Assessment of biological dosimetric margin for stereotactic body radiation therapy

Purpose: To develop a novel biological dosimetric margin (BDM) and to create a biological conversion factor (BCF) that compensates for the difference between physical dosimetric margin (PDM) and BDM, which provides a novel scheme of a direct estimation of the BDM from the physical dose (PD) distribution. Methods: The offset to isocenter was applied in 1‐mm steps along left‐right (LR), anterior‐posterior (AP), and cranio‐caudal (CC) directions for 10 treatment plans of lung stereotactic body radiation therapy (SBRT) with a prescribed dose of 48 Gy. These plans were recalculated to biological equivalent dose (BED) by the linearquadratic model for the dose per fraction (DPF) of d = 3–20 Gy/fr and α/β= 3 - 10. BDM and PDM were defined so that the region that satisfied that the dose covering 95% (or 98%) of the clinical target volume was greater than or equal to the 90% of the prescribed PD and BED, respectively. An empirical formula of the BCF was created as a function of the DPF. Results: There was no significant difference between LR and AP directions for neither the PDM nor BDM. On the other hand, BDM and PDM in the CC direction were significantly larger than in the other directions. BCFs of D95% and D98% were derived for the transverse (LR and AP) and longitudinal (CC) directions. Conclusions: A novel scheme to directly estimate the BDM using the BCF was developed. This technique is expected to enable the BED‐based SBRT treatment planning using PD‐based treatment planning systems

Clinicopathological Features and Surgical Outcomes of Small Bowel Metastasis from Renal Cell Carcinoma

Small bowel metastasis from renal cell carcinoma (RCC) is rare, and its clinicopathological characteristics are unclear; thus, we revisited the concept of this tumor and reviewed its diagnostic and treatment modalities. We filtered MEDLINE searches of articles published in English between 1950 and 2019, and identified 100 patients who had undergone treatment, including 1 patient from our clinic. We extracted patient characteristics, treatment, and prognostic data, resulting in clinicopathological data on 100 patients (83 men, 17 women). Mean age was 63 years (range, 16-86 years). Tumor sites were duodenum, jejunum, ileum, and multiple sites in 30, 37, 25, and 7 patients, respectively. The 1-, 3-, and 5-year overall survival rates after diagnosis were 53.0%, 36.0%, and 36.0%. Curative resection patients showed 62.1% 5-year survival after surgery, vs. 27.5% in noncurative surgical management cases. Good prognoses can be expected if these tumors are identified early for complete removal. Surgery is the only curative option. To determine the best management strategy and improve prognostic accuracy, we continue to collect and analyze epidemiological and pathological data. Although this condition is rare, surgery should be considered if curative resection is expected. Prognosis after curative resection is not poor, but recurrence is not unlikely

Curved-space classical solutions of a massive supermatrix model

We investigate here a supermatrix model with a mass term and a cubic interaction. It is based on the super Lie algebra osp(1|32,R), which could play a role in the construction of the eleven-dimensional M-theory. This model contains a massive version of the IIB matrix model, where some fields have a tachyonic mass term. Therefore, the trivial vacuum of this theory is unstable. However, this model possesses several classical solutions where these fields build noncommutative curved spaces and these solutions are shown to be energetically more favorable than the trivial vacuum. In particular, we describe in details two cases, the SO(3) \times SO(3) \times SO(3) (three fuzzy 2-spheres) and the SO(9) (fuzzy 8-sphere) classical backgrounds.Comment: 16 pages, no figure, v2: shortened and clarified version, v3: some minor typos correcte

Current Disease Management of Primary Urethral Carcinoma

Context: Primary urethral cancer (PUC) is a rare cancer entity. Owing to the low incidence of this malignancy, the main body of literature consists mainly of case reports, making evidence-based management recommendations difficult. Objective: To review reported disease management strategies of PUC and their impact on oncological outcomes. Evidence acquisition: A systematic research was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement using Medline, Scopus, and Web of Science, to find studies of the past 10yr including ≥20 patients, and investigating treatment strategies and their impact on outcomes of the three most frequent histologies: urothelial carcinoma, adenocarcinoma, and squamous cell carcinoma. Evidence synthesis: In localized PUC, penis-sparing surgery can be performed in males, while in females, complete urethrectomy with surrounding tissue is advised to minimize recurrence due to positive margins. Radiotherapy (RT) has worse survival and recurrence rates, as well as more adverse effects, than surgery, limiting its use in genital-preserving therapy. Locally advanced PUC should be treated with multimodal therapy, as monotherapies result in inferior recurrence and survival rates. Extent of surgery is still undecided, favoring radical cyst(oprostat)ectomy with total urethrectomy (RCU). Lymph node involvement is a predictor of survival, highlighting the role of lymph node dissection for disease control and staging. RT can improve survival in combination with surgery and/or chemotherapy (CHT). Neoadjuvant platinum-based CHT can improve overall and recurrence-free survival. At recurrence, salvage therapy with surgery and/or CHT can improve survival. Superficial urothelial carcinoma of the prostatic urethra can be treated with transurethral resection. Stromal invasion often features concomitant bladder cancer with a poor prognosis and requires RCU with or without systemic preoperative CHT. Conclusions: PUC is a rare malignancy with an often poor natural course, requiring a stage- and gender-specific risk-based treatment strategy. The role of systematic perioperative CHT and the extent of surgery are becoming more important. Patient summary: In this review, we looked at the treatment options for primary urethral cancer. We found that while an organ-confined disease can be managed with local resection, growth beyond the organ border makes a combination of different treatment modalities, such as surgery and systematic chemotherapy, necessary to improve outcomes

Regular pulse checks for patients with non-cardioembolic stroke in rehabilitation hospitals to improve recognition and detection of atrial fibrillation (the ESCORT study): protocol for a prospective multicenter observational study

BackgroundCryptogenic stroke (CS) are heterogeneous in origin; however, most CS are embolic mechanism. Paroxysmal atrial fibrillation (AF) is suspected to be a major type of CS that leads to severe cerebral infarction without anticoagulant use. Therefore, the identification of AF is vital in patients with CS. However, patients are often unaware of AF because they have no symptoms, and AF may not be detected on an electrocardiogram (ECG) or Holter ECG on admission. After patients with stroke are treated in the acute phase, they are promptly transferred to a rehabilitation hospital for functional recovery. Once the patient is transferred to a hospital, a few attempts are made to detect AF. In addition, rehabilitation therapists are considered to have insufficient awareness of the possibility of undiagnosed AF.ObjectiveThis study aimed to increase the understanding of the importance of AF detection in patients with ischemic stroke among therapists in rehabilitation hospitals and to investigate whether regular pulse screening can aid in the detection of AF. If AF was detected, we determined the rate and timing of AF detection and identified the patient characteristics.MethodsThis multicenter prospective observational study aimed to detect AF in patients with non-cardiac stroke at rehabilitation hospitals. Therapists performed pulse checks before, during, and after rehabilitation. If arrhythmia or tachycardia was detected, an ECG was performed, and the physician checked for AF. If the patient complained of chest symptoms, electrocardiography (ECG) was performed to check for AF. We investigated the characteristics, laboratory data, cognitive status, complications, such as stroke recurrence, and functional outcomes of patients with AF.ResultsThe study is in the enrollment phase. Recruitment began in September 2022 and will end in August 2023. Patients have provided written informed consent. The main results have been submitted for publication in your journal.ConclusionThe findings of this study will help identify patients with AF in rehabilitation hospitals and improve awareness among therapists

Perturbative dynamics of fuzzy spheres at large N

We clarify some peculiar aspects of the perturbative expansion around a classical fuzzy-sphere solution in matrix models with a cubic term. While the effective action in the large-N limit is saturated at the one-loop level, we find that the ``one-loop dominance'' does not hold for generic observables due to one-particle reducible diagrams. However, we may exploit the one-loop dominance for the effective action and obtain various observables to all orders from one-loop calculation by simply shifting the center of expansion to the ``quantum solution'', which extremizes the effective action. We confirm the validity of this method by comparison with the direct two-loop calculation and with Monte Carlo results in the 3d Yang-Mills-Chern-Simons matrix model. From the all order result we find that the perturbative expansion has a finite radius of convergence.Comment: 21 pages, 9 figures, (v2) all order analyses added, (v3) some typos correcte

A Rare Case of Diffuse Large B-cell Lymphoma in a Patient with IgG4-Related Autoimmune Pancreatitis

A 61-year-old Japanese man with IgG4-related autoimmune pancreatitis was referred to our hospital because of perspiration during food intake. Abdominal computed tomography (CT) with contrast media revealed multiple mesenteric lymphadenopathies. An open surgical abdominal biopsy and subsequent histopathological analysis revealed abnormally large lymphoid cells that were negative for CD3, CD5, and c-myc and positive for CD20 and bcl-2, leading to a diagnosis of diffuse large B-cell lymphoma. Here, we discuss the risk of malignancies, particularly malignant lymphoma in patients with IgG4-related disease. The importance of pathological analysis to reach the appropriate diagnosis in such cases should be emphasized

Dynamical aspects of the fuzzy CP2^{2} in the large NN reduced model with a cubic term

``Fuzzy CP^2'', which is a four-dimensional fuzzy manifold extension of the well-known fuzzy analogous to the fuzzy 2-sphere (S^2), appears as a classical solution in the dimensionally reduced 8d Yang-Mills model with a cubic term involving the structure constant of the SU(3) Lie algebra. Although the fuzzy S^2, which is also a classical solution of the same model, has actually smaller free energy than the fuzzy CP^2, Monte Carlo simulation shows that the fuzzy CP^2 is stable even nonperturbatively due to the suppression of tunneling effects at large N as far as the coefficient of the cubic term ($\alpha$) is sufficiently large. As \alpha is decreased, both the fuzzy CP$^2$ and the fuzzy S^2 collapse to a solid ball and the system is essentially described by the pure Yang-Mills model (\alpha = 0). The corresponding transitions are of first order and the critical points can be understood analytically. The gauge group generated dynamically above the critical point turns out to be of rank one for both CP^2 and S^2 cases. Above the critical point, we also perform perturbative calculations for various quantities to all orders, taking advantage of the one-loop saturation of the effective action in the large-N limit. By extrapolating our Monte Carlo results to N=\infty, we find excellent agreement with the all order results.Comment: 27 pages, 7 figures, (v2) References added (v3) all order analyses added, some typos correcte

Lanthanum Deposition in the Stomach: Usefulness of Scanning Electron Microscopy for Its Detection

After having been treated with lanthanum carbonate administration for 4 years for hyperphosphatemia, a 75-year-old Japanese woman undergoing hemodialysis was diagnosed with lanthanum phosphate deposition in the stomach. The deposition, seen as white microgranules, was observed using esophagogastroduodenoscopy with magnifying observation. To the best of our knowledge, these are the minutest endoscopy images of lanthanum phosphate deposition in the gastric mucosa. Scanning electron microscopy (SEM) observation enabled easier identification of the deposited material, which was visible as bright areas. The present case suggests the usefulness of SEM observation in the detection of lanthanum phosphate deposition in the gastrointestinal tract