放射治療四肢軟組織肉瘤優(yōu)于傳統(tǒng)放療

    IMRT bests conventional radiation for soft-tissue sarcomas of the extremities

    亞特蘭大——美國放射腫瘤學(xué)會(huì)（ASTRO）年會(huì)上陳述的一項(xiàng)最新研討顯現(xiàn)，調(diào)強(qiáng)放療（IMRT）對(duì)四肢軟安排肉瘤部分操控效果顯著優(yōu)于傳統(tǒng)放療。

    紐約留念斯隆-凱特琳癌癥中間放射腫瘤教授Kaled M. Alektiar醫(yī)師陳述稱，IMRT 5年部分操控率為92.4%,而外照耀放療（EBRT）為85%.即便IMRT醫(yī)治患者多為危險(xiǎn)程度較高者，IMRT仍可使患者獲益。“IMRT醫(yī)治患者≥3級(jí)緩慢淋巴水腫發(fā)病率顯著較低。”

    研討者評(píng)價(jià)了320例承受確定性手術(shù)和放療的原發(fā)性非轉(zhuǎn)移性四肢軟安排肉瘤患者的狀況。其間155例承受傳統(tǒng)EBRT,一般為三維適形放療，別的165例承受MIRT.大都腫瘤（74.7%）坐落下肢，45.6%的腫瘤直徑≥10 cm,92.2%坐落深部安排，82.5%為高度惡性，40%接近或陽性手術(shù)切緣。大都患者（75.9%）承受了輔佐化療。

    IMRT組患者陽性或接近切緣的份額顯著高于傳統(tǒng)EBRT組（47.9% vs. 31.6%;P=0.003），承受IMRT患者多為安排學(xué)高度惡性，雖然兩組區(qū)別僅為顯著性臨界水平（86.7% vs. 78.1%;P=0.055）。

    此外，更多IMRT組患者承受了術(shù)前放療（21.2% vs. 3.2%;P<0.001）。兩組患者在生齒統(tǒng)計(jì)學(xué)、腫瘤巨細(xì)、深度以及醫(yī)治預(yù)備期間CT使用等其他方面未見區(qū)別。

    中位隨訪時(shí)刻49.5個(gè)月（IMRT組和EBRT組分別為42個(gè)月和87個(gè)月）。IMRT組和EBRT組5年部分復(fù)發(fā)率分別為7.6%和15%,兩組中位部分復(fù)發(fā)時(shí)刻均為18個(gè)月。合計(jì)8例患者需求截肢，其間IMRT組3例，EBRT組5例。

    多變量分析標(biāo)明，可顯著猜測(cè)部分復(fù)發(fā)的3個(gè)要素分別為IMRT[危險(xiǎn)比（HR），0.46;P=0.02）、年紀(jì)<50歲（HR,0.44;P=0.04）和腫瘤最長維度10 cm（HR,0.53;P=0.05）。

    IMRT 組和EBRT組5年總生存率分別為69.1%和75.6%,無顯著區(qū)別。

    兩組患者3級(jí)或4級(jí)急性毒性（包含感染、非感染創(chuàng)傷并發(fā)癥和放射性皮炎）發(fā)作率類似。IMRT組患者醫(yī)治間隔時(shí)刻顯著較短，均勻0.8天，而傳統(tǒng)EBRT組為2.2天。IMRT組無1例患者發(fā)作緩慢≥3級(jí)淋巴水腫，而傳統(tǒng)EBRT組有4例患者（P=0.053）。

    該研討由紐約維爾康奈兒醫(yī)學(xué)院臨床與轉(zhuǎn)化科學(xué)中間贊助，Aktiar醫(yī)師陳述無有關(guān)利益沖突。

    By: NEIL OSTERWEIL, Internal Medicine News Digital Network

    ATLANTA – Intensity-modulated radiation therapy proved significantly better than conventional radiation for local control of soft-tissue sarcomas of the extremities, according to new study results, investigators reported at the annual meeting of the American Society for Radiation Oncology.

    The 5-year local control rate with intensity-modulated radiation therapy （IMRT） was 92.4%, compared with 85% for external-beam radiation therapy （EBRT）， said Dr. Kaled M. Alektiar, a radiation oncologist at Memorial Sloan-Kettering Cancer Center in New York.

    The benefits of IMRT were seen despite a preponderance of higher risks in patients treated with IMRT. And, “the morbidity profile, especially for chronic lymphedema of grade 3 or higher, was significantly less,” Dr. Alektiar said.

    He and his coinvestigators looked at 320 patients who underwent definitive surgery and radiation therapy at Memorial Sloan-Kettering for primary, nonmetastatic soft-tissue sarcomas of the extremities. Of this group, 155 received EBRT with a conventional technique, usually three-dimensional conformal radiation, and 165 patients received IMRT.

    Most of the tumors （74.7%） were in the lower extremity, 45.6% were at least 10 cm in diameter, 92.2% were in deep tissue, 82.5% were high grade, and 40% had close or positive surgical margins. The majority of patients （75.9%） received adjuvant chemotherapy.

    There were significantly more patients with positive or close margins in the IMRT group than in the conventional EBRT group （47.9% vs. 31.6%; P = .003）， and more patients treated with IMRT had high-grade histology tumors, although this difference had only borderline significance （86.7% vs. 78.1%; P =.055）。

    Additionally, significantly more patients in the IMRT group received preoperative radiation （21.2% vs. 3.2%; P less than .001）。 Otherwise, the groups were balanced in terms of demographics, tumor size, depth, and use of CT in treatment planning.

    The median follow-up was 49.5 months （42 months for patients treated with IMRT, and 87 months for those treated with EBRT）。 The 5-year local recurrence rates were 7.6% for IMRT and 15% for conventional EBRT. The median time to local recurrence was 18 months in each group.

    Eight patients required amputations for salvage, including three in the IMRT cohort and five in the conventional radiation cohort.

    In multivariate **ysis, three factors that were significantly prognostic for local failure were IMRT （hazard ratio, 0.46; P = .02）， age less than 50 years （HR, 0.44; P = .04）， and a tumor size of 10 cm or less in the longest dimension （HR, 0.53; P = .05）。

    Overall survival at 5 years was 69.1% for IMRT and 75.6% for EBRT, a difference that was not significant.

    Rates of grade 3 or 4 acute toxicities, including infected and noninfected wound complications and radiation dermatitis, were similar between the groups. Patients treated with IMRT had significantly shorter treatment interruptions, at a mean of 0.8 days, compared with 2.2 days for patients treated with conventional EBRT. Chronic grade 3 or higher lymphedema did not occur in any patients treated with IMRT, compared with four patients treated with conventional EBRT （P = .053）。

    The study was supported by a grant from the Clinical and Translational Science Center at Weill Cornell Medical College, New York. Dr. Aktiar reported having no relevant financial disclosures.