UK 2022 Consensus on Normal Tissue Dose-Volume Constraints for Oligometastatic, Primary Lung and Hepatocellular Carcinoma Stereotactic Ablative Radiotherapy.

The use of stereotactic ablative radiotherapy (SABR) in the UK has expanded over the past decade, in part as the result of several UK clinical trials and a recent NHS England Commissioning through Evaluation programme. A UK SABR Consortium consensus for normal tissue constraints for SABR was published in 2017, based on the existing literature at the time. The published literature regarding SABR has increased in volume over the past 5 years and multiple UK centres are currently working to develop new SABR services. A review and update of the previous consensus is therefore appropriate and timely. It is hoped that this document will provide a useful resource to facilitate safe and consistent SABR practice.

Selective targeting of the G2/M cell cycle checkpoint to improve the therapeutic index of radiotherapy.

Despite tremendous advances in radiotherapy techniques, allowing dose escalation to tumour tissues and sparing of organs at risk, cure rates from radiotherapy or chemoradiotherapy remain suboptimal for most cancers. In tandem with our growing understanding of tumour biology, we are beginning to appreciate that targeting the molecular response to radiation-induced DNA damage holds great promise for selective tumour radiosensitisation. In particular, approaches that inhibit cell cycle checkpoint controls offer a means of exploiting molecular differences between tumour and normal cells, thereby inducing so-called cancer-specific synthetic lethality. In this overview, we discuss cellular responses to radiation-induced damage and discuss the potential of using G2/M cell cycle checkpoint inhibitors as a means of enhancing tumour control rates.

The hallmarks of cancer and the radiation oncologist: updating the 5Rs of radiobiology.

A comprehensive, mechanistic understanding of radiobiological phenomena that can be integrated within the broader context of cancer biology offers the prospect of transforming clinical practice in radiation oncology. In this review, we revisit the six established biological hallmarks of cancer and examine how they have provided insights into novel therapeutic strategies. In addition, we discuss the potential of two emerging hallmarks to continue to expand our understanding beyond the narrow confines of the traditional 5Rs of radiobiology.

Embryonal rhabdomyosarcoma of the orbit in a 35-year-old man.

A 35-year-old man had rapidly progressive proptosis of the right eye with associated chemosis over a period of several weeks. Computed tomography demonstrated a solid extraconal mass in the inferior anterior right orbit. Pathologic examination revealed the lesion to be an embryonal rhabdomyosarcoma. Consistent with the diagnosis, immunohistochemical assays demonstrated positive staining with myoglobin, desmin, and muscle-specific actin. The lesion grew rapidly and was further surgically excised. Subsequently, treatment with radiation and chemotherapy was initiated. Primary embryonal rhabdomyosarcoma of the orbit is an extremely rare tumor in adults, and, to our knowledge, this patient represents the oldest individual reported to have developed such a tumor, as documented by immunohistochemical analysis.