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Início Publicações / RSS - Radiotherapy & Oncology

- Radiotherapy & Oncology

Radiotherapy and Oncology
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  • Contents
  • Editorial Board
  • Ultra high dose rate Synchrotron Microbeam Radiation Therapy. Preclinical evidence in view of a clinical transfer
    Spatially fractionated radiotherapy was developed and reported in 1909 by Alban Köhler, a German radiologist, to reduce extensive damage to skin and adjacent tissues when he irradiated deep seated tumours with low voltage (60–70 kV) X-rays. To this effect, he held a shielding iron wire grid tightly against the skin before exposure. The heavily irradiated, necrotic spots of the unshielded skin healed in few weeks. Variants of grid therapy were then used successfully in clinical external beam radiotherapy since the 1930s [1].

  • Treatment of a first patient with FLASH-radiotherapy
    When compared to conventional radiotherapy (RT) in pre-clinical studies, FLASH-RT was shown to reproducibly spare normal tissues, while preserving the anti-tumor activity. This marked increase of the differential effect between normal tissues and tumors prompted its clinical translation. In this context, we present here the treatment of a first patient with FLASH-RT.

  • Feasibility of proton FLASH effect tested by zebrafish embryo irradiation
    During the last decades, radiotherapy dose delivery techniques were notably improved with respect to tumor conformity, e.g., by sophisticated beam delivery techniques like intensity modulated radiation therapy. One disadvantage also of modern photon beam techniques is the exposure of the surrounding normal tissue, which is linked to a risk of severe acute and late effects. Alternatives for reducing the risk are provided by the application of charged particles with their inverse depth dose profile or could be possible by the recently described Flash effect that promises normal tissue protection thanks to dose delivery by beam pulses of high dose rate [1].

  • Clinical translation of FLASH radiotherapy: Why and how?
    Radiation therapy (RT) is a major actor in cancer management, with more than half of all cancer patients treated with RT, mostly given with curative potential. RT generally exploits the empirical observation that normal tissues can recover from the harmful effects of ionizing radiation to a higher extent than tumors. This differential effect can be exacerbated by two factors that can independently increase the normal tissue tolerance. The first factor is the fractionation of the total dose with a good protection of normal tissues at 2 Gy per fraction and even more pronounced below 2 Gy/fraction [1].

  • Reduced cognitive deficits after FLASH irradiation of whole mouse brain are associated with less hippocampal dendritic spine loss and neuroinflammation
    Radiation therapy is an important treatment modality for a broad range of brain tumors. However, the ability to cure tumors through dose intensity is limited by normal tissue injury, particularly when a large volume of the brain (up to the whole brain) must be included in the treatment volume as is the case for many clinical indications. In the prospective randomized trial RTOG 0614, 64.9% of patients developed a significant decrement in cognitive function by 24 weeks after whole brain radiation therapy [1].

  • PHASER: A platform for clinical translation of FLASH cancer radiotherapy
    Cancer is a leading and epidemically increasing cause of death globally in both the developed and developing world. Because radiation therapy is a pillar of curative cancer therapy, two major challenges must be addressed to reduce cancer mortality substantially: (1) fundamentally increasing the therapeutic index of radiotherapy, maximizing tumor eradication while minimizing toxicity; (2) increasing global access to the highest quality radiotherapy.

  • Dosimetric and preparation procedures for irradiating biological models with pulsed electron beam at ultra-high dose-rate
    The progress of radiotherapy (RT) over the last few decades was mostly obtained in improving the spatial and dosimetric accuracy of the delivered dose to the patient [1,2]. Lately, a RT technique called FLASH-RT has emerged and questioned some established RT concepts regarding the effects of radiation on healthy tissue. Indeed, preclinical studies in FLASH-RT have shown that irradiations with an ultra-high dose-rate increase the differential response between normal tissues and tumors [3–6]. In order to reveal differential biological effects, radiobiological studies required a traceable, accurate and repeatable dose delivery.

  • EGCG, a green tea polyphenol, as one more weapon in the arsenal to fight radiation esophagitis?
    Radiotherapy (RT) is a mainstay in the treatment of locally advanced non-small cell lung cancer (NSCLC). The addition of chemotherapy (CHT) to RT improves the survival of patients with NSCLC [1]. A concurrent approach is superior to a sequential CHT-RT approach in patients with PS 0–1 and stage III NSCLC [2]. If, for any reason, CHT cannot be given to such patients, the hyperfractionated acceleration of RT improves the treatment outcome compared with conventional fractionation [3]. However, these more efficacious treatment modalities are also more aggressive, i.e., more toxic.

  • Imaging of regional ventilation: Is CT ventilation imaging the answer? A systematic review of the validation data
    The idea of deriving information about regional pulmonary function from respiratory-correlated computed tomography (CT), especially 4-Dimensional Computed Tomography (4DCT) and inhale/exhale breath-hold CT (BHCT), without exogenous contrast is highly attractive. In the context of radiotherapy treatment planning, respiratory-correlated thoracic CT scans are acquired routinely for lung cancer patients, a population with significant impairment of respiratory function, and breast cancer patients, where radiation-induced lung toxicity remains a major dose-limiting factor.

  • Big data analysis of associations between patient reported outcomes, observer reported toxicities, and overall quality of life in head and neck cancer patients treated with radiation therapy
    Patient reported outcomes (PROs) have become a common component of data collection in clinical trials in oncology in recent years [1–8]. They can provide information about treatment toxicity that is complementary to the observer-reported Common Terminology Criteria for Adverse Events (CTCAE) rating system that is typically employed in US-based oncology trials [9]. Although the CTCAE system is essential for assessing the safety of treatments being investigated, studies generally show only fair to moderate associations between clinician and patient reported outcomes, with clinicians typically underestimating symptom severity as rated by patients [10–15].

  • Boron neutron capture therapy for locally recurrent head and neck squamous cell carcinoma: An analysis of dose response and survival
    Head and neck squamous cell carcinoma (HNSCC) can be cured with surgery and radiotherapy with or without systemic therapy, but locoregional recurrence is not uncommon. Cancers that recur locally are often considered inoperable, and may pose a therapeutic challenge, because reirradiation is often associated with substantial toxicity, and chemotherapy and immunotherapy have limited efficacy in most patients [1,2]. Intensity modulated radiotherapy (IMRT) and stereotactic radiotherapy (SRT) may allow delivery of relatively high re-treatment radiation doses without excessive adverse effects to the normal tissues and may improve tumor local control rates in selected patients [3–10].

  • ESTRO ACROP consensus guideline for target volume delineation in the setting of postmastectomy radiation therapy after implant-based immediate reconstruction for early stage breast cancer
    Breast cancer is the most common non-skin cancer in women worldwide. The vast majority of patients have non-metastatic disease at diagnosis [1]. The rates of mastectomy with an immediate breast reconstruction (IBR), mainly an implant/prosthesis-based reconstruction (IBR-i), as a surgical treatment for early breast cancer patients are increasing [2,3].

  • Tumor localization accuracy for high-precision radiotherapy during active breath-hold
    For thoracoabdominal neoplasms, respiratory motion management techniques may improve target control rates by enhancing the accuracy of target dose delivery, and augmenting normal tissue sparing by accommodating tumor motion during the radiotherapy course [1,2]. Treatment planning that accounts for respiratory motion minimizes errors in target and organs-at-risk (OARs) delineation from motion-induced artifacts, which could consequently contribute to reducing the target margin and decrease the treated volume [3].

  • Clinical features and survival outcomes between ascending and descending types of nasopharyngeal carcinoma in the intensity-modulated radiotherapy era: A big-data intelligence platform-based analysis
    Nasopharyngeal carcinoma (NPC) disproportionately burdens southeast Asia, where the highest incidence is in Southern China [1]. Annually, there are 87,000 new NPC diagnosis, and approximately 70% of patients are classified as locoregionally advanced disease [2]. Radiotherapy (RT) is the primary treatment modality for locoregionally advanced NPC [3], which can be categorized by characteristics of natural disease progression as follows: 1) predominantly advanced local disease with early stage cervical lymph node involvement as ascending type (type A, T3-4N0-1); 2) advanced lymph node disease but early stage local invasion as descending type (type D, T1-2N2-3); and 3) predominantly advanced local disease along with advanced lymph node disease (type AD, T3-4N2-3) [4,5].

  • The first prototype of spot-scanning proton arc treatment delivery
    Pencil beam scanning (PBS) technique [1,2] has become a popular treatment modality in proton therapy [3], which offers superior dosimetric properties compared to photon therapy and passive scatter proton beam therapy [4–7]. In PBS, the narrow beams (spots) deliver the therapeutic radiation dose from several fixed beam directions via spots in an optimized fashion. However, the dosimetric quality of the PBS plan could be limited [8] due to the large lateral penumbra [9], uncertainties from patient’s daily setup and proton range [10–16], and limited angles for delivery given the treatment delivery efficiency [17–19].

  • In vitro biological response of cancer and normal tissue cells to proton irradiation not affected by an added magnetic field
    To optimize beam delivery and conformality of proton therapy, MRI integration has been proposed. Therefore, we investigated if proton irradiation in a magnetic field would change biological responses. Our data in cancer cell lines and stem cell-derived organoid models suggest that a magnetic field does not modify the biological response.

  • The impact of sarcopenia on tolerance of radiation and outcome in patients with head and neck cancer receiving chemoradiation
    The general treatment paradigm for locally advanced head and neck cancer (HNC) is concurrent chemotherapy and radiation (CRT). The addition of chemotherapy improves survival outcomes [1–3] and is associated with significant toxicities, including mucositis, dysphagia, and nausea/vomiting. Maintenance of nutrition during treatment presents a challenge. Patients may present with anorexia and malnutrition prior to treatment as a result of their cancer [4]. Most patients then lose significant amounts of weight [5] during treatment.

  • An evaluation of the mid-ventilation method for the planning of stereotactic lung plans
    Practice varies between radiotherapy departments with respect to the method used to account for breathing motion within the planning target volume (PTV). Where information on breathing motion is available in the form of a 4D-CT, there are two conflicting approaches. One approach is to define an internal target volume (ITV) [1] that covers the clinical target volume (CTV) in all phases of the 4D-CT, and to add margins to this, covering the non-respiratory geometric uncertainties. Although ICRU [1] defines the ITV in relation to the CTV, in cases where no margin for sub-clinical spread is required this is equivalent to covering the Gross Tumour Volume (GTV) in all phases of the 4D-CT.

  • Long-term outcomes and late adverse effects of a prospective study on proton radiotherapy for patients with low-grade glioma
    Low-grade gliomas account for 20% of all gliomas and typically occur in young patients who survive years with their illness [1–3]. Choice of treatment must therefore weigh the goals of disease control against late adverse effects [4]. Radiation therapy has been shown to increase PFS in LGG [5], but with risk of late neurocognitive and neuroendocrine toxicity [6–8].

  • Evaluating radiotherapy treatment delay using Failure Mode and Effects Analysis (FMEA)
    The whole process of radiation therapy for cancer treatment is very complex, which is comprised of various advanced technologies such as medical linear accelerator (linac), imaging system, treatment planning system, etc. Additionally, the process of radiation therapy is time-sensitive and contains many discrete coordinated steps that are susceptible to errors and delays that may compel to postpone the start of the treatment.

  • Radiation-induced and neurofibromatosis-associated malignant peripheral nerve sheath tumors (MPNST) have worse outcomes than sporadic MPNST
    Malignant peripheral nerve sheath tumor (MPNST) is a malignant tumor arising either from a peripheral nerve de novo, a preexisting benign nerve sheath tumor (usually neurofibroma), or in a patient with neurofibromatosis type 1 (NF1). The diagnosis of sporadic MPNST is based on the constellation of light microscopic, immunohistochemical and ultrastructural features suggesting Schwann cell differentiation (WHO 2013 edition page 187) [1]. Approximately 10% of MPNSTs develop as a consequence of prior radiation therapy [2–5].

  • Optimal cumulative cisplatin dose in nasopharyngeal carcinoma patients based on induction chemotherapy response
    Nasopharyngeal carcinoma (NPC) is an endemic malignancy in South China [1]. Based on its epidemiology and biological characteristics, NPC is different from other head and neck cancers [2]. Cisplatin-based concurrent chemoradiotherapy (CCRT) has been established as the standard treatment regimen for local advanced NPC patients [3,4]. Recently, the application of induction chemotherapy (IC) before CCRT has received considerable attention. According to previous studies, IC plays an important role in decreasing risk of distant metastasis and improving clinical outcomes [5–7].

  • Influence of tumour laterality on patient survival in non-small cell lung cancer after radiotherapy
    Survival in non-small cell lung cancer (NSCLC) remains poor; in the UK less than 10% of patients survive at five years. This is despite recent advances in radiotherapy technology that have enabled a larger proportion of locally advanced patients to be treated with curative intent, while maintaining the dose received by normal tissues within acceptable safety limits [1,2].

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