[Curative radiotherapy of localized prostate cancer. Treatment methods and results]

Three-Dimensional Conformal External Beam Radiotherapy versus the Combination of External Radiotherapy with High-Dose Rate Brachytherapy in Localized Carcinoma of the Prostate: Comparison of Acute Toxicity

Aims and background

Radiotherapy represents one of the basic therapeutic methods in treatment of localized carcinoma of the prostate. Optimal irradiation dose is the cornerstone of a successful treatment. Along with local control of the disease and overall survival of the patient, possible acute and long-term side effects need to be monitored very closely.

Methods

A non-randomized prospective study comparing the acute genitourinary and gastrointestinal toxicity in patients irradiated for localized carcinoma of the prostate. Fifty-seven patients were treated with three-dimensional conformal external beam radiotherapy alone, and in the second treatment arm a combination of external beam radiotherapy and high-dose rate brachytherapy was employed in 40 patients.

Results

Three-dimensional conformai external beam radiotherapy. Acute G1 genitourinary toxicity was recorded in 35.1% of patients, G2 in 22.8%, and G2-3 in one patient (1.7%). Acute gastrointestinal toxicity was experienced by 54.4% of patients, G1 in 28.1%, G2 in 17.5%, and G3 in 8.8%. Three-dimensional conformal external beam radiotherapy + brachytherapy. Acute G1 genitourinary toxicity was recorded in 37.5% and grade 2 in 15% of the patients. Only G1 acute gastrointestinal toxicity was recorded in 40% of the patients.

Conclusions

Acute G1 genitourinary toxicity was experienced by a similar percentage of patients in both treatment arms. Acute G2 genitourinary toxicity was more frequent in the three-dimensional conformal radiotherapy arm. Higher acute genitourinary toxicity, G3 or G4, was recorded only in one patient per treatment arm. Acute gastrointestinal toxicity was more frequent in the three-dimensional conformal radiotherapy arm. Higher acute gastrointestinal toxicity, G2 and G3, was only observed in the three-dimensional conformal radiotherapy arm. The acute toxicity observed was of a low grade. The combination of external beam radiotherapy with brachytherapy resulted in a lower incidence of gastrointestinal toxicity than external beam radiotherapy alone.

[Regressive changes after short-term neoadjuvant antihormonal therapy in prostatic carcinoma: the value of Gleason grading]

Although neoadjuvant, antihormonal therapy does not lead to an improvement in the outcome of prostatic carcinoma it is still used in the short-term in a subset of patients. Here we report the regressive changes due to this short-term treatment and analyse the impact on Gleason grading. The most frequent regressive changes in 82 tumors treated short-term were determined and quantified. The results were compared to a matched control group and also to the preoperative needle biopsies.A steep increase in regressive changes was observed within the first 4 weeks. After this point, changes increased only mildly. Within the first 2 weeks of treatment no significant changes compared to control tissue were present. Compared to the preoperative needle biopsies, pretreated tumors showed a significant upgrading. After 2 weeks of neoadjuvant antihormonal therapy, regressive changes are so great, that Gleason grading can no longer be recommended.