Tratamiento radioterápico del cáncer mama: estándares y nuevas tendencias. Irradiación parcial acelerada de la mama

Radiotherapy as a part of the breast cancer treatment has evolved in the last decades. Post-mastectomy radiotherapy produces a substantial reduction in the risk of local recurrence as well as a moderate, but definitive reduction in long-term breast cancer mortality in women at high risk of locoregional failure. Whole-breast irradiation, as part of breast-conservation therapy, has well-established results with good cosmesis, and low toxicity. Results from the BCT trials suggest that the risk for ipsilateral breast cancer recurrence resides within close proximity to the original tumor site. This has led investigators to consider the role of an accelerated and more tumor bed-focused course of radiotherapy. Accelerated partial-breast irradiation (APBI) is a collection of radiotherapy techniques that deliver higher daily doses of radiation to the surgical cavity with margin over a shorter time than whole breast irradiation (from 6-6.5 weeks to 1 week). Early results of this approach have demonstrated excellent local control, minimal acute toxicity, and are more convenient for the patient. Phase III randomized clinical trials are currently underway to assess local control, acute and chronic toxicities. APBI extend the choise of breast conservatio

Role of fluorine-18 fluorodeoxyglucose PET/CT in head and neck oncology: the point of view of the radiation oncologist

Squamous cell carcinoma is the most common malignant tumour of the head and neck. The initial TNM staging, the evaluation of the tumour response during treatment, and the long-term surveillance are crucial moments in the approach to head and neck squamous cell carcinoma (HNSCC). Thus, at each of these moments, the choice of the best diagnostic tool providing the more precise and larger information is crucial. Positron emission tomography with fluorine-18 fludeoxyglucose integrated with CT (F-18-FDG-PET/CT) rapidly gained clinical acceptance, and it has become an important imaging tool in routine clinical oncology. However, controversial data are currently available, for example, on the role of F-18-FDG-PET/CT imaging during radiotherapy planning, the prognostic value or its real clinical impact on treatment decisions. In this article, the role of F-18-FDG-PET/CT imaging in HNSCC during pre-treatment staging, radiotherapy planning, treatment response assessment, prognosis and follow-up is reviewed focusing on current evidence and controversial issues. A proposal on how to integrate F-18-FDG-PET/CT in daily clinical practice is also described

The emerging role of AMPK in the regulation of breathing and oxygen supply

Regulation of breathing is critical to our capacity to accommodate deficits in oxygen availability and demand during, for example, sleep and ascent to altitude. It is generally accepted that a fall in arterial oxygen increases afferent discharge from the carotid bodies to the brainstem and thus delivers increased ventilatory drive, which restores oxygen supply and protects against hypoventilation and apnoea. However, the precise molecular mechanisms involved remain unclear. We recently identified as critical to this process the AMP-activated protein kinase (AMPK), which is key to the cell-autonomous regulation of metabolic homoeostasis. This observation is significant for many reasons, not least because recent studies suggest that the gene for the AMPK-α1 catalytic subunit has been subjected to natural selection in high-altitude populations. It would appear, therefore, that evolutionary pressures have led to AMPK being utilized to regulate oxygen delivery and thus energy supply to the body in the short, medium and longer term. Contrary to current consensus, however, our findings suggest that AMPK regulates ventilation at the level of the caudal brainstem, even when afferent input responses from the carotid body are normal. We therefore hypothesize that AMPK integrates local hypoxic stress at defined loci within the brainstem respiratory network with an index of peripheral hypoxic status, namely afferent chemosensory inputs. Allied to this, AMPK is critical to the control of hypoxic pulmonary vasoconstriction and thus ventilation–perfusion matching at the lungs and may also determine oxygen supply to the foetus by, for example, modulating utero-placental blood flow

Short-term Toxicity of High Dose Rate Brachytherapy in Prostate Cancer Patients with Inflammatory Bowel Disease

Aims: Inflammatory bowel disease (IBD) has historically been considered a risk factor for increased bowel toxicity in patients receiving pelvic external beam radiotherapy. The risk is reduced in intensity-modulated radiotherapy compared with three-dimensional conformal radiotherapy. The effect of brachytherapy has been less extensively researched. Despite the increased dose to the gross tumour volume and decreased dose to organs at risk, previous studies have recommended avoidance of low dose rate (LDR) brachytherapy in patients with IBD, due to increased bowel toxicity. We investigated the effect of high dose rate (HDR) brachytherapy in IBD. Materials and methods: Eleven IBD patients across four different sites (in the UK and Spain) who received HDR brachytherapy, between 2012 and 2015, were followed for up to 12 months. Acute bowel and urinary toxicity data were collected and recorded. Results: The median length of follow-up was 6 months (range between 6 weeks and 12 months). Five patients had Crohn's disease and six patients had ulcerative colitis. Only one patient (with Crohn's disease) had active disease at the time of treatment. This patient reported no bowel toxicity. Of the remaining patients, two suffered grade 1 diarrhoea (at 6 weeks and 6 months); three suffered grade 1 proctitis (at 6 weeks and 6 months). There was no grade ≥2 bowel toxicity. The most severe toxicity was grade 2 urinary frequency in one patient (at 6 weeks). Discussion: This small, prospective case series suggests that, in the short term, HDR brachytherapy is safe and well tolerated in IBD patients. Therefore, IBD should not automatically disqualify patients from, at least, HDR brachytherapy. The reason why these results differ from previous LDR studies possibly reflects the benefit of inverse planning, which more readily achieves rectal dose constraints in HDR brachytherapy