Anal squamous cell carcinoma: a retrospective case series.

BACKGROUND: Anal cancer is a relatively rare cancer with 660 cases diagnosed in 2000-2015 in Ireland (1). The current standard treatment is radical chemoradiotherapy (CRT). The aim of our study was to review the treatment and outcomes of patients with localised anal squamous cell carcinoma (SCC), who received radical treatment in our radiation oncology network between 2008 and 2014 inclusive. METHODS: Data were collected retrospectively from ARIA® oncology information system and patient charts. Statistical analyses were performed using IBM® SPSS® statistical software version 25.0. RESULTS: Seventy-nine cases of anal SCC were identified. Mean age of patients at commencement of radiotherapy (RT) was 60.2 years (standard deviation: 13.1 years). The most common total RT dose was 50.4 Gy in 28 fractions (N = 58; 73.4%). Median follow-up was 5.6 years. Two (2.6%) patients had persistent disease, seventeen (21.8%) patients developed loco-regional recurrence and nine (11.5%) patients developed solid organ metastases, four of whom had complete treatment response at the primary site. Eight patients underwent salvage anal surgery following completion of RT. Median overall survival was 10.5 years (95% confidence interval (CI) 5.1-15.8 years), median loco-regional relapse-free survival was 10.4 years (95% CI 4.4-16.3 years) and median disease-free survival was 9.3 years (95% CI 6.3-12.2 years). CONCLUSION: Our study demonstrates that treatment for anal SCC and outcomes following definitive CRT in Ireland during the study period were comparable to international standards.

Treatment of multiple intracranial metastases in radiation oncology: a contemporary review of available technologies.

The use of stereotactic radiosurgery to treat multiple intracranial metastases, frequently concurrently, has become increasingly common. The ability to accurately and safely deliver stereotactic radiosurgery treatment to multiple intracranial metastases (MIM) relies heavily on the technology available for targeting, planning, and delivering the dose. A number of platforms are currently marketed for such applications, each with intrinsic capabilities and limitations. These can be broadly categorised as cobalt-based, linac-based, and robotic. This review describes the most common representative technologies for each type along with their advantages and current limitations as they pertain to the treatment of multiple intracranial metastases. Each technology was used to plan five clinical cases selected to represent the clinical breadth of multiple metastases cases. The reviewers discuss the different strengths and limitations attributed to each technology in the case of MIM as well as the impact of disease-specific characteristics (such as total number of intracranial metastases, their size and relative proximity) on plan and treatment quality.

Determining normal tissue dose in intracranial stereotactic radiosurgery: A diameter-based predictive nomogram.

Purpose: A major factor in dose-fractionation selection for intracranial metastases in stereotactic radiosurgery (SRS) is the size of the target lesion and consequently the dose-volume to the surrounding normal brain tissue (NTV), as this has been correlated with brain radiation necrosis (RN). This study outlines the development and validation of a predictive model that can estimate the NTV for a range of dose-fractionation schemes based on target diameter from a patient's MRI. Methods: Data from a cohort of historical SRS clinical treatment plans were used to extract three key input parameters for the model - conformity index, gradient index, and a scaling factor which were then defined as a function of target volume. The relationship between the measured tumour diameter and the NTV was established by approximating the target to a spherical volume covered by the prescription dose. A scaling factor (λNTV) describes the non-linear fall-off of dose beyond the target. This was then used to provide a first-order approximation of the resulting NTV. The predictive model was retrospectively validated using linear regression against actual NTV values from 39 historical SRS plans which were independent to the derivation process. The model was validated for both three-dimensional (3D) target diameter and axial-only two-dimensional (2D) estimates of target diameter values. Results: The prediction model directly relates lesion diameter to NTV volume (cc) and thus RN risk for a given dose-fractionation. The predicted NTV (cc) for both 3D- and 2D-based volume estimates could statistically significantly predict the actual NTV (cc): R2=0.942 (p<.0005) for 3D-based estimate, and R2=0.911 (p=<.0005) for axial-only 2D-based estimate. Conclusion: This knowledge-based method for NTV prediction in intracranial SRS provides the clinician with a decision support tool to appropriately select dose-fractionation prior to treatment planning.

Imaging response assessment following stereotactic body radiotherapy for solid tumour metastases of the spine: Current challenges and future directions.

Patients with metastatic disease are routinely serially imaged to assess disease burden and response to systemic and local therapies, which places ever-expanding demands on our healthcare resources. Image interpretation following stereotactic body radiotherapy (SBRT) for spine metastases can be challenging; however, appropriate and accurate assessment is critical to ensure patients are managed correctly and resources are optimised. Here, we take a critical review of the merits and pitfalls of various imaging modalities, current response assessment guidelines, and explore novel imaging approaches and the potential for radiomics to add value in imaging assessment.

The emerging role of stereotactic radiotherapy in gastrointestinal malignancies: a review of the literature and analysis from the Irish perspective.

Primary and secondary malignancies of the liver and pancreas result in significant morbidity and mortality, with increasing incidence and increasing demands on health services worldwide. Surgery is the only curative single modality of treatment and remains the gold standard. Unfortunately, up to 80% of the patients present with unresectable disease, and so, alternative efficacious local and systemic treatments are needed. Technologic advances in radiotherapy over recent decades have meant that precision high-dose treatment with stereotactic body radiotherapy (SBRT) has emerged as a viable cost-effective outpatient-based treatment in the management of these difficult to treat abdominal malignancies. This article reviews the current indications for SBRT in these settings, comparing it with other treatments including surgery, chemotherapy, radiofrequency ablation, and trans-arterial chemoembolisation. We also review the current use of abdominal SBRT and future projections in the Irish healthcare setting.

Clinical review of treatment outcomes and patterns of failure with adjuvant radiotherapy in node-positive malignant melanoma.

INTRODUCTION: Adjuvant radiotherapy is proven to prevent lymph node field relapse after therapeutic lymphadenectomy for melanoma, but does not improve overall survival based on current data. There remains a high rate of distant relapse. This study reports patterns of failure in patients treated with adjuvant radiotherapy, looking at factors associated with distant metastasis and comparing this to recent literature. METHODS: This retrospective study included patients treated with adjuvant nodal irradiation after lymphadenectomy between June 2012 and March 2015. RESULTS: Twenty-one patients were treated during this period. Median follow-up was 13.5 months. There were no lymph node field recurrences. Distant metastasis (DM) rate was 48%. DM rate was significantly higher (P = 0.027) in patients with extracapsular extension (ECE) (71%) than those without ECE (0%). DM rate was higher in those with a maximum tumour size of >3 cm (71%) than those with tumour size <3 cm (30%) (P = 0.160). Number of nodes, BRAF status or nodal site did not correlate with rate of DM. The median time to DM was 16 weeks after completion of radiotherapy. CONCLUSION: Radiotherapy is well tolerated and effective in regional control. However, patients are at risk of early distant relapse, particularly those with ECE or large tumour size. There are currently no useful prognostic markers to differentiate the risk of regional versus distant recurrence, and the optimal treatment paradigm remains undefined. Research on adjuvant systemic therapies and abscopal effects of radiotherapy have shown improved management of distant metastasis; creating an even greater need for effective regional control strategies.

An Unusual Case of Marginal Zone B-Cell Lymphoma Arising in the Breast - Its Diagnosis and the Role of Radiotherapy in its Management.

BACKGROUND: Primary lymphoma of the breast accounts for 0.04-0.5% of all breast malignancies and approximately 1% of all extranodal lymphomas. For stage IE node-negative disease, involved field radiotherapy is recommended except for very young women in whom the risk of breast cancer is a concern. The rate of complete response for limited stage extranodal marginal B-cell lymphoma is in excess of 90%. CASE REPORT: We report the case of a 62-year-old lady who presented with a unilateral painless palpable right breast lump. She subsequently underwent a trucut biopsy of the lesion. The histology revealed a low-grade B-cell non-Hodgkin's lymphoma (NHL). Immunohistochemistry showed that more than 95% of the cells were B cells which were CD 20+/CD 45+ and BC L6+. This confirmed the diagnosis of marginal zone lymphoma. Staging work-up was negative for distant metastases. Serum alkaline phosphatase and lactate dehydrogenase were normal. The patient had no 'B' symptoms. Her final diagnosis was clinical stage IAE NHL, and she was referred for curative radiotherapy. CONCLUSION: Radiation treatment is a safe and extremely effective modality of treatment for early stage I marginal zone B-cell lymphomas of the breast.