AAPM Task Group Report 267: A joint AAPM GEC-ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy.

Brachytherapy utilizes a multitude of radioactive sources and treatment techniques that often exhibit widely different spatial and temporal dose delivery patterns. Biophysical models, capable of modeling the key interacting effects of dose delivery patterns with the underlying cellular processes of the irradiated tissues, can be a potentially useful tool for elucidating the radiobiological effects of complex brachytherapy dose delivery patterns and for comparing their relative clinical effectiveness. While the biophysical models have been used largely in research settings by experts, it has also been used increasingly by clinical medical physicists over the last two decades.

Survival prediction in patients with gynecological cancer irradiated for brain metastases.

Background And Purpose: This large population-based, retrospective, single-center study aimed to identify prognostic factors in patients with brain metastases (BM) from gynecological cancers.

Material And Methods: One hundred and forty four patients with BM from gynecological cancer treated with radiotherapy (RT) were identified. Primary cancer diagnosis, age, performance status, number of BM, presence of extracranial disease, and type of BM treatment were assessed.

MRI-guided dynamic risk assessment in cervical cancer based on tumor hypoxia at diagnosis and volume response at brachytherapy.

Background And Purpose: Improvements in treatment outcome for patients with locally advanced cervical cancer (LACC) require a better classification of patients according to their risk of recurrence. We investigated whether an imaging-based approach, combining pretreatment hypoxia and tumor response during therapy, could improve risk classification.

Material And Methods: Ninety-three LACC patients with T2-weigthed (T2W)-, dynamic contrast enhanced (DCE)- and diffusion weighted (DW)-magnetic resonance (MR) images acquired before treatment, and T2W- and, for 64 patients, DW-MR images, acquired at brachytherapy, were collected.

Chronic fatigue in long-term survivors of head and neck cancer treated with radiotherapy.

Background: There is lack of evidence on chronic fatigue (CF) following radiotherapy (RT) in survivors of head and neck cancer (HNC). We aimed to compare CF in HNC survivors > 5 years post-RT with a reference population and investigate factors associated with CF and the possible impact of CF on health-related quality of life (HRQoL).

Material And Methods: In this cross-sectional study we included HNC survivors treated in 2007-2013.

Lung cancer reirradiation: Exploring modifications to utilization, treatment modalities and factors associated with outcomes.

Background: Patients treated for lung cancer (LC) often experience locoregional failure after initial treatment. Due to technological advances, thoracic reirradiation (re-RT) has become a viable treatment option. We sought to investigate the use of thoracic re-RT in LC patients over a time period characterized by technological advances in a large, multi-center cohort.

Radiation-induced long-term dysphagia in survivors of head and neck cancer and association with dose-volume parameters.

Background: Although dysphagia is a common side effect after radiotherapy (RT) of head and neck cancer (HNC), data on long-term dysphagia is scarce. We aimed to 1) compare radiation dose parameters in HNC survivors with and without dysphagia, 2) investigate factors associated with long-term dysphagia and its possible impact on health-related quality of life (HRQoL), and 3) investigate how our data agree with existing NTCP models.

Methods: This cross-sectional study conducted in 2018-2020, included HNC survivors treated in 2007-2013.

Investigating survival, quality of life and cognition in PROton versus photon therapy for mutated diffuse grade 2 and 3 GLIOmas (PRO-GLIO): a randomised controlled trial in Norway and Sweden.

Introduction: The use of proton therapy increases globally despite a lack of randomised controlled trials demonstrating its efficacy and safety. Proton therapy enables sparing of non-neoplastic tissue from radiation. This is principally beneficial and holds promise of reduced long-term side effects.

Surface-guided positioning eliminates the need for skin markers in radiotherapy of right sided breast cancer: A single center randomized crossover trial.

Background And Purpose: To prospectively investigate whether surface guided setup of right sided breast cancer patients can increase efficiency and accuracy compared to traditional skin marker/tattoo based setup.

Material And Methods: Twenty-five patients were included in this study. Each patient was positioned using skin marks and tattoos (procedure A) for half of the fractions and surface guidance using AlignRT (procedure B) for the other half of the fractions.

A Prospective Study of High Dose-Rate Brachytherapy or Stereotactic Body Radiotherapy of Intra-Prostatic Recurrence: Toxicity and Long Term Clinical Outcome.

Background: Up to half of patients with localized prostate cancer experience biochemical relapse within 10 years after definitive radiotherapy. The aim of this prospective study was to investigate the toxicity, dose to the organs at risk (OARs), and efficacy of dose-intensified focal salvage radiotherapy.

Methods And Material: Thirty-three patients (median age 68.

Dose-effect relationship between vaginal dose points and vaginal stenosis in cervical cancer: An EMBRACE-I sub-study.

Background And Purpose: To evaluate dose-effect relationships between vaginal dose points and vaginal stenosis in patients treated for locally advanced cervical cancer with radio(chemo)therapy and image-guided adaptive brachytherapy.

Material And Methods: Patients from six centres participating in the EMBRACE-I study were included. Information on doses to different vaginal dose points, including the Posterior-Inferior Border of Symphysis (PIBS) points and recto-vaginal reference (RV-RP) point, were retrieved from the treatment planning system.

Overall survival after initial radiotherapy for brain metastases; a population based study of 2140 patients with non-small cell lung cancer.

Background: Brain metastases (BM) occur in about 30% of all patients with non-small cell lung cancer (NSCLC). BM treatment guidelines recommend more frequent use of stereotactic radiotherapy (SRT). Overall, studies report no difference in overall survival (OS) comparing SRT to whole-brain radiotherapy (WBRT).

A Nordic-Baltic perspective on indications for proton therapy with strategies for identification of proper patients.

The beneficial effects of protons are primarily based on reduction of low to intermediate radiation dose bath to normal tissue surrounding the radiotherapy target volume. Despite promise for reduced long-term toxicity, the percentage of cancer patients treated with proton therapy remains low. This is probably caused by technical improvements in planning and delivery of photon therapy, and by high cost, low availability and lack of high-level evidence on proton therapy.

Education and training for image-guided adaptive brachytherapy for cervix cancer-The (GEC)-ESTRO/EMBRACE perspective.

Image-guided adaptive brachytherapy (IGABT) has been shown to improve local/regional control and survival for cervix cancer patients while reducing morbidity. However, the technique is complex involving several conceptual, methodological, and technical innovations compared to conventional brachytherapy. The delivery of high-quality IGABT which will translate into improved outcomes is therefore critically dependent on effective education and training of all health professionals involved in the brachytherapy treatment process.

GEC-ESTRO/ACROP recommendations for quality assurance of ultrasound imaging in brachytherapy.

Ultrasound (US) is an important imaging modality in brachytherapy (BT). In particular for low-dose-rate (LDR) and high-dose-rate (HDR) prostate implants transrectal ultrasound (TRUS) is widespread. Besides the common use of US for prostate implants, US can also be applied in gynecological and anal cancer therapies as examples amongst others.

Dose deviations induced by respiratory motion for radiotherapy of lung tumors: Impact of CT reconstruction, plan complexity, and fraction size.

A thorax phantom was used to assess radiotherapy dose deviations induced by respiratory motion of the target volume. Both intensity modulated and static, non-modulated treatment plans were planned on CT scans of the phantom. The plans were optimized using various CT reconstructions, to investigate whether they had an impact on robustness to target motion during delivery.

Dose planning variations related to delineation variations in MRI-guided brachytherapy for locally advanced cervical cancer.

Purpose: To examine the variability in prescribed dose due to contouring variations in intracavitary image-guided adaptive brachytherapy for cervical cancer. To identify correlations between dosimetric outcomes and delineation uncertainty metrics.

Methods And Materials: A data set from an EMBRACE sub-study on contouring uncertainties was used, consisting of magnetic resonance images of six patients with cervical cancer delineated by 10 experienced observers (target volumes and organs at risk).

Ring Versus Ovoids and Intracavitary Versus Intracavitary-Interstitial Applicators in Cervical Cancer Brachytherapy: Results From the EMBRACE I Study.

Purpose: The aim of this study was to investigate the influence of brachytherapy technique and applicator type on target dose, isodose surface volumes, and organ-at-risk (OAR) dose.

Methods And Materials: Nine hundred two patients treated with tandem/ovoids (T&O) (n = 299) and tandem/ring (T&R) (n = 603) applicators from 16 EMBRACE centers were analyzed. Patients received external beam radiation therapy and magnetic resonance imaging guided brachytherapy with dose prescription according to departmental practice.

Image registration, contour propagation and dose accumulation of external beam and brachytherapy in gynecological radiotherapy.

This review provides an overview of the current status of image registration for image guided gynaecological brachytherapy including combination with external beam radiotherapy. Contour propagation between individual fractions and dose accumulation can be useful for cervix cancer radiotherapy. Contour mapping and applicator reconstruction with rigid registration based on the applicator geometry provide good accuracy.

Importance of Technique, Target Selection, Contouring, Dose Prescription, and Dose-Planning in External Beam Radiation Therapy for Cervical Cancer: Evolution of Practice From EMBRACE-I to II.

Purpose: To describe the evolution of external beam radiation therapy (EBRT) from EMBRACE-I (general guidelines for EBRT) to the initial phase of the EMBRACE-II study (detailed protocol for EBRT).

Methods And Materials: EMBRACE-I enrolled 1416 locally advanced cervical cancer patients treated with chemoradiation including image-guided adaptive brachytherapy during 2008 to 2015. From March 2016 until March 2018, 153 patients were enrolled in the ongoing EMBRACE-II study, which involves a comprehensive detailed strategy and accreditation procedure for EBRT target contouring, treatment planning, and image guidance.

Ten-year survival after High-Dose-Rate Brachytherapy combined with External Beam Radiation Therapy in high-risk prostate cancer: A comparison with the Norwegian SPCG-7 cohort.

Background: The survival benefit of dose-escalation with High-Dose-Rate brachytherapy (HDR-BT) boost combined with External Beam Radiotherapy (EBRT) for the treatment of high-risk prostate cancer (PCa) remains debatable. We investigated 10-year PCa-specific mortality (PCSM) and overall mortality (OM) in high-risk patients treated with HDR-BT/EBRT (calculated EQD2 = 102 Gy) compared to EBRT alone (70 Gy).

Methods: HDR-BT boosts (10 Gy × 2) were given 2 weeks apart followed by 50 Gy conformal EBRT (2 Gy × 25) to the prostate and seminal vesicles.

Isodose surface volumes in cervix cancer brachytherapy: Change of practice from standard (Point A) to individualized image guided adaptive (EMBRACE I) brachytherapy.

Purpose: To investigate the isodose surface volumes (ISVs) for 85, 75 and 60 Gy EQD2 for locally advanced cervix cancer patients.

Materials And Methods: 1201 patients accrued in the EMBRACE I study were analysed. External beam radiotherapy (EBRT) with concomitant chemotherapy was followed by MR based image-guided adaptive brachytherapy (MR-IGABT).

Target volume delineation of anal cancer based on magnetic resonance imaging or positron emission tomography.

Purpose: To compare target volume delineation of anal cancer using positron emission tomography (PET) and magnetic resonance imaging (MRI) with respect to inter-observer and inter-modality variability.

Methods: Nineteen patients with anal cancer undergoing chemoradiotherapy were prospectively included. Planning computed tomography (CT) images were co-registered with 18F-fluorodexocyglucose (FDG) PET/CT images and T2 and diffusion weighted (DW) MR images.

Impact of dose escalation and adaptive radiotherapy for cervical cancers on tumour shrinkage-a modelling study.

Tumour shrinkage occurs during fractionated radiotherapy and is regulated by radiation induced cellular damage, repopulation of viable cells and clearance of dead cells. In some cases additional tumour shrinkage during external beam therapy may be beneficial, particularly for locally advanced cervical cancer where a small tumour volume may simplify and improve brachytherapy. In the current work, a mathematical tumour model is utilized to investigate how local dose escalation affects tumour shrinkage, focusing on implications for brachytherapy.

Short-course PET based simultaneous integrated boost for locally advanced cervical cancer.

Background: Patients with large, locally advanced cervical cancers (LACC) are challenging to treat. The purpose of this work is to use 18F-FDG PET as planning basis for a short-course simultaneous integrated boost (SIB) in external beam radiotherapy of LACC in order to increase tumour shrinkage and likelihood of local control.

Methods: Ten previously treated patients with LACC were included, all with pre-treatment FDG PET/CT images available.

Dose painting by numbers in a standard treatment planning system using inverted dose prescription maps.

Background: Dose painting by numbers (DPBN) is a method to deliver an inhomogeneous tumor dose voxel-by-voxel with a prescription based on biological medical images. However, planning of DPBN is not supported by commercial treatment planning systems (TPS) today. Here, a straightforward method for DPBN with a standard TPS is presented.