前立腺癌放射線療法の将来

Abstract

T2以下の局在性前立腺癌における治療成績をretrospectiveに検討した.conventionalな外照射療法の根治性は前立腺全摘除術に比較して低く, 放射線療法の適応としては, 期待余命の限られた局在性前立腺癌に限定されるものと思われた.前立腺癌へのradiosurgeryの応用は可能と考えられた

Fifty-seven patients with clinically localized prostate cancer were treated by radical prostatectomy or external radiation therapy following pelvic lymphadenectomy. Comparing the outcome of radiotherapy with that of prostatectomy in 42 T2 patients without lymph node metastasis, the 5-year cause-specific survival did not differ between the radical prostatectomy group (n = 31) and radiotherapy group (n = 11). The 5-year disease-free survival of the prostatectomy group, however, was superior to that of radiotherapy group (p = 0.01). To cure patients with T2 prostate cancer, therefore, it is supposed that radical prostatectomy should be performed. To improve the treatment outcome after radiotherapy, stereotactic radiosurgery for prostate cancer has been attempted in our institution. Phantom experiments using a linear accelerator demonstrated a round dose distribution, and high reproducibility of prostate positioning was confirmed by CT when a thermoplastic immobilization device was used to fix the pelvis. In one patient with localized prostate cancer treated by radiosurgery, acute complication has not been recognized during the 5 week follow-up. Radiosurgery may be available to treat clinically localized prostate cancer.