Blom-Goldman Ulla, Svane Gunilla, Wennberg Berit, Lideståhl Anders, Lind Pehr A R M
Department of Oncology, Karolinska University Hospital, Stockholm, Sweden.
Acta Oncol. 2007;46(2):187-93. doi: 10.1080/02841860600949586.
Our aim was to reduce the rates of clinical and radiological pneumonitis in local-regional radiotherapy (RT) for breast cancer compared to a previous treatment series by applying a pre-planned lung dose volume constraint. 3-D dose planning was performed in 66 women with the aim of not exceeding an ipsilateral V20 of 30%. The patients were followed for short-term signs/symptoms of post-RT pneumonitis and radiological changes on chest CT 4 months after RT. Radiological abnormalities were scored with a CT-adapted modification of a semi-quantitative classification system originally proposed by Arriagada which accounts for severity and affected lung regions. The abnormal subvolumes were contoured and the mean doses were calculated. Three cases of mild and one case of moderate symptomatic pneumonitis were diagnosed. The mean V20 was higher in symptomatic than in unaffected patients, 29% vs. 24% (p =0.04). Mild/moderate radiological changes were frequently observed on CT in regions with average doses >30 Gy. According to multivariate modeling, a trend for association was found between the studied dosimetric factors V13, V20, V30 and mean lung dose, and moderate-severe changes on CT but not with patient specific covariates, e.g. chemotherapy or tamoxifen exposure. 3-D planned local-regional RT with a preplanned lung dose volume constraint of V20 <30% resulted in few cases of moderate symptomatic pneumonitis. Mild/moderate radiological changes were still detectable on CT in subvolumes receiving doses >30 Gy. Long-term follow-up for evaluation of possible late morbidity is warranted.
我们的目标是，通过应用预先规划的肺剂量体积限制，与先前的治疗系列相比，降低局部区域放射治疗（RT）乳腺癌时临床和放射性肺炎的发生率。对66名女性进行了三维剂量规划，目标是使同侧V20不超过30%。对患者进行随访，观察放疗后肺炎的短期体征/症状以及放疗后4个月胸部CT的影像学变化。采用最初由阿里亚加达提出的半定量分类系统的CT适应性修改版本对影像学异常进行评分，该系统考虑了严重程度和受影响的肺区域。勾勒出异常子体积并计算平均剂量。诊断出3例轻度和1例中度症状性肺炎。有症状患者的平均V20高于未受影响患者，分别为29%和24%（p = 0.04）。在平均剂量>30 Gy的区域，CT上经常观察到轻度/中度影像学变化。根据多变量建模，在所研究的剂量学因素V13、V20、V30和平均肺剂量与CT上的中度至重度变化之间发现了关联趋势，但与患者特定的协变量（如化疗或他莫昔芬暴露）无关。三维计划的局部区域放疗，预先规划的肺剂量体积限制为V20<30%，导致中度症状性肺炎的病例很少。在接受剂量>30 Gy的子体积中，CT上仍可检测到轻度/中度影像学变化。有必要进行长期随访以评估可能的晚期发病率。
