Clinical validation of FDG-PET/CT in the radiation treatment planning for patients with oesophageal cancer.

BACKGROUND: The aim of this prospective study was to determine the proportion of locoregional recurrences (LRRs) that could have been prevented if radiotherapy treatment planning for oesophageal cancer was based on PET/CT instead of CT. MATERIALS AND METHODS: Ninety oesophageal cancer patients, eligible for high dose (neo-adjuvant) (chemo)radiotherapy, were included. All patients underwent a planning FDG-PET/CT-scan. Radiotherapy target volumes (TVs) were delineated on CT and patients were treated according to the CT-based treatment plans. The PET images remained blinded. After treatment, TVs were adjusted based on PET/CT, when appropriate. Follow up included CT-thorax/abdomen every 6months. If LRR was suspected, a PET/CT was conducted and the site of recurrence was compared to the original TVs. If the LRR was located outside the CT-based clinical TV (CTV) and inside the PET/CT-based CTV, we considered this LRR possibly preventable. RESULTS: Based on PET/CT, the gross tumour volume (GTV) was larger in 23% and smaller in 27% of the cases. In 32 patients (36%), >5% of the PET/CT-based GTV would be missed if the treatment planning was based on CT. The median follow up was 29months. LRRs were seen in 10 patients (11%). There were 3 in-field recurrences, 4 regional recurrences outside both CT-based and PET/CT-based CTV and 3 recurrences at the anastomosis without changes in TV by PET/CT; none of these recurrences were considered preventable by PET/CT. CONCLUSION: No LRR was found after CT-based radiotherapy that could have been prevented by PET/CT. The value of PET/CT for radiotherapy seems limited.

Prognostic factors for postoperative morbidity and tumour response after neoadjuvant chemoradiation followed by resection for rectal cancer.

BACKGROUND AND PURPOSE: In patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation followed by rectal resection, postoperative morbidity is a significant clinical problem. Pathologic complete tumour response seems to give the best prognosis in the long term. Little is known about the factors that are associated with postoperative complications and pathologic complete response. The aim of this retrospective study was to identify and describe these factors. METHODS: Ninety-nine consecutive patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiation (50 Gy and capecitabine) followed by surgery at our institute between January 2007 and May 2012 were identified. Postoperative complications were graded according to the Clavien-Dindo classification. Pathologic tumour response was categorized as complete response or no/partial response. RESULTS: Postoperative complications occurred in 68 patients (69%) and grade 3-5 complications in 25 patients (25%). The 30-day and 90-day mortality were 1% (n = 1) and 2% (n = 2), respectively. A young age (p = 0.021) and a preoperative or postoperative blood transfusion (p = 0.015) independently predicted complications. Intraoperative or postoperative blood transfusion (p = 0.007) and ypT0-1 stage (p = 0.037) were independent predictors for grade 3-5 complications. Complete response rate was 22% (n = 22); 4% (n = 4) of patients showed no response. No independent factors predicting complete response were found. CONCLUSIONS: Neoadjuvant chemoradiation followed by rectal resection is associated with significant postoperative morbidity but minimal postoperative mortality. A complete response rate of 22% was achieved.

Survival after definitive (chemo)radiotherapy in esophageal cancer patients: a population-based study in the north-East Netherlands.

BACKGROUND: Definitive (chemo)radiotherapy is employed in esophageal cancer patients as an alternative for patients considered medically unfit for surgery or having unresectable tumors. We evaluated a population-based cohort to improve the selection for intensified nonsurgical strategies and to identify prognostic factors. METHODS: Patients who had squamous cell carcinoma (SCC) or adenocarcinoma (AC) were treated in four referral centers in the north-east Netherlands with definitive chemoradiotherapy (dCRT) or radiotherapy (dRT) between 1996 and 2008. RESULTS: Of the 287 included patients, 110 were treated with dCRT and 177 with dRT. Median overall survival (OS) was 11 months (95 % confidence interval: 10-12 months), with OS of 22 and 8 % and disease-free survival (DFS) of 16 and 5 % at 2 and 5 years, respectively. DFS at 2 and 5 years was 24 and 9 % for SCC versus 10 and 2 % for AC patients (P = 0.006). OS after 2 and 5 years was 29 and 14 % for SCC patients versus 17 and 3 % for AC patients (P = 0.044). On multivariate Cox regression, SCC was an independent prognostic factor for DFS [P = 0.020, hazard ratio (HR) = 0.71] and OS (P = 0.047, HR = 0.76). On matched cohort analysis, DFS was higher in the dCRT group compared with dRT patients (P = 0.016). The locoregional failure rate was lower in the dCRT group and in SCC patients (P = 0.001 and 0.046). CONCLUSIONS: Long-term results and the local control rate in SCC patients were better after definitive (chemo)radiotherapy compared with in AC patients. SCC was an independent prognostic factor for survival. Definitive chemoradiotherapy leads to improved local control rate and DFS.

Target volume delineation variation in radiotherapy for early stage rectal cancer in the Netherlands.

PURPOSE: The aim of this study was to measure and improve the quality of target volume delineation by means of national consensus on target volume definition in early-stage rectal cancer. METHODS AND MATERIALS: The CTV's for eight patients were delineated by 11 radiation oncologists in 10 institutes according to local guidelines (phase 1). After observer variation analysis a workshop was organized to establish delineation guidelines and a digital atlas, with which the same observers re-delineated the dataset (phase 2). Variation in volume, most caudal and cranial slice and local surface distance variation were analyzed. RESULTS: The average delineated CTV volume decreased from 620 to 460 cc (p<0.001) in phase 2. Variation in the caudal CTV border was reduced significantly from 1.8 to 1.2 cm SD (p=0.01), while it remained 0.7 cm SD for the cranial border. The local surface distance variation (cm SD) reduced from 1.02 to 0.74 for anterior, 0.63 to 0.54 for lateral, 0.33 to 0.25 for posterior and 1.22 to 0.46 for the sphincter region, respectively. CONCLUSIONS: The large variation in target volume delineation could significantly be reduced by use of consensus guidelines and a digital delineation atlas. Despite the significant reduction there is still a need for further improvement.