GEC-ESTRO ACROP recommendations in skin brachytherapy

Purpose: The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations on behalf of the GEC-ESTRO Group. Methods: We have done an exhaustive review of published articles to look for general recommendations. Results: Randomized controlled trials, systemic reviews and meta-analysis are lacking in literature and there is wide variety of prescription techniques successfully used across the radiotherapy centers. BT can be delivered as superficial application (also called contact BT or plesiotherapy) or as interstitial for tumours thicker than 5 mm within any surface, including very irregular. In selected cases, particularly in tumours located within curved surfaces, BT can be advantageous modality from dosimetric and planning point of view when compared to external beam radiotherapy. The general rule in skin BT is that the smaller the target volume, the highest dose per fraction and the shortest overall length of treatment can be used. Conclusion: Skin cancer incidence is rising worldwide. BT offers an effective non-invasive or minimally invasive and relative short treatment that particularly appeals to elder and frail population

gec estro acrop recommendations in skin brachytherapy

Abstract Purpose The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations on behalf of the GEC-ESTRO Group. Methods We have done an exhaustive review of published articles to look for general recommendations. Results Randomized controlled trials, systemic reviews and meta-analysis are lacking in literature and there is wide variety of prescription techniques successfully used across the radiotherapy centers. BT can be delivered as superficial application (also called contact BT or plesiotherapy) or as interstitial for tumours thicker than 5 mm within any surface, including very irregular. In selected cases, particularly in tumours located within curved surfaces, BT can be advantageous modality from dosimetric and planning point of view when compared to external beam radiotherapy. The general rule in skin BT is that the smaller the target volume, the highest dose per fraction and the shortest overall length of treatment can be used. Conclusion Skin cancer incidence is rising worldwide. BT offers an effective non-invasive or minimally invasive and relative short treatment that particularly appeals to elder and frail population

Evaluating clinical dosimetry of modern techniques in brachytherapy for gynaecological cancers and the feasibility of using deformable image registration and knowledge-based planning for brachytherapy

Aim: To evaluate dosimetric plan quality and clinical outcomes for advanced brachytherapy (BT) of gynaecological malignancies following implementation of evidence-based planning aims. For cervical cancer BT, to test the feasibility of deformable image registration (DIR) for organ at risk (OAR) dose accumulation, and of simple knowledge-based planning (KBP) for OAR dose prediction. Method: Dosimetry and clinical outcomes for the above patient groups were comprehensively evaluated for a five-year period that included various changes. KBP models based on overlap volume histograms were developed to predict OAR D2cm3 and were assessed on goodness of fit and of prediction and on dosimetric performance when used as planning optimisation criteria. DIR was applied to 39 cervical cancer patients and reproducibility was assessed for different implementation methods. Accumulated DVH parameters (D2cm3 and D0.1cm3) for bladder and rectum were compared with dose summation without DIR. Results: 21 patients with vaginal malignancies were evaluated. Local control was achieved in 67%. Median CTV D90 was 78.3Gy. Median D2cm3 to bladder and rectum was 64.8Gy and 62.9Gy respectively. 70 patients with locally advanced cervical cancer were evaluated. 100% had a CTV_HR dose > 85Gy and rectum D2cm3 < 90Gy. Local control was achieved for 95.2% of patients. KBP-based optimization proved to be feasible and decreased mean OAR doses. Using DIR, summed D2cm3 and D0.1cm3 decreased within clinical uncertainties. Adding contour information improved reproducibility. Conclusion: Implementation of evidence-based planning aims for advanced BT for vaginal malignancies and cervical cancer showed consistent plan quality considering the e-b recommendations, excellent local control and acceptable toxicity. The KBP planning method predicting D2cm3 was able to automate optimization of BT plans for cervical cancer. DIR is not yet feasible for routine dose summation in BT

A comparison of radiotherapy techniques for the irradiation of the whole scalp

No abstract available.Dissertation (MSc)--University of Pretoria, 2010.Medical Oncologyunrestricte

Superficial High Dose Rate Brachytherapy for the Treatment of Lower Eyelid Carcinomas

Basal and Squamous cell carcinomas of the eyelid account for a large proportion of skin cancers. Historically the eyelid has been a challenging area to successfully treat and achieve good cosmetic outcomes for patients. This work aims to establish a new way to treat lower eyelid basal and squamous cell carcinomas by using an intraluminal catheter and a high dose rate iridium brachytherapy source. Different mould techniques were used to place the catheter under the lower eyelid, with the aid of a stereotactic head phantom. The optimal mould was then scanned, and a treatment plan was established using Oncentra Brachytherapy software, in combination with the AAPM TG43 algorithm for dose. Two methods were used to verify this plan. Gafchromic film was placed under the mould and analysed using FilmQA Pro software. For organs at risk, optically stimulated luminescence dosimeters were used for point doses and read out using microstarii software. Different setups involving varying levels of bolus around the catheter were tested to eliminate the air gaps to remove the uncertainty of density differences. The results showed that an effective treatment plan can be created using an intraluminal catheter and 6 mm of bolus between the skin and catheter to produce an appropriate dose distribution in the patient for the GEC-ESTRO recommended fractionation scheme of 4 Gy per fraction, with a total of 10–12 fractions, 3 times a week for a total dose 40–48 Gy.Thesis (MPhil) -- University of Adelaide, School of Physical Sciences, 202

A 3D US Guidance System for Permanent Breast Seed Implantation: Development and Validation

Permanent breast seed implantation (PBSI) is a promising breast radiotherapy technique that suffers from operator dependence. We propose and have developed an intraoperative 3D ultrasound (US) guidance system for PBSI. A tracking arm mounted to a 3D US scanner registers a needle template to the image. Images were validated for linear and volumetric accuracy, and image quality in a volunteer. The tracking arm was calibrated, and the 3D image registered to the scanner. Tracked and imaged needle positions were compared to assess accuracy and a patient-specific phantom procedure guided with the system. Median/mean linear and volumetric error was ±1.1% and ±4.1%, respectively, with clinically suitable volunteer scans. Mean tracking arm error was 0.43mm and 3D US target registration error ≤0.87mm. Mean needle tip/trajectory error was 2.46mm/1.55°. Modelled mean phantom procedure seed displacement was 2.50mm. To our knowledge, this is the first reported PBSI phantom procedure with intraoperative 3D image guidance

Optimisation of the End-To-End Phantom for Real-time High Dose Rate Prostate Brachytherapy Verification

High dose rate (HDR) brachytherapy is a form of close range radiotherapy whereby dose is delivered by means of an internal radiation source. By doing so, a high level of dose con-formity and accuracy can be achieved. However, due to the high source activity coupled with the close proximity of radio-sensitive organs such as the rectum, bladder and urethra, there exists the potential of incorrect dose delivery; the irradiation of these organs may con-sequently lead to post-treatment complications. As a result, the need for accurate forms of quality assurance methodology which can verify different aspects of the treatment delivery is paramount. These methodologies must be able to perform real-time dose analysis to monitor crucial organ exposure as well as accurately localise the HDR source within space to verify its position according to the treatment plan. An End-to-end Phantom was developed with anatomically correct Gel Prostate phantoms to create an anthropomorphic representation of the clinical environment. This allowed the testing of clinically relevant treatment plans on the MP987 detector system to test its source localisation capabilities. It was shown that when comparing to the TPS defined dwell po-sitions, the system was able to determine positions on average to within (3.69±0.14)mm,(3.70±0.15)mm, (3.53±0.12)mm and (0.30±0.06)s for the x, y, z and t coordinates respec-tively