Simões Rita, Gulliford Sarah, Shah Punita, McAtavey Eve, Richardson Elizabeth, Chowdhury Umme, Fray Laura, Butt Roeum, Augustin Yolanda, Sarang Ruqayyah, Kilinc Refia, Iqbal Maryam, Moulay-Dehbi Hakim, Miles Elizabeth, Hoskin Peter, Zaidi Shane, Harrington Kevin J, Miah Aisha B
The Institute of Cancer Research, London, UK.
The Royal Marsden Hospital, London, UK.
Clin Transl Radiat Oncol. 2025 Jul 19;54:101020. doi: 10.1016/j.ctro.2025.101020. eCollection 2025 Sep.
Radiotherapy (RT) plans for soft tissue sarcoma of the extremities (STSE) are optimised to achieve maximum target coverage whilst avoiding high doses to weight-bearing bones and intermediate doses to the normal tissue (NT) limb corridor. Within this study, novel lower extremity NT outlining guidelines and atlas were developed based on the hypothesis that using these for RT planning may reduce RT toxicity. Usability and applicability of the guidance were also investigated.
Guidelines for NT outlining were developed. Two STSE cases were selected and a set of reference volumes was outlined on each case by one Therapeutic Radiographer/Radiation Therapist (RTT) and peer-reviewed by a consultant radiation oncologist (RO). NTs were then outlined following the guidelines by 11 (8 RTT and 3 RO) and 12 (9 RTT and 3 RO) additional observers, respectively for cases 1 and 2. Dice coefficient (DICE), Maximum Hausdorff distance (maxHD) and mean surface distance (MSD) were calculated for individual NT volumes against the reference volumes. The Kruskal-Wallis test was performed. Analysis of interobserver variability was then used to inform guidance improvement.
Good agreement and reproducibility were observed in DICE, MSD and maxHD for the anterior, posterior, adductor and gluteal muscle compartments, femur and femoral head and neck, knee and hip joints. Moderate agreement was observed for the lateral rotator and iliopsoas muscle compartments, and the femoral and inguinofemoral neurovascular bundle. Poor agreement was observed for the deep thigh neurovascular bundle.
Our results identify that the new NT outlining guidance for STSE is reproducible between observers and within a multi-professional environment, with consistent RTT and RO scores. This reproducibility is attributed to the use of guidelines. This study has also identified areas for refinement of the guidelines, particularly for the deep thigh neurovascular bundle.
四肢软组织肉瘤（STSE）的放射治疗（RT）计划需进行优化，以实现最大靶区覆盖，同时避免对负重骨给予高剂量照射，并避免对正常组织（NT）肢体通道给予中等剂量照射。在本研究中，基于使用这些指南进行RT计划可能降低RT毒性的假设，制定了新的下肢NT勾勒指南和图谱。还对该指南的可用性和适用性进行了研究。
制定了NT勾勒指南。选择了2例STSE病例，由一名放射治疗技师/放射治疗师（RTT）在每个病例上勾勒出一组参考体积，并由一名放射肿瘤学顾问（RO）进行同行评审。然后，分别由另外11名（8名RTT和3名RO）和12名（9名RTT和3名RO）观察者按照指南对病例1和病例2的NT进行勾勒。计算每个NT体积与参考体积的骰子系数（DICE）、最大豪斯多夫距离（maxHD）和平均表面距离（MSD）。进行了Kruskal-Wallis检验。然后使用观察者间变异性分析来指导指南的改进。
在前侧、后侧、内收肌和臀肌间隙、股骨及股骨头和颈部、膝关节和髋关节的DICE、MSD和maxHD方面观察到良好的一致性和可重复性。在外侧旋转肌和髂腰肌间隙以及股部和腹股沟股神经血管束方面观察到中等一致性。在大腿深部神经血管束方面观察到较差的一致性。
我们的结果表明，STSE新的NT勾勒指南在观察者之间以及多专业环境中具有可重复性，RTT和RO的评分一致。这种可重复性归因于指南的使用。本研究还确定了指南需要完善的领域，特别是大腿深部神经血管束。
