Edwin P.M. Jansen

Variability in target volume delineation on CT scans of the breast

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.

Neo-adjuvant chemotherapy followed by surgery and chemotherapy or by surgery and chemoradiotherapy for patients with resectable gastric cancer (CRITICS)

BackgroundRadical surgery is the cornerstone in the treatment of resectable gastric cancer. The Intergroup 0116 and MAGIC trials have shown benefit of postoperative chemoradiation and perioperative chemotherapy, respectively. Since these trials cannot be compared directly, both regimens are evaluated prospectively in the CRITICS trial. This study aims to obtain an improved overall survival for patients treated with preoperative chemotherapy and surgery by incorporating radiotherapy concurrently with chemotherapy postoperatively.Methods/designIn this phase III multicentre study, patients with resectable gastric cancer are treated with three cycles of preoperative ECC (epirubicin, cisplatin and capecitabine), followed by surgery with adequate lymph node dissection, and then either another three cycles of ECC or concurrent chemoradiation (45 Gy, cisplatin and capecitabine). Surgical, pathological, and radiotherapeutic quality control is performed. The primary endpoint is overall survival, secondary endpoints are disease-free survival (DFS), toxicity, health-related quality of life (HRQL), prediction of response, and recurrence risk assessed by genomic and expression profiling. Accrual for the CRITICS trial is from the Netherlands, Sweden, and Denmark, and more countries are invited to participate.ConclusionResults of this study will demonstrate whether the combination of preoperative chemotherapy and postoperative chemoradiotherapy will improve the clinical outcome of the current European standard of perioperative chemotherapy, and will therefore play a key role in the future management of patients with resectable gastric cancer.Trial registrationclinicaltrials.gov NCT00407186

Impact of the Extent of Surgery and Postoperative Chemoradiotherapy on Recurrence Patterns in Gastric Cancer

PURPOSE The Intergroup 0116 trial has demonstrated that postoperative chemoradiotherapy (CRT) improves survival in gastric cancer. We retrospectively compared survival and recurrence patterns in two phase I/II studies evaluating more intensified postoperative CRT with those from the Dutch Gastric Cancer Group Trial (DGCT) that randomly assigned patients between D1 and D2 lymphadenectomy. PATIENTS AND METHODS Survival and recurrence patterns of 91 patients with adenocarcinoma of the stomach who had received surgery followed by radiotherapy combined with fluorouracil and leucovorin (n = 5), capecitabine (n = 39), or capecitabine and cisplatin (n = 47) were analyzed and compared with survival and recurrence patterns of 694 patients from the DGCT (D1, n = 369; D2, n = 325). For both groups, the Maruyama Index of Unresected Disease (MI) was calculated and correlated with survival and recurrence patterns. RESULTS With a median follow-up of 19 months in the CRT group, local recurrence rate after 2 years was significantly higher in the surgery only (DGCT) group (17% v 5%; P = .0015). Separate analysis of CRT patients who underwent a D1 dissection (n = 39) versus DGCT-D1 (n = 369) showed fewer local recurrences after chemoradiotherapy (2% v 8%; P = .001), whereas comparison of CRT-D2 (n = 25) versus DGCT-D2 (n = 325) demonstrated no significant difference. CRT significantly improved survival after a microscopically irradical (R1) resection. The MI was found to be a strong independent predictor of survival. CONCLUSION After D1 surgery, the addition of postoperative CRT had a major impact on local recurrence in resectable gastric cancer.

Target volumes in radiotherapy for high-grade malignant glioma of the brain.

Delineation of the clinical target volume (CTV) in radiation treatment planning of high-grade glioma is a controversial issue. The use of computerized tomography (CT) and magnetic resonance imaging (MRI) has greatly improved the accuracy of tumor localization in three-dimensional planning. This review aims at critically analyzing available literature data in which tumor extent of high-grade glioma has been assessed using CT and/or MRI and relating this to postmortem observations. Attention is given to the pattern of tumor spread at initial presentation and to tumor recurrence pattern after external beam irradiation. Special emphasis is given to the site of tumor regrowth after radiation treatment in relation to the boundaries of the CTV. Guidelines for delineating CTV will be inferred from this information, taking data on radiation effects on the normal brain into account.

Does the combination of radiotherapy and debulking surgery favor survival in paranasal sinus carcinoma

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.

Highlights of the EORTC St. Gallen International Expert Consensus on the primary therapy of gastric, gastroesophageal and oesophageal cancer – Differential treatment strategies for subtypes of early gastroesophageal cancer

The 1st St. Gallen EORTC Gastrointestinal Cancer Conference 2012 Expert Panel clearly differentiated treatment and staging recommendations for the various gastroesophageal cancers. For locally advanced gastric cancer (≥T3N+), the preferred treatment modality was pre- and postoperative chemotherapy. The majority of panel members would also treat T2N+ or even T2N0 tumours with a similar approach mainly because pretherapeutic staging was considered highly unreliable. It was agreed that adenocarcinoma of the gastroesophageal junction (AEG) is classified best according to Siewert et al. Preoperative radiochemotherapy (RCT) is the preferred treatment for AEG type I and II tumours. For AEG type III, i.e. tumours which may be considered as gastric cancer, perioperative chemotherapy is the majority approach. For resectable squamous cell cancer of the oesophagus a clear majority recommended radiochemotherapy followed by surgery as optimal approach, irrespective of tumour size. In contrast, definitive RCT was judged appropriate for advanced tumours with extended lymph node involvement (N2) or for cancers of the upper oesophagus. Additional recommendations are presented on the use of endosonography, PET-CT scan and laparoscopy for staging and on the preferred approach to surgery.

Preoperative Chemoradiotherapy with Capecitabine and Oxaliplatin in Locally Advanced Rectal Cancer. A Phase I–II Multicenter Study of the Dutch Colorectal Cancer Group

BackgroundWe studied the maximum tolerated dose (MTD) and efficacy of oxaliplatin added to capecitabine and radiotherapy (Capox-RT) as neoadjuvant therapy for rectal cancer.MethodsT3-4 rectal cancer patients received escalating doses of oxaliplatin (day 1 and 29) with a fixed dose of capecitabine of 1000 mg/m2 twice daily (days 1–14, 25–38) added to RT with 50.4 Gy and surgery after 6–8 weeks. The MTD, determined during phase I, was used in the subsequent phase II, in which R0 resection rate (a negative circumferential resection margin) was the primary end point.ResultsTwenty-one patients were evaluable. In the phase I part, oxaliplatin at 85 mg/m2 was established as MTD. In phase II, the main toxicity was grade III diarrhea (18%). All patients underwent surgery, and 20 patients had a resectable tumor. An R0 was achieved in 17/21 patients, downstaging to T0-2 in 7/21 and a pCR in 2/21.ConclusionCombination of Capox-RT has an acceptable acute toxicity profile and a high R0 resection rate of 81% in locally advanced rectal cancer. However the pCR rate was low.

Interobserver Variation of Clinical Target Volume Delineation in Gastric Cancer

PURPOSE To evaluate interobserver variability in clinical target volume (CTV) delineation in gastric cancer performed with the help of a delineation guide. PATIENTS AND METHODS Ten radiotherapy centers that participate in the CRITICS Phase III trial were provided with a delineation atlas, preoperative CT scans, a postoperative planning CT scan, and clinical information for a gastric cancer case and were asked to construct a CTV and create a dosimetric plan according to departmental policy. RESULTS The volumes of the CTVs and planning target volumes (PTVs) differed greatly, with a mean (SD) CTV volume of 392 (176) cm(3) (range, 240-821 cm(3)) and PTV volume of 915 (312) cm(3) (range, 634-1677 cm(3)). The overlapping volume was 376 cm(3) for the CTV and 890 cm(3) for the PTV. The greatest differences in the CTV were seen at the cranial and caudal parts. After planning, dose coverage of the overlapping PTV volume showed less variability than the CTV. CONCLUSION In this series of 10 plans, variability of the CTV in postoperative chemoradiotherapy for gastric cancer is large. Strict and clear delineation guidelines should be provided, especially in Phase III multicenter studies. Adaptations of these guidelines should be evaluated in clinical studies.

Chemotherapy versus chemoradiotherapy after surgery and preoperative chemotherapy for resectable gastric cancer (CRITICS): an international, open-label, randomised phase 3 trial

BACKGROUND Both perioperative chemotherapy and postoperative chemoradiotherapy improve survival in patients with resectable gastric cancer from Europe and North America. To our knowledge, these treatment strategies have not been investigated in a head to head comparison. We aimed to compare perioperative chemotherapy with preoperative chemotherapy and postoperative chemoradiotherapy in patients with resectable gastric adenocarcinoma. METHODS In this investigator-initiated, open-label, randomised phase 3 trial, we enrolled patients aged 18 years or older who had stage IB- IVA resectable gastric or gastro-oesophageal adenocarcinoma (as defined by the American Joint Committee on Cancer, sixth edition), with a WHO performance status of 0 or 1, and adequate cardiac, bone marrow, liver, and kidney function. Patients were enrolled from 56 hospitals in the Netherlands, Sweden, and Denmark, and were randomly assigned (1:1) with a computerised minimisation programme with a random element to either perioperative chemotherapy (chemotherapy group) or preoperative chemotherapy with postoperative chemoradiotherapy (chemoradiotherapy group). Randomisation was done before patients were given any preoperative chemotherapy treatment and was stratified by histological subtype, tumour localisation, and hospital. Patients and investigators were not masked to treatment allocation. Surgery consisted of a radical resection of the primary tumour and at least a D1+ lymph node dissection. Postoperative treatment started within 4-12 weeks after surgery. Chemotherapy consisted of three preoperative 21-day cycles and three postoperative cycles of intravenous epirubicin (50 mg/m2 on day 1), cisplatin (60 mg/m2 on day 1) or oxaliplatin (130 mg/m2 on day 1), and capecitabine (1000 mg/m2 orally as tablets twice daily for 14 days in combination with epirubicin and cisplatin, or 625 mg/m2 orally as tablets twice daily for 21 days in combination with epirubicin and oxaliplatin), received once every three weeks. Chemoradiotherapy consisted of 45 Gy in 25 fractions of 1·8 Gy, for 5 weeks, five daily fractions per week, combined with capecitabine (575 mg/m2 orally twice daily on radiotherapy days) and cisplatin (20 mg/m2 intravenously on day 1 of each 5 weeks of radiation treatment). The primary endpoint was overall survival, analysed by intention-to-treat. The CRITICS trial is registered at ClinicalTrials.gov, number NCT00407186; EudraCT, number 2006-004130-32; and CKTO, 2006-02. FINDINGS Between Jan 11, 2007, and April 17, 2015, 788 patients were enrolled and randomly assigned to chemotherapy (n=393) or chemoradiotherapy (n=395). After preoperative chemotherapy, 372 (95%) of 393 patients in the chemotherapy group and 369 (93%) of 395 patients in the chemoradiotherapy group proceeded to surgery, with a potentially curative resection done in 310 (79%) of 393 patients in the chemotherapy group and 326 (83%) of 395 in the chemoradiotherapy group. Postoperatively, 233 (59%) of 393 patients started chemotherapy and 245 (62%) of 395 started chemoradiotherapy. At a median follow-up of 61·4 months (IQR 43·3-82·8), median overall survival was 43 months (95% CI 31-57) in the chemotherapy group and 37 months (30-48) in the chemoradiotherapy group (hazard ratio from stratified analysis 1·01 (95% CI 0·84-1·22; p=0·90). After preoperative chemotherapy, in the total safety population of 781 patients (assessed together), there were 368 (47%) grade 3 adverse events; 130 (17%) grade 4 adverse events, and 13 (2%) deaths. Causes of death during preoperative treatment were diarrhoea (n=2), dihydropyrimidine deficiency (n=1), sudden death (n=1), cardiovascular events (n=8), and functional bowel obstruction (n=1). During postoperative treatment, grade 3 and 4 adverse events occurred in 113 (48%) and 22 (9%) of 233 patients in the chemotherapy group, respectively, and in 101 (41%) and ten (4%) of 245 patients in the chemoradiotherapy group, respectively. Non-febrile neutropenia occurred more frequently during postoperative chemotherapy (79 [34%] of 233) than during postoperative chemoradiotherapy (11 [4%] of 245). No deaths were observed during postoperative treatment. INTERPRETATION Postoperative chemoradiotherapy did not improve overall survival compared with postoperative chemotherapy in patients with resectable gastric cancer treated with adequate preoperative chemotherapy and surgery. In view of the poor postoperative patient compliance in both treatment groups, future studies should focus on optimising preoperative treatment strategies. FUNDING Dutch Cancer Society, Dutch Colorectal Cancer Group, and Hoffmann-La Roche.

Registration accuracy and image quality of time averaged mid-position CT scans for liver SBRT

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 1.8mm (± 0.5mm). 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 3.0mm (± 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.