enough margins in RT planning.

Comparative analysis of radiation dose and image quality between thyroid shielding and unshielding during CT examination of the neck.

OBJECTIVE: The purpose of this study is to evaluate the feasibility of thyroid shielding by measuring radiation dose, CT attenuation, and noise of superficial neck structures during CT examination. SUBJECTS AND METHODS: We divided 84 patients without abnormalities seen on CT into two groups depending on whether shielding with a cotton spacer was applied over the thyroid. On CT images, we measured the CT attenuation and noises in the strap and sternocleidomastoid (SCM) muscles. The superficial radiation dose was measured using a head CT dose phantom containing ionization chambers located at the 3, 6, 9, and 12 o'clock positions. RESULTS: With thyroid shielding, the CT attenuation was significantly increased (shielded strap and SCM muscles, 117.6 ± 19.2 HU and 113.7 ± 31.8 HU, respectively; unshielded strap and SCM muscles, 84.1 ± 12.2 HU and 78.4 ± 10.1 HU, respectively; p < 0.05), whereas noise was unaffected (shielded strap and SCM muscles, 7.2 ± 4.2 HU and 10.8 ± 4.9 HU, respectively; unshielded strap and SCM muscles, 8.6 ± 4.9 HU and 10.7 ± 6.6 HU, respectively; p > 0.05). On the phantom study, the shield significantly reduced the superficial unshielded dose at the 12 o'clock position only (27.5% reduction; p < 0.01). CONCLUSION: Below the shielded surface, thyroid shielding significantly reduced the superficial radiation dose of the neck without a remarkable noise increase while increasing CT attenuation.

Radiography, Bone Scan, and F-18 FDG PET/CT Imaging Findings in a Patient with Paget's Disease.

BACKGROUND: A 52-year-old female patient sought evaluation at our hospital for an incidental abnormal finding on an abdominal radiograph. METHODS: The initial radiograph showed irregular sclerotic changes involving the right pelvic bone. At the same time, bone scintigraphy showed intense hot uptake in the right iliac and pubic bones. CT images showed characteristic thickening of the pelvic brim, suggesting the mixed phase of Paget's disease. RESULTS: The level of alkaline phosphatase (ALP) was 266 IU/l. (18)F-FDG PET/CT images also showed diffusely increased (18)F-FDG uptake in the right pelvic bone. However, the findings of (18)F-FDG PET/CT were less notable than those of bone scintigraphy. CONCLUSION: We report the imaging findings of a patient with Paget's disease evaluated by radiography, bone scintigraphy, and (18)F-FDG PET/CT.

Sonography of biopsy-proven Langerhans cell histiocytosis in lymph nodes of the neck.

OBJECTIVE: The purpose of this series is to describe the sonographic findings of lymph nodes of the neck involved by Langerhans cell histiocytosis (LCH). METHODS: We reviewed and interpreted available images of lymph nodes in patients with cervical lymphadenopathies involved by LCH for the past decade. In all patients, each abnormal lymph node was pathologically confirmed by the use of a sonographically guided core needle biopsy or an incisional biopsy. RESULTS: We characterized 3 different kinds of imaging findings for cervical lymph nodes involved by LCH: (1) a lymphomalike lesion, (2) a lesion similar to reactive lymphadenopathy, and (3) a cystic lymph node. CONCLUSIONS: There was no specific imaging finding to diagnose lymphadenopathy involved by LCH. In our study, we characterized 3 different imaging patterns of lymph node involvement by LCH. This study represents an initial step to organize specific findings for LCH.

Dielectric properties of Ni-coated BaTiO/sub 3-/PMMA composite.

Dielectric properties of Ni-coated BaTiO(3)-PMMA (polymethyl methacrylate) composite were studied from an embedded capacitor application viewpoint. Volume loading of up to 50% was attempted, and the results were compared with uncoated BaTiO(3)-PMMA composite. Ni-coating on BaTiO(3) powder was found to greatly improve the dielectric properties of the composite, especially the dielectric constant value. K values of about 100 with temperature-stable X7E characteristics were realized.