[en] Purpose: To determine the prognostic role of co-morbidity in medically inoperable early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Methods and materials: Between 2000 and 2007, 88 consecutive early-stage medically inoperable NSCLC patients were treated by linac-based SBRT. The dose was either 45 Gy or 67.5 Gy in three fractions prescribed to the isocenter. Baseline co-morbidities were retrospectively retrieved by consultation of a formal electronic registry of diagnoses as well as patients' charts. The age-adjusted Charlson Co-morbidity Index (CCI) was scored for each patient and subjected to univariate and multivariate analysis. Results: With a median follow-up of 44 months, the actuarial local control rate at 4 years was 89% while the median overall survival was 22 months. The median age-adjusted CCI score was 5. The age-adjusted CCI was a significant predictor of overall survival on both univariate (p = 0.002) and multivariate analysis (p = 0.011). Patients with an age-adjusted CCI score of 3 or less had a median survival of 41 months versus only 11 months for those scoring 6 or more. Conclusion: The number and seriousness of co-morbidities predict overall survival in medically inoperable early-stage NSCLC treated with SBRT. Because the determination of medical operability is frequently based on both objective measures and subjective clinical judgment, it is recommended that co-morbidity be formally indexed in all studies examining the outcomes of SBRT.

[en] Background and purpose: Image-guided on-line correction of the target position allows radiotherapy of prostate cancer with narrow set-up margins. The present study investigated the residual set-up error after on-line prostate localization and its impact on margins. Materials and methods: Prostate localization based on two orthogonal X-ray images of gold markers implanted in the prostate was performed with an on-board imager at four treatment sessions for 90 patients. The set-up error in the sagittal plane residual after couch adjustment was evaluated on lateral verification portal images. Results: The set-up error was less than 3.0 mm in 92% of the cases in the anterior-posterior (AP) direction and in 95% of the cases in the cranio-caudal (CC) direction. The set-up error was dominated by internal prostate motion taking place during the set-up procedure. Set-up margins were calculated using two formalisms: margins designed to ensure a minimum CTV dose of 95% for 90% of the patient population were 3.6 mm (AP) and 3.5 mm (CC). Patient-independent normal distributed set-up errors would result in margins of 4.3 mm (AP) and 4.0 mm (CC) to ensure complete CTV inclusion in the PTV with 90% probability. Conclusion: Internal prostate motion during the set-up procedure was the main contributor to residual set-up errors

[en] Background and purpose: To examine the accuracy of the BeamCath[reg] urethral catheter technique for prostate localization during radiotherapy. Materials and methods: Sixty-four patients were CT scanned twice with the BeamCath[reg] catheter, and once without the catheter. The catheter contains radiopaque fiducial markers for prostate visualization on setup images. It is held in place by a balloon inflated with air in the bladder. The repeated CT scans were co-registered and the relative shifts of the BeamCath[reg] isocenter fiducial, the prostate center-of-mass, and external skin markers were evaluated. The displacement of the BeamCath[reg] isocenter fiducial relative to its position at the planning CT scan was also determined on setup films for 53 consecutive patients (222 setup films). Results: The standard deviation (SD) of the prostate movement relative to the BeamCath[reg] isocenter fiducial was 0.9 mm in the left-right (LR), 2.8 mm in the cranial-caudal (CC), and 1.6 mm in the anteroposterior (AP) directions, respectively. When the balloon radius differed more than 1 mm between the CT scans (14 of 64 cases) the SD in the CC direction increased to 4.5 mm. The SD of the prostate movement relative to the pelvic bone was 0.6 mm (LR), 2.4 mm (CC), and 2.8 mm (AP), while the prostate movement relative to external skin markers was considerably larger. Removal of the catheter resulted in a mean cranial prostate movement of 1.5 mm relative to the pelvic bone. Caudal catheter displacements of 7-30 mm were observed in 5% of the setup films. In these cases, recatherization was necessary to obtain reliable prostate localization. Conclusions: The BeamCath[reg] catheter technique markedly improved prostate localization in all directions when compared with skin markers. In the AP direction, the BeamCath[reg] technique was also superior to the use of bony structures. However, in the CC direction the catheter position was very vulnerable to changes in the balloon volume

[en] Background and purpose: Lung tissue is a special challenge for a dose calculation algorithm, especially in the case of extracranial stereotactic radiotherapy (ESRT) due to small field sizes in combination with large variations in tissue density. The present study investigates the choice of dose calculation algorithm for 18 patients with a single lung tumor and 8 patients with a single liver tumor. The dose calculation is performed with both the pencil beam convolution algorithm and the collapsed cone convolution algorithm with the same number of monitor units in both cases. In addition, the dose calculation with the collapsed cone convolution algorithm is also performed with modified field sizes in order to match the Planning Target Volume (PTV) peripheral dose of the pencil beam based treatment. Results: For liver tumors, the mean Clinical Target Volume (CTV) dose calculated by the collapsed cone convolution algorithm and the pencil beam convolution algorithm is almost identical. For lung tumors, the mean CTV dose determined by the collapsed cone convolution algorithm differs up to 20%. Plans obtained by the two algorithms have field sizes which differ up to 8 mm for the same number of monitor units and minimum dose to the lung PTV. Conclusions: The choice of dose calculation algorithm can have a large influence on a treatment plan for ESRT of the lungs

[en] Temporary sacral nerve stimulation for faecal incontinence caused by pelvic radiation injuries was successful in 7 of 13 patients (54%). The improvement of total incontinence episodes during the temporary stimulation period was a median of 83% (range 25-93%). This may be a viable treatment option for radiation-induced faecal incontinence.

[en] Purpose: To report outcomes of a single institution study of stereotactic body radiotherapy (SBRT) for unresectable cholangiocarcinoma. The dose-volume dependency of the observed gastrointestinal toxicity is explored. Methods and materials: Twenty-seven patients with unresectable cholangiocarcinoma (n = 26 Klatskin tumours and one intrahepatic cholangiocarcinoma (IHCC)) were treated by linac-based SBRT. The dose schedule was 45 Gy in three fractions prescribed to the isocenter. Results: The median progression-free survival and overall survival were 6.7 and 10.6 months, respectively. With a median follow-up of 5.4 years, 6 patients had severe duodenal/pyloric ulceration and 3 patients developed duodenal stenosis. Duodenal radiation exposure was higher in patients developing moderate to high-grade gastrointestinal toxicity with the difference in mean maximum dose to 1 cm³ of duodenum reaching statistical significance. A statistically significant association between grade ≥ 2 ulceration and volume of duodenum exposed to selected dose levels was not established. Conclusion: The outcomes of SBRT for unresectable cholangiocarcinoma appear comparable to conventionally fractionated chemoradiotherapy with or without brachytherapy boost. The practical advantages of SBRT are of particular interest for such poor prognosis patients. Patient selection, however, is key in order to avoid compromising such practical gains with excessive gastrointestinal toxicity.

[en] Background and purpose: To correlate long-term colorectal dysfunctions following radical radiotherapy for bladder or prostate cancer with clinical parameters and dose-volume histogram parameters of the small intestine, rectum, and anal canal volume. Materials and methods: Seventy-one patients previously treated for bladder or prostate cancer were interviewed following CT-based radiotherapy of 60-70 Gy with questions concerning long-term colorectal dysfunctions. Median follow-up time was 30 months (range 12-109 months). Clinical parameters and parameters from the dose-volume histograms were correlated with colorectal dysfunctions (Spearman's test). Median and quartile values of all parameters were used as cut-off values for statistical analyses. A logistic regression model was used for analysis of urgency and incontinence in relation to median or maximum radiation dose to the anal canal volume. Results: Rectum length, volume and several dose-volume parameters from the anal canal volume and rectal volume were correlated with late organ dysfunctions. In a logistic model, fecal urgency and incontinence were dependent of dose-volume parameters from the anal canal volume. No relation between age or follow-up time and late effects were found. Dose-volume parameters of the small intestine were not related to any late dysfunctions. Conclusions: A relationship between several late anorectal dysfunctions and dose-volume parameters from the rectum and anal canal volume was demonstrated. It is recommended to exclude the anal canal volume from the high dose-volume and to apply rectal shielding whenever possible to prevent late anorectal dysfunctions

[en] Background: Faecal incontinence (FI) after radiotherapy is a known phenomenon, but has received little attention to date. This article aimed to review current knowledge on faecal incontinence related to radiotherapy for prostate cancer. Methods: PubMed was searched for English-language articles published from January 1966 to December 2009 using the primary keywords 'faecal incontinence', 'prostate cancer' and 'radiotherapy'. Prospective, retrospective and controlled trials reporting FI as a complication of radiotherapy for prostate cancer were included. The retrieved titles and abstracts were screened permissively and evaluated as to whether they satisfied the predefined inclusion and exclusion criteria. Results: Nine hundred and ninety four articles were identified from the search. After step-wise review, 213 papers were selected for full article review of which 40 were selected for this review. The incidence of faecal incontinence following radiotherapy for prostate cancer varied from 1.6% to 58%. The mechanism of faecal incontinence was not entirely clear but it is most likely due to injury to the nerve plexus of the rectal muscular layer. Correlation between rectal dose-volume parameters and incidence is equivocal, although some studies suggest parameters confined to the lower rectum and/or anal canal may be of value to predict the extent of the injury and could be used as constraints in the dose planning process. Conclusions: Interpretation of data is limited due to lack of large cohort studies with data on pre-treatment continence status and because variable instruments have been used to assess the severity of the condition. Well-designed prospective studies are needed to investigate dosimetric parameters focusing on the anal canal and sphincter apparatus. Considering the spatial distribution of radiation to the rectum may identify a more direct linkage between radiation damage and faecal incontinence.

[en] Background. An international survey of radiation therapy (RT) of liver metastases was undertaken by the Liver Cancer Workgroup of the Third International Consensus on Metastases Workshop at the 2010 American Society for Radiation Oncology (ASTRO) meeting. Material and methods. Canadian, European, Australian, New Zealand and American centers participated in this online survey. The survey had four objectives: 1) to describe the practice patterns for RT of liver metastases; 2) to report on the use of low-dose RT for symptomatic liver metastases; 3) to report on the use of technology; and 4) to describe the regional differences in the management of liver metastases. Results. A total of 69 individuals treating liver metastases with radiotherapy responded to the survey. Regional response rates ranged from 39% to 50%. The primary professional affiliation of all respondents was evenly distributed amongst ASTRO, CARO, ESTRO and TROG/RANZCR. A 36% increase in the average annual number of referrals over the past five years is reported. The majority of referrals were for radical RT. The most common technologies used were 4D-CT (61%), SBRT (55%), IGRT (50%), and/or IMRT (28%). A uniform treatment approach was not found. The most commonly employed radical regimens were 45 Gy in 3 fractions, 40-50 Gy in 5 fractions, and 45 Gy in 15 fractions. Palliative regimens included 20 Gy in 5 fractions, 30 Gy in 10 fractions, 8 Gy in 1 fraction, and 10 Gy in 2 fractions. Conclusions. This survey suggests radiation oncologists will be seeing more referrals for liver RT. The majority of experience in liver metastases RT is with radical SBRT for focal metastases rather than low-dose palliative RT for symptom control. There is significant variation in technology utilization and dose regimens. Prospective studies or registries may allow for comparison of regimens and identification of parameters to optimize patient selection

[en] Purpose: To test the effect of stereotactic body radiotherapy (SBRT) in the treatment of medically inoperable patients with limited-stage non-small-cell lung cancer (NSCLC) in a Phase II trial. Methods and Materials: Forty patients with Stage I NSCLC were treated with SBRT with a central dose of 15 Gy x 3 within 5-8 days. Results: Eight patients (20%) obtained a complete response, 15 (38%) had a partial response, and 12 (30%) had no change or could not be evaluated. Only 3 patients had a local recurrence, and the local control rate 2 years after SBRT was 85%. At 2 years, 54% were without local or distant progression, and overall survival was 47%. Within 6 months after treatment, one or more Grade ≥2 reactions were observed in 48% of the patients. Conclusions: Stereotactic body radiotherapy in patients with limited-stage NSCLC resulted in a high probability of local control and a promising survival rate. The toxicity after SBRT of lung tumors was moderate. However, deterioration in performance status, respiratory insufficiency, and other side effects were observed