Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

PURPOSE

The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases.

MATERIALS AND METHODS

In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm(3) or metastases in the brainstem.

RESULTS

The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy  with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different.

CONCLUSION

The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary.

Two cases of fatal necrosis of the lesser pelvis in patients treated with combined radiotherapy and hyperthermia for cervical carcinoma

This study reports two cases of fatal necrosis of the lesser pelvis in patients with advanced cervical carcinoma, who had received combined radiotherapy and hyperthermia. The necrosis reached far from the high dose area, in one of the cases even outside the radiation portals. Both patients initially had treatment-related morbidity which responded well to surgical treatment. After a disease-free interval, a rapidly progressive necrosis developed. Necrosis to this extent after combined modality treatment has, to the authors' knowledge, not been described.

The prognostic significance of p53 expression for survival and local control in rectal carcinoma treated with surgery and postoperative radiotherapy

PURPOSE

To investigate whether p53 immunoreactivity is a prognostic factor for survival and pelvic control in rectal carcinoma treated with surgery and postoperative radiotherapy.

METHODS AND MATERIALS

From 1981 through 1989, 146 patients with rectal carcinoma received postoperative radiotherapy and were followed for at least 5 years or until death. The specimens of 123 of these 146 patients could be retrieved and examined immunohistochemically for p53 expression. The prognostic value for survival and pelvic control of p53 expression and other patient and treatment factors was examined by univariate and multivariate analyses.

RESULTS

p53 expression has no prognostic significance for overall survival in this group of 123 patients. The only prognostic factor for survival in this material is tumor stage (p < 0.01). The actuarial pelvic recurrence rates of p53- and p53+ cases are different in favor of the p53- ones. In the univariate analysis this difference is significant (p = 0.05). However, in the multivariate analysis the influence of p53 expression, additional to stage, becomes nonsignificant (p = 0.10). This indicates that p53 expression is not a strong independent prognostic factor for pelvic recurrence. In the multivariate analysis stage turns out to be the only predictor of pelvic recurrence (p = 0.03). When only recurrences inside the radiation field are considered, there is no difference between p53+ and p53-cases.

CONCLUSION

Based on this material, we have found no convincing evidence that p53 expression is an important predictor of survival or local control in rectal cancer treated with surgery and postoperative radiotherapy. We have found no evidence that possible differences in radiosensitivity between p53+ and p53- tumors have clinical significance for this group of patients.

Postoperative local radiotherapy in rectal cancer: treatment results with limited radiation fields

PURPOSE

The purpose of this study is to determine the treatment results and complication rates of postoperative local radiotherapy, with doses per fraction of 2.25 to 2.50 Gy, in patients with rectal carcinoma who have received macroscopically radical surgery.

METHODS AND MATERIALS

A retrospective analysis was done of the records of all consecutive patients (N = 147) with rectal carcinoma Dukes' Stage B or C who have received postoperative local radiotherapy in our institution in the years 1981 through 1989. All patients have been treated on a limited target area covered by only local radiation fields. Locoregional fields covering the whole iliac node chains have not been given. In our treatment protocol doses per fraction were from 2.25 to 2.50 Gy and total doses from 50 to 55 Gy. The minimum follow-up was 24 months; eight patients have been lost to follow-up.

RESULTS

The overall 5-year survival rate for the whole group of patients was 39%. The actuarial 2- and 5-year pelvic recurrence rates were 14% and 22% respectively for Dukes' B patients and 30% and 38% respectively for Dukes' C patients. The difference between the pelvic recurrence rates of Stage B and Stage C patients was statistically significant (p = 0.009). No other factors with prognostic significance for pelvic recurrence were found. The interval between surgery and radiotherapy especially had no influence on pelvic recurrence rates. The 35 pelvic recurrences were classified as follows: 17 in-field, 5 marginal, 1 out-of-field, and 9 peritoneal seeding; in three patients there was not enough information for classification. Of the 32 classified pelvic recurrences, the five marginal recurrences were probably geographical misses, only the one out-of-field recurrences, the five marginal recurrences were probably geographical misses; only the one out-of-field recurrence might have been prevented with locoregional radiotherapy. Serious complications caused by the radiotherapy have occurred in 3% of the patients.

CONCLUSION

We conclude that the results of postoperative local radiotherapy alone are comparable with the published results of locoregional radiation. Even when relatively high doses per fraction are given low complication rates are seen.

Adjuvant postoperative radiotherapy in carcinoma of the rectum and recto-sigmoid

The adjuvant postoperative irradiation is an efficient treatment method to diminish the chance on pelvic recurrences in high risk group patients having rectosigmoid or rectumcarcinomas Dukes B or C and/or in case of positive surgical margins. We reviewed the literature and our own patient material treated at the University Hospital Utrecht in the years 1980-1983. Our results are comparable with the results published in Boston. Because of the high percentage local recurrence in the perineum following APR, we changed our technique and dose. Our results from 1980-1983 and the technique and dose used since 1985 is described. We also recommend some preventive measures to lower the complication rate.