Irene Karam

Magnetic resonance-guided high-intensity focused ultrasound combined with radiotherapy for palliation of head and neck cancer-a pilot study.

BackgroundRadiotherapy is a critical component of the multidisciplinary management of cancers of the head and neck. It may comprise the primary curative treatment modality or is used in an adjuvant setting to improve local control and survival by preventing seeding and reseeding of distant metastases from persistent reservoirs of locoregional disease. Although considerable advances have been made recently in the fields of radiotherapy, systemic treatment and surgery for head and neck tumours, locoregional recurrence rates remain high and treatment side effects may have severe impact on patients’ quality of life.Magnetic resonance-guided high-intensity focused ultrasound (MRg-HIFU) is a novel technique in the treatment of cancer that has the potential to improve tumour cure rates and decrease treatment-related toxicity. Clinical applications of HIFU are being used increasingly for the treatment of several tumour sites, for example uterine leiomyomas and prostate cancer.Methods/DesignThe pilot study presented here is an initial step toward utilizing MRg-HIFU for head and neck cancer treatment. The rationale for novel treatment options in head and neck cancer is reviewed as well as emerging evidence that support the increasing clinical utilization of MRg-HIFU.DiscussionThis pilot study aims to assess safety, toxicity and feasibility of MRg-HIFU treatments to the head and neck region and to evaluate changes caused by MRg-HIFU within the treated tumour regions based on post-treatment MRI.

Survey of current practices from the International Stereotactic Body Radiotherapy Consortium (ISBRTC) for head and neck cancers

AIM To provide a multi-institutional description of current practices of stereotactic body radiotherapy (SBRT) for head and neck cancer. MATERIALS & METHODS 15 international institutions with significant experience in head and neck SBRT were asked to complete a questionnaire covering clinical and technical factors. RESULTS SBRT is used 10-100% of the time for recurrent primary head and neck cancer, and 0-10% of the time in newly diagnosed disease. Five centers use a constraint for primary disease of 3-5 cm and 25-30 cc. Nine institutions apply a clinical target volume expansion of 1-10 mm and 14 use a planning target volume margin of 1-5 mm. Fractionation regimens vary between 15 and 22 Gy in 1 fraction to 30-50 Gy in 5 or 6 fractions. The risk of carotid blowout quoted in the re-irradiation setting ranges from 3 to 20%. CONCLUSION There is considerable heterogeneity in patient selection and techniques in head and neck SBRT practice among experienced centers.

Stereotactic body radiotherapy for head and neck cancer: an addition to the armamentarium against head and neck cancer

In the recent years, stereotactic body radiation therapy (SBRT) has emerged as a potential therapy for head and neck malignancies. Although early results appear to be promising, serious acute and late effects have been observed, mainly in patients who have had prior external beam radiotherapy. This review will discuss the radiobiology of SBRT, clinical rationale and outcomes for SBRT in head and neck cancers and focus on the benefits and potential limitations in both de novo and re-irradiation settings.

Stereotactic Body Radiotherapy

Stereotactic body radiation therapy (SBRT) consists of the delivery of precise, conformal, hypofractionated, and ablative therapy in a single or a small number of fractions to extracranial regions. Over the last decade, it is rapidly being integrated into mainstream radiation oncology practices. The indications for SBRT continue to grow, as does the technology associated with its delivery. This chapter presents a detailed overview of clinically relevant topics including patient selection and outcomes, and the technological aspects of planning and delivery of SBRT. The tumor streams covered in this chapter are lung, liver, spine, pancreas, renal cell carcinoma, adrenal, prostate, and head and neck. The chapter concludes by highlighting two novel areas, cardiac arrhythmias and pediatric oncology, in which the use of SBRT is emerging.

Magnetic Resonance-based Response Assessment and Dose Adaptation in Human Papilloma Virus Positive Tumors of the Oropharynx treated with Radiotherapy (MR-ADAPTOR): An R-IDEAL stage 2a-2b/Bayesian phase II trial

Highlights • Treatment de-escalation in HPV+ oropharynx cancer is an active area of research.• A Bayesian phase II trial of MR-guided radiotherapy dose adaptation is proposed.• High dose volume will be adapted on weekly MRI based on tumor response.• The non-inferiority of dose adaptation compared to standard IMRT will be assessed.

Radiotherapy for patients with unresected locally advanced breast cancer

BACKGROUND Management of locally-advanced breast cancer is determined by multiple factors, but in patients without distant metastases often involves neoadjuvant systemic therapy, surgery and radiation. If the primary tumour remains unresectable following systemic therapy, radiotherapy may be used for tumour shrinkage prior to surgery. When metastatic disease is present, locoregional radiotherapy is generally reserved for management of tumour-related symptoms. We reviewed our experience of high-dose radiotherapy for unresected locally-advanced breast cancer. METHODS A retrospective chart review was conducted of patients with unresected locally advanced breast cancer (LABC) receiving external beam radiotherapy to the breast, chest wall and/or regional lymph nodes. Patients were stratified based on the presence of metastatic disease at presentation. Patient demographics, disease characteristics, and treatment outcomes were recorded. RESULTS Forty-three cases were analyzed between 2004 and 2016. Median follow-up was 25 months from diagnosis and 14 months from completion of radiotherapy. There were 24 cases (56%) with metastatic disease on presentation, and 19 (44%) without. Tumour shrinkage occurred within 3 months of completing radiotherapy in 36 cases (84%). Ulceration and bleeding improved following radiotherapy in 13 (54%) of the 24 applicable cases. Twenty-six patients (60%) developed moist desquamation but none experienced grade 4 or 5 radiation dermatitis. Median locoregional progression-free survival for all patients was 12 months from completion of radiotherapy. Locoregional progression-free survival (P=0.2) and overall survival (OS) (P=0.4) were not significantly different between patients with and without distant metastases at presentation. CONCLUSIONS Radiotherapy provided good response and symptom control in most patients in this study; there is a role for palliative radiotherapy in patients with LABC.

Automated metastatic brain lesion detection: a computer aided diagnostic and clinical research tool

The accurate localization of brain metastases in magnetic resonance (MR) images is crucial for patients undergoing stereotactic radiosurgery (SRS) to ensure that all neoplastic foci are targeted. Computer automated tumor localization and analysis can improve both of these tasks by eliminating inter and intra-observer variations during the MR image reading process. Lesion localization is accomplished using adaptive thresholding to extract enhancing objects. Each enhancing object is represented as a vector of features which includes information on object size, symmetry, position, shape, and context. These vectors are then used to train a random forest classifier. We trained and tested the image analysis pipeline on 3D axial contrast-enhanced MR images with the intention of localizing the brain metastases. In our cross validation study and at the most effective algorithm operating point, we were able to identify 90% of the lesions at a precision rate of 60%.