Relationships between Regional Radiation Doses and Cognitive Decline in Children Treated with Cranio-Spinal Irradiation for Posterior Fossa Tumors.

Pediatric posterior fossa tumor (PFT) survivors who have been treated with cranial radiation therapy often suffer from cognitive impairments that might relate to IQ decline. Radiotherapy (RT) distinctly affects brain regions involved in different cognitive functions. However, the relative contribution of regional irradiation to the different cognitive impairments still remains unclear.

Locally advanced cervical cancer: Is it relevant to report image-guided adaptive brachytherapy using point A dose?

Purpose: To evaluate the usefulness of reporting the point A dose in patients with locally advanced cervical cancer treated with image-guided adaptive brachytherapy (IGABT).

Methods And Materials: Dosimetric data from patients treated with a combination of chemoradiation and intracavitary IGABT were examined in light of their outcomes. Prescribing followed the Groupe Européen de Curiethérapie-European Society for Radiation Oncology recommendations.

A review of uncertainties in radiotherapy dose reconstruction and their impacts on dose-response relationships.

Proper understanding of the risk of radiation-induced late effects for patients receiving external photon beam radiotherapy requires the determination of reliable dose-response relationships. Although significant efforts have been devoted to improving dose estimates for the study of late effects, the most often questioned explanatory variable is still the dose. In this work, based on a literature review, we provide an in-depth description of the radiotherapy dose reconstruction process for the study of late effects.

Tumor dose-volume response in image-guided adaptive brachytherapy for cervical cancer: A meta-regression analysis.

Purpose: Image-guided adaptive brachytherapy is a high precision technique that allows dose escalation and adaptation to tumor response. Two monocentric studies reported continuous dose-volume response relationships, however, burdened by large confidence intervals. The aim was to refine these estimations by performing a meta-regression analysis based on published series.

Evaluation of MVCT imaging dose levels during helical IGRT: comparison between ion chamber, TLD, and EBT3 films.

The purpose of this investigation was to evaluate the dose on megavoltage CT (MVCT) images required for tomotherapy. As imaging possibilities are often used before each treatment and usually used several times before the session, we tried to evaluate the dose delivered during the procedure. For each scanning mode (fine, normal, and coarse), we first established the relative variation of these doses according to different technical parameters (explored length, patient setup).

Vaginal dose assessment in image-guided brachytherapy for cervical cancer: Can we really rely on dose-point evaluation?

Purpose: Although dose-volume parameters in image-guided brachytherapy have become a standard, the use of posterior-inferior border of the pubic symphysis (PIBS) points has been recently proposed in the reporting of vaginal doses. The aim was to evaluate their pertinence.

Methods And Materials: Nineteen patients who received image-guided brachytherapy after concurrent radiochemotherapy were included.

Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX).

Risk of Subsequent Leukemia After a Solid Tumor in Childhood: Impact of Bone Marrow Radiation Therapy and Chemotherapy.

Purpose: To investigate the roles of radiation therapy and chemotherapy in the occurrence of subsequent leukemia after childhood cancer.

Methods And Materials: We analyzed data from a case-control study with 35 cases and 140 controls. The active bone marrow (ABM) was segmented into 19 compartments, and the radiation dose was estimated in each.

Clinical outcomes of definitive chemoradiation followed by intracavitary pulsed-dose rate image-guided adaptive brachytherapy in locally advanced cervical cancer.

Objective: To report the outcomes and late toxicities of patients with locally advanced cervical cancer treated with concomitant chemoradiation (CRT) followed by intracavitary image-guided adaptive brachytherapy (IGABT).

Methods: Data from consecutive patients with histologically proven stage IB-IVA cervical cancer treated with curative intent in a single institution were analyzed. After pelvic +/- para-aortic external-beam radiation therapy, they received pulsed-dose rate IGABT following GEC-ESTRO recommendations.

Thyroid Radiation Dose and Other Risk Factors of Thyroid Carcinoma Following Childhood Cancer.

Context: Thyroid carcinoma is a frequent complication of childhood cancer radiotherapy. The dose response to thyroid radiation dose is now well established, but the potential modifier effect of other factors requires additional investigation.

Objective: This study aimed to investigate the role of potential modifiers of the dose response.

Pulsed-dose rate image-guided adaptive brachytherapy in cervical cancer: Dose-volume effect relationships for the rectum and bladder.

Purpose: To establish dose-volume effect correlations for late bladder and rectum side effects in patients treated for locally advanced cervical cancer with concomitant chemoradiation followed by pulsed-dose rate image-guided adaptive brachytherapy.

Material And Methods: The dosimetric data, converted in 2 Gy equivalent, from 217 patients were confronted to late morbidity defined as any event lasting or occurring 90 days after treatment initiation. Toxicity was assessed using the CTC-AE 3.

Field size dependent mapping of medical linear accelerator radiation leakage.

The purpose of this study was to investigate the suitability of a graphics library based model for the assessment of linear accelerator radiation leakage. Transmission through the shielding elements was evaluated using the build-up factor corrected exponential attenuation law and the contribution from the electron guide was estimated using the approximation of a linear isotropic radioactive source. Model parameters were estimated by a fitting series of thermoluminescent dosimeter leakage measurements, achieved up to 100 cm from the beam central axis along three directions.

Intrafractional organs movement in three-dimensional image-guided adaptive pulsed-dose-rate cervical cancer brachytherapy: assessment and dosimetric impact.

Purpose: To prospectively evaluate the intrafractional movements of organs at risk (OARs) and their dosimetric impact during the delivery of pulsed-dose-rate brachytherapy in cervical cancer.

Patients And Methods: An MRI on Day 1 was used for treatment planning in 19 patients. CT scans were acquired at Days 1, 2, and 3 with delineation of the OARs.

Impact of treatment time and dose escalation on local control in locally advanced cervical cancer treated by chemoradiation and image-guided pulsed-dose rate adaptive brachytherapy.

Purpose: To report the prognostic factors for local control in patients treated for locally advanced cervical cancer with image guided pulsed-dose rate brachytherapy.

Materials/methods: Patients treated with curative intent by a combination of external beam radiotherapy and pulsed-dose rate brachytherapy were selected. Local failure was defined as any relapse in the cervix, vagina, parametria, or uterus during follow-up.

D2cm³/DICRU ratio as a surrogate of bladder hotspots localizations during image-guided adaptive brachytherapy for cervical cancer: assessment and implications in late urinary morbidity analysis.

Purpose: To evaluate the efficiency and potential implications of the lowest dose evaluated in the maximally exposed 2cm(3) of the bladder/dose evaluated at the International Commission for Radiation Units and Measurements (ICRU) bladder point (D2cm(3)/DICRU) ratio as surrogate to locate the D2cm(3) in patients treated with MRI-guided adaptive brachytherapy for cervical cancer.

Methods And Materials: The D2cm(3) area of the bladder was located in 69 patients, using the Digital Imaging and Communications in Medicine coordinates of its barycenter, with respect to the ICRU bladder point. The D2cm(3)/DICRU ratio was correlated with the longitudinal coordinate of the D2cm(3).

Retrospective reconstructions of active bone marrow dose-volume histograms.

Purpose: To present a method for calculating dose-volume histograms (DVH's) to the active bone marrow (ABM) of patients who had undergone radiation therapy (RT) and subsequently developed leukemia.

Methods And Materials: The study focuses on 15 patients treated between 1961 and 1996. Whole-body RT planning computed tomographic (CT) data were not available.

Functional data analysis in NTCP modeling: a new method to explore the radiation dose-volume effects.

Purpose/objective(s): To describe a novel method to explore radiation dose-volume effects. Functional data analysis is used to investigate the information contained in differential dose-volume histograms. The method is applied to the normal tissue complication probability modeling of rectal bleeding (RB) for patients irradiated in the prostatic bed by 3-dimensional conformal radiation therapy.

Improving safety in radiotherapy: the implementation of the Global Risk Analysis method.

Purpose: To report the application of the Global Risk Analysis (GRA), an innovative proactive risk analysis method, to a radiotherapy department.

Material And Methods: Analyses were conducted by a multidisciplinary working group with the support of a quality engineer. First, a mapping of hazardous situations was developed.

Risk of second bone sarcoma following childhood cancer: role of radiation therapy treatment.

Bone sarcoma as a second malignancy is rare but highly fatal. The present knowledge about radiation-absorbed organ dose-response is insufficient to predict the risks induced by radiation therapy techniques. The objective of the present study was to assess the treatment-induced risk for bone sarcoma following a childhood cancer and particularly the related risk of radiotherapy.

A multi-plane source model for out-of-field head scatter dose calculations in external beam photon therapy.

Our purpose was to assess the out-of-field dose component related to head scatter radiation in high-energy photon therapy beams and then derive a multisource model for this dose component. For scattered photons, several planar sources have been defined, with number, location and tilt depending on the complexity of the field shape. In the absence of precise knowledge of out-of-field scattering characteristics, several assumptions are made to derive emission spectra and radiation intensity from measurements.

Thyroid adenomas after solid cancer in childhood.

Purpose: Very few childhood cancer survivor studies have been devoted to thyroid adenomas. We assessed the role of chemotherapy and the radiation dose to the thyroid in the risk of thyroid adenoma after childhood cancer.

Methods And Materials: A cohort of 3254 2-year survivors of a solid childhood cancer treated in 5 French centers before 1986 was established.

Total heart volume as a function of clinical and anthropometric parameters in a population of external beam radiation therapy patients.

The aim of this paper was to determine anthropometric parameters leading to the least uncertain estimate of heart size when connecting a computational phantom to an external beam radiation therapy (EBRT) patient. From computed tomography images, we segmented the heart and calculated its total volume (THV) in a population of 270 EBRT patients of both sexes, aged 0.7–83 years.

Dosimetric benefits of intensity-modulated radiotherapy combined with the deep-inspiration breath-hold technique in patients with mediastinal Hodgkin's lymphoma.

Purpose: To assess the additional benefits of using the deep-inspiration breath-hold (DIBH) technique with intensity-modulated radiotherapy (IMRT) in terms of the protection of organs at risk for patients with mediastinal Hodgkin's disease.

Methods And Materials: Patients with early-stage Hodgkin's lymphoma with mediastinal involvement were entered into the study. Two simulation computed tomography scans were performed for each patient: one using the free-breathing (FB) technique and the other using the DIBH technique with a dedicated spirometer.

Involved-node radiotherapy and modern radiation treatment techniques in patients with Hodgkin lymphoma.

Purpose: To assess the clinical outcome of the involved-node radiotherapy (INRT) concept using modern radiation treatments (intensity-modulated radiotherapy [IMRT] or deep-inspiration breath-hold radiotherapy [DIBH) in patients with localized supradiaphragmatic Hodgkin lymphoma.

Methods And Materials: All but 2 patients had early-stage Hodgkin lymphoma, and they were treated with chemotherapy prior to irradiation. Radiation treatments were delivered using the INRT concept according to European Organization for Research and Treatment of Cancer guidelines.