目的：藉由與其他不同型式的「高劑量率鼻咽腔內置入器」（High dose rate intracavitary nasopha-ryngeal applicator之比較以評估「鹿特丹鼻咽置入器」（Rotterdam Nasopharyngeal Applicator）之優點與限制材料與方法：我們比較了長庚紀念醫院林口分院為鼻咽癌「高劑量率近接治療」所使用的三種不同型式之「鼻咽腔內置入器」此三種分別是：單管金屬置入器（Single metal tandem）；氣球置入器（Balloon applicator）和鹿特丹置入器（Rotterdam applicator）。我們以一位AJCC stage T1之鼻咽癌病人，分別置入三種不同型式之置入器，以獲得一組用鹿特丹置入器所產生之電腦斷層模擬影像，和另兩種置入器所產生的x光素片模擬影像。另找五個不同程度原發腫瘤侵犯 （tumor extent）的病人，此五位病人的腫瘤侵犯分別是T2o：腫瘤侵犯到口咽腔（oropharynx）T2n：腫瘤侵犯到鼻腔（nasal cavity）T2b：侵犯到咽旁區（parapharyngeal space）T3：侵犯到顱底（skull base）T4：侵犯到顱內（brain），將此五位病人的磁振造影（MRI）病灶畫在商業用的電腦斷層治療計劃軟體上，以模擬計算此鹿特丹放置器在六種病灶情形所分別產生的放射劑量分佈。此外，該位AJCC stage T1鼻咽癌病人以單管金屬置入器（Single metal tandem）；氣球置入器（Balloon applicator）所產生的放射劑量分布也被拿來與鹿特丹置入器所產生的計量分布相比較。而此鹿特丹置入器的適用性（feasibility），再現性（reproducibility），和舒適度（comfort）也同時加以評估。結果：我們發現鹿特丹置入器（Rotterdam applicator）具有再現性，並且較之於其他兩種置入器，於鼻咽黏膜或黏膜下腫瘤區域（Mucosa or submucosa tumor area），具有最好的放射劑量分布（radiation dose distribution）。且其給予T1病灶區域處方劑量（prescribed dose）時並不會增加太多的過多劑量（hot spot）。但因鹿特丹置入器需放置於病人鼻咽腔內為時約二至數天之久，所以需給予靜脈鎮痛輸液以緩和對病人所造成的的不適。此外，鹿特丹置入器之治療範圍很難涵蓋太大之咽旁區（huge parapharyngeal space）及顱內腫瘤，否則則需付出極高過多劑量（hot spot）之代價和骨頭嚴重壞死或穿孔（necrosis or perforation）的風險。結果：我們建議小的鼻咽腔腫瘤（small nasopharyngeal tumor）可以鹿特丹置入器（Rotterdam applicator）作為追加劑量之用，然而此置入器在外形結構上仍有很大的修飾空間以更進一步改善其在鼻咽區域之放射劑量分布。

Purpose: To use Rotterdam nasopharyngeal applicator to examine its results on radiation dose distribution and investigate the possible indications for the treatment of nasopharyngeal tumor. Materials and Methods: We compared three types of HDR nasopharyngeal brachytherapy applicators that were used in Chang Gung Memorial Hospital-Linkou. The three types of applicators were: single metal tandem, balloon applicator and Rotterdam applicator. Three types of applicators were tested in one patient with AJCC stage T1 nasopharyngeal cancer. We further selected five patients with different tumor extension as representative to compare the radiation dose distribution. The five repre-sentative case included T2o: tumor extended to oropharynx, T2n: tumor to nasal cavity, T2b: tumor to parapharynx space, T3: tumor to skull base and T4: tumor to brain. We use MRI to define the tumor, CT scan and commercial software to calculate the radiation dose. The feasibility, reproducibility and patients' comfort were also be evaluated. Results: We found that Rotterdam applicator was more reproducible and best radiation dose distribution to nasopharyngeal mucosa or submucosa tumor area compared to the other 2 applicators. The Rotterdam applicator can deliver prescribed dose to the lesion area without too much hot spot in the treatment of T1-T2a NPC. However, when Rotterdam applicator was placed to the nasopharynx for few days during the treatment, patients would feel much discomfort. It therefore needed intravenous medication or fluid to relieve patients' discomfort. Besides, Rotterdam applicator also has the limitation in coverage of tumor with huge parapharyngeal space extension or to intracranial area. For the treatment of advanced NPC, it may still be at the price of very high radiation hot spot and face the risk of severe necrosis or bone perforation. Conclusion : With the treatment of small nasopharyngeal tumor, we will suggest Rotterdam applicator to be the choice as an aid of brachytherapy boost. However, there will be a great potential to improve the shape of the Rotterdam applicator to fit better in our patients in order to be common use for the improvement of the radiation dose distribution to the nasopharyngeal area.