Part II: A new perspective for modeling the bone remodeling process: Biology, mechanics, and pathologies.

In this paper, we explore the effects of biological (pathological) and mechanical damage on bone tissue within a benchmark model. Using the Finite Element Methodology, we analyze and numerically test the model's components, capabilities, and performance under physiologically and pathologically relevant conditions. Our findings demonstrate the model's effectiveness in simulating bone remodeling processes and self-repair mechanisms for micro-damage induced by biological internal conditions and mechanical external ones within bone tissue.

Simulation of the electrical stimulation of the rat brain using sleep frequencies: A finite element modeling approach.

A realistic rat brain model was used to simulate current density and electric field distributions under frequencies characteristic of sleeping states (0.8, 5, and 12 Hz). Two anode-electrode setups were simulated: plate vs.

Moderate Hypofractionated Protracted Radiation Therapy and Dose Escalation for Prostate Cancer: Do Dose and Overall Treatment Time Matter?

Purpose: This was a retrospective study of 2 sequential dose escalation regimens of twice-weekly 4 Gy/fractions hypofractionated intensity modulated radiation therapy (IMRT): 56 Gy and 60 Gy delivered within a protracted overall treatment time (OTT) of 6.5 and 7 weeks, respectively.

Methods And Materials: 163 prostate cancer patients with cT1c-T3a disease and nodal involvement risk ≤20% (Roach index) were treated twice weekly to the prostate ± seminal vesicles with 2 sequential dose-escalated IMRT schedules: 56 Gy (14 × 4 Gy, n=81) from 2003 to 2007 and 60 Gy (15 × 4 Gy, n=82) from 2006 to 2010.

11C-Choline PET/CT in the primary diagnosis of prostate cancer: impact on treatment planning.

Aim: Aim of the present study was to evaluate the usefulness of 11C-choline PET/CT for detecting lymphatic or haematogenous spread and for planning radiotherapy in patients with medium-to-high risk prostate cancer.

Methods: We have included 61 consecutive patients recently diagnosed with cancer prostate by biopsy. All patients were classified as medium-to-high risk: Gleason: 7-9; PSA: 6.

Hypofractionated external beam radiotherapy to boost the prostate with ≥85 Gy/equivalent dose for patients with localised disease at high risk of lymph node involvement: feasibility, tolerance and outcome.

Aims: To evaluate the tolerance and preliminary outcome of prostate cancer patients at high risk of lymph node involvement treated with normofractionated whole pelvic radiotherapy (WPRT) followed by a hypofractionated boost to the prostate with an intensity-modulated radiotherapy (IMRT) technique.

Materials And Methods: Between 2004 and 2011, 78 T1-4N0M0 prostate cancer patients at high risk of lymph node involvement (70 patients with a Roach index ≥ 15%; 57 with T-stage ≥ 3a; 40 with Gleason score ≥ 8) underwent WPRT to a median normofractionated dose of 50.4 Gy (range 48.

Comparative analysis of numerical integration schemes of density equation for a computational model of bone remodelling.

In this study, a computational model of bone remodelling problem as proposed by Weinans et al. (1992) is described and solved by other temporal integration techniques different from the Euler scheme. This model considers three types of numerical integration schemes of the evolution of the material density during the remodelling: Euler, Heun and Runge-Kutta methods.

Twice-weekly hypofractionated intensity-modulated radiotherapy for localized prostate cancer with low-risk nodal involvement: toxicity and outcome from a dose escalation pilot study.

Purpose: To evaluate the toxicity and preliminary outcome of patients with localized prostate cancer treated with twice-weekly hypofractionated intensity-modulated radiotherapy (IMRT).

Methods And Materials: Between 2003 and 2006, 82 prostate cancer patients with a nodal involvement risk ≤20% (Roach index) have been treated to the prostate with or without seminal vesicles with 56 Gy (4 Gy/fraction twice weekly) and an overall treatment time of 6.5 weeks.

Hypofractionated extracranial stereotactic radiotherapy boost for gynecologic tumors: a promising alternative to high-dose rate brachytherapy.

The purpose of this study is to report toxicity and outcome results in patients with gynaecological tumours treated with a final boost using extra-cranial stereotactic radiotherapy (SRT) with a linac-based micro-multileaf collimator technique as an alternative to high-dose rate brachytherapy (HDR-BT). Since January 2002, 26 patients with either endometrial (n = 17) or cervical (n = 9) cancer were treated according to this protocol: 45-50.4 Gy external radiotherapy (RT) to the pelvic +/- para-aortic regions followed by a final SRT boost of 2 x 7 Gy to the vaginal vault (4-7 day interval between fractions).

Boosting the tumor bed from deep-seated tumors in early-stage breast cancer: a planning study between electron, photon, and proton beams.

Purpose: To assess the potential dosimetric advantages and drawbacks of photon beams (modulated or not), electron beams (EB), and protons as a boost for the tumor bed in deep-seated early-stage breast cancer.

Material And Methods: Planning CTs of 14 women with deep-seated tumors (i.e.

Dose escalation study with two different hypofractionated intensity modulated radiotherapy techniques for localized prostate cancer: acute toxicity.

To assess acute gastrointestinal (GI) and genitourinary (GU) toxicities in patients with localized prostate cancer treated with a sequential dose escalation hypofractionated intensity-modulated radiotherapy (IMRT) study using two different delivery methods. Since 2003, 88 and 48 patients were sequentially treated to 56 Gy and to 60 Gy (4 Gy/fraction twice weekly), respectively. IMRT with 6 MV beams was delivered with five fields in Geneva and with nine in Barcelona.

Hypofractionated boost to the dominant tumor region with intensity modulated stereotactic radiotherapy for prostate cancer: a sequential dose escalation pilot study.

Purpose: To evaluate the feasibility, tolerability, and preliminary outcomes in patients with prostate cancer treated according to a hypofractionated dose escalation protocol to boost the dominant tumor-bearing region of the prostate.

Methods And Materials: After conventional fractionated external radiotherapy to 64 to 64.4 Gy, 50 patients with nonmetastatic prostate cancer were treated with an intensity-modulated radiotherapy hypofractionated boost under stereotactic conditions to a reduced prostate volume to the dominant tumor region.

Stereotactic radiotherapy for ocular melanoma: initial experience using closed eyes for ocular target immobilization.

To assess the reliability and target positioning reproducibility with eyes closed in uveal melanoma patients treated with a micromultileaf-based linear accelerator dedicated for stereotactic radiotherapy. Five consecutive patients treated with curative radiotherapy for uveal melanoma were monitored for positioning reproducibility with resimulation CT scans performed every two days while on treatment (23 resimulation CTs available). All patients underwent MRIs of the orbits before simulation to help to define the target and organs at risk (e.

Endorectal MRI assessment of local relapse after surgery for prostate cancer: A model to define treatment field guidelines for adjuvant radiotherapy in patients at high risk for local failure.

Purpose: To assess the role of endorectal magnetic resonance imaging (MRI) in defining local relapse after radical prostatectomy for prostate cancer to help to reassess the clinical target volume (CTV) for adjuvant postprostatectomy radiotherapy.

Methods And Materials: Sixty patients undergoing an endorectal MRI before salvage radiotherapy were selected. Spatial coordinates of the relapses were assessed using two reference points: the inferior border of the pubic symphysis (point 1) and the urethro-vesical anastomosis (point 2).

Fractionated stereotactic radiotherapy boost for gynecologic tumors: an alternative to brachytherapy?

Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique.

Methods And Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse.

Target repositioning optimization in prostate cancer: is intensity-modulated radiotherapy under stereotactic conditions feasible?

Purpose: To assess repositioning reproducibility of the prostate when treatment setup conditions before radiotherapy (RT) are optimized and internal organ motion is reduced with an endorectal inflatable balloon.

Methods And Materials: Thirty-two patients were treated with 64 Gy to the prostate and seminal vesicles using a three-dimensional conformal radiotherapy technique, followed by a boost (two fractions of 5-8 Gy, 3-5 days apart) delivered to a reduced prostate volume (the peripheral tumor bearing zone with 3-mm margins) using intensity-modulated RT. A commercially available infrared-guided stereotactic repositioning system and a rectal balloon were used.