A 5- to 8-year randomized study on the treatment of cervical radiculopathy: anterior cervical decompression and fusion plus physiotherapy versus physiotherapy alone.

OBJECTIVE The aim of this study was to evaluate the 5- to 8-year outcome of anterior cervical decompression and fusion (ACDF) combined with a structured physiotherapy program as compared with that following the same physiotherapy program alone in patients with cervical radiculopathy. No previous prospective randomized studies with a follow-up of more than 2 years have compared outcomes of surgical versus nonsurgical intervention for cervical radiculopathy. METHODS Fifty-nine patients were randomized to ACDF surgery with postoperative physiotherapy (30 patients) or to structured physiotherapy alone (29 patients).

Time-dependent dose-response relation for absence of vaginal elasticity after gynecological radiation therapy.

Background And Purpose: To investigate the dose-response relation between the dose to the vagina and the patient-reported symptom 'absence of vaginal elasticity' and how time to follow-up influences this relation.

Material And Methods: The study included 78 long-term gynecological cancer survivors treated between 1991 and 2003 with external beam radiation therapy. Of those, 24 experienced absence of vaginal elasticity.

Factors Affecting the Outcome of Surgical Versus Nonsurgical Treatment of Cervical Radiculopathy: A Randomized, Controlled Study.

Study Design: Prospective randomized controlled trial.

Objective: To analyze factors that may influence the outcome of anterior cervical decompression and fusion (ACDF) followed by physiotherapy versus physiotherapy alone for treatment of patients with cervical radiculopathy.

Summary Of Background Data: An understanding of patient-related factors affecting the outcome of ACDF is important for preoperative patient selection.

Predicting the sensitivity to ion therapy based on the response to photon irradiation--experimental evidence and mathematical modelling.

Background/aim: The use of ion radiation therapy is growing due to the continuously increasing positive clinical experience obtained. Therefore, there is a high interest in radio-biological experiments comparing the relative efficiency in cell killing of ions and photons as photons are currently the main radiation modality used for cancer treatment. This comparison is particularly important since the treatment planning systems (TPSs) used at the main ion therapy Centers make use of parameters describing the cellular response to photons, respectively ions, determined in vitro.

Impact of dose and sensitivity heterogeneity on TCP.

This present paper presents an analytical description and numerical simulations of the influence of macroscopic intercell dose variations and intercell sensitivity variations on the probability of controlling the tumour. Computer simulations of tumour control probability accounting for heterogeneity in dose and radiation sensitivity were performed. An analytical expression for tumor control probability accounting for heterogeneity in sensitivity was also proposed and validated against simulations.

Surgery versus nonsurgical treatment of cervical radiculopathy: a prospective, randomized study comparing surgery plus physiotherapy with physiotherapy alone with a 2-year follow-up.

Study Design: Prospective randomized controlled trial.

Objective: To study the outcome of anterior cervical decompression and fusion combined with a structured physiotherapy program compared with the same physiotherapy program alone for patients with cervical radiculopathy.

Summary Of Background Data: Knowledge concerning the effects of interventions for patients with cervical radiculopathy is scarce due to a lack of randomized studies.

Investigation of the dose- and time-dependence of the induction of different types of cell death in a small‑cell lung cancer cell line: Implementation of the repairable-conditionally repairable model.

The purpose of this study was to quantify and model various types of cell death for a small-cell lung cancer (SCLC) cell line (U1690) after exposure to a 137Cs source and as well as to compare the linear-quadratic (LQ) and repairable-conditionally repairable model (RCR). This study is based on four different experiments that were taken place at Cancer Centrum Karolinska (CCK). A human small-cell lung cancer (SCLC) cell line after the exposure to a 137Cs source was used for the extraction of the clonogenic cell survival curve.

Physical function outcome in cervical radiculopathy patients after physiotherapy alone compared with anterior surgery followed by physiotherapy: a prospective randomized study with a 2-year follow-up.

Study Design: Prospective randomized study.

Objective: To investigate differences in physical functional outcome in patients with radiculopathy due to cervical disc disease, after structured physiotherapy alone (consisting of neck-specific exercises with a cognitive-behavioral approach) versus after anterior cervical decompression and fusion (ACDF) followed by the same structured physiotherapy program.

Summary Of Background Data: No earlier studies have evaluated the effectiveness of a structured physiotherapy program or postoperative physical rehabilitation after ACDF for patients with magnetic resonance imaging-verified nerve compression due to cervical disc disease.

Dose-response relationships for an atomized symptom of fecal incontinence after gynecological radiotherapy.

Purpose: The aim of this study was to investigate what bowel organ and delivered dose levels are most relevant for the development of 'emptying of all stools into clothing without forewarning' so that the related dose-responses could be derived as an aid in avoiding this distressing symptom in the future.

Material And Methods: Of the 77 gynecological cancer survivors treated with radiotherapy (RT) for gynecological cancer, 13 developed the symptom. The survivors were treated between 1991 and 2003.

A model for the relative biological effectiveness of protons: the tissue specific parameter α/β of photons is a predictor for the sensitivity to LET changes.

Background: The biological effects of particles are often expressed in relation to that of photons through the concept of relative biological effectiveness, RBE. In proton radiotherapy, a constant RBE of 1.1 is usually assumed.

The influence of dose heterogeneity on tumour control probability in fractionated radiation therapy.

Theoretical modelling of tumour control probability (TCP) with respect to non-uniformity in the dose to the tumour, alternate fractionation schemes and tumour kinetics is a very useful tool for assessment of the influence of changes in dosimetric or radiobiological factors on the outcome of the treatment. Various attempts have been made to also include effects from non-uniform dose to the tumour volume, but the problem has not been fully solved and many factors were totally neglected or not accurately taken into account. This paper presents derivations of analytical expressions of TCP for macroscopic inter-cell dose variations and for random inter-fractional variations in average tumour dose, based on binomial statistics for the TCP and the well-known linear quadratic model for the cell survival.

Limitations (and merits) of PENELOPE as a track-structure code.

Purpose: To outline the limitations of PENELOPE (acronym of PENetration and Energy LOss of Positrons and Electrons) as a track-structure code, and to comment on modifications that enable its fruitful use in certain microdosimetry and nanodosimetry applications.

Methods: Attention is paid to the way in which inelastic collisions of electrons are modelled and to the ensuing implications for microdosimetry analysis.

Results: Inelastic mean free paths and collision stopping powers calculated with PENELOPE and two well-known optical-data models are compared.

Health-related quality of life in patients with surgically treated lumbar disc herniation: 2- and 7-year follow-up of 117 patients.

Background And Purpose: Health-related quality of life (HRQoL) instruments have been of increasing interest for evaluation of medical treatments over the past 10-15 years. In this prospective, long-term follow-up study we investigated the influence of preoperative factors and the change in HRQoL over time after lumbar disc herniation surgery.

Methods: 117 patients surgically treated for lumbar disc herniation (L4-L5 or L5-S1) were evaluated with a self-completion HRQoL instrument (EQ-5D) preoperatively, after 2 years (96 patients) and after 7 years (89 patients).

A Monte Carlo program for the analysis of low-energy electron tracks in liquid water.

A Monte Carlo code for the event-by-event simulation of electron transport in liquid water is presented. The code, written in C++, can accommodate different interaction models. Currently it implements cross sections for ionizing collisions calculated with the model developed by Dingfelder et al (1998 Radiat.

Comparison of dose response models for predicting normal tissue complications from cancer radiotherapy: application in rat spinal cord.

Seven different radiobiological dose-response models have been compared with regard to their ability to describe experimental data. The first four models, namely the critical volume, the relative seriality, the inverse tumor and the critical element models are mainly based on cell survival biology. The other three models: the Lyman (Gaussian distribution), the parallel architecture and the Weibull distribution models are semi-empirical and rather based on statistical distributions.

Toolkit for determination of dose-response relations, validation of radiobiological parameters and treatment plan optimization based on radiobiological measures.

Accurately determined dose-response relations of the different tumors and normal tissues should be estimated and used in the clinic. The aim of this study is to demonstrate developed tools that are necessary for determining the dose-response parameters of tumors and normal tissues, for clinically verifying already published parameter sets using local patient materials and for making use of all this information in the optimization and comparison of different treatment plans and radiation techniques. One of the software modules (the Parameter Determination Module) is designed to determine the dose-response parameters of tumors and normal tissues.

Dose-response relations for stricture in the proximal oesophagus from head and neck radiotherapy.

Background And Purpose: Determination of the dose-response relations for oesophageal stricture after radiotherapy of the head and neck.

Material And Methods: In this study 33 patients who developed oesophageal stricture and 39 patients as controls are included. The patients received radiation therapy for head and neck cancer at Karolinska University Hospital, Stockholm, Sweden.

Vascular structure and binomial statistics for response modeling in radiosurgery of cerebral arteriovenous malformations.

Radiation treatment of arteriovenous malformations (AVMs) has a slow and progressive vaso-occlusive effect. Some studies suggested the possible role of vascular structure in this process. A detailed biomathematical model has been used, where the morphological, biophysical and hemodynamic characteristics of intracranial AVM vessels are faithfully reproduced.

A systems biology approach to radiation therapy optimization.

During the last 20 years, the field of cellular and not least molecular radiation biology has been developed substantially and can today describe the response of heterogeneous tumors and organized normal tissues to radiation therapy quite well. An increased understanding of the sub-cellular and molecular response is leading to a more general systems biological approach to radiation therapy and treatment optimization. It is interesting that most of the characteristics of the tissue infrastructure, such as the vascular system and the degree of hypoxia, have to be considered to get an accurate description of tumor and normal tissue responses to ionizing radiation.

Esophageal stricture after radiotherapy in patients with head and neck cancer: experience of a single institution over 2 treatment periods.

Background: Risk factors for development of a stricture of the upper esophagus after radiotherapy for head and neck cancer are poorly defined.

Methods: This was a retrospective case-control study of patients diagnosed and treated for esophageal stricture after radiotherapy for head and neck cancer.

Results: The incidence of esophageal stricture after external beam radiation therapy (EBRT) was 3.

Clinical and radiobiological advantages of single-dose stereotactic light-ion radiation therapy for large intracranial arteriovenous malformations. Technical note.

Object: Radiation treatment of large arteriovenous malformations (AVMs) remains difficult and not very effective, even though seemingly promising methods such as staged volume treatments have been proposed by some radiation treatment centers. In symptomatic patients harboring large intracranial AVMs not amenable to embolization or resection, single-session high-dose stereotactic radiation therapy is a viable option, and the special characteristics of high-ionization-density light-ion beams offer several treatment advantages over photon and proton beams. These advantages include a more favorable depth-dose distribution in tissue, an almost negligible lateral scatter of the beam, a sharper penumbra, a steep dose falloff beyond the Bragg peak, and a higher probability of vascular response due to high ionization density and associated induction of endothelial cell proliferation and/or apoptosis.

Comparison of the helical tomotherapy and MLC-based IMRT radiation modalities in treating brain and cranio-spinal tumors.

The investigation of the clinical efficacy and effectiveness of Intensity Modulated Radiotherapy (IMRT) using Multileaf Collimators (MLC) and Helical Tomotherapy (HT) has been an issue of increasing interest over the past few years. In order to assess the suitability of a treatment plan, dosimetric criteria such as dose-volume histograms (DVH), maximum, minimum, mean, and standard deviation of the dose distribution are typically used. Nevertheless, the radiobiological parameters of the different tumors and normal tissues are often not taken into account.