To evaluate interobserver variability in clinical target volume (CTV) delineation in gastric cancer performed with the help of a delineation guide.
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.
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.
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.
Adjuvant chemotherapy improves patient survival rates after resection for pancreatic adenocarcinoma, but the optimal duration and time to initiate chemotherapy is unknown.
Patients with pancreatic ...ductal adenocarcinoma treated within the international, phase III, European Study Group for Pancreatic Cancer-3 (version 2) study were included if they had been randomly assigned to chemotherapy. Overall survival analysis was performed on an intention-to-treat basis, retaining patients in their randomized groups, and adjusting the overall treatment effect by known prognostic variables as well as the start time of chemotherapy.
There were 985 patients, of whom 486 (49%) received gemcitabine and 499 (51%) received fluorouracil; 675 patients (68%) completed all six cycles of chemotherapy (full course) and 293 patients (30%) completed one to five cycles. Lymph node involvement, resection margins status, tumor differentiation, and completion of therapy were all shown by multivariable Cox regression to be independent survival factors. Overall survival favored patients who completed the full six courses of treatment versus those who did not (hazard ratio HR, 0.516; 95% CI, 0.443 to 0.601; P < .001). Time to starting chemotherapy did not influence overall survival rates for the full study population (HR, 0.985; 95% CI, 0.956 to 1.015). Chemotherapy start time was an important survival factor only for the subgroup of patients who did not complete therapy, in favor of later treatment (P < .001).
Completion of all six cycles of planned adjuvant chemotherapy rather than early initiation was an independent prognostic factor after resection for pancreatic adenocarcinoma. There seems to be no difference in outcome if chemotherapy is delayed up to 12 weeks, thus allowing adequate time for postoperative recovery.
This meta-analysis investigates the oncological safety of breast-conserving therapy BCT in BRCA-mutation carriers and the risk for contralateral breast cancer (CBC) compared with non-carriers, ...potential risk factors for ipsilateral breast recurrence (IBR) or CBC and grades these factors based on the level of evidence. A PubMed search was conducted through April 2013 to identify studies that described the risk for IBR and CBC after BCT in BRCA-mutation carriers versus non-carriers as well as studies that investigated risk factors for IBR and CBC in BRCA-mutation carriers. Results were summarized using meta-analysis when sufficient studies were available. Ten studies investigated the oncological safety of BCT in BRCA-mutation carriers versus non-carriers. There was no significant difference in IBR between carriers and controls (RR 1.45, 95 % CI 0.98–2.14). However, a significant higher risk for IBR in BRCA-mutation carriers was observed in studies with a median follow-up ≥7 years (RR 1.51, 95 % CI 1.15–1.98). CBCs were significantly greater in carriers versus controls (RR 3.56, 95 % CI 2.50–5.08). Use of adjuvant chemotherapy and oophorectomy were associated with a significantly lower risk for IBR in BRCA-mutation carriers. Three factors were associated with a lower risk for CBC in BRCA-mutation carriers: oophorectomy, use of tamoxifen, and age at first breast cancer. Based on current evidence, the use of BCT in BRCA-mutation carriers can be considered a reasonable option since it does not seem to increase the risk for IBR. However, several aspects should be taken into account before the final decision-making.
Radical 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.
In 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.
Results 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.
clinicaltrials.gov NCT00407186.
CONTEXT Adjuvant fluorouracil has been shown to be of benefit for patients with resected pancreatic cancer. Gemcitabine is known to be the most effective agent in advanced disease as well as an ...effective agent in patients with resected pancreatic cancer. OBJECTIVE To determine whether fluorouracil or gemcitabine is superior in terms of overall survival as adjuvant treatment following resection of pancreatic cancer. DESIGN, SETTING, AND PATIENTS The European Study Group for Pancreatic Cancer (ESPAC)-3 trial, an open-label, phase 3, randomized controlled trial conducted in 159 pancreatic cancer centers in Europe, Australasia, Japan, and Canada. Included in ESPAC-3 version 2 were 1088 patients with pancreatic ductal adenocarcinoma who had undergone cancer resection; patients were randomized between July 2000 and January 2007 and underwent at least 2 years of follow-up. INTERVENTIONS Patients received either fluorouracil plus folinic acid (folinic acid, 20 mg/m2, intravenous bolus injection, followed by fluorouracil, 425 mg/m2 intravenous bolus injection given 1-5 days every 28 days) (n = 551) or gemcitabine (1000 mg/m2 intravenous infusion once a week for 3 of every 4 weeks) (n = 537) for 6 months. MAIN OUTCOME MEASURES Primary outcome measure was overall survival; secondary measures were toxicity, progression-free survival, and quality of life. RESULTS Final analysis was carried out on an intention-to-treat basis after a median of 34.2 (interquartile range, 27.1-43.4) months' follow-up after 753 deaths (69%). Median survival was 23.0 (95% confidence interval CI, 21.1-25.0) months for patients treated with fluorouracil plus folinic acid and 23.6 (95% CI, 21.4-26.4) months for those treated with gemcitabine (χ21 = 0.7; P = .39; hazard ratio, 0.94 95% CI, 0.81-1.08). Seventy-seven patients (14%) receiving fluorouracil plus folinic acid had 97 treatment-related serious adverse events, compared with 40 patients (7.5%) receiving gemcitabine, who had 52 events (P < .001). There were no significant differences in either progression-free survival or global quality-of-life scores between the treatment groups. CONCLUSION Compared with the use of fluorouracil plus folinic acid, gemcitabine did not result in improved overall survival in patients with completely resected pancreatic cancer. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00058201
We compared the calculated risks of radiation-induced secondary malignant neoplasms (SMNs) for patients treated for thymic tumors with 3D-CRT, IMRT, or single-field uniform dose (SFUD) proton beam ...therapy (PBT) using the pencil beam scanning (PBS) technique. A cancer-induction model based on the organ equivalent dose (OED) concept was used. For twelve patients, treated with 3D-CRT for thymic tumors, alternative IMRT and SFUD plans were retrospectively prepared. The resulting DVHs for organs at risk (OARs) were extracted and used to estimate the risk of SMNs. The OED was calculated using a mechanistic model for carcinoma induction. Two limit cases were considered; the linear-exponential model, in which the repopulation/repair of the cells is neglected, and the plateau model, in which full repopulation/repair of the irradiated cells is assumed. The calculated risks for SMNs for the different radiation modalities and dose-relation models were used to calculate relative risks, which were compared pairwise. The risks for developing SMNs were reduced for all OARs, and for both dose-relation models, if SFUD was used, compared to 3D-CRT and IMRT. In conclusion, PBS shows a potential benefit to reduce the risk of SMNs compared to 3D-CRT and IMRT in the treatment of thymic tumors.
The aim of this planning study was to compare the dosimetric outcomes of Volumetric Modulated Arc Therapy (VMAT), Proton Beam Therapy (PBT), and conventional External Beam Radiation Therapy (cEBRT) ...in the treatment of thoracic spinal metastases originating from breast or prostate cancer. Our study utilized data from 30 different treatment plans and evaluated target coverage and doses to vital organs at risk (OARs), such as the spinal cord, heart, esophagus, and lungs. The results showed that VMAT and PBT achieved superior target coverage and significantly lower doses to the spinal cord compared to cEBRT (target: median PTV
: 75.2 for cEBRT vs. 92.9 and 91.7 for VMAT (
< 0.001) and PBT (
< 0.001), respectively; spinal cord: median D
: 105.1 for cEBRT vs. 100.4 and 103.6 for VMAT (
< 0.001) and PBT (
= 0.002), respectively). Specifically, VMAT was notable for its superior target coverage and PBT for significantly lower doses to heart, lungs, and esophagus. However, VMAT resulted in higher lung doses, indicating potential trade-offs among different techniques. The study demonstrated the relative advantages of VMAT and PBT over traditional RT in the palliative treatment of spinal metastases using conventional fractionation. These findings underscore the potential of VMAT and PBT to improve dosimetric outcomes, suggesting that they may be more suitable for certain patient groups for whom the sparing of specific OARs is especially important.
Gastric cancer (GC) radiotherapy involves irradiation of large tumour volumes located in the proximities of critical structures. The advantageous dose distributions produced by scanned-proton beams ...could reduce the irradiated volumes of the organs at risk (OARs). However, treatment-induced side-effects may still appear. The aim of this study was to estimate the normal tissue complication probability (NTCP) following proton therapy of GC, compared to photon radiotherapy.
Eight GC patients, previously treated with volumetric-modulated arc therapy (VMAT), were retrospectively planned with scanned proton beams carried out with the single-field uniform-dose (SFUD) method. A beam-specific planning target volume was used for spot positioning and a clinical target volume (CTV) based robust optimisation was performed considering setup- and range-uncertainties. The dosimetric and NTCP values obtained with the VMAT and SFUD plans were compared.
With SFUD, lower or similar dose-volume values were obtained for OARs, compared to VMAT. NTCP values of 0% were determined with the VMAT and SFUD plans for all OARs (p>0.05), except for the left kidney (p<0.05), for which lower toxicity was estimated with SFUD.
The NTCP reduction, determined for the left kidney with SFUD, can be of clinical relevance for preserving renal function after radiotherapy of GC.
Proton-beam therapy of large abdominal cancers has been questioned due to the large variations in tissue density in the abdomen. The aim of this study was to evaluate the importance of these ...variations for the dose distributions produced in adjuvant radiotherapy of gastric cancer (GC), implemented with photon-based volumetric modulated arc therapy (VMAT) or with proton-beam single-field uniform-dose (SFUD) method.
Eight GC patients were included in this study. For each patient, a VMAT- and an SFUD-plan were created. The prescription dose was 45 Gy (IsoE) given in 25 fractions. The plans were prepared on the original CT studies and the doses were thereafter recalculated on two modified CT studies (one with extra water filling and the other with expanded abdominal air-cavity volumes).
Compared to the original VMAT plans, the SFUD plans resulted in reduced median values for the V18 of the left kidney (26%), the liver mean dose (14.8 Gy (IsoE)) and the maximum dose given to the spinal cord (26.6 Gy (IsoE)). However, the PTV coverage decreased when the SFUD plans were recalculated on CT sets with extra air- (86%) and water-filling (87%). The added water filling only led to minor dosimetric changes for the OARs, but the extra air caused significant increases of the median values of V18 for the right and left kidneys (10% and 12%, respectively) and of V10 for the liver (12%). The density changes influenced the dose distributions in the VMAT plans to a minor extent.
SFUD was found to be superior to VMAT for the plans prepared on the original CT sets. However, SFUD was inferior to VMAT for the modified CT sets.
A potential financial relationship between investigators and pharmaceutical manufacturers has been associated with an increased likelihood of reporting favorable conclusions about a sponsor's ...proprietary agent in pharmacoeconomic studies. The purpose of this study is to investigate whether there is an association between financial relationships and outcome in economic analyses of new targeted therapies in oncology.
We searched PubMed (last update June 2011) for economic analyses of targeted therapies (including monoclonal antibodies, tyrosine-kinase inhibitors, and mammalian target of rapamycin inhibitors) in oncology. The trials were qualitatively rated regarding the cost assessment as favorable, neutral, or unfavorable on the basis of prespecified criteria.
Overall, 81 eligible studies were identified. Economic analyses that were funded by pharmaceutical companies were more likely to report favorable qualitative cost estimates (28 82% of 34 v 21 45% of 47; P = .003). The presence of an author affiliated with manufacturer was not associated with study outcome. Furthermore, if only studies including a conflict of interest statement were included (66 of 81), studies that reported any financial relationship with manufacturers (author affiliation and/or funding and/or other financial relationship) were more likely to report favorable results of targeted therapies compared with studies without financial relationship (32 71% of 45 v nine 43% of 21; P = .025).
Our study reveals a potential threat for industry-related bias in economic analyses of targeted therapies in oncology in favor of analyses with financial relationships between authors and manufacturers. A more balanced funding of economic analyses from other sources may allow greater confidence in the interpretation of their results.
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