Vicini Frank A, Douglas Arthur, Todor Dorin, Julian Thomas, Lyden Maureen
William Beaumont Hospital, Royal Oak, MI.
Virginia Commonwealth University, Richmond, VA.
J Contemp Brachytherapy. 2010 Mar;2(1):1-8. doi: 10.5114/jcb.2010.13716. Epub 2010 Apr 1.
Preliminary dosimetric findings in patients managed with the Contura Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) on a multi-institutional phase IV registry trial were reviewed.
CT-based 3D planning with dose optimization was performed for all patients. For the study, new ideal dosimetric goals were developed: 1) ≥ 95% of the prescribed dose (PD) covering ≥ 90% of the target volume (TV), 2) a maximum skin dose ≤ 125% of the PD, 3) maximum rib dose ≤ 145% of the PD, and 4) the V150 ≤ 50 cc and V200 ≤ 10 cc. The frequency of concurrently achieving these dosimetric goals using the Contura MLB was investigated.
194 cases were evaluable. Employing the MLB, all ideal dosimetric criteria were achieved in 76% of cases. Evaluating dosimetric criteria separately, 90% and 89% of cases met the new ideal skin and rib dose criteria, respectively. In 96%, ideal TV coverage goals were achieved and in 96%, dose homogeneity criteria (V150 and V200) were met. For skin spacing ≥ 5-7 mm, the median skin dose was 121% of the PD and when < 5 mm, the median skin dose was 124.4%. For rib distancees < 5 mm, the median rib dose was reduced to 136.4% of the PD. For skin spacing < 7 mm and distance to rib < 5 mm, the median skin and rib doses were concurrently limited to 121% and 142.8% of the PD, respectively.
The Contura MLB catheter provides potential improvements in dosimetric capabilities (i.e., reduced skin and rib doses and improved TV coverage) in many clinical scenarios.
回顾在一项多机构IV期注册试验中，使用Contura多腔球囊（MLB）乳腺近距离放射治疗导管进行加速局部乳腺照射（APBI）的患者的初步剂量学研究结果。
对所有患者进行基于CT的三维剂量优化计划。本研究制定了新的理想剂量学目标：1）规定剂量（PD）的≥95%覆盖≥90%的靶区体积（TV）；2）最大皮肤剂量≤PD的125%；3）最大肋骨剂量≤PD的145%；4）V150≤50cc且V200≤10cc。研究了使用Contura MLB同时达到这些剂量学目标的频率。
194例患者可评估。使用MLB时，76%的病例达到了所有理想剂量学标准。分别评估剂量学标准时，90%和89%的病例符合新的理想皮肤和肋骨剂量标准。96%的病例达到了理想的靶区覆盖目标，96%的病例符合剂量均匀性标准（V150和V200）。当皮肤间距≥5 - 7mm时，中位皮肤剂量为PD的121%，当<5mm时，中位皮肤剂量为124.4%。当肋骨距离<5mm时，中位肋骨剂量降至PD的136.4%。当皮肤间距<7mm且距肋骨距离<5mm时，中位皮肤和肋骨剂量分别同时限制在PD的121%和142.8%。
Contura MLB导管在许多临床情况下可改善剂量学性能（即降低皮肤和肋骨剂量，提高靶区覆盖）。
