Course Of Radical Radiotherapy Research Articles

Measurement and Incorporation of Laryngeal Motion Using cine-MRI on an MR-Linear Accelerator to Generate Radiation Therapy Plans for Early-stage Squamous Cell Cancers of the Glottis

IntroductionSwallow-related motion of the larynx is most significant in the cranio-caudal directions and of short duration. Conventional target definition for radical radiotherapy includes coverage of the whole larynx. This study longitudinally examined respiration- and swallow-related laryngeal motions using cine-MRI. We further analysed the dosimetry to organs at risk by comparing 3D-conformal radiotherapy (3D-CRT), Volumetric-Modulated Arc Therapy (VMAT) and Intensity-Modulated Radiotherapy (IMRT) techniques. MethodsFifteen patients with T1-2 N0 glottic squamous cell carcinomas were prospectively recruited for up to three cine-MRI scans on the Elekta Unity MR-Linear accelerator, at the beginning, middle and end of a course of radical radiotherapy. Swallow frequency and motion of the hyoid bone, cricoid and thyroid cartilages and vocal cords were recorded during swallow and rest. Adapted treatment volumes consisted of GTV + 0.5-1 cm to a CTV with an additional ITV for personalised resting-motion. Swallow-related motion was deemed infrequent and was not accounted for in the ITV. We compared radiotherapy plans for 3D-CRT (whole larynx), VMAT (whole larynx), VMAT and IMRT (ITV for resting motion). ResultsResting- and swallow- motions were most prominent in the craniocaudal plane. There were no significant changes in the magnitudes of motions over the course of radiotherapy. There was a trend for a progressive reduction in the frequency of swallow. Treatment of partial-larynx volumes with intensity-modulated methods significantly reduced the dose to carotid arteries compared to whole-larynx. Robustness analysis demonstrated that when accounting for intra-fraction swallow, the total dose delivered to the ITV/PTV was maintained above 95%. ConclusionsSwallow-related motions are infrequent and accounting for resting motion in an ITV is sufficient. VMAT/IMRT techniques that treat more conformal targets can significantly spare critical organs at risk such as the carotid arteries and thyroid gland, potentially reducing the risk of carotid artery stenosis related and other complications long-term.

Proton Beam Therapy in the Reirradiation Setting of Brain and Base of Skull Tumour Recurrences

The therapeutic management of local tumour recurrence after a first course of radical radiotherapy is always complex. Surgery and reirradiation carry increased morbidity due to radiation-induced tissue changes. Proton beam therapy (PBT) might be advantageous in the reirradiation setting, thanks to its distinct physical characteristics. Here we systematically reviewed the use of PBT in the management of recurrent central nervous system (CNS) and base of skull (BoS) tumours, as published in the literature. The research question was framed following the Population, Intervention, Comparison and Outcomes (PICO) criteria: the population of the study was cancer patients with local disease recurrence in the CNS or BoS; the intervention was radiation treatment with PBT; the outcomes of the study focused on the clinical outcomes of PBT in the reirradiation setting of local tumour recurrences of the CNS or BoS. The identification stage resulted in 222 records in Embase and 79 in Medline as of March 2023. Sixty-eight duplicates were excluded at this stage and 56 were excluded after screening as not relevant, not in English or not full-text articles. Twelve full-text articles were included in the review and are presented according to the site of disease, namely BoS, brain or both brain and BoS. This review showed that reirradiation of brain/BoS tumour recurrences with PBT can provide good local control with acceptable toxicity rates. However, reirradiation of tumour recurrences in the CNS or BoS setting needs to consider several factors that can increase the risk of toxicities. Therefore, patient selection is crucial. Randomised evidence is needed to select the best radiation modality in this group of patients.

Target Volume Dynamics During Radiation Therapy in Lung Cancer - Identifying the Window of Opportunity

To assess the dynamic changes in the target volume (TV) during the course of radical radiotherapy in Lung Cancer. We studied 83 consecutive patients with lung cancer treated with radical intent from January 2012 till December 2017.These patients received concurrent CTRT or Neoadjuvant Chemotherapy followed by Radiotherapy (RT) or RT alone. Radiotherapy was delivered to a total dose of 60-66Gy either with conventional fractionation or hypofractionation, using 3DCRT or IMRT technique. The gross tumor volume was contoured on the CBCTs and volume changes were computed from baseline planning scan for assessing the impact of treatment. Seventy-eight patients were found to be eligible for volume analysis (NSCLC = 69, SCLC = 9, CTRT = 38, NACT = 9, no chemotherapy = 31, conventional fractionation = 51, hypo fractionated RT = 27, 3DCRT = 38, IMRT = 40). The mean tumor volume at the beginning of radiotherapy was 105.62cc (range 4-689cc). The weekly mean percentage change in the volume of primary disease from pre-RT volume were 5.4% after week 1, 13.5% after week 2, 18.8% after week 3, 26.2% after week 4, 25.4% after week 5 and 31.5 % after week 6 (Pearson correlation coefficient - 0.607-1; moderate to strong relationship). Mean change in volume from week 1 to week 2 was 7.3%, week 2 to week 3 was 7.9%, week 3 to week 4 was 7.8%, week 4 to week 5 was 1% and week 5 to week 6 was 6.4 %. The weekly changes in volume with conventional fraction were 2.1%, 11%,17.2%,26.2%,25.3% and 31.5%, from week 1 till week 6; and with hypofractionation were 11.73%,17.63% and 23.87% from baseline till week 1, week 2 and after week 3 respectively. Weekly percentage changes seen with conventional fractionation were as follows: 8.4% for week 1-2; 7.2% for week 2-3; 7.8% for week 3-4; 1% for week 4-5 and 6.4% for week 5-6. For the entire cohort, at a median follow up of 36 months, 2-year overall survival (OS) rate was 65% and at 3-years was 56%. The 2-year PFS was 42% and 3 year was 30% with median PFS of 16 months. In patients with stable target volume, median PFS was 22 months compared to 14 months in patients with early volume reduction; early target increase and late decrease showed a similar PFS of 12 months (p value = 0.913, using log rank test). Also, patients with volume change at week 3 had statistically significant longer PFS compared to rest. Patients with a 20% volume change at week 4 had statistically significant longer OS. Patients with more than 10% and 30% volume change at week 4 had a trend towards better LRC (0.08) and OS (0.09) respectively. We observed that the maximum change in volume during treatment was seen at 3rd-4th week. This has implications, particularly for adaptive re-planning which may be done at mid treatment to reduce the doses delivered to normal tissue without compromising on the dose received by the target volume. We also observed significant correlation between various outcome parameters and volume changes during radiation for lung cancer.

Conservative therapy vs active surgical tactics in the treatment of patients with оrоstomas and pharyngostomas

The aim — to develop an integrated therapeutic algorithm and to evaluate its effectiveness for surgical treatment optimizing in patients with оrоstomas and pharyngostomas.Materials and methods. The treatment results of 90 (3 (3.33 %) women and 87 (96.77 %) men, mean age 56.98 ± 0.42 years) with orostomas and pharyngostomas that occurred in the postoperative period of radical treatment for malignant extracranial tumors of the head and neck. The localization of the primary tumor was as follows: 37 (41.11 %) had oral tumors, 29 (32.22 %) — different parts of the pharynx, 24 (26.67 %) had recurrent and residual tumors of the larynx after radical course of radiotherapy. Patients were treated with conservative and surgical methods. The quality of life was assessed using a specialized scale (Performance status scale for head and neck patients).Results and discussions. It is established that the application of the developed algorithm allows to optimize the medical process and statistically significantly improve the quality of life of patients in terms of «habitual diet completeness « and «the possibility of public food intake» in 1.8 and 2.5 times respectively (p < 0.05).Conclusions. The integrated algorithm with application of both conservative and surgical methods, in particular, plastic closure, allows to achieve stable healing of the orostomas and pharyngostomas and to improve the social adaptation of this category of patients.

P2.02-046 Prognostic Value of Early Tumor Regression during Chemo-Radiotherapy in Locally Advanced Non-Small Cell Lung Cancer

Volumetric changes are observed on serial cone-beam computed tomography (CBCT) images obtained for image-guidance throughout the course of radical radiotherapy for non-small cell lung cancer (NSCLC). This study aims to a) examine whether the magnitude of tumor regression is correlated with disease control and survival; b) explore the potential difference between adenocarcinoma and non-adenocarcinoma NSCLC subtypes. In a previous study from our institution, primary tumor volumes were assessed on weekly CBCT images of 60 NSCLC patients treated with radical radiotherapy from January 2006 to June 2007. We performed a retrospective review of these patients, documenting patient-, tumor-, and treatment-related details. Outcome measures included loco-regional failure free survival (LRFFS), distant failure free survival (DFFS), disease free survival (DFS) and overall survival (OS), which were calculated using Kaplan-Meier method. Uni-variable analysis (UVA) and multivariable analysis (MVA) were performed using Cox regression model. Further analysis was performed for the adenocarcinoma and non-adenocarcinoma subgroups. Forty-five patients with locally advanced NSCLC were included in this study. Median follow-up was 22.1 months for all patients, and 90 months for alive patients (range: 0.9-108). The distribution of 7th ed. AJCC stage was as follows: stage II 8.9%; IIIA 66.7%; IIIB 24.4%. Twenty patients (44.4%) had adenocarcinoma, while 25 patients (55.6%) had non-adenocarcinoma. Twenty-eight patients (62.3%) received total radiation dose ≥ 60Gy, 15 patients (33.3%) received 45Gy as neoadjuvant therapy, and 2 patients (4.4%) received 58-59Gy due to missed fractions. 23 patients (51.1%) had more than 30% regression by fraction 15 and 32 patients (71.1%) by treatment completion. In UVA, adenocarcinoma (p=0.03) was associated with better LRFFS; young age was associated with better LRFFS (p=0.02), DFFS (p=0.048) and OS (p=0.04). In MVA, large regression by fraction 15 was associated with better DFS (p=0.047). For patients with adenocarcinoma, MVA showed that large regression by fraction 15 was associated with better DFFS (p=0.01), DFS (p=0.01) and OS (p=0.02). For patients with non-adenocarcinoma, larger regression by treatment completion and trimodality therapy (radiation dose of 45Gy) were associated with better LRFFS (p=0.02, 0.04). Evaluation of tumor regression on CBCT images during radiotherapy may be predictive of treatment response. Early tumor regression, as indicated by regression ≥ 30% by fraction 15, was associated with better DFS for all patients; and this was associated with better DFFS, DFS and OS for the adenocarcinoma cohort. This observation may provide insight into when and how to best utilize adaptive radiotherapy.

Comparing Weekly versus Three Weekly Schedules of Cisplatinum Concomitant with Radical Radiotherapy in Locally Advanced Carcinoma Uterine Cervix

Aims and 0bjectives: To determine and evaluate the difference/s, in terms of tumor control and side effects, between weekly and three weekly cisplatin concomitant with radical course of radiotherapy for locally advanced carcinoma of cervix. Materials and methods: The study was conducted on sixty previously untreated, histopathologically proven patients of locally advanced carcinoma of uterine cervix. The patients were treated with External Beam Radiotherapy (EBRT) 50Gy in 25 fractions over 5 weeks and concomitant cisplatin, followed by intra-cavity HDR brachytherapy (ICBT) 700cGy to point A, once in a week for three weeks. The patients were assigned randomly either of two groups of 30 patients each. In Group I (Study Group) the patients received three weekly cisplatin 75 mg/m2 for 2 cycles while in Group II (Control Group) the patients received weekly cisplatin 40 mg/m2 for 5 cycles. Evaluation of response and toxicity was done weekly during treatment and monthly thereafter. The data thus obtained was assessed and analysed using SPSS version 20.0 statistical tool. Results: There was statistically insignificant higher incidence of hematological , skin , mucosal toxicity and GI toxicity in group I. Stage wise disease status at the end of sixth month follow up was as follows: Stage IIA-NED* (80% vs. 100%), RD** (20% vs. 0%);Stage IIB - NED (80% vs. 76.67%), RD (20% vs. 23.53%); Stage IIIA - NED (60% vs. 100%), RD (40% vs. 0%); Stage IIIB- NED (60% vs. 60%), RD (40% vs. 40%). Tumor response was not significantly different in the two groups with respect to age distribution, rural/ urban distribution, histopathological distribution and treatment interruption (*No Evidence of Disease **Residual Disease). Conclusion: Three weekly cisplatin, concomitant with radiation seems to be the potential, effective and acceptable alternate as standard of treatment for locally advanced carcinoma cervix; especially for increased work load and limited resource facilities.

OA09.05 Positron Emission Tomography (PET) with 18F-Fluoroazomycin Arabinoside (FAZA) to Assess Tumor Hypoxia in Non-Small Cell Lung Cancer (NSCLC)

Tumor hypoxia is an adverse prognostic factor in many cancers. Hypoxia tracer 18F-FAZA provides a non-invasive method of hypoxia imaging. This study aims to evaluate the feasibility and potential benefits of using FAZA-PET scans to assess NSCLC tumor hypoxia. The initial 17 patients of an ongoing study with stage II–III NSCLC have been analyzed prospectively by imaging with FAZA-PET before initiation of a radical course of radiotherapy. The hypoxic volume (HV) was defined as all voxels within the tumor with standard uptake value (SUV) more than 1.2 times the aorta SUVmean. The Tmax/Bmean ratio (T/B) was defined as maximum tumor SUV divided by aorta SUVmean. The hypoxic fraction (HF) was determined by dividing the HV by the entire gross tumor volume. Spearman correlation and Fisher’s test were used to explore potential correlations among several variables. Median primary and nodal FAZA SUVmax were 1.7 (range: 1.0-3.8) and 1.7 (range: 1.0-3.3). Median primary and nodal T/B ratios were 1.4 (range: 1.0–2.5) and 1.3 (range: 1.0–2.2). Median primary and nodal HF were 3.9% (range: 0.0-38.2%) and 0.6% (range: 0.0-50.7%). The median time from diagnostic FDG PET to study FAZA PET scans was 28 days (range: 1–63). Median primary and nodal FDG SUVmax were 13.5 (range: 5.1–32.2) and 8.3 (range: 2.3–15.7). Larger primary tumor volume is correlated with higher FAZA-T/B (p=0.01) and higher HF (p=0.01). Primary tumors with higher T/B also had higher HF (p<0.0001). The same correlations also apply to nodal disease. Nodal FAZA SUVmax is correlated with primary FAZA SUVmax (p<0.0001). When comparing FAZA-PET with FDG-PET, nodal FDG SUVmax is correlated with nodal FAZA T/B (p=0.01) and nodal FAZA HF (p=0.01), which was not observed for primary disease. For each patient, the nodal station with the highest FAZA SUVmax correlates with the highest FDG SUVmax (p=0.02). Imaging intra-lesional hypoxia in NSCLC primary and nodal tumors is feasible and can be achieved with FAZA-PET. Larger tumor volume is correlated with higher T/B and HF in both primary and nodal masses. In the nodal volume only, higher FDG activity is correlated with higher FAZA T/B and higher HF. Ongoing trial accrual and follow-up of our patient cohort will provide more information with regards to the imaging and clinical value of FAZA-PET. This study may eventually lead to using FAZA-PET as a guiding tool to escalate dose to the hypoxic region of the tumor.

Intra thoracic anatomical changes in lung cancer patients during the course of radiotherapy

Background and purposeConebeam-CT (CBCT) guidance is often used for setup verification of lung cancer patients treated with radiotherapy. The purpose of this study was to quantify intra-thoracic anatomical changes (ITACs) during the radiotherapy treatment and to hand over a decision support system to guide the radiation therapy technologist and radiation oncologist in prioritizing these changes. Materials and methods1793 CBCT-scans of 177 lung cancer patients treated in 2010 in our institute with radical radiotherapy were evaluated. Our decision support system: “the Traffic Light Protocol”, was retrospectively applied to these CBCT-scans. The protocol has four levels: red (immediate action before treatment), orange (action before next fraction), yellow (no action required) and green (no change). ResultsIn 128 patients (72%), 210 ITACs were observed with a maximum level of red, orange and yellow in 12%, 36% and 24% respectively. Types of observed ITACs were, tumor regression (35%), tumor baseline shift (27%), changes in atelectasis (19%), tumor progression (10%), pleural effusion (6%) and infiltrative changes (3%). ConclusionsITACs have been observed in 72% of all lung cancer patients during the course of radical radiotherapy. The clinical relevance of the proposed ITAC classification in lung radiotherapy needs to be validated in a prospective analysis.

Recording a patient diet over the radical course of radiotherapy for prostate cancer using a diet diary: a feasibility study

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Failure pattern following complete resection plus radiotherapy and temozolomide is at the resection margin in patients with glioblastoma

Glioblastomas (GBM) are highly motile cancers that invade through normal brain. In the absence of curative chemotherapy this invasion, beyond surgical and radiotherapy margins, to distant brain sites is thought to be an important cause of treatment failure. Paradoxically, studies analyzing failure patterns have consistently shown that the large majority of failures occur at the original tumor site. This conflict may be explained by the fact these cancers are often only sub-totally resected and radiotherapy and chemotherapies fail to control this significant local cancer burden. We analyzed the failure pattern in 20 consecutive patients with complete resection of the gadolinium-enhancing portion of GBM demonstrated on the immediate post-operative magnetic resonance study, and who underwent a radical course of radiotherapy and chemotherapy. We found that recurrences occurred only at the resection margin in 17 of 20 patients. Recurrences were exclusively distant in 2 of 20 patients and occurred at both the resection margin and a distant site in 1 of 20 cases. We found that even in cases of complete resection of the gadolinium-enhancing portion of GBM 85% of recurrences are localized to the resection margin.

A pilot study of two radiation fractionation regimens in patients with cancer of the cervix, who were HIV positive and not on antiretroviral therapy

The Department of Radiation Oncology at the previously named Pretoria Academic Hospital (now the Steve Biko Hospital) undertook a pilot study between 2000 and 2001 of 20 patients who were human immunodeficiency virus-positive with locally advanced cancer of the cervix. At the time of the study, these patients were not on antiretroviral therapy, as per government policy. The patients were randomised into two arms. Six patients underwent a short palliative course of radiotherapy and 13 received a protracted and radical course of radiotherapy. One patient was lost to follow-up. Although the results were not statistically significant, the short course of palliative radiotherapy was adequate in terms of toxicity. As expected, the radical course was associated with a greater and more significant toxicity, because of the suppressed immune status of the participants.

Recording a patient diet over the radical course of radiotherapy for prostate cancer using a diet diary: a feasibility study

AbstractAims: To obtain an estimate of dietary fibre and fluid intake in Australian men undergoing prostate radiotherapy and to establish feasibility and patient compliance with recording normal diet without intervention during the radical course of radiotherapy.Methods: Eleven participants were enrolled and treated with 74–78 Gray (Gy) to the prostate over 8 weeks. Participants were instructed to record a diary of their food and fluid intake and bowel motions for the duration of treatment. Treating radiation therapists were instructed to initial the diet diary daily. Diet diaries were assessed for compliance by analysing the number of days over the treatment period and the number of diary pages submitted. The diet diaries were analysed for nutrient intake of fibre and fluids.Results: A total of 10 of 11 participants submitted a diet record for the full duration of treatment with a median compliance of 100% (range 90.4–100%) of days recorded. The mean (standard deviation) of fibre and fluids recorded in the diets were 21.5 g (5.5) and 2227.1 g (733.1), respectively.Conclusions: It is feasible for patients to record a diet diary over a radical course of prostate radiotherapy. In this study, most patients were highly compliant with submitting a diet record for each day during treatment.

Tumor Regression and Positional Changes in Non-small Cell Lung Cancer During Radical Radiotherapy

We have used respiratory-correlated cone beam computed tomography (rcCBCT) imaging to study the volumetric and positional changes that occur throughout the course of radical radiotherapy in non-small cell lung cancer (NSCLC). Tumor volumes and centers of mass were recorded and analyzed on weekly serial rcCBCT images of NSCLC patients treated with radical radiotherapy to a dose ≥45 Gy with concurrent chemotherapy. Sixty patients with locally advanced NSCLC were included; in 31 patients, the primary tumor was peripheral and thus suitable for contouring. There was a mean percent decrease of 40.2% by fraction 15 and 51.1% by treatment completion. Among all 60 patients, 19 patients (32%) had more than 30% regression by fraction 15 and 25 patients (81%) by treatment completion. Statistically significant tumor migration in at least one direction between the first and the last 2 weeks was demonstrated in 14 of 27 patients. Clinically relevant changes (atelectasis and effusions) were noted in 11 of 29 visually assessed patients. Current rcCBCT image quality allows assessment of tumors located more peripherally. Significant tumor regression was documented in the majority of patients. In view of these observations, the suitability of adaptive radiotherapy in radical lung cancer treatment should be further investigated.

Assessing the daily consistency of bladder filling using an ultrasonic Bladderscan device in men receiving radical conformal radiotherapy for prostate cancer

Consistency in target organ and organ at risk position from planning to treatment is an important basic principle of radiotherapy. This study evaluates the effectiveness of bladder-filling instructions in achieving a consistent and reproducible bladder volume at the time of planning CT and daily during the course of radical radiotherapy for prostate cancer. It also assessed the rate of bladder filling before and at the end of radiotherapy. 30 men attending for radiation therapy planning for prostate cancer received written and verbal bladder-filling instructions. They had their bladder volume assessed using a bladder ultrasound scanner post-void, immediately prior to planning CT scan and then daily immediately prior to treatment while in the therapy position. The inflow was calculated using the void and full bladder volumes and the time for the bladder to fill. The mean bladder volume at the time of planning was 282 ml (range 89-608 ml, standard deviation (SD) = 144.5 ml). This fell during treatment, with a mean value for all treatments of 189 ml (range 11-781 ml, SD = 134 ml). During radiotherapy, 76% (828/1090), 53% (579/1090) and 36% (393/1090) of bladder volumes had >50 ml, >100 ml and >150 ml difference, respectively when compared with their volume at the time of planning. Inflow reduced from 4.6 ml min(-1), SD = 2.9 min(-1) at planning to 2.5 min(-1), SD = 1.8 min(-1) after radiotherapy. The Bladderscan device (BVI 6400 Bladderscan, Verathon Medical UK, Sandford, UK) provides an effective means of assessing bladder volume prior to radiotherapy for prostate cancer. The evaluated bladder-filling protocol does not produce consistent, reproducible bladder volumes for radiotherapy.

Adaptive 18Fluoro-2-deoxyglucose Positron Emission Tomography/Computed Tomography-based Target Volume Delineation in Radiotherapy Planning of Head and Neck Cancer

Aims This study investigated an adaptive threshold-based method to delineate the target volume using 18fluoro-2-deoxyglucose ( 18FDG) positron emission tomography/computed tomography (PET/CT) before and during a course of radical radiotherapy or chemoradiotherapy in locally advanced squamous cell carcinoma of the head and neck. Materials and methods Ten patients were enrolled between March 2006 and May 2008. 18FDG PET/CT scans were carried out 72 h before the start of radiotherapy and then at three time points during radiotherapy (8–18, 36–50 and 66 Gy). Functional volumes were delineated using an adaptive iterative algorithm weighted according to the mean standard uptake value (SUV mean) within the region of interest. The background 18FDG uptake, maximum standard uptake value (SUV max) and SUV mean within the volumes were assessed. Results There was no significant reduction in the primary target volumes defined by the adaptive threshold during radiotherapy. However, the SUV max significantly reduced within the primary ( P = 0.003–0.011) and lymph node ( P < 0.0001) target volume at 36–50 and 36–66 Gy compared with 0 Gy. The SUV mean was negatively correlated to radiation dose ( P < 0.0001–0.014). The ratio between the background uptake of 18FDG and the SUV mean significantly reduced for both the lymph node target volume at 36–50 Gy and the primary volume at 66 Gy. The lack of significant correlation between the defined volume and radiation dose was because the SUV mean within the region of interest used to define the edge of the volume was equal to or less than the background 18FDG uptake and the software was unable to effectively differentiate between tumour and background uptake. Conclusions The adaptive threshold method may be of benefit when used to define the target volume before the start of radiotherapy. This method was not beneficial during radiotherapy because the software is not sensitive enough to distinguish tumour from background and define a volume. 18FDG PET/CT-guided volumes delineated by automatic adaptive thresholding methods should only be used for dose escalation with the pretreatment imaging.

The dosimetric consequences of anatomic changes in head and neck radiotherapy patients

To investigate anatomical response-related changes in the head and neck region during a course of radical radiotherapy and their impact on the planned dosimetry. The study consisted of 10 patients with primary mucosal carcinoma. Patients' nutritional requirements were managed as per departmental protocol to minimise weight loss during treatment. Kilovoltage computed tomography (CT) scans were acquired once 40 to 50 Gy had been delivered. Gross tumour volumes (GTV) and organs at risk were delineated and the initial optimised treatment plan was overlaid on the repeat CT. Comparisons were made between scans and absolute volume variations, centres of structures, dice similarity coefficients and the subsequent dosimetric impact were assessed. Median weight loss at second scan was 3%. Primary and lymph node GTVs reduced by 49.9% (range 21.3-82%) and 73.7% (range 61.7-88.6%), respectively, yet continued to receive the prescribed dose. Maximum dose to spinal cord and brainstem changed minimally. Spared and un-spared parotid gland volumes reduced by median 23.5% and 20.5%, respectively, with no consistent translational displacement direction and minimal change in the mean dose. Despite some significant geometric changes, nutritional management ensured patient size and shape was maintained in these consecutively selected patients and subsequently there was no apparent under-dosing of targets or over-dosing of normal structures with this technique. Further investigations which model gradual change and allow cumulative dosimetry are required to better characterise what occurs during the treatment course.

The potential advantages of 18FDG PET/CT-based target volume delineation in radiotherapy planning of head and neck cancer

Purpose This study investigated two fixed threshold methods to delineate the target volume using 18FDG PET/CT before and during a course of radical radiotherapy in locally advanced squamous cell carcinoma of the head and neck. Materials and methods Patients were enrolled into the study between March 2006 and May 2008. 18FDG PET/CT scans were carried out 72 h prior to the start of radiotherapy and then at 10, 44 and 66 Gy. Functional volumes were delineated according to the SUV Cut Off (SUVCO) (2.5, 3.0, 3.5, and 4.0 bwg/ml) and percentage of the SUVmax (30%, 35%, 40%, 45%, and 50%) thresholds. The background 18FDG uptake and the SUVmax within the volumes were also assessed. Results Primary and lymph node volumes for the eight patients significantly reduced with each increase in the delineation threshold (for example 2.5–3.0 bwg/ml SUVCO) compared to the baseline threshold at each imaging point. There was a significant reduction in the volume ( p ⩽ 0.0001–0.01) after 36 Gy compared to the 0 Gy by the SUVCO method. There was a negative correlation between the SUVmax within the primary and lymph node volumes and delivered radiation dose ( p ⩽ 0.0001–0.011) but no difference in the SUV within the background reference region. The volumes delineated by the PTSUVmax method increased with the increase in the delivered radiation dose after 36 Gy because the SUVmax within the region of interest used to define the edge of the volume was equal or less than the background 18FDG uptake and the software was unable to effectively differentiate between tumour and background uptake. Conclusions The changes in the target volumes delineated by the SUVCO method were less susceptible to background 18FDG uptake compared to those delineated by the PTSUVmax and may be more helpful in radiotherapy planning. The best method and threshold have still to be determined within institutions, both nationally and internationally.

Rectal Filling at Planning Does Not Predict Stability of the Prostate Gland during a Course of Radical Radiotherapy if Patients with Large Rectal Filling are Re-imaged

Aims It has been suggested that large rectal filling is associated with an increased risk of prostate motion in radiotherapy. The aim of the present study was to determine if there is a correlation between rectal distension on planning computed tomography and the intrafraction and interfraction stability of the prostate gland during a course of radical radiotherapy for prostate cancer if a protocol was used to rescan patients with excessive rectal diameter during planning. Materials and methods The computed tomography planning scans of 89 patients with adenocarcinoma of the prostate treated with conformal radiotherapy were reviewed. All patients had three gold seed fiducial markers implanted into the prostate before planning computed tomography. About one in five patients had repeat computed tomography because their rectum was judged to be too large at the time of the first planning computed tomography. Rectal distension was assessed on planning computed tomography using outlines following European Organization for Research and Treatment of Cancer guidelines by measuring the rectal volume, the average cross-sectional area and the mean anterior–posterior diameter of the rectum. Daily kV images were obtained before and after treatment delivery to determine positional matching of the fiducial markers in the superior–inferior, anterior–posterior and right–left dimensions. Results In total, 2860 pre- and post-treatment daily kV image pairs were obtained of 89 patients (average 32.1 image pairs per patient). The median rectal cross-sectional area was 7.3 cm 2 (range 2.8–17.1), the median rectal volume was 54.8 cm 3 (range 20.9–128.2), and the median anterior–posterior rectal diameter was 3.03 cm (range 1.58–8.30). Unifactor linear regression models showed no statistically significant relationship between intra- and interfraction prostate stability and rectal volume on planning computed tomography. Conclusions No statistically significant relationship between rectal distension on planning computed tomography and the intra- and interfraction stability of the prostate gland was identified if patients with a large rectal volume were rescanned for planning.

Geographical Variation in Radiotherapy Services Across the UK in 2007 and the Effect of Deprivation

Aims Modelling of demand has shown substantial underprovision of radiotherapy in the UK. We used national audit data to study geographical differences in radiotherapy waiting times, access and dose fractionation across the four countries of the UK and between English strategic health authorities. Materials and methods We used a web-based tool to collect data on diagnosis, dose fractionation and waiting times on all National Health Service patients in the UK starting a course of radiotherapy in the week commencing 24 September 2007. Cancer incidence for the four countries of the UK and for England by primary care trust was used to model demand for radiotherapy aggregated by country and by strategic health authority. Results Across the UK, excluding skin cancer, 2504 patients were prescribed 33 454 fractions in the audit week. Waits for radical radiotherapy exceeded the recommended 4 week maximum for 31% of patients (range 0–62%). Fractions per million per year ranged from 17 678 to 36 426 and radical fractions per incident cancer ranged from 3.0 to 6.7. Patients who were treated received similar treatment in terms of fractions per radical course of radiotherapy (18.2–23.0). Access rates ranged from 25.2 to 48.8%, nearing the modelled optimum of 50.7% in three regions. Fractions per million prescribed as a first course of treatment varied from 43.9 to 90.3% of modelled demand. The percentage of patients failing to meet the 4 week Joint Council for Clinical Oncology target for radical radiotherapy rose as activity rates increased ( r = 0.834), indicating a mismatch of demand and capacity. In England, a comparison between strategic health authorities showed that increasing deprivation was correlated with lower rates of access to radiotherapy ( r = −0.820). Conclusions There are substantial differences across the UK in the radiotherapy provided to patients and its timeliness. Radiotherapy capacity does not reflect regional variations in cancer incidence across the UK (3618–5800 cases per million per year). In addition, deprivation is a major unrecognised influence on radiotherapy access rates. In regions with higher levels of deprivation, fewer patients with cancer receive radiotherapy and the proportion treated radically is lower. This probably reflects late presentation with advanced disease, poor performance status and co-morbid illness. To provide an equitable, evidence-based service, the needs of the local population should be assessed using demand modelling based on local cancer incidence. Ideally this should include data on deprivation, performance status and stage at presentation. The results should be compared with local radiotherapy activity data to understand waits, access and dose fractionation in order to plan adequate provision for the future. The development of a mandatory radiotherapy data set in England will facilitate this, but to assist change it is essential that the results are analysed and fed back to clinicians and commissioners.

Evaluation of a Fatigue Initiative: Information on Exercise for Patients Receiving Cancer Treatment

Aims An observational cohort study in patients undergoing treatment at a single cancer centre to evaluate the usefulness of providing written information on exercise and fatigue to patients at the start of their treatment, to assess whether patients exercised during treatment and their level of fatigue before and after treatment. Materials and methods Participants were 205 patients of mean age 63.4 years (115 men and 90 women), starting a course of radical radiotherapy, postoperative radiotherapy and palliative radiotherapy or chemotherapy between October 2004 and June 2005 for genitourinary, gynaecological or breast cancer. A patient-held folder was provided, containing written information on cancer or treatment-related fatigue and the use of exercise to manage this, together with flyers for workshops on fatigue management held at local palliative care centres. Study evaluation questionnaires were used for patients to rate the information's usefulness and provide information regarding fatigue. Fatigue level was documented using Brief Fatigue Inventory score sheets. The main research variables were patient rating of the usefulness of the written information provided, whether patients reported being able to exercise during their cancer treatment and self-completed fatigue scores. Results The information provided was rated as helpful or very helpful by 70–78% of patients. Overall, 144/163 patients (88.3%) reported exercising during treatment (70.2% of all patients in the fatigue initiative). Patients receiving radical or postoperative radiotherapy as compared with chemotherapy, and those using the information supplied were more likely to exercise during treatment. There was a significant overall increase in mean fatigue from the start to the end of cancer treatment ( P < 0.001). Patients who did not exercise, younger patients, those with breast cancer and those receiving chemotherapy (compared with radical or postoperative radiotherapy) all had higher fatigue scores. Conclusions Provision of written information on exercise to manage fatigue was rated as helpful by most patients receiving cancer therapies; patients who were able to exercise during treatment had lower fatigue levels.