[Re-irradiation with hyperthermia in patients with recurrent breast cancer]. / Reïrradiatie met hyperthermie bij patiënten met een recidiefmammacarcinoom.

In the Daniel den Hoed Cancer Centre in Rotterdam, the Netherlands, patients with recurrent breast cancer within a previously irradiated area, are treated by application of hyperthermia in addition to reirradiation. In this development, the following issues are important: (a) the choice of an effective and tolerable reirradiation schedule; (b) the establishment of the limitations of the hyperthermia techniques available; (c) the finding that additional hyperthermia has to be applied to the total tissue volume at risk for tumour recurrence; (d) the assessment of the value of additional hyperthermia by a randomised study. With the reirradiation schedule of 8 x 4 Gy and the hyperthermia application technique at present available, local control is achieved in 76% of the patients for a median duration of 32 months. The probability of local control is related to tumour size. The treatment is tolerated well, with acceptable toxicity. In patients with recurrent breast cancer in a previously irradiated area, combined reirradiation and hyperthermia is very effective, well tolerated and little toxic.

Reirradiation combined with hyperthermia in recurrent breast cancer results in a worthwhile local palliation.

Both experimental and clinical research have shown that hyperthermia (HT) gives valuable additional effects when applied in combination with radiotherapy (RT). The purpose of this study was evaluation of results in patients with recurrent breast cancer, treated at the Daniel den Hoed Cancer Center (DHCC) with reirradiation (re-RT; eight fractions of 4 Gy twice weekly) combined with HT. All 134 patients for whom such treatment was planned were included in the analysis. The complete response rate in 119 patients with macroscopic tumour was 71%. Including the 15 patients with microscopic disease, the local control rate was 73%. The median duration of local control was 32 months, and toxicity was acceptable. The complete response (CR) rate was higher, and the toxicity was less with the later developed 433-MHz HT technique compared with the 2450-MHz technique used initially. With this relatively well-tolerated treatment, palliation by local tumour control of a worthwhile duration is achieved in the majority of patients. The technique used for hyperthermia appeared to influence the achieved results. The value of HT in addition to this re-RT schedule has been confirmed by a prospective randomized trial in a similar patient group. In The Netherlands, this combined treatment is offered as standard to patients with breast cancer recurring in previously irradiated areas.

Hyperthermia may decrease the development of telangiectasia after radiotherapy.

CASE REPORT: A patient with recurrent breast cancer was reirradiated twice on adjacent fields with a time interval of 9 months. The first time she was treated with reirradiation alone, the second time with reirradiation plus hyperthermia. The reirradiation schedule for both fields was 8 x 4 Gy in 4 weeks. Both fields overlapped partly with the field of postoperative radiotherapy, which was applied 57 and 66 months earlier to a total dose of 40.5 Gy. RESULTS: During the 52 to 61 months follow-up, a remarkable difference in telangiectasia development, between the parts of the reirradiation fields overlapping with the primary radiotherapy field, became apparent. Telangiectasia was observed 9 months after treatment with reirradiation alone and progressed to confluent in 47 months after treatment. In the reirradiation plus hyperthermia area, the maximum observed telangiectasia was slight until 52 months after treatment. DISCUSSION: The difference in the development of telangiectasia between these fields cannot be explained by differences in any of the known radiation treatment related prognostic factors. A protective effect by hyperthermia has been suggested by Haveman and coworkers, who have shown experimentally that heat treatment leads to enhanced proliferation of endothelial cells, thereby inducing a fast repopulation and replacement of X-ray damaged cells. CONCLUSION: This difference in telangiectasia formation is an interesting observation. Whether such a protective effect of hyperthermia is of general relevance has to become clear from more extensive clinical studies.

Postoperative radiation therapy for rectal cancer. An interim analysis of a prospective, randomized multicenter trial in The Netherlands.

The authors assessed the potential benefit of postoperative radiation therapy for rectal cancer in a two-arm, prospective multicenter trial. One hundred seventy-two patients who had undergone surgical resection for rectal adenocarcinoma were randomly assigned to either treatment consisting of external irradiation to a dose of 5000 cGy in 5 weeks or a control group (no adjuvant therapy). It was assumed that the number of cells remaining after radical surgery would be low and that the dose of 5000 cGy would be adequate in eradicating the majority of those cells. The number of local recurrences was lower in the treated group of patients, but the difference was not statistically significant. It was assumed that if a significant reduction in the number of local recurrences could be obtained, improved (disease-free) survival would result. No influence on disease-free or overall survival could be detected. These results were in agreement with those reported in Europe and the US, and it was concluded that postoperative radiation therapy alone cannot be justified as a routine procedure in the primary management of resectable rectal cancer.

Late radiation damage in prostate cancer patients treated by high dose external radiotherapy in relation to rectal dose.

A retrospective analysis of the incidence of radiation proctitis was performed in 154 patients with carcinoma of the prostate treated with external radiotherapy assisted by CT-scan planning from 1983 to 1985. An attempt was made to assess a dose-response relationship for proctitis. Multivariate Cox regression analysis showed that previous bowel disease or surgery, anterior rectal dose, and average rectal dose contributed to a higher risk of proctitis. The anterior rectal dose was the most important indicator. No statistically significant correlation was found for the posterior rectal dose. The actuarial 2-year incidence of moderate or severe proctitis was 22% for anterior rectal doses less than 70 Gy and 20% for anterior rectal doses between 70 and 75 Gy, but increased to 60% when the dose was more than 75 Gy. A dose effect relation was evident, with a sharp dose-response gradient around 75 Gy at the anterior rectal wall.

Low dose reirradiation in combination with hyperthermia: a palliative treatment for patients with breast cancer recurring in previously irradiated areas.

Ninety-seven patients with breast cancer recurring in a previously irradiated area (mean dose 44 Gy) were reirradiated in combination with hyperthermia and had evaluable tumor responses. In the reirradiation series, radiotherapy was given twice weekly in most patients, with a fraction size varying from 200 to 400 cGy, the total dose varying from 8 to 32 Gy. Hyperthermia was given following the radiotherapy fractions. The combined treatment resulted in 35% complete and 55% partial responses. Duration of response was median 4 months for partial response and 26 months for complete response, respectively. The median survival time for all patients was 12 months. Acute skin reaction was mild, with more than moderate erythema in only 14/97 patients. Thermal burns occurred in 44/97 patients, generally at sites where pain sensation was decreased, and therefore they did not cause much inconvenience. In the 19 patients who survived more than 2 years, no late radiation damage was observed. When patients who received a "high dose" (greater than 29 Gy and hyperthermia) were compared with those who received a "low dose" (less than 29 Gy and hyperthermia), a higher complete response rate was observed in the high dose group (58% vs. 24%), whereas no difference in acute toxicity was found. We conclude that reirradiation with 8 x 4 Gy in combination with hyperthermia twice weekly is a safe, effective and well tolerated method for palliative treatment of patients with breast cancer recurring in previously irradiated areas.