Tumor bed brachytherapy for locally advanced laryngeal cancer: a feasibility assessment of combination with ferromagnetic hyperthermia

Purpose. To assess the feasibility of adding hyperthermia to an original method of organ-preserving brachytherapy treatment for locally advanced head and neck tumors. Methods and materials. The method involves organ-preserving tumor resection and adjunctive high-dose-rate (HDR) brachytherapy delivered via afterloading catheters. These catheters are embedded in a polymeric implant prepared intraoperatively to fill the resection cavity, allowing precise computer planning of dose distribution in the surrounding at-risk tumor bed tissue. Theoretical and experimental analyzes address the feasibility of heating the tumor bed implant by coupling energy from a 100 kHz magnetic field applied externally into ferromagnetic particles, which are uniformly distributed within the implant. The goal is to combine adjuvant hyperthermia (40 °C–45 °C) to at-risk tissue within 5 mm of the resection cavity for thermal enhancement of radiation and chemotherapy response. Results. A five-year relapse free survival rate of 95.8% was obtained for a select group of 48 male patients with T3N0M0 larynx tumors, when combining organ-preserving surgery with HDR brachytherapy from a tumor bed implant. Anticipating the need for additional treatment in patients with more advanced disease, a theoretical analysis demonstrates the ability to heat at-risk tissue up to 10 mm from the surface of an implant filled with magnetically coupled ferromagnetic balls. Using a laboratory induction heating system, it takes just over 2 min to increase the target tissue temperature by 10 °C using a 19% volume fraction of ferromagnetic spheres in a 2 cm diameter silicone implant. Conclusion. The promising clinical results of a 48 patient pilot study demonstrate the feasibility of a new organ sparing treatment for laryngeal cancer. Anticipating the need for additional therapy, theoretical estimations of potential implant heating are confirmed with laboratory experiments, preparing the way for future implementation of a thermobrachytherapy implant approach for organ-sparing treatment of locally advanced laryngeal cancer

Isotope thermometery in nuclear multifragmentation

A systematic study of the effect of fragment$-$fragment interaction, quantum statistics, $\gamma$-feeding and collective flow is made in the extraction of the nuclear temperature from the double ratio of the isotopic yields in the statistical model of one-step (Prompt) multifragmentation. Temperature is also extracted from the isotope yield ratios generated in the sequential binary-decay model. Comparison of the thermodynamic temperature with the extracted temperatures for different isotope ratios show some anomaly in both models which is discussed in the context of experimentally measured caloric curves.Comment: uuencoded gzipped file containing 20 pages of text in REVTEX format and 12 figures (Postscript files). Physical Review C (in press

Isotopic and Microcanonical Temperatures in Nuclear Multifragmentation

A systematic comparison of different isotopic temperatures with the thermodynamical temperature of a multifragment system is made on the basis of the Statistical Multifragmentation Model. It is demonstrated that isotopic temperatures are strongly affected by the secondary decays of hot primary fragments and the population of particle-stable excited states in final fragments. The He-Li temperatures, measured recently by the ALADIN group, are reproduced fairly well both as a function of excitation energy and bound charge. Our analysis confirms the anomaly in the nuclear caloric curve.Comment: 10 pages in LaTeX, 3 ps figures, accepted for publication in Phys. Rev.

Clinical Significance of Sentinel Lymph Node Detection in Patients with Invasive Cervical Cancer

The clinical significance of determining sentinel lymph nodes (SLN) in patients with invasive cervical cancer was studied. From 2013 to 2014, 30 cervical cancer patients (T1a1NxM0-T1b1NxM0) were treated at the Gynecological Oncology Department of the Cancer Research Institute. The day before surgery, four submucosal injections of 99mTc Al2O3 at a total dose of 80 MBq were made in each quadrant around the cervical tumor. Patients were submitted to preoperative lymphoscintigraphy and intraoperative SLN detection. The feasibility of preserving the reproductive potential in patients after radical abdominal trachelectomy was assessed. The 3-year, overall, disease-free and metastasis-free survival rates were analyzed. Thirty-four SLNs were detected by single-photon emission computed tomography (SPECT) and 42 SLNs were identified by intraoperative gamma probe. The sensitivity in detecting SLNs was 100% for intraoperative SLN identification and 80% for SPECT image. The reproductive potential was preserved in 86% of patients. The 3-year overall and metastases-free survival rates were 100%. Recurrence occurred in 8.6% of cases

Cation distribution in manganese cobaltite spinels Co3−xMnxO4 (0 ≤ x ≤ 1) determined by thermal analysis

Thermogravimetric analysis was used in order to study the reduction in air of submicronic powders of Co3−x Mn x O4 spinels, with 0 ≤ x ≤ 1. For x = 0 (i.e. Co3O4), cation reduction occurred in a single step. It involved the CoIII ions at the octahedral sites, which were reduced to Co2+ on producing CoO. For 0 < x ≤ 1, the reduction occurred in two stages at increasing temperature with increasing amounts of manganese. The first step corresponded to the reduction of octahedral CoIII ions and the second was attributed to the reduction of octahedral Mn4+ ions to Mn3+. From the individual weight losses and the electrical neutrality of the lattice, the CoIII and Mn4+ ion concentrations were calculated. The distribution of cobalt and manganese ions present on each crystallographic site of the spinel was determined. In contrast to most previous studies that took into account either CoIII and Mn3+ or Co2+, CoIII and Mn4+ only, our thermal analysis study showed that Co2+/CoIII and Mn3+/Mn4+ pairs occupy the octahedral sites. These results were used to explain the resistivity measurements carried out on dense ceramics prepared from our powders sintered at low temperature (700–750 °C) in a Spark Plasma Sintering apparatus

Quasiparticle transport equation with collision delay. II. Microscopic Theory

For a system of non-interacting electrons scattered by neutral impurities, we derive a modified Boltzmann equation that includes quasiparticle and virial corrections. We start from quasiclassical transport equation for non-equilibrium Green's functions and apply limit of small scattering rates. Resulting transport equation for quasiparticles has gradient corrections to scattering integrals. These gradient corrections are rearranged into a form characteristic for virial corrections

Memory effects on descent from nuclear fission barrier

Non-Markovian transport equations for nuclear large amplitude motion are derived from the collisional kinetic equation. The memory effects are caused by the Fermi surface distortions and depend on the relaxation time. It is shown that the nuclear collective motion and the nuclear fission are influenced strongly by the memory effects at the relaxation time $\tau \geq 5\cdot 10^{-23}{\rm s}$. In particular, the descent of the nucleus from the fission barrier is accompanied by characteristic shape oscillations. The eigenfrequency and the damping of the shape oscillations depend on the contribution of the memory integral in the equations of motion. The shape oscillations disappear at the short relaxation time regime at $\tau \to 0$, which corresponds to the usual Markovian motion in the presence of friction forces. We show that the elastic forces produced by the memory integral lead to a significant delay for the descent of the nucleus from the barrier. Numerical calculations for the nucleus $^{236}$U shows that due to the memory effect the saddle-to-scission time grows by a factor of about 3 with respect to the corresponding saddle-to-scission time obtained in liquid drop model calculations with friction forces.Comment: 22 pages, 8 figures, submitted to Phys. Rev.

Применение эффекту Кирлиан для оценки структурообразования в водных системах

Технічно реалізовано два підходи до реєстрації ефекту Кірліан у рідинах. Проаналізовано три методи формування краплі рідини. На прикладі інформаційно-структурованих вод – «Моршинської» та «Даяни» – продемонстровані можливості розробленої апаратури. Показано, що в якості статистично достовірного структуризатора рідин може бути використаний магнітний прилад – Коректор функціонального стану (КФС).Two technical approaches were used two methods of register Kirlian effect in liquids. Three methods of liquid drop formation have been analyzed. Using informationally structured waters “Morshinskaya” and “Dayana” as the example. It was shown that magnet device, Corrector of functional state, can be used as statistically valid structurizer of liquids.Технически реализовано два подхода к регистрации эффекта Кирлиан в жидкостях Проанализировано три метода формирования капли жидкости. На примере информационно структурированных вод «Моршинской» и «Даяны» – продемонстрированы возможности разработанной аппаратуры. Показано, что в качестве статистически достоверного структуризатора жидкости можно использовать магнитный прибор – Корректор функционального состояния (КФС)

Breakup Temperature of Target Spectators in Au + Au Collisions at E/A = 1000 MeV

Breakup temperatures were deduced from double ratios of isotope yields for target spectators produced in the reaction Au + Au at 1000 MeV per nucleon. Pairs of $^{3,4}$He and $^{6,7}$Li isotopes and pairs of $^{3,4}$He and H isotopes (p, d and d, t) yield consistent temperatures after feeding corrections, based on the quantum statistical model, are applied. The temperatures rise with decreasing impact parameter from 4 MeV for peripheral to about 10 MeV for the most central collisions. The good agreement with the breakup temperatures measured previously for projectile spectators at an incident energy of 600 MeV per nucleon confirms the observed universality of the spectator decay at relativistic bombarding energies. The measured temperatures also agree with the breakup temperatures predicted by the statistical multifragmentation model. For these calculations a relation between the initial excitation energy and mass was derived which gives good simultaneous agreement for the fragment charge correlations. The energy spectra of light charged particles, measured at $\theta_{lab}$ = 150$^{\circ}$, exhibit Maxwellian shapes with inverse slope parameters much higher than the breakup temperatures. The statistical multifragmentation model, because Coulomb repulsion and sequential decay processes are included, yields light-particle spectra with inverse slope parameters higher than the breakup temperatures but considerably below the measured values. The systematic behavior of the differences suggests that they are caused by light-charged-particle emission prior to the final breakup stage. PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-qComment: 29 pages, TeX with 11 included figures; Revised version accepted for publication in Z. Phys. A Two additional figure