• 4D cone beam CT phase sorting using high frequency optical surface measurement during image guided radiotherapy.

      Price, Gareth J; Marchant, Thomas E; Parkhurst, James M; Sharrock, Phillip J; Whitfield, Gillian A; Moore, Christopher J; The Christie Hospital NHS Foundation Trust, Manchester (2011-03-16)
    • Accuracy and precision of an IGRT solution.

      Webster, Gareth J; Rowbottom, Carl G; Mackay, Ranald I; North Western Medical Physics, Christie Hospital NHS Trust, Manchester, United Kingdom. Gareth.Webster@physics.cr.man.ac.uk (2009)
      Image-guided radiotherapy (IGRT) can potentially improve the accuracy of delivery of radiotherapy treatments by providing high-quality images of patient anatomy in the treatment position that can be incorporated into the treatment setup. The achievable accuracy and precision of delivery of highly complex head-and-neck intensity modulated radiotherapy (IMRT) plans with an IGRT technique using an Elekta Synergy linear accelerator and the Pinnacle Treatment Planning System (TPS) was investigated. Four head-and-neck IMRT plans were delivered to a semi-anthropomorphic head-and-neck phantom and the dose distribution was measured simultaneously by up to 20 microMOSFET (metal oxide semiconductor field-effect transmitter) detectors. A volumetric kilovoltage (kV) x-ray image was then acquired in the treatment position, fused with the phantom scan within the TPS using Syntegra software, and used to recalculate the dose with the precise delivery isocenter at the actual position of each detector within the phantom. Three repeat measurements were made over a period of 2 months to reduce the effect of random errors in measurement or delivery. To ensure that the noise remained below 1.5% (1 SD), minimum doses of 85 cGy were delivered to each detector. The average measured dose was systematically 1.4% lower than predicted and was consistent between repeats. Over the 4 delivered plans, 10/76 measurements showed a systematic error > 3% (3/76 > 5%), for which several potential sources of error were investigated. The error was ultimately attributable to measurements made in beam penumbrae, where submillimeter positional errors result in large discrepancies in dose. The implementation of an image-guided technique improves the accuracy of dose verification, particularly within high-dose gradients. The achievable accuracy of complex IMRT dose delivery incorporating image-guidance is within +/- 3% in dose over the range of sample points. For some points in high-dose gradients, submillimeter errors in position can lead to errors > 3%. The precision of the delivery system was demonstrated to be within the experimental noise of the detector system of 1.5% (1 SD).
    • Addition of novel degenerate electrical waveform stimulation with photodynamic therapy significantly enhances its cytotoxic effect in keloid fibroblasts: first report of a potential combination therapy.

      Sebastian, A; Allan, Ernest; Allan, Donald; Colthurst, J; Bayat, A; Plastic & Reconstructive Surgery Research, School of Translational Medicine, Manchester Interdisciplinary Biocentre (MIB), The University of Manchester, UK. (2011-12)
      We recently reported use of photodynamic therapy (PDT) for treating keloid disease (KD). However, in view of high recurrence rates post any treatment modality, adjuvant therapies should be considered. Additionally, we previously demonstrated the effect of a novel electrical waveform, the degenerate wave (DW) on differential gene expression in keloid fibroblasts.
    • An analysis of breast motion using high-frequency, dense surface points captured by an optical sensor during radiotherapy treatment delivery.

      Price, Gareth J; Sharrock, Phillip J; Marchant, Thomas E; Parkhurst, J M; Burton, D; Jain, Pooja; Price, Patricia M; Moore, Christopher J; North Western Medical Physics, The Christie NHS Foundation Trust, Manchester, UK. Gareth.Price@physics.cr.man.ac.uk (2009-11-07)
      Patient motion is an important factor affecting the quality of external beam radiotherapy in breast patients. We analyse the motion of a dense set of surface points on breast patients throughout their treatment schedule to assess the magnitude and stability of motion, in particular, with respect to breast volume. We use an optical sensor to measure the surface motion of 13 breast cancer patients. Patients were divided into two cohorts dependent upon breast volume. Measurements were made during radiotherapy treatment beam delivery for an average of 12 fractions per patient (total 158 datasets). The motion of each surface point is parameterized in terms of its period, amplitude and relative phase. Inter-comparison of the motion parameters across treatment schedules and between patients is made through the creation of corresponding regions on the breast surfaces. The motion period is spatially uniform and is similar in both patient groups (mean 4 s), with the small volume cohort exhibiting greater inter-fraction period variability. The mean motion amplitude is also similar in both groups with a range between 2 mm and 4 mm and an inter-fraction variability generally less than 1 mm. There is a phase lag of up to 0.4 s across the breast, led by the sternum. Breast patient motion is reasonably stable between and during treatment fractions, with the large volume cohort exhibiting greater repeatability than the small volume one.
    • Analysis of the measurement precision of an amorphous silicon EPID used for MLC leaf position quality control and the long-term calibration stability of an optically controlled MLC.

      Budgell, Geoff J; Clarke, Mathew F; North Western Medical Physics, Christie Hospital NHS Foundation Trust, Withington, Manchester, M20 4BX, UK. (2008-08-07)
      Electronic portal imaging devices (EPIDs) have been shown to be suitable for multileaf collimator (MLC) leaf positioning quality control (QC). In our centre, a continuous dataset is available of 2 years of film measurements followed by 3 years of EPID measurements on five MLC-equipped linear accelerators of identical head design. The aim of this work was to analyse this unique dataset in order to determine the relative precision of film and EPID for MLC leaf positioning measurements and to determine the long-term stability of the MLC calibration. The QC dataset was examined and periods without MLC adjustments that contained at least four successive collimator position measurements (a minimum of 6 months) were identified. By calculating the standard deviations (SD) of these results, the reproducibility of the measurements can be determined. Comparison of the film and EPID results enables their relative measurement precision to be assessed; on average film gave an SD of 0.52 mm compared to 0.13 mm for EPIDs. The MLC and conventional collimator results were compared to assess MLC calibration stability; on average, for EPID measurements, the MLC gave an SD of 0.12 mm compared to 0.14 mm for a conventional collimator. The long-term relative individual leaf positions were compared and found to vary between 0.07 and 0.15 mm implying that they are stable over long time periods. These results suggest that the calibration of an optically controlled MLC is inherently very stable between disturbances to the optical system which normally occur on service days.
    • Assessing the effect of a contouring protocol on postprostatectomy radiotherapy clinical target volumes and interphysician variation.

      Mitchell, Darren M; Perry, Lesley A; Smith, Steve; Elliott, Tony; Wylie, James P; Cowan, Richard A; Livsey, Jacqueline E; Logue, John P; Department of Clinical Oncology, Christie Hospital, Manchester, United Kingdom. dmmitchell@doctors.org.uk (2009-11-15)
      PURPOSE: To compare postprostatectomy clinical target volume (CTV) delineation before and after the introduction of a contouring protocol and to investigate its effect on interphysician variability METHODS AND MATERIALS: Six site-specialized radiation oncologists independently delineated a CTV on the computed tomography (CT) scans of 3 patients who had received postprostatectomy radiotherapy. At least 3 weeks later this was repeated, but with the physicians adhering to the contouring protocol from the Medical Research Council's Radiotherapy and Androgen Deprivation In Combination After Local Surgery (RADICALS) trial. The volumes obtained before and after the protocol were compared and the effect of the protocol on interphysician variability assessed. RESULTS: An increase in mean CTV for all patients of 40.7 to 53.9 cm(3) was noted as a result of observing the protocol, with individual increases in the mean CTV of 65%, 15%, and 24% for Patients 1, 2, and 3 respectively. A reduction in interphysician variability was noted when the protocol was used. CONCLUSIONS: Substantial interphysician variation in target volume delineation for postprostatectomy radiotherapy exists, which can be reduced by the use of a contouring protocol. The RADICALS contouring protocol increases the target volumes when compared with those volumes typically applied at our center. The effect of treating larger volumes on the therapeutic ratio and resultant toxicity should be carefully monitored, particularly if the same dose-response as documented in radical prostate radiotherapy applies to the adjuvant and salvage setting. Prostate cancer, Postprostatectomy, Radiotherapy, Target volume.
    • Assessment of bladder motion for clinical radiotherapy practice using cine-magnetic resonance imaging.

      McBain, Catherine A; Khoo, Vincent S; Buckley, David L; Sykes, Jonathan S; Green, Melanie M; Cowan, Richard A; Hutchinson, Charles E; Moore, Christopher J; Price, Patricia M; Academic Department of Radiation Oncology, The University of Manchester, Christie Hospital NHS Foundation Trust, Wilmslow Road, Manchester, United Kingdom. (2009-11-01)
      PURPOSE: Organ motion is recognized as the principal source of inaccuracy in bladder radiotherapy (RT), but there is currently little information on intrafraction bladder motion. METHODS AND MATERIALS: We used cine-magnetic resonance imaging (cine-MRI) to study bladder motion relevant to intrafraction RT delivery. On two occasions, a 28 minute cine-MRI sequence was acquired from 10 bladder cancer patients and 5 control participants immediately after bladder emptying, after abstinence from drinking for the preceding hour. From the resulting cine sequences, bladder motion was subjectively assessed. To quantify bladder motion, the bladder was contoured in imaging volume sets at 0, 14, and 28 min to measure changes to bladder volumes, wall displacements, and center of gravity (COG) over time. RESULTS: The dominant source of bladder motion during imaging was bladder filling (up to 101% volume increase); rectal and small bowel movements were transient, with minimal impact. Bladder volume changes were similar for all participants. However for bladder cancer patients, wall displacements were larger (up to 58 mm), less symmetrical, and more variable compared with nondiseased control bladders. CONCLUSIONS: Significant and individualized intrafraction bladder wall displacements may occur during bladder RT delivery. This important source of inaccuracy should be incorporated into treatment planning and verification.
    • Auditory cortical activation and speech perception in cochlear implant users.

      Green, Kevin M J; Julyan, Peter J; Hastings, David L; Ramsden, Richard T; Department of Otolaryngology, Manchester Royal Infirmary Manchester, UK. kmjgreen@rcsed.ac.uk (2008-03)
      Cochlear implantation is generally accepted as a successful means of restoring auditory sensation to profoundly deaf individuals. Although most patients can expect a satisfactory outcome following implantation, some have poor speech perception outcomes. This investigation used [18F]-fluorodeoxyglucose positron emission tomography to measure cortical activity resulting from auditory stimulation in seven 'good' and four 'poor' cochlear implant recipients. Activations were significantly greater in both the primary and association cortices in the good compared with the poor implant users. We suggest that the ability to access the more specialised speech processing abilities of the auditory association cortices helps determine outcome following cochlear implantation.
    • Bias in iterative reconstruction of low-statistics PET data: benefits of a resolution model.

      Walker, M D; Asselin, M-C; Julyan, Peter J; Feldmann, M; Talbot, P S; Jones, T; Matthews, J C; School of Cancer and Enabling Sciences, Wolfson Molecular Imaging Centre, MAHSC, The University of Manchester, Manchester, UK. (2011-02-21)
      Iterative image reconstruction methods such as ordered-subset expectation maximization (OSEM) are widely used in PET. Reconstructions via OSEM are however reported to be biased for low-count data. We investigated this and considered the impact for dynamic PET. Patient listmode data were acquired in [(11)C]DASB and [(15)O]H(2)O scans on the HRRT brain PET scanner. These data were subsampled to create many independent, low-count replicates. The data were reconstructed and the images from low-count data were compared to the high-count originals (from the same reconstruction method). This comparison enabled low-statistics bias to be calculated for the given reconstruction, as a function of the noise-equivalent counts (NEC). Two iterative reconstruction methods were tested, one with and one without an image-based resolution model (RM). Significant bias was observed when reconstructing data of low statistical quality, for both subsampled human and simulated data. For human data, this bias was substantially reduced by including a RM. For [(11)C]DASB the low-statistics bias in the caudate head at 1.7 M NEC (approx. 30 s) was -5.5% and -13% with and without RM, respectively. We predicted biases in the binding potential of -4% and -10%. For quantification of cerebral blood flow for the whole-brain grey- or white-matter, using [(15)O]H(2)O and the PET autoradiographic method, a low-statistics bias of <2.5% and <4% was predicted for reconstruction with and without the RM. The use of a resolution model reduces low-statistics bias and can hence be beneficial for quantitative dynamic PET.
    • Biodistribution, pharmacokinetics and metabolism of interleukin-1 receptor antagonist (IL-1RA) using [¹⁸F]-IL1RA and PET imaging in rats.

      Cawthorne, Christopher; Prenant, C; Smigova, A; Julyan, Peter J; Maroy, R; Herholz, K; Rothwell, N; Boutin, H; Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK. (2011-02)
      Positron emission tomography (PET) has the potential to improve our understanding of the preclinical pharmacokinetics and metabolism of therapeutic agents, and is easily translated to clinical studies in humans. However, studies involving proteins radiolabelled with clinically relevant PET isotopes are currently limited. Here we illustrate the potential of PET imaging in a preclinical study of the biodistribution and metabolism of ¹⁸F-labelled IL-1 receptor antagonist ([¹⁸F]IL-1RA) using a novel [¹⁸F]-radiolabelling technique.
    • Brain inflammation is induced by co-morbidities and risk factors for stroke.

      Drake, C; Boutin, H; Jones, M S; Denes, A; McColl, B W; Selvarajah, J R; Hulme, S; Georgiou, R F; Hinz, R; Gerhard, A; et al. (2011-08)
      Chronic systemic inflammatory conditions, such as atherosclerosis, diabetes and obesity are associated with increased risk of stroke, which suggests that systemic inflammation may contribute to the development of stroke in humans. The hypothesis that systemic inflammation may induce brain pathology can be tested in animals, and this was the key objective of the present study. First, we assessed inflammatory changes in the brain in rodent models of chronic, systemic inflammation. PET imaging revealed increased microglia activation in the brain of JCR-LA (corpulent) rats, which develop atherosclerosis and obesity, compared to the control lean strain. Immunostaining against Iba1 confirmed reactive microgliosis in these animals. An atherogenic diet in apolipoprotein E knock-out (ApoE(-/-)) mice induced microglial activation in the brain parenchyma within 8 weeks and increased expression of vascular adhesion molecules. Focal lipid deposition and neuroinflammation in periventricular and cortical areas and profound recruitment of activated myeloid phagocytes, T cells and granulocytes into the choroid plexus were also observed. In a small, preliminary study, patients at risk of stroke (multiple risk factors for stroke, with chronically elevated C-reactive protein, but negative MRI for brain pathology) exhibited increased inflammation in the brain, as indicated by PET imaging. These findings show that brain inflammation occurs in animals, and tentatively in humans, harbouring risk factors for stroke associated with elevated systemic inflammation. Thus a "primed" inflammatory environment in the brain may exist in individuals at risk of stroke and this can be adequately recapitulated in appropriate co-morbid animal models.
    • Chemoradiotherapy for locally advanced pancreatic cancer: a radiotherapy dose escalation and organ motion study.

      Henry, Ann M; Ryder, W David J; Moore, Christopher J; Sherlock, David J; Geh, J I; Dunn, P; Price, Patricia M; Academic Department of Radiation Oncology, The University of Manchester, Department of Medical Statistics, Christie Hospital NHS Trust, Manchester, UK. (2008-09)
      AIMS: To determine the efficacy of radiation dose escalation and to examine organ motion during conformal radiotherapy for locally advanced pancreatic cancer. MATERIALS AND METHODS: Thirty-nine patients who were consecutively treated with chemoradiotherapy were studied. Fifteen patients, treated from 1993 to 1997, received 50 Gy in 20 fractions (group I). Twenty-four patients, treated from 1997 to 2003, received an escalated dose of 55 Gy in 25 fractions (group II). Intra-fraction pancreatic tumour motion was assessed in three patients using megavoltage movies during radiation delivery to track implanted radio-opaque markers. RESULTS: Improved survival rates were seen in latterly treated group II patients (P=0.083), who received escalated radiotherapy to smaller treatment volumes due to advances in verification. Worse toxicity effects (World Health Organization grade 3-4) were reported by some patients (<10%), but treatment compliance was similar in both groups, indicating equivalent tolerance. Substantial intra-fraction tumour displacement due to respiratory motion was observed: this was greatest in the superior/inferior (mean=6.6 mm) and anterior/posterior (mean=4.75 mm) directions. Lateral displacements were small (<2 mm). CONCLUSIONS: Dose escalation is feasible in pancreatic cancer, particularly when combined with a reduction in irradiated volume, and enhanced efficacy is indicated. Large, globally applied margins to compensate for pancreatic tumour motion during radiotherapy may be inappropriate. Strategies to reduce respiratory motion, and/or the application of image-guided techniques that incorporate individual patients' respiratory motion into radiotherapy planning and delivery, will probably improve pancreatic radiotherapy.
    • Comparison of IPSM 1990 photon dosimetry code of practice with IAEA TRS-398 and AAPM TG-51.

      Vargas-Castrillón, Silvia T; Cutanda Henriquez, Francisco; NW Medical Physics, Christie Hospital NHS Foundation Trust, Manchester, UK. stvcastrillon@hotmail.com (2009)
      Several codes of practice for photon dosimetry are currently used around the world, supported by different organizations. A comparison of IPSM 1990 with both IAEA TRS-398 and AAPM TG-51 has been performed. All three protocols are based on the calibration of ionization chambers in terms of standards of absorbed dose to water, as it is the case with other modern codes of practice. This comparison has been carried out for photon beams of nominal energies: 4 MV, 6 MV, 8 MV, 10 MV and 18 MV. An NE 2571 graphite ionization chamber was used in this study, cross-calibrated against an NE 2611A Secondary Standard, calibrated in the National Physical Laboratory (NPL). Absolute dose in reference conditions was obtained using each of these three protocols including: beam quality indices, beam quality conversion factors both theoretical and NPL experimental ones, correction factors for influence quantities and absolute dose measurements. Each protocol recommendations have been strictly followed. Uncertainties have been obtained according to the ISO Guide to the Expression of Uncertainty in Measurement. Absorbed dose obtained according to all three protocols agree within experimental uncertainty. The largest difference between absolute dose results for two protocols is obtained for the highest energy: 0.7% between IPSM 1990 and IAEA TRS-398 using theoretical beam quality conversion factors.
    • A computationally efficient method for automatic registration of orthogonal x-ray images with volumetric CT data.

      Chen, Xin; Varley, Martin R; Shark, Lik-Kwan; Shentall, Glyn S; Kirby, Mike C; ADSIP Research Centre, University of Central Lancashire, Preston, UK. xchen2@uclan.ac.uk (2008-02-21)
      The paper presents a computationally efficient 3D-2D image registration algorithm for automatic pre-treatment validation in radiotherapy. The novel aspects of the algorithm include (a) a hybrid cost function based on partial digitally reconstructed radiographs (DRRs) generated along projected anatomical contours and a level set term for similarity measurement; and (b) a fast search method based on parabola fitting and sensitivity-based search order. Using CT and orthogonal x-ray images from a skull and a pelvis phantom, the proposed algorithm is compared with the conventional ray-casting full DRR based registration method. Not only is the algorithm shown to be computationally more efficient with registration time being reduced by a factor of 8, but also the algorithm is shown to offer 50% higher capture range allowing the initial patient displacement up to 15 mm (measured by mean target registration error). For the simulated data, high registration accuracy with average errors of 0.53 mm +/- 0.12 mm for translation and 0.61 +/- 0.29 degrees for rotation within the capture range has been achieved. For the tested phantom data, the algorithm has also shown to be robust without being affected by artificial markers in the image.
    • The cost effectiveness of in vivo dosimetry is not proven.

      Mackay, Ranald I; Williams, Peter C; North Western Medical Physics, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK. ranald.mackay@physics.cr.man.ac.uk (2009-04)
      In vivo dosimetry is a check of the radiotherapy treatment process. Recently, it has been argued that in vivo dosimetry at the start of every patient's radiotherapy is cost effective. We have examined and extended the cost effectiveness argument and show that the model does not deliver the stated benefits.
    • Design and implementation of a head-and-neck phantom for system audit and verification of intensity-modulated radiation therapy.

      Webster, Gareth J; Hardy, Mark J; Rowbottom, Carl G; Mackay, Ranald I; North Western Medical Physics, Christie Hospital NHS Foundation Trust, Manchester, U.K. Gareth.Webster@physics.cr.man.ac.uk (2008)
      The head and neck is a challenging anatomic site for intensity-modulated radiation therapy (IMRT), requiring thorough testing of planning and treatment delivery systems. Ideally, the phantoms used should be anatomically realistic, have radiologic properties identical to those of the tissues concerned, and allow for the use of a variety of devices to verify dose and dose distribution in any target or normaltissue structure. A phantom that approaches the foregoing characteristics has been designed and built; its specific purpose is verification for IMRT treatments in the head-andneck region. This semi-anatomic phantom, HANK, is constructed of Perspex (Imperial Chemical Industries, London, U.K.) and provides for the insertion of heterogeneities simulating air cavities in a range of fixed positions. Chamber inserts are manufactured to incorporate either a standard thimble ionization chamber (0.125 cm3: PTW, Freiburg, Germany) or a smaller PinPoint chamber (0.015 cm3: PTW), and measurements can be made with either chamber in a range of positions throughout the phantom. Coronal films can also be acquired within the phantom, and additional solid blocks of Perspex allow for transverse films to be acquired within the head region. Initial studies using simple conventional head-and-neck plans established the reproducibility of the phantom and the measurement devices to within the setup uncertainty of +/- 0.5 mm. Subsequent verification of 9 clinical head-and-neck IMRT plans demonstrated the efficacy of the phantom in making a range of patient-specific dose measurements in regions of dosimetric and clinical interest. Agreement between measured values and those predicted by the Pinnacle3 treatment planning system (Philips Medical Systems, Andover, MA) was found to be generally good, with a mean error on the calculated dose to each point of +0.2% (range: -4.3% to +2.2%; n = 9) for the primary planning target volume (PTV), -0.1% (range: -1.5% to +2.0%; n = 8) for the nodal PTV, and +0.0% (range: -1.8% to +4.3%, n = 9) for the spinal cord. The suitability of the phantom for measuring combined dose distributions using radiographic film was also evaluated.The phantom has proved to be a valuable tool in the development and implementation of clinical head-and-neck IMRT, allowing for accurate verification of absolute dose and dose distributions in regions of clinical and dosimetric interest.
    • Dosimetry audit for a multi-centre IMRT head and neck trial.

      Clark, Catharine H; Hansen, Vibeke Nordmark; Chantler, Hannah; Edwards, Craig; James, Hayley V; Webster, Gareth J; Miles, Elizabeth; Guerrero Urbano, M Teresa; Bhide, Shree A; Bidmead, A Margaret; et al. (2009-10)
      BACKGROUND AND PURPOSE: PARSPORT was a multi-centre randomised trial in the UK which compared Intensity-Modulated Radiotherapy (IMRT) and conventional radiotherapy (CRT) for patients with head and neck cancer. The dosimetry audit goals were to verify the plan delivery in participating centres, ascertain what tolerances were suitable for head and neck IMRT trials and develop an IMRT credentialing program. MATERIALS AND METHODS: Centres enrolling patients underwent rigorous quality assurance before joining the trial. Following this each centre was visited for a dosimetry audit, which consisted of treatment planning system tests, fluence verification films, combined field films and dose point measurements. RESULTS: Mean dose point measurements were made at six centres. For the primary planning target volume (PTV) the differences with the planned values for the IMRT and CRT arms were -0.6% (1.8% to -2.4%) and 0.7% (2.0% to -0.9%), respectively. Ninety-four percent of the IMRT fluence films for individual fields passed gamma criterion of 3%/3mm and 75% of the films for combined fields passed gamma criterion 4%/3mm (no significant difference between dynamic delivery and step and shoot delivery). CONCLUSIONS: This audit suggests that a 3% tolerance could be applied for PTV point doses. For dose distributions tolerances of 3%/3mm on individual fields and 4%/3mm for combined fields are proposed for multi-centre head and neck IMRT trials.
    • Early clinical evaluation of a novel three-dimensional structure delineation software tool (SCULPTER) for radiotherapy treatment planning.

      McBain, Catherine A; Moore, Christopher J; Green, Matthew M L; Price, Gareth J; Sykes, Jonathan R; Amer, Aminah; Khoo, Vincent S; Price, Patricia M; Academic Department of Radiation Oncology, The University of Manchester, Manchester, UK. (2008-08)
      Modern radiotherapy treatment planning (RTP) necessitates increased delineation of target volumes and organs at risk. Conventional manual delineation is a laborious, time-consuming and subjective process. It is prone to inconsistency and variability, but has the potential to be improved using automated segmentation algorithms. We carried out a pilot clinical evaluation of SCULPTER (Structure Creation Using Limited Point Topology Evidence in Radiotherapy) - a novel prototype software tool designed to improve structure delineation for RTP. Anonymized MR and CT image datasets from patients who underwent radiotherapy for bladder or prostate cancer were studied. An experienced radiation oncologist used manual and SCULPTER-assisted methods to create clinically acceptable organ delineations. SCULPTER was also tested by four other RTP professionals. Resulting contours were compared by qualitative inspection and quantitatively by using the volumes of the structures delineated and the time taken for completion. The SCULPTER tool was easy to apply to both MR and CT images and diverse anatomical sites. SCULPTER delineations closely reproduced manual contours with no significant volume differences detected, but SCULPTER delineations were significantly quicker (p<0.05) in most cases. In conclusion, clinical application of SCULPTER resulted in rapid and simple organ delineations with equivalent accuracy to manual methods, demonstrating proof-of-principle of the SCULPTER system and supporting its potential utility in RTP.
    • Education and training for intensity-modulated radiotherapy in the UK.

      Routsis, D; Staffurth, J; Beardmore, C; Mackay, Ranald I; Oncology Centre, Addenbrooke's Hospital, Cambridge University Hospital NHS Trust, Cambridge, UK. donna.routsis@addenbrookes.nhs.uk (2010-10)
      A growing body of evidence as to the benefits of intensity-modulated radiotherapy (IMRT) has led to the recommendation for its adoption as a treatment option for cancer patients within the UK. Routine clinical implementation of this technology has been slow. One of the causal factors was identified as being the need to improve confidence by improving the understanding and technical skills for IMRT of clinical oncology staff. This report determines and describes the additional knowledge and skills required for IMRT practice for clinical oncologists, clinical scientists (radiotherapy physicists) and radiographers, derived from reviewing evidence from other nations' IMRT practices and adapting them to UK needs. This knowledge and skills specification can be used to inform IMRT educational curricula. Novel educational methods to maintain the required understanding and skills are also described.
    • Efficacy of photodynamic therapy as a treatment for Gorlin syndrome-related basal cell carcinomas.

      Loncaster, Juliette A; Swindell, Ric; Slevin, F; Sheridan, Linda; Allan, Donald; Allan, Ernest; Department of Clinical Oncology, Christie Hospital, Manchester M20 4BX, UK. juliette.loncaster@christie.nhs.uk (2009-08)
      AIMS: The management of the multiple basal cell carcinomas (BCCs) that develop throughout life of patients with Gorlin syndrome can be challenging. Surgical excision can result in significant disfigurement from scarring and tissue defects. Radiotherapy is contraindicated because of enhanced radiation tumourigenesis in these patients. Photodynamic therapy (PDT) is a simple, repeatable out-patient procedure, which is associated with minimal skin deterioration. It is now routinely used to treat superficial sporadic BCCs, using a topically-applied photosensitiser and external light, but its role in the management of Gorlin syndrome-related BCCs has yet to be established. In particular, Gorlin syndrome is often associated thick, nodular lesions which can be resistant to treatment with topical PDT. MATERIALS AND METHODS: We report our outcome data for 33 Gorlin patients (138 lesions) treated with PDT. Lesion thicknesses were assessed using ultrasound, both prior to treatment and during follow-up, to quantify treatment response and to guide the choice of treatment methods. Topical PDT was used to treat superficial lesions (<2 mm thick) and a systemic photosensitiser +/- light delivered by interstitially-placed optical fibres was employed for thicker lesions (>2 mm). RESULTS AND CONCLUSIONS: Local control rates of 56.3% at 12 months were achieved overall. The use of a systemic photosensitiser +/- interstitial light delivery extended the remit of PDT, allowing thicker lesions (>2 mm) to be treated, resulting in local control rates of 59.3% in this group. PDT can be considered as a treatment option for patients with multiple BCCs as a result of Gorlin syndrome. The use of ultrasound to accurately assess lesion thickness helps to select the optimum treatment method. Systemic photosensitisers and interstitial optical fibres can be used to treat thicker lesions, offering a treatment option for patients with thick nodular tumours who wish to avoid surgery.