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.

Quantitative assessment of lung density changes after 3-D radiotherapy for breast cancer.

Our aim was to reduce the rates of clinical and radiological pneumonitis in local-regional radiotherapy (RT) for breast cancer compared to a previous treatment series by applying a pre-planned lung dose volume constraint. 3-D dose planning was performed in 66 women with the aim of not exceeding an ipsilateral V20 of 30%. The patients were followed for short-term signs/symptoms of post-RT pneumonitis and radiological changes on chest CT 4 months after RT. Radiological abnormalities were scored with a CT-adapted modification of a semi-quantitative classification system originally proposed by Arriagada which accounts for severity and affected lung regions. The abnormal subvolumes were contoured and the mean doses were calculated. Three cases of mild and one case of moderate symptomatic pneumonitis were diagnosed. The mean V20 was higher in symptomatic than in unaffected patients, 29% vs. 24% (p =0.04). Mild/moderate radiological changes were frequently observed on CT in regions with average doses >30 Gy. According to multivariate modeling, a trend for association was found between the studied dosimetric factors V13, V20, V30 and mean lung dose, and moderate-severe changes on CT but not with patient specific covariates, e.g. chemotherapy or tamoxifen exposure. 3-D planned local-regional RT with a preplanned lung dose volume constraint of V20 <30% resulted in few cases of moderate symptomatic pneumonitis. Mild/moderate radiological changes were still detectable on CT in subvolumes receiving doses >30 Gy. Long-term follow-up for evaluation of possible late morbidity is warranted.

Capecitabine as third line therapy in patients with advanced colorectal cancer.

This study sought to determine whether third line therapy with capecitabine (cap.) could provide any clinical benefit in patients with advanced colorectal cancer who have progressed on 5-Fu combination therapy with both irinotecan and oxaliplatin. Twenty patients who were pretreated with and had progressed on irinotecan+Nordic FLv (5-Fu/leukovorin) and oxaliplatin+c.i. 5-Fu/leukovorin were studied. Cap. was administered at 1000-1250 mg/m2 bid d1-14 q 3 w. Time to progression (TTP) (either radiological or clinical) and overall survival (OS) were estimated with the Kaplan-Meier actuarial method. The median number of administered cap. courses was four. No radiological or biochemical responses were observed. Three patients were classified as having stable disease at three months. Two of these patients had, however, minor radiological progression and a =100% increase in CEA compared to base line. Seventeen patients were classified as having progressive disease during the first three months period. Median TTP and OS were 2.8 months and 6.1 months, respectively. A response rate of =15% for third line cap. in metastatic CRC can be ruled out. Median PFS was limited in the study population. This observation and the few cases with SD at three months, lead us to believe that little or no clinical benefit can be expected from single drug cap. in patients with irinotecan- and oxaliplatin-combination resistant advanced colorectal cancer.

Technical factors associated with radiation pneumonitis after local +/- regional radiation therapy for breast cancer.

PURPOSE: To assess the incidence of, and clinical factors associated with, symptomatic radiation pneumonitis (RP) after tangential breast/chest wall irradiation with or without regional lymph node treatment. METHODS AND MATERIALS: The records of 613 patients irradiated with tangential photon fields for breast cancer with >6 months follow-up were reviewed. Clinically significant RP was defined as the presence of new pulmonary symptoms requiring steroids. Data on clinical factors previously reported to be associated with RP were collected, e.g., tamoxifen or chemotherapy exposure and age. The central lung distance (CLD) and the average of the superior and inferior mid lung distance (ALD) in the lateral tangential field were measured on simulator films as a surrogate for irradiated lung volume. Many patients were treated with partly wide tangential fields that included a heart block shielding a part of the lower lung. RESULTS: RP developed in 15/613 (2.4%) patients. In the univariate analysis, there was an increased incidence of RP among patients treated with local-regional radiotherapy (RT) (4.1%) vs. those receiving local RT only (0.9%) (p = 0.02), and among patients receiving chemotherapy (3.9%) vs. those not treated with chemotherapy (1.4%) (p = 0.06). According to multivariate analysis, only the use of nodal RT remained independently associated with RP (p = 0.03). There was no statistically significant association between ranked CLD or ALD measurements and RP among patients treated with nodal irradiation with tangential beams. However, there was a statistically nonsignificant trend for increasing rates of RP with grouped ALD values: below 2 cm (4% RP rate), between 2 and 3 cm (6%), and above 3 cm (14%). CONCLUSIONS: RP was an uncommon complication, both with local and local-regional RT. The addition of regional lymph node irradiation slightly increased the incidence of RP among patients treated with the partly wide tangential field technique. Concern for RP should, however, not deter patients with node-positive breast cancer from receiving local-regional RT.