Nishioka Takeshi, Shiga Tohru, Shirato Hiroki, Tsukamoto Eriko, Tsuchiya Kazuhiko, Kato Takashi, Ohmori Keiichi, Yamazaki Akira, Aoyama Hidefumi, Hashimoto Seiko, Chang Ta-Chen, Miyasaka Kazuo
Division of Radiation Oncology, Department of Radiology, School of Medicine, Hokkaido University, Sapporo, Japan.
Int J Radiat Oncol Biol Phys. 2002 Jul 15;53(4):1051-7. doi: 10.1016/s0360-3016(02)02854-7.
Accurate diagnosis of tumor extent is important in three-dimensional conformal radiotherapy. This study reports the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) and magnetic resonance imaging/computed tomography (MRI/CT) for better targets delineation in radiotherapy planning of head-and-neck cancers.
The subjects consisted of 12 patients with oropharyngeal carcinoma and 9 patients with nasopharyngeal carcinoma (NPC) who were treated with radical radiotherapy between July 1999 and February 2001. Image fusion between 18FDG-PET and MRI/CT was performed using an automatic multimodality image registration algorithm, which used the brain as an internal reference for registration. Gross tumor volume (GTV) was determined based on clinical examination and 18FDG uptake on the fusion images. Clinical target volume (CTV) was determined following the usual pattern of lymph node spread for each disease entity along with the clinical presentation of each patient.
Except for 3 cases with superficial tumors, all the other primary tumors were detected by 18FDG-PET. The GTV volumes for primary tumors were not changed by image fusion in 19 cases (89%), increased by 49% in one NPC, and decreased by 45% in another NPC. Normal tissue sparing was more easily performed based on clearer GTV and CTV determination on the fusion images. In particular, parotid sparing became possible in 15 patients (71%) whose upper neck areas near the parotid glands were tumor-free by 18FDG-PET. Within a mean follow-up period of 18 months, no recurrence occurred in the areas defined as CTV, which was treated prophylactically, except for 1 patient who experienced nodal recurrence in the CTV and simultaneous primary site recurrence.
This preliminary study showed that image fusion between 18FDG-PET and MRI/CT was useful in GTV and CTV determination in conformal RT, thus sparing normal tissues.
在三维适形放疗中，准确诊断肿瘤范围至关重要。本研究报告了使用（18）F - 氟 - 2 - 脱氧 - D - 葡萄糖正电子发射断层扫描（18FDG - PET）与磁共振成像/计算机断层扫描（MRI/CT）之间的图像融合，以在头颈部癌放疗计划中更好地勾画靶区。
研究对象包括1999年7月至2001年2月期间接受根治性放疗的12例口咽癌患者和9例鼻咽癌（NPC）患者。使用自动多模态图像配准算法进行18FDG - PET与MRI/CT之间的图像融合，该算法以大脑作为内部配准参考。基于临床检查和融合图像上的18FDG摄取情况确定大体肿瘤体积（GTV）。根据每种疾病实体的淋巴结转移常见模式以及每位患者的临床表现确定临床靶体积（CTV）。
除3例浅表肿瘤外，其他所有原发性肿瘤均被18FDG - PET检测到。19例（89%）原发性肿瘤的GTV体积在图像融合后未改变，1例NPC患者增加了49%，另1例NPC患者减少了45%。基于融合图像上更清晰的GTV和CTV确定，更容易实现正常组织的保护。特别是，15例（71%）患者通过18FDG - PET显示腮腺附近上颈部区域无肿瘤，从而有可能实现腮腺保护。在平均18个月的随访期内，除1例患者在CTV区域出现淋巴结复发并同时伴有原发部位复发外，接受预防性治疗的CTV区域未出现复发。
这项初步研究表明，18FDG - PET与MRI/CT之间的图像融合在适形放疗中确定GTV和CTV方面有用，从而保护正常组织。
