Giles Sharon L, Imseeh Georgios, Rivens Ian, Ter Haar Gail R, Taylor Alexandra, deSouza Nandita M
1 The CRUK Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden Hospital , London , United Kingdom.
2 Department of Gynae-Oncology, The Royal Marsden Hospital , London , United Kingdom.
Br J Radiol. 2019 Jun;92(1098):20181037. doi: 10.1259/bjr.20181037. Epub 2019 May 14.
To assess the feasibility of targeting recurrent gynaecological tumours with MR guided high intensity focused ultrasound (MRgHIFU).
20 patients with recurrent gynaecological tumours were prospectively scanned on a Philips/Profound 3 T Achieva MR/ Sonalleve HIFU system. Gross tumour volume (GTV) and planning target volume (PTV) were delineated on W and diffusion-weighted imaging (DWI). Achievable treatment volumes that (i) assumed bowel and/or urogenital tract preparation could be used to reduce risk of damage to organs-at-risk (TV), or (ii) assumed no preparations were possible (TV) were compared with PTV on virtual treatment plans. Patients were considered treatable if TV ≥ 50 % PTV.
11/20 patients (55%) were treatable if preparation strategies were used: nine had central pelvic recurrences, two had tumours in metastatic locations. Treatable volume ranged from 3.4 to 90.3 ml, representing 70 ± 17 % of PTVs. Without preparation, 6/20 (30%) patients were treatable (four central recurrences, two metastatic lesions). Limiting factors were disease beyond reach of the HIFU transducer, and bone obstructing tumour access. DWI assisted tumour outlining, but differences from W imaging in GTV size (16.9 ± 23.0%) and PTV location (3.8 ± 2.8 mm in phase-encode direction) limited its use for treatment planning.
Despite variation in size and location within the pelvis, ≥ 50 % of tumour volumes were considered targetable in 55 % patients while avoiding adjacent critical structures. A prospective treatment study will assess safety and symptom relief in a second patient cohort.
Target size, location and access make MRgHIFU a viable treatment modality for treating symptomatic recurrent gynaecological tumours within the pelvis.
评估磁共振引导高强度聚焦超声（MRgHIFU）靶向治疗复发性妇科肿瘤的可行性。
对20例复发性妇科肿瘤患者在飞利浦/Profound 3T Achieva MR/ Sonalleve HIFU系统上进行前瞻性扫描。在T2加权成像（T2WI）和扩散加权成像（DWI）上勾画大体肿瘤体积（GTV）和计划靶体积（PTV）。在虚拟治疗计划中，将（i）假设可采用肠道和/或泌尿生殖道准备以降低危及器官损伤风险的可实现治疗体积（TV），或（ii）假设无法进行准备的可实现治疗体积（TV）与PTV进行比较。如果TV≥50%PTV，则认为患者可接受治疗。
如果采用准备策略，11/20例患者（55%）可接受治疗：9例为盆腔中央复发，2例为转移部位肿瘤。可治疗体积范围为3.4至90.3ml，占PTV的70±17%。未进行准备时，6/20例患者（30%）可接受治疗（4例中央复发，2例转移灶）。限制因素包括HIFU换能器无法触及的疾病以及阻碍肿瘤进入的骨骼。DWI有助于肿瘤轮廓勾画，但GTV大小与T2WI成像的差异（16.9±23.0%）以及PTV位置在相位编码方向上的差异（3.8±2.8mm）限制了其在治疗计划中的应用。
尽管盆腔内肿瘤大小和位置存在差异，但在55%的患者中，≥50%的肿瘤体积被认为可靶向治疗，同时避免邻近关键结构。一项前瞻性治疗研究将评估第二组患者的安全性和症状缓解情况。
肿瘤大小、位置和可及性使MRgHIFU成为治疗盆腔内有症状复发性妇科肿瘤的可行治疗方式。
