Recommendations regarding cardiac stereotactic body radiotherapy for treatment refractory ventricular tachycardia

BACKGROUND

Ventricular tachycardia (VT) is a potentially lethal complication of structural heart disease. Despite optimal management, a subgroup of patients continue to suffer from recurrent VT. Recently, cardiac stereotactic body radiotherapy (CSBRT) has been introduced as a treatment option in patients with VT refractory to antiarrhythmic drugs and catheter ablation.

OBJECTIVE

The purpose of this study was to establish an expert consensus regarding the conduct and use of CSBRT for refractory VT.

METHODS

We conducted a modified Delphi process. Thirteen experts from institutions from Germany and Switzerland participated in the modified Delphi process. Statements regarding the following topics were generated: treatment setting, institutional expertise and technical requirements, patient selection, target volume definition, and monitoring during and after CSBRT. Agreement was rated on a 5-point Likert scale. Cutoffs for agreement were defined in analogy to the RAND methodology.

RESULTS

There was strong agreement regarding the experimental status of the procedure and the preference for treatment in clinical trials. CSBRT should be conducted at specialized centers with a strong expertise in the management of patients with ventricular arrhythmias and in stereotactic body radiotherapy for moving targets. CSBRT should be restricted to patients with refractory VT with optimal antiarrhythmic medication who underwent prior catheter ablation or have contraindications. Target volume delineation for CSBRT is complex. Therefore, interdisciplinary processes that should include cardiology/electrophysiology and radiation oncology as well as medical physics, radiology, and nuclear medicine are needed. Optimal follow-up is required.

CONCLUSION

Prospective trials and pooled registries are needed to gain further insight into this promising treatment option for patients with refractory VT.

Selinexor decreases HIF-1α via inhibition of CRM1 in human osteosarcoma and hepatoma cells associated with an increased radiosensitivity

BACKGROUND

The nuclear pore complexes (NPCs) are built of about 30 different nucleoporins and act as key regulators of molecular traffic between the cytoplasm and the nucleus for sizeable proteins (> 40 kDa) which must enter the nucleus. Various nuclear transport receptors are involved in import and export processes of proteins through the nuclear pores. The most prominent nuclear export receptor is chromosome region maintenance 1 (CRM1), also known as exportin 1 (XPO1). One of its cargo proteins is the prolyl hydroxylase 2 (PHD2) which is involved in the initiation of the degradation of hypoxia-inducible factors (HIFs) under normoxia. HIFs are proteins that regulate the cellular adaptation under hypoxic conditions. They are involved in many aspects of cell viability and play an important role in the hypoxic microenvironment of cancer. In cancer, CRM1 is often overexpressed thus being a putative target for the development of new cancer therapies. The newly FDA-approved pharmaceutical Selinexor (KPT-330) selectively inhibits nuclear export via CRM1 and is currently tested in additional Phase-III clinical trials. In this study, we investigated the effect of CRM1 inhibition on the subcellular localization of HIF-1α and radiosensitivity.

METHODS

Human hepatoma cells Hep3B and human osteosarcoma cells U2OS were treated with Selinexor. Intranuclear concentration of HIF-1α protein was measured using immunoblot analysis. Furthermore, cells were irradiated with 2-8 Gy after treatment with Selinexor compared to untreated controls.

RESULTS

Selinexor significantly reduced the intranuclear level of HIF-1α protein in human hepatoma cells Hep3B and human osteosarcoma cells U2OS. Moreover, we demonstrated by clonogenic survival assays that Selinexor leads to dose-dependent radiosensitization in Hep3B-hepatoma and U2OS-osteosarcoma cells.

CONCLUSION

Targeting the HIF pathway by Selinexor might be an attractive tool to overcome hypoxia-induced radioresistance.

Patient-Reported Outcomes Assessing the Impact of Palliative Radiotherapy on Quality of Life and Symptom Burden in Head and Neck Cancer Patients: A Systematic Review

Incurable head and neck cancer has a poor prognosis and impairs a patient's health-related quality of life. Palliative radiotherapy may improve or stabilize health-related quality of life and symptoms, best measured by patient-reported outcomes. There is no systematic analysis if palliative radiotherapy for head and neck cancer improves or stabilizes health-related quality of life or symptoms as validly measured by patient-reported outcomes. Therefore, the primary objective of this systematic review (PROSPERO-ID: CRD42020166434) was to assess the effect of palliative radiotherapy for head and neck cancer on patient-reported outcomes. The secondary objective was to assess the rate and quality of use of patient-reported outcomes in relevant studies claiming a "palliative effect" of radiotherapy. The databases MEDLINE/PubMed, EMBASE, Cochrane CENTRAL, "ClinicalTrials.gov" were searched. Concerning the primary objective, four studies were eligible to assess the effectiveness of palliative radiotherapy as measured by patient-reported outcomes. A narrative synthesis suggests a favorable impact of palliative radiotherapy on health-related quality of life and symptom burden. The risk of bias, however, is considerable and the overall quality of evidence low. Concerning the secondary objective, over 90% of studies claiming a "palliative effect" of palliative radiotherapy did either not use patient-reported outcomes or did so by limited quality. In conclusion, implementation of patient-reported outcomes in studies assessing palliative radiotherapy for head and neck cancer should be fostered. Palliative radiotherapy remains an option for head and neck cancer patients, although more studies focusing on patient-reported outcomes are needed.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42020166434.

Metastases-directed Radiotherapy in Addition to Standard Systemic Therapy in Patients with Oligometastatic Breast Cancer: Study protocol for a randomized controlled multi-national and multi-center clinical trial (OLIGOMA)

BACKGROUND

Several recent randomized therapeutic exploratory trials demonstrated improvement of progression-free survival and in some even overall survival using stereotactic body radiotherapy in patients with oligometastatic disease. However, only very few patients enrolled in these trials had breast cancer, and results from confirmatory trials are lacking.

METHODS/DESIGN

The OLIGOMA-trial is a randomized controlled multi-national multi-center therapeutic confirmatory trial studying the role of local ablative radiotherapy as an additive treatment in patients with oligometastatic breast cancer receiving standard systemic therapy. Patients will be randomized 1:1 to standard systemic therapy according to national guidelines with or without radiotherapy to all metastatic sites. Randomization will be stratified according to type and line of systemic therapy, which has to be determined by a multidisciplinary tumor board before enrollment. Patients with up to five metastatic lesions are eligible, including patients with up to three brain metastases (only in case of extracranial disease) and with locoregional recurrence (only in case of additional metastatic lesions). In the standard arm, palliative radiotherapy to symptomatic metastases is permitted if at least one lesion remains untreated. The co-primary endpoints are progression-free survival and quality of life. The primary hypothesis is that progression-free survival in the experimental arm will be superior to the standard arm while simultaneously demonstrating non-inferiority of quality of life at 12 weeks after randomization. Secondary endpoints are feasibility, overall survival, toxicity, quality of life and patient satisfaction. A translational sub-study with collection of ctDNA will be conducted.

DISCUSSION

The OLIGOMA-trial will provide high level evidence on the use of and benefit from local ablative radiotherapy for patients with oligometastatic breast cancer.

TRIAL REGISTRATION

The OLIGOMA-trial is registered at clinicialtrials.gov under the identification NCT04495309. The related information was first posted on July 31st 2020.

Post-neoadjuvant treatment with capecitabine and trastuzumab emtansine in breast cancer patients-sequentially, or better simultaneously?

PURPOSE

Following neoadjuvant chemotherapy for breast cancer, postoperative systemic therapy, also called post-neoadjuvant treatment, has been established in defined risk settings. We reviewed the evidence for sequencing of postoperative radiation and chemotherapy, with a focus on a capecitabine and trastuzumab emtansine (T-DM1)-based regimen.

METHODS

A systematic literature search using the PubMed/MEDLINE/Web of Science database was performed. We included prospective and retrospective reports published since 2015 and provided clinical data on toxicity and effectiveness.

RESULTS

Six studies were included, five of which investigated capecitabine-containing regimens. Of these, four were prospective investigations and one a retrospective matched comparative analysis. One randomized prospective trial was found for T‑DM1 and radiotherapy. In the majority of these reports, radiation-associated toxicities were not specifically addressed.

CONCLUSION

Regarding oncologic outcome, the influence of sequencing radiation therapy with maintenance capecitabine chemotherapy in the post-neoadjuvant setting is unclear. Synchronous administration of capecitabine is feasible, but reports on possible excess toxicities are partially conflicting. Dose reduction of capecitabine should be considered, especially if normofractionated radiotherapy is used. In terms of tolerance, hypofractionated schedules seem to be superior in terms of toxicity in concurrent settings. T‑DM1 can safely be administered concurrently with radiotherapy.

Impact of guideline changes on adoption of hypofractionation and breast cancer patient characteristics in the randomized controlled HYPOSIB trial

Purpose

Hypofractionated radiotherapy is the standard of care for adjuvant whole breast radiotherapy (RT). However, adoption has been slow. The indication for regional nodal irradiation has been expanded to include patients with 0–3 involved lymph nodes. We investigated the impact of the publication of the updated German S3 guidelines in 2017 on adoption of hypofractionation and enrollment of patients with lymph node involvement within a randomized controlled phase III trial.

Methods

In the experimental arm of the HYPOSIB trial (NCT02474641), hypofractionated RT with simultaneous integrated boost (SIB) was used. In the standard arm, RT could be given as hypofractionated RT with sequential boost (HF_seq), normofractionated RT with sequential boost (NF_seq), or normofractionated RT with SIB (NF_SIB). The cutoff date for the updated German S3 guidelines was December 17, 2017. Temporal trends were analyzed by generalized linear regression models. Multiple logistic regression models were used to investigate the influence of time (prior to/after guideline) and setting (university hospital/other institutions) on the fractionation patterns.

Results

Enrollment of patients with involved lymph nodes was low throughout the trial. Adoption of HF_seq increased over time and when using the guideline publication date as cutoff. Results of the multiple logistic regressions showed an interaction between time and setting. Furthermore, the use of HF_seq was significantly more common in university hospitals.

Conclusion

The use of HF_seq in the standard arm increased over the course of the HYPOSIB trial and after publication of the S3 guideline update. This was primarily driven by patients treated in university hospitals. Enrolment of patients with lymph node involvement was low throughout the trial.

Adjuvant hypofractionated radiotherapy with simultaneous integrated boost after breast-conserving surgery: results of a prospective trial

PURPOSE

We report results of a multicenter prospective single-arm phase II trial (ARO-2013-04, NCT01948726) of moderately accelerated hypofractionated radiotherapy with a simultaneous integrated boost (SIB) in patients with breast cancer receiving adjuvant radiotherapy after breast-conserving surgery.

METHODS

The eligibility criteria included unifocal breast cancer with an indication for adjuvant radiotherapy to the whole breast and boost radiotherapy to the tumor bed. The whole breast received a dose of 40 Gy and the tumor bed a total dose of 48 Gy in 16 fractions of 2.5 and 3 Gy, respectively. Radiotherapy could be given either as 3D conformal RT (3D-CRT) or as intensity-modulated radiotherapy (IMRT). The study was designed as a prospective single-arm trial to evaluate the acute toxicity of the treatment regimen. The study hypothesis was that the frequency of acute skin reaction grade ≥2 would be 20% or less.

RESULTS

From November 2013 through July 2014, 149 patients were recruited from 12 participating centers. Six patients were excluded, leaving 143 patients for analysis. Eighty-four patients (58.7%) were treated with 3D-CRT and 59 (41.3%) with IMRT. Adherence to the treatment protocol was high. The rate of grade ≥2 skin toxicity was 14.7% (95% confidence interval 9.8-21.4%). The most frequent grade 3 toxicity (11%) was hot flashes.

CONCLUSION

This study demonstrated low toxicity of and high treatment adherence to hypofractionated adjuvant radiotherapy with SIB in a multicenter prospective trial, although the primary hypothesis was not met.

Tumor-dose-rate variations during robotic radiosurgery of oligo and multiple brain metastases

Purpose

For step-and-shoot robotic stereotactic radiosurgery (SRS) the dose delivered over time, called local tumor-dose-rate (TDR), may strongly vary during treatment of multiple lesions. The authors sought to evaluate technical parameters influencing TDR and correlate TDR to clinical outcome.

Material and methods

A total of 23 patients with 162 oligo (1–3) and multiple (>3) brain metastases (OBM/MBM) treated in 33 SRS sessions were retrospectively analyzed. Median PTV were 0.11 cc (0.01–6.36 cc) and 0.50 cc (0.12–3.68 cc) for OBM and MBM, respectively. Prescription dose ranged from 16 to 20 Gy prescribed to the median 70% isodose line. The maximum dose-rate for planning target volume (PTV) percentage p in time span s during treatment (TDR_s,p) was calculated for various p and s based on treatment log files and in-house software.

Results

TDR_60min,98% was 0.30 Gy/min (0.23–0.87 Gy/min) for OBM and 0.22 Gy/min (0.12–0.63 Gy/min) for MBM, respectively, and increased by 0.03 Gy/min per prescribed Gy. TDR_60min,98% strongly correlated with treatment time (ρ = −0.717, p < 0.001), monitor units (MU) (ρ = −0.767, p < 0.001), number of beams (ρ = −0.755, p < 0.001) and beam directions (ρ = −0.685, p < 0.001) as well as lesions treated per collimator (ρ = −0.708, P < 0.001). Median overall survival (OS) was 20 months and 1‑ and 2‑year local control (LC) was 98.8% and 90.3%, respectively. LC did not correlate with any TDR, but tumor response (partial response [PR] or complete response [CR]) correlated with all TDR in univariate analysis (e.g., TDR_60min,98%: hazard ration [HR] = 0.974, confidence interval [CI] = 0.952–0.996, p = 0.019). In multivariate analysis only concomitant targeted therapy or immunotherapy and breast cancer tumor histology remained a significant factor for tumor response. Local grade ≥2 radiation-induced tissue reactions were noted in 26.3% (OBM) and 5.2% (MBM), respectively, mainly influenced by tumor volume (p < 0.001).

Conclusions

Large TDR variations are noted during MBM-SRS which mainly arise from prolonged treatment times. Clinically, low TDR corresponded with decreased local tumor responses, although the main influencing factor was concomitant medication.

DEGRO practical guideline for partial-breast irradiation

Purpose

This consensus statement from the Breast Cancer Working Group of the German Society for Radiation Oncology (DEGRO) aims to define practical guidelines for accelerated partial-breast irradiation (APBI).

Methods

Recent recommendations for relevant aspects of APBI were summarized and a panel of experts reviewed all the relevant literature. Panel members of the DEGRO experts participated in a series of conferences, supplemented their clinical experience, performed a literature review, and formulated recommendations for implementing APBI in clinical routine, focusing on patient selection, target definition, and treatment technique.

Results

Appropriate patient selection, target definition for different APBI techniques, and basic rules for appropriate APBI techniques for clinical routine outside of clinical trials are described. Detailed recommendations for APBI in daily practice, including dose constraints, are given.

Conclusion

Guidelines are mandatory to assure optimal results of APBI using different techniques.

Radiosurgery for ventricular tachycardia: preclinical and clinical evidence and study design for a German multi-center multi-platform feasibility trial (RAVENTA)

Background

Single-session high-dose stereotactic radiotherapy (radiosurgery) is a new treatment option for otherwise untreatable patients suffering from refractory ventricular tachycardia (VT). In the initial single-center case studies and feasibility trials, cardiac radiosurgery has led to significant reductions of VT burden with limited toxicities. However, the full safety profile remains largely unknown.

Methods/design

In this multi-center, multi-platform clinical feasibility trial which we plan is to assess the initial safety profile of radiosurgery for ventricular tachycardia (RAVENTA). High-precision image-guided single-session radiosurgery with 25 Gy will be delivered to the VT substrate determined by high-definition endocardial electrophysiological mapping. The primary endpoint is safety in terms of successful dose delivery without severe treatment-related side effects in the first 30 days after radiosurgery. Secondary endpoints are the assessment of VT burden, reduction of implantable cardioverter defibrillator (ICD) interventions [shock, anti-tachycardia pacing (ATP)], mid-term side effects and quality-of-life (QoL) in the first year after radiosurgery. The planned sample size is 20 patients with the goal of demonstrating safety and feasibility of cardiac radiosurgery in ≥ 70% of the patients. Quality assurance is provided by initial contouring and planning benchmark studies, joint multi-center treatment decisions, sequential patient safety evaluations, interim analyses, independent monitoring, and a dedicated data and safety monitoring board.

Discussion

RAVENTA will be the first study to provide the initial robust multi-center multi-platform prospective data on the therapeutic value of cardiac radiosurgery for ventricular tachycardia.

Trial registration number

NCT03867747 (clinicaltrials.gov). Registered March 8, 2019. The study was initiated on November 18th, 2019, and is currently recruiting patients.

Graphic abstract

Commercially Available Gene Expression Assays as Predictive Tools for Adjuvant Radiotherapy? A Critical Review

Background

Gene expression assays are increasingly used for decision-making regarding adjuvant chemotherapy in patients with hormone receptor-positive, HER2-negative breast cancer. There are some clinical situations in which there is also a need for better prognostic and predictive markers to better estimate the amount of benefit from adjuvant radiotherapy. The rising availability of gene expression analyses prompts the question whether their results can also be used to guide clinical decisions regarding adjuvant radiation.

Summary

Multiple studies suggest a correlation between results from gene expression assays and locoregional recurrence rates. Only few publications addressed the predictive value of results from gene expression analysis for the role of adjuvant radiotherapy in different settings.

Key Messages

To date, the available evidence on the possible predictive value of gene expression assays for radiotherapy does not support their inclusion into the decision-making process for adjuvant radiation. This is due to methodological weaknesses and limitations regarding patient selection, the nonrandomized design of all studies in terms of radiotherapy use, and limited availability of tissue from prospective trials. Thus, utilization of the present knowledge for clinical indication of radiotherapy should be very cautious.

Heart-sparing radiotherapy techniques in breast cancer patients: a recommendation of the breast cancer expert panel of the German society of radiation oncology (DEGRO)

PURPOSE

The aim of this review was to analyze the respective efficacy of various heart-sparing radiotherapy techniques.

MATERIAL AND METHODS

Heart-sparing can be performed in three different ways in breast cancer radiotherapy: by seeking to keep the heart out of treated volumes (i.e. by prone position or specific breathing techniques such as deep inspiration breath-hold [DIBH] and/or gating), by solely irradiating a small volume around the lumpectomy cavity (partial breast irradiation, PBI), or by using modern radiation techniques like intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) or protons. This overview presents the available data on these three approaches.

RESULTS

Studies on prone position are heterogeneous and most trials only refer to patients with large breasts; therefore, no definitive conclusion can be drawn for clinical routine. Nonetheless, there seems to be a trend toward better sparing of the left anterior descending artery in supine position even for these selected patients. The data on the use of DIBH for heart-sparing in breast cancer patients is consistent and the benefit compared to free-breathing is supported by several studies. In comparison with whole breast irradiation (WBI), PBI has an advantage in reducing the heart dose. Of note, DIBH and PBI with multicatheter brachytherapy are similar with regard to the dose reduction to heart structures. WBI by IMRT/VMAT techniques without DIBH is not an effective strategy for heart-sparing in breast cancer patients with "standard" anatomy. A combination of DIBH and IMRT may be used for internal mammary radiotherapy.

CONCLUSION

Based on the available findings, the DEGRO breast cancer expert panel recommends the use of DIBH as the best heart-sparing technique. Nonetheless, depending on the treatment volume and localization, other techniques may be employed or combined with DIBH when appropriate.