Wust Peter, von Borczyskowski Daniel Wischka, Henkel Thomas, Rosner Christian, Graf Reinhold, Tilly Wolfgang, Budach Volker, Felix Roland, Kahmann Frank
Clinic for Radiation Medicine, Charité Medical School, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany.
Radiother Oncol. 2004 Oct;73(1):39-48. doi: 10.1016/j.radonc.2004.08.003.
To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to work out strategies for improvement.
A group of 174 patients with localised prostate cancer was treated with permanent seed implantation between 1999 and 2001, either alone (140 patients) or in combination with external radiotherapy (34 patients). For the majority (114/174, i.e. 66%) a CT was performed four weeks after implantation and analysed in the planning system VariSeed. In the postimplant analysis, dosimetric descriptors (doses, volumes) were determined for the prostate and rectum and compared with the intraoperative values. In addition, a questionnaire was sent to all patients to assess and quantify acute and chronic toxicity (urinary, rectal, sexual) and the impact on subjective acceptance and quality of life (return rate of questionnaires 83%). The derived score changes were correlated with clinical and dosimetric factors.
In the mono-brachytherapy group 14% (16/140) required a bladder catheter, of them 8% (9/140) with a manifest urinary obstruction. Long-term rectal toxicity (<5%) and impairment of potency (<30%) are moderate and obviously below other treatment options. Urinary toxicity is dominant with an overall long-term dysuria up to 30% (at a mean observation interval of ten months), and a significant trend to decline with follow-up time. Conversely, the erectile function tends to deteriorate with follow-up time. Nevertheless, quality of life is not significantly reduced and acceptance is high. Our analysis suggests that the main factor for urinary toxicity and impaired erectile function is the dose load to larger portions of the prostate (D(50)>240 Gy), which appears to be attributed to unnecessarily high numbers of seeds (for a fixed activity per seed) and needles. The rectal toxicity is correlated with the high dose regions in the rectum (>/=145 Gy). Urinary toxicity is lower for combined-brachytherapy, while rectal toxicity and impairment of potency are slightly higher.
Toxicity spectrum and quality of life after permanent seed implantation for early prostate cancer are acceptable for nearly all patients (98%). To further improve tolerance we should attempt to achieve a better dose homogeneity, i.e. by reducing D(50). Therefore, special attention should be given to D(50) during the real-time planning process. The necessity of more homogeneous dose distributions might imply a reduction of the activity per seed, e.g. from 0.7 mCi down to 0.6 mCi.
评估永久性前列腺籽源植入后的急性及长期毒性。寻找副作用的预测性临床或剂量学因素，以制定改进策略。
1999年至2001年间，一组174例局限性前列腺癌患者接受了永久性籽源植入治疗，其中单独植入（140例患者）或联合外照射放疗（34例患者）。大多数患者（114/174，即66%）在植入后4周进行了CT扫描，并在VariSeed计划系统中进行分析。在植入后分析中，确定前列腺和直肠的剂量学参数（剂量、体积），并与术中值进行比较。此外，向所有患者发送问卷，以评估和量化急性和慢性毒性（泌尿、直肠、性功能方面）以及对主观接受度和生活质量的影响（问卷回复率83%）。得出的评分变化与临床和剂量学因素相关。
在单纯近距离治疗组中，14%（16/140）的患者需要留置膀胱导管，其中8%（9/140）有明显的尿路梗阻。长期直肠毒性（<5%）和性功能损害（<30%）程度中等，明显低于其他治疗方法。泌尿毒性较为突出，总体长期排尿困难发生率高达30%（平均观察期为10个月），且有随随访时间下降的显著趋势。相反，勃起功能随随访时间有恶化趋势。然而，生活质量并未显著降低，患者接受度较高。我们的分析表明，泌尿毒性和勃起功能受损的主要因素是前列腺较大部分的剂量负荷（D(50)>240 Gy），这似乎归因于种子（每粒种子固定活度）和针的数量过多。直肠毒性与直肠高剂量区域（≥145 Gy）相关。联合近距离治疗的泌尿毒性较低，而直肠毒性和性功能损害略高。
早期前列腺癌永久性籽源植入后的毒性谱和生活质量对几乎所有患者（98%）来说都是可以接受的。为进一步提高耐受性，我们应尝试实现更好的剂量均匀性，即降低D(50)。因此，在实时计划过程中应特别关注D(50)。更均匀剂量分布的必要性可能意味着降低每粒种子的活度，例如从0.7 mCi降至0.6 mCi。
