RF後以經皮脊椎成形術注射可緩解疼痛預防腫瘤惡化


  July 15, 2004 - 根據一項刊載於七月號血管與介入性放射學期刊(Journal of vascular and interventional radiology)的前瞻性試驗結果顯示,患有惡性骨腫瘤病患,使用高頻波燒灼術(RF)隨後透過經皮脊椎成形術注射骨水泥,可緩解疼痛且預防腫瘤惡化。
  
  來自日本三重大學放射學科的Atsushiro Nakatsuka醫學博士以及他的同事們認為,無法切除的惡性骨腫瘤會導致難以治療的疼痛,進而影響病患的生活品質;研究人員指出,標準用於病灶上腫瘤轉移的緩和療法是體外放射線燒灼治療,對於疼痛的緩解有50%到90%的效果,而最佳效果產生則是在12到20週後。
  
  研究人員認為,在考量到大部分骨骼轉移病患的生命是有限的情況下,刻不容緩地達到疼痛緩解是值得的;已有82%到97%接受脊髓成形術的病患,其疼痛症狀在4週內獲得緩解,而接受高頻波燒灼術的緩解效果,甚至高達90%到100%。
  
  研究人員召募了17位病患,總共有23個骨腫瘤,大小從1.25公分到15公分(平均4.9±3.5公分),分布在脊椎(17位)、髂骨(3位)、薦骨(2位)以及坐骨(1位);每個位置都接受利用骨切片針置入的電極所釋放最大輸出高頻波能量12分鐘,隨後將甲基丙烯酸甲酯注入腫瘤中,以穩定骨骼並預防隨後產生的骨折。
  
  此外,有一個因切片針無法置入成骨的坐骨病灶中的失敗病例。
  
  手術一週後,所有患有難以治療疼痛的病患(13位)都報告他們以疼痛量表(VAS)評估的疼痛指數,且平均疼痛量表指數顯著地下降(從8.2±2.4到1.1±1.8;P<.0001);5位病患在治療後3到12個月間(平均4.9個月)報告發生因腫瘤復發,及骨轉移所引起的再發性疼痛;1年的存活率為60.1%。
  
  腫瘤的壞死發生在14%到100%的腫瘤容積(平均71%±24%),在小的(小於5公分)與大的腫瘤(大於5公分)間發現平均壞死速率有顯著性差異(78%±23%相較於59%±22%;P<.036);研究人員解釋,較小腫瘤的病患並沒有發現腫瘤再生長所造成的再發性疼痛,這可能與高頻波燒灼術的治療反應率有關。
  
  4位(24%)患有脊髓轉移的病患發生神經損傷,且在接受高頻波燒灼術治療時下肢有放射性疼痛;這些病患中有3位的惡性腫瘤是位於脊椎的後側皮質,且發生了不完全的半身不遂;第4位病患的腫瘤侵襲到椎蒂而發生神經根病變;這些病患中的3位在經過復健後症狀改善。
  
  研究人員認為,高頻波的能量顯然地將脊髓加溫,高頻波燒灼術將組織加溫到45℃,對於脊髓與週邊神經會產生細胞毒性;在這個試驗中,所使用的電極在尖端具有內在冷卻裝置,且在腫瘤組織裡面或是附近即時監測溫度是不可能的。
  
  根據研究人員表示,合併高頻波燒灼術與脊椎成形術,在1週內顯然地在達成腫瘤壞死以及穩定被燒灼的病灶是有效的,所有疼痛的病患在1週內,即使是難以治療的疼痛也都被改善;他們暗示,未來對於改善惡性骨癌病患接受高頻波治療的安全性方面,核磁共振溫度計可能是一項有用的測量溫度技術。

RF Ablation Followed by Bone C

By Yael Waknine
Medscape Medical News

July 15, 2004 — Radiofrequency (RF) ablation followed by percutaneous vertebroplasty with bone cement relieves pain and prevents tumor enhancement in patients with malignant bone neoplasms, according to the results of a preliminary study published in the July issue of the Journal of Vascular and Interventional Radiology.

“Unresectable malignant bone tumors cause refractory pain that affects the patient’s quality of life,” write Atsushiro Nakatsuka, MD, and colleagues of the Department of Radiology at the Mie University School of Medicine in Japan. According to the authors, standard palliative treatment for focal metastatic tumors is external-beam radiation therapy, which has a 50% to 90% effect on pain relief with maximum benefit occurring after 12 to 20 weeks.

“Considering the limited life expectancy of most patients with bone metastases, it is desirable to achieve pain relief without delay,” the authors write, pointing out that pain relief has been achieved within four weeks in 82% to 97% of patients treated with vertebroplasty and in 90% to 100% of patients treated with RF ablation.

The investigators recruited 17 patients with 23 bone tumors measuring 1.25 to 15 cm in diameter (mean, 4.9 ± 3.5 cm), located in the spine (n = 17), iliac bone (n = 3), sacrum (n = 2), and ischial bone (n = 1). Each site was treated with RF energy for 12 minutes at the maximum allowable output from an electrode placed using a bone biopsy needle. Polymethyl methacrylate was then injected into the tumor to stabilize the treated bone and prevent subsequent fracture.

One case of technical failure occurred in which the biopsy needle could not be placed in an osteoblastic ischial lesion.

At one week after the procedure, all patients with refractory pain (n = 13) reported reduced pain scores as measured using a visual analog scale (VAS), and the mean VAS score was significantly decreased (from 8.4 ± 2.4 to 1.1 ± 1.8; P < .0001). Five patients reported recurrent pain due to local tumor recurrences and bone metastases within three to 12 months (mean, 4.9 months) of treatment. Survival rate at one year was 60.1%.

Necrosis occurred in 14% to 100% of tumor volume (mean, 71% ± 24%). A significant difference in mean necrosis rate was found between small (5 cm or smaller) and large (> 5 cm) tumors (78% ± 23% vs. 59% ± 22%; P < .036). “[R]ecurrent pain as a result of tumor regrowth was not reported by patients with small tumors,” the authors note. “This may be related to the response rate to RF ablation.”

Neural damage occurred in four patients (24%) having spine metastases and experiencing radiating pain of the lower extremities during RF ablation. Three of these patients had a malignancy in the posterior cortex of the spine and developed incomplete hemiplegia. The fourth patient with tumor invading the pedicle developed radiculopathy. Rehabilitation improved symptoms in three of these patients.

“RF energy obviously heated the spinal cord...RF ablation that heats tissue to 45º C is cytotoxic to the spinal cord and peripheral nerves,” the authors write, pointing out that the electrode used in the study had an internally cooled tip, and real-time monitoring of temperature in and around the tumor tissue was not possible.

“The combined use of RF ablation and vertebroplasty appears to be useful in achieving tumor necrosis and stabilizing the ablated lesions within one week.... [R]efractory pain was [also] improved within one week in all patients who had experienced pain,” according to the authors. “In the future, [Magnetic resonance] thermometry might prove to be a useful technique for temperature monitoring to improve the safety of RF therapy for bone malignancies,” they suggest.

The authors report no financial disclosures.

J Vasc Interv Radiol. 2004;15:707-712  

Reviewed by Gary D. Vogin, MD

    



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