[en] Background and purpose: Interstitial implants for brachytherapy boost in the breast conserving therapy of breast cancer can be performed in two ways; implants during the tumor excision (per-operative implants) or after the external beam therapy (delayed interstitial implants). Differences in cosmetic outcome were investigated. Patients and methods: Cosmetic results in 47 patients having a per-operative implant were compared to 123 patients having a delayed interstitial implant in a matched case-control study. Cosmesis was scored on a four-point-scale varying from 0 (excellent) to 3 (poor). Results: After mean follow-up of 63 months, three observers found no difference in cosmetic outcome between the two groups after adjustment for variables found to be related with cosmesis (difference in mean score 0.50, P=0.26). Implant volume at 100% isodose was not found to differ (P=0.084) between the per-operative group (mean 102 cm³, S.D. 34 cm³) and the delayed group (mean 93 cm³, S.D. 29 cm³). Conclusions: Performing per-operative implants has not led to smaller implants. The method of performing brachytherapy does not result in marked differences in cosmetic outcome

[en] Purpose and background: The purpose was to validate the accuracy of motion models derived from deformable registration from four-dimensional computed tomography (4DCT) and breath-hold contrast enhanced computed tomography (BHCCT) scans for liver SBRT. Additionally, the image quality of the time averaged mid-position (MidP) CT constructed using the detected motion model was assessed. Materials and methods: 4DCT and BHCCT liver scans of 11 patients were acquired with 1 or 2 fiducial markers. Using parametric sampling the markers were digitally removed. Phase-based optical flow was used to register the 4D frames and the BHCCT, and create MidP data. We compared the deformable registration of the markerless scans with the actual displacement of the markers to assess registration accuracy. The noise levels of the MidP scans were compared to those of the 4DCT and BHCCT data. Results: We found an average misregistration of 1.8 mm (±0.5 mm). The constructed MidPCT scan contained around three times less noise than the original 4D scan. The residual error between the MidPCT and the BHCCT was 3.0 mm (±0.9 mm). Conclusions: High precision deformable image registration of 4DCT and BHCCT liver cancer patients was achieved and used to create motion compensated MidPCT scans, with increased contrast-to-noise (CNR) levels. This improved visualisation of tumours and anatomy, facilitates radiotherapy treatment planning

[en] Purpose: To determine the contribution of debulking surgery on local control and survival in paranasal sinus tumors. As most patients present with locally advanced disease, the possibility of radical surgery is limited. Consequently, radiotherapy is often needed as monotherapy or as an adjunct to surgery. Methods and Materials: Between 1977 and 1996, 73 patients (50 male: 23 female) with a paranasal sinus carcinoma were treated. The histology distribution was as follows: squamous cell carcinoma, 55%; adenocarcinoma, 19%; adenoid cystic carcinoma, 11%; and undifferentiated carcinoma, 15%.The clinical T classification was (UICC/TNM 1997): T2 14%, T3 27%, and T4 59%. Pathological neck nodes were found in 11% of patients. Treatment consisted of surgery only in 3, chemotherapy only in 1, radiotherapy only in 18, both surgery and radiotherapy in 50 patients. One patient did not receive any treatment at all. Three patients had concurrent chemotherapy. Median follow-up was 66 months (range, 1-213 months). Results: Five-year local control (LC) was 65% with combination of radiotherapy and debulking surgery in comparison with 47% with radiotherapy alone, but this difference was not statistically significant (p = 0.58). However, combination treatment gave significantly better 5-year overall survival (OS) (60% vs. 9%; p = 0.001) and 5-year disease-free survival (DFS) (53% vs. 6%; p < 0.0001). Cox-regression analysis showed that pathologic N status (p = 0.04), palliative intention of treatment (p = 0.018), clinical orbital invasion (p = 0.003), and orbital wall invasion (p = 0.003) were parameters significantly associated with poor local control. Total radiation dose of greater than 65 Gy (p = 0.05) and treatment consisting of radiotherapy alone (p = 0.002) were associated with worse overall survival; for disease-free survival clinical orbital invasion (p = 0.0005), age of greater than 65 years (p = 0.013) and pathologic T4 classification (p = 0.002) were significant factors for an unfavorable outcome. In 19 of 73 patients, 26 serious (mainly ophthalmological) complications were reported; in the majority of these, the visual tract was (partly) included in the treatment fields because of tumor extension. To analyze on which basis patients were selected for the combination therapy, a logistic regression was performed, concluding that clinical T4 classification (p = 0.05), radiological evidence of skull base invasion (p = 0.005), age of greater than 65 years (p = 0.026), radiological evidence of nasopharynx invasion (p = 0.02), clinical suspicion of palate invasion (p = 0.02), and radiological evidence of skin invasion (p = 0.009) were associated with choosing radiotherapy alone. Conclusion: Debulking surgery of paranasal sinus malignancies followed by high-dose radiotherapy to the involved sites was associated with better survival and (although not statistically significant) local control. Patient selection, based on clinical and radiological impression of tumor extension, was the main factor explaining these favorable results. We favor this combination regimen because the surgery gives quick relief of complaints and, at the same time, offers an excellent histologically proven staging method, enabling radiotherapy to be adjusted to the involved sites, thereby decreasing the risk of complications. This can all be achieved with a very low orbital exenteration rate

[en] Purpose: To determine the intra- and interobserver variation in delineation of the target volume of breast tumors on computed tomography (CT) scans in order to perform conformal radiotherapy. Materials and Methods: The clinical target volume (CTV) of the breast was delineated in CT slices by four radiation oncologists on our clinically used delineation system. The palpable glandular breast tissue was marked with a lead wire on 6 patients before CT scanning, whereas 4 patients were scanned without a lead wire. The CTV was drawn by each observer on three separate occasions. Planning target volumes (PTVs) were constructed by expanding the CTV by 7 mm in each direction, except toward the skin. The deviation in the PTV extent from the average extent was quantified in each orthogonal direction for each patient to find a possible directional dependence in the observer variations. In addition, the standard deviation of the intra- and interobserver variation in the PTV volume was quantified. For each patient, the common volumes delineated by all observers and the smallest volume encompassing all PTVs were also calculated. Results: The patient-averaged deviations in PTV extent were larger in the posterior (42 mm), cranial (28 mm), and medial (24 mm) directions than in the anterior (6 mm), caudal (15 mm), and lateral (8 mm) directions. The mean intraobserver variation in volume percentage (5.5%, 1 SD) was much smaller than the interobserver variation (17.5%, 1 SD). The average ratio between the common and encompassing volume for the four observers separately was 0.82, 0.74, 0.82, and 0.80. A much lower combined average ratio of 0.43 was found because of the large interobserver variations. For the observer who placed the lead wire, the intraobserver variation in volume was decreased by a factor of 4 on scans made with a lead wire in comparison to scans made without a lead wire. For the other observers, no improvement was seen. Based on these results, an improved delineation protocol was designed. Conclusions: Intra- and especially interobserver variation in the delineation of breast target volume on CT scans can be rather large. A detailed delineation protocol making use of CT scans with lead wires placed on the skin around the palpable breast by the delineating observer reduces the intraobserver variation. To reduce the interobserver variation, better imaging techniques and pathology studies relating glandular breast tissue to imaging may be needed to provide more information on the extent of the clinical target volume

[en] Objectives: This study was initiated to investigate the feasibility and efficacy of preoperative radiotherapy with weekly paclitaxel and carboplatin in locally advanced gastric cancer. Methods: In a prospective study, patients with locally advanced gastric cancer stage IB-IV(M0) were treated with chemoradiotherapy followed by surgery 4–6 weeks after the last irradiation. Chemoradiotherapy consisted of radiation to a total dose of 45 Gy given in 25 fractions of 1.8 Gy, combined with concurrent weekly carboplatin and paclitaxel. Results: Between December 2007 and January 2012, 25 patients with cT3 (64%) or cT4 (36%) gastric cancer were included. One patient discontinued concurrent chemotherapy in the 4th week due to toxicity, but completed radiotherapy. Another patient discontinued chemoradiotherapy after the 3rd week due to progressive disease. Grade III adverse events of chemoradiotherapy were: gastrointestinal 12%, haematological 12% and other 8%. All patients, except one who developed progressive disease, were operated. Surgical complications were: general/infectious 48%, anastomotic leakage 12%, and bowel perforation 8%. Postoperative mortality was 4%. Microscopically radical resection rate was 72%. Pathological complete response rate was 16% and near complete response rate 24%. Conclusions: In this study, preoperative chemoradiotherapy for patients with locally advanced gastric cancer was associated with manageable toxicity and encouraging pathological response rates

[en] Purpose: The internationally validated Memorial Sloan-Kettering Cancer Center (MSKCC) gastric carcinoma nomogram was based on patients who underwent curative (R0) gastrectomy, without any other therapy. The purpose of the current study was to assess the performance of this gastric cancer nomogram in patients who received chemoradiation therapy after an R0 resection for gastric cancer. Methods and Materials: In a combined dataset of 76 patients from the Netherlands Cancer Institute (NKI), and 63 patients from MSKCC, who received postoperative chemoradiation therapy (CRT) after an R0 gastrectomy, the nomogram was validated by means of the concordance index (CI) and a calibration plot. Results: The concordance index for the nomogram was 0.64, which was lower than the CI of the nomogram for patients who received no adjuvant therapy (0.80). In the calibration plot, observed survival was approximately 20% higher than the nomogram-predicted survival for patients receiving postoperative CRT. Conclusions: The MSKCC gastric carcinoma nomogram significantly underpredicted survival for patients in the current study, suggesting an impact of postoperative CRT on survival in patients who underwent an R0 resection for gastric cancer, which has been demonstrated by randomized controlled trials. This analysis stresses the need for updating nomograms with the incorporation of multimodal strategies