Post J G, te Poele J A, Oussoren Y, Stewart F A
Division of Experimental Therapy, Netherlands Cancer Institute, Amsterdam.
Radiother Oncol. 1995 Nov;37(2):124-30. doi: 10.1016/0167-8140(95)01621-m.
The aim of this project was to measure the irradiation tolerance of normal (non tumour bearing) mouse bladder after previous intravesical photodynamic therapy (PDT). Illumination with a range of light doses at 24 h after Photofrin was used as the initial PDT treatment and irradiation with a range of X-ray doses was given at 12 or 24 weeks after the initial therapy. Functional bladder damage was assessed from changes in micturition frequency (tested regularly for a follow-up period of 53 weeks after irradiation) and from cystometry measurements of the bladder at 53-56 weeks. PDT alone caused a marked increase in micturition frequency, with (partial) recovery by the time of irradiation. Irradiation alone caused a modest, transient acute response within 5 weeks and a progressive, permanent late response starting from about 25 weeks depending on X-ray dose. A reduced bladder capacity was also evident at 53-56 weeks after 20 Gy X-rays and after PDT alone. Irradiation after previous intravesical PDT caused an acute reaction similar to X-rays alone, but there was a much earlier expression of late functional bladder damage. The final level of damage prior to sacrifice at 53-56 weeks, was not significantly greater than after X-rays alone. These results suggest that irradiation after previous whole bladder PDT, for refractory bladder tumours, may lead to an increased risk of persistent increases in micturition frequency and reduced bladder capacity, beginning at very early times after irradiation.
本项目的目的是测量正常（无肿瘤）小鼠膀胱在先前膀胱内光动力疗法（PDT）后的辐射耐受性。以Photofrin作为初始PDT治疗后24小时用一系列光剂量进行照射，并在初始治疗后12周或24周给予一系列X射线剂量照射。通过排尿频率的变化（在照射后53周的随访期内定期检测）和在53 - 56周时膀胱的膀胱内压测量来评估功能性膀胱损伤。单独的PDT导致排尿频率显著增加，在照射时（部分）恢复。单独照射在5周内引起适度的短暂急性反应，并根据X射线剂量从大约25周开始出现进行性的永久性晚期反应。在20 Gy X射线照射后以及单独PDT治疗后53 - 56周时，膀胱容量降低也很明显。先前膀胱内PDT后进行照射引起的急性反应与单独X射线照射相似，但晚期功能性膀胱损伤的表现要早得多。在53 - 56周处死前的最终损伤水平，并不比单独X射线照射后显著更高。这些结果表明，对于难治性膀胱肿瘤，先前全膀胱PDT后进行照射，可能会导致在照射后很早的时候就出现排尿频率持续增加和膀胱容量降低的风险增加。
