Accelerated intensity-modulated radiotherapy to breast in prone position: dosimetric results

PURPOSE: To report the physics and dosimetry results of a trial of accelerated intensity-modulated radiotherapy to the whole breast with a concomitant boost to the tumor bed in patients treated in the prone position. METHODS AND MATERIALS: Patients underwent computed tomography planning and treatment in the prone position on a dedicated treatment platform. The platform has an open aperture on the side to allow for the index breast to fall away from the chest wall. Noncontrast computed tomography images were acquired at 2.5- or 3.75-mm-thick intervals, from the level of the mandible to below the diaphragm. A dose of 40.5 Gy was delivered to the entire breast at 2.7-Gy fractions in 15 fractions. An additional dose of 0.5 Gy was delivered as a concomitant boost to the lumpectomy site, with a 1-cm margin, using inverse planning, for a total dose of 48 Gy in 15 fractions. No more than 10% of the heart and lung volume was allowed to receive >18 and >20 Gy, respectively. RESULTS: Between September 2003 and August 2005, 91 patients were enrolled in the study. The median volume of heart that received > or =18 Gy was 0.5%, with a maximal value of 4.7%. The median volume of ipsilateral lung that received > or =20 Gy was 0.8%, with a maximum of 7.2%. CONCLUSION: This technique for whole breast radiotherapy is feasible and enables an accelerated regimen in the prone position while sparing the lung and heart.     

Stereotactic radiotherapy for primary lung cancer and pulmonary metastases: a noninvasive treatment approach in medically inoperable patients

PURPOSE: The clinical results of dose escalation using stereotactic radiotherapy to increase local tumor control in medically inoperable patients with Stage I-II non-small-cell lung cancer or pulmonary metastases were evaluated. METHODS AND MATERIALS: Twenty patients with Stage I-II non-small-cell lung cancer and 41 patients with 51 pulmonary metastases not amenable to surgery were treated with stereotactic radiotherapy at 3 x 10 Gy (n = 19), 3 x 12-12.5 Gy to the planning target volume enclosing 100%-isodose, with normalization to 150% at the isocenter; n = 26) or 1 x 26 Gy to the planning target volume enclosing 80%-isodose (n = 26). The median follow-up was 11 months (range, 2-61 months) for primary lung cancer patients and 9 months (range, 2-37 months) for patients with metastases. RESULTS: The actuarial local control rate was 92% for lung cancer patients and 80% for metastasis patients > or =1 year after treatment and was significantly improved by increasing the dose from 3 x 10 Gy to 3 x 12-12.5 Gy or 1 x 26 Gy (p = 0.038). The overall survival rate after 1 and 2 years was 52% and 32%, respectively, for lung cancer patients and 85% and 33%, respectively, for metastasis patients, impaired because of systemic disease progression. After 12 months, 60% of patients with primary lung cancer and 35% of patients with pulmonary metastases were without systemic progression. No severe acute or late toxicity was observed, and only 2 patients (3%) developed symptomatic Grade 2 pneumonitis, which was successfully treated with oral steroids. CONCLUSION: Stereotactic radiotherapy for lung tumors offers a very effective treatment option locally without significant complications in medically impaired patients who are not amenable to surgery. Patient selection is important, because those with a low risk of systemic progression are more likely to benefit from this approach.     

三维适形放射治疗常规外照射后复发的非小细胞肺癌

目的：研究三维适形放射治疗常规放射治疗后复发的非小细胞肺癌可行性，观察近期疗效及早期并发症的发生率。方法：2000年10月至2001年2月，12例非小细胞肺癌疗后复发病例，由美国CMS公司2．6．1三维治疗计划系统设计放射治疗计划，剂量体积直方图（DVH）评价和优化放射治疗计划，体部固定装置及多叶光栏技术实施适形放射治疗。计划靶区为临床所见肿瘤区外放1．0－1．5cm，计划照射剂量为40－60Gy,2.5-3.0Gy/次，1次／d,5d/周。照射方法为固定野、非共面野或旋转弧。计划靶区体积（PTV）中位体积为295cm^3(76.4-512.4cm^3)。按美国放射肿瘤学协作组（RTOG）和世界卫生组织（WHO）标准观察急性放射反应及近期疗效。结果：12例患者均顺利完成治疗。初次放射治疗至再放射治疗的中位间隔时间为19个月（12－32个月），再放射治疗肿瘤中位剂量51．2Gy(42.0-67.5Gy)。近期疗效为完全缓解（CR）8．3％（1／12），部分缓解（PR）66．7％（8／12），无变化（NR）25．0％（3／12），进展（PD）0％（0／12），总有效率为75．0％（9／12）。根据PTOG分级，急性放射性食管炎发生率1－2级16．7％（2／12），3级0％（0／12）；急性放射性肺炎发生率1－2级16．7％（2／12），3级0％（0／12）；骨髓抑制发生率1－2级8．3％（1／12）；3级0％（0／12）；心脏损伤发生率1－2级16．7％（2／12），3级0％（0／12）。12例患者的中位随访期为5个月（3－7个月），随访率为100％。结论：三维适形放射治疗后复发的非小细胞肺癌有较好的近期疗效，早期并发症较低，能为患者耐受，晚期并发症的发生率及远期疗效有待进一步观察。     

Promising clinical outcome of stereotactic body radiation therapy for patients with inoperable Stage I/II non-small-cell lung cancer

PURPOSE: To evaluate the efficacy and toxicity of hypofractionated stereotactic body radiotherapy in patients with Stage I/II non-small-cell lung cancer. METHODS AND MATERIALS: Forty-three patients with inoperable Stage I/II non-small-cell lung cancer underwent treatment prospectively using the stereotactic gamma-ray whole-body therapeutic system (body gamma-knife radiosurgery) with 30 rotary conical-surface Co(60) sources focused on the target volume. Low-speed computed tomography simulation was conducted, which was followed by three-dimensional conformal radiotherapy planning. A total dose of 50 Gy was delivered at 5 Gy/fraction to the 50% isodose line covering the planning target volume, whereas a total dose of 70 Gy was delivered at 7 Gy/fraction to the gross target volume. The median follow-up duration was 27 months. RESULTS: Three to 6 months after treatment, the complete response rate for body-gamma knife radiosurgery was 63%, and the overall response rate was 95%. The 1-year, 2-year, and 3-year local control rates were all 95% in all patients. The 1-year, 2-year, and 3-year overall survival rates were 100%, 91%, and 91%, respectively, in patients with Stage I disease and 73%, 64%, and 64%, respectively, in those with Stage II disease. Only 2.3% (1/43) of the patients had Grade 3 pneumonitis. CONCLUSION: Our highly focused stereotactic body radiotherapy method resulted in promising local control and survival with minimal toxicity.     

早期乳腺癌保乳术后4种放疗技术的剂量参数比较

目的：比较早期乳腺癌保乳术后常规切线野（TW）、野中野调强（FIF - IMRT）、切线逆向调强（T -IMRT）和容积调强（VMAT）4种放射治疗技术的靶区和危及器官的剂量参数。方法：15例左侧早期（pT1-2 N0 M0）乳腺癌患者保乳术后接受放疗。CT 模拟定位扫描后勾画靶区和危及器官,在同一患者 CT 影像上分别做 TW、FIF - IMRT、T - IMRT 和 VMAT 4种治疗计划设计。PTV 剂量为50Gy,V47.5≥95%。4种计划的剂量限制相同。在剂量-体积直方图中读取4种计划靶区剂量的分布参数,心脏、双侧肺脏及对侧乳腺受照剂量和体积,对各参数的均数进行比较,并比较4组平均机器跳数差异。结果：4种计划都满足 V47.5≥95%。VMAT 与 T - IMRT、FIF - IMRT 和 TW 计划相比,明显提高了靶区适行指数（CI,P ﹤0.05）。VMAT、T - IMRT和 FIF - IMRT 与 TW 相比,明显改善了靶区均匀性指数（HI,P ﹤0.05）。VMAT 增加了危及器官（心脏和同侧肺脏）V 5、V10和 V20的受照射体积,但是没有增加﹥ V30的照射体积。VMAT 明显增加了右侧乳腺和右侧肺脏照射剂量（P ﹤0.05）,T - IMRT 和 FIF - IMRT 明显降低了右侧乳腺和右侧肺脏照射剂量（P ﹤0.05）。VMAT 与T - IMRT、FIF - IMRT 和 TW 相比,明显增加了机器跳数（P ﹤0.05）。结论：早期乳腺癌保乳术后放射治疗4种计划比较,VMAT 明显提高了靶区的适行性和均匀性,增加了正常组织的受照射剂量和机器跳数,延长了治疗时间。T - IMRT 和 FIF - IMRT 也提高了靶区的适行性和均匀性,降低了正常组织的受照射剂量。     

Three-dimensional photon dosimetry: a comparison of treatment of the intact breast in the supine and prone position

PURPOSE: To compare the adequacy of target coverage, dose homogeneity, and volume of normal tissue irradiated in treatment of the intact breast in the supine and prone position. METHODS AND MATERIALS: Fifteen patients with early breast cancer who presented for treatment to the intact breast after excisional biopsy were studied. A specially designed device was used for the prone setup to displace the contralateral breast away from the tangential field borders. Treatment planning computed tomography was performed for each patient in both the supine and prone positions. Dosimetric data were obtained in both positions and isodose distributions were calculated for each patient in both positions. RESULTS: The volume of breast receiving greater than 5% of the prescribed dose was significantly less in the prone position. Medial wedges were either not used or their angles were reduced for all patients in the prone position compared with the supine position. The average volume of lung receiving >10 Gy and >20 Gy was significantly less in the prone positions. The volume of heart irradiated at critical dose levels did not vary consistently in the prone and supine positions. The integral dose delivered to the contralateral breast was not significantly different. CONCLUSION: Treatment of the intact breast in the prone position may result in improved dose homogeneity within the target volume as well as sparing of normal lung compared with treatment in the conventional supine position.     

立体定向放射治疗早期中央型肺癌的疗效观察

  目的   探讨立体定向放射治疗早期中央型肺癌的临床疗效及不良反应。   方法   回顾性分析2006年11月至2010年12月立体定向放射治疗的17例分期为T1/T2N0M0的中央型非小细胞肺癌患者, 根据肿瘤位置及分期, 给予不同的分割剂量, 中位处方剂量56(48~60)Gy, 中位分割次数5(3~10)次, 中位治疗体积46.2(13.8~92.2)mL。   结果   治疗后3个月疗效评价: 9例病变完全缓解, 7例部分缓解, 1例稳定, 治疗反应率94.1%;中位随访期19.5(4~64)个月, 中位生存时间43个月, 1、2年局控率、无进展生存、总生存分别为100%、87.5%, 80.8%、67.3%和82.4%、68.4%。随访期内见呼吸困难、疲劳、肺不张等不良反应, 其中3级不良反应1例, 未见4~5级不良反应。   结论   根据肿瘤位置及分期不同, 给予不同的剂量分割模式, 立体定向放疗可以较好的应用于早期中央型肺癌的治疗。      

Three-dimensional conformal simultaneously integrated boost technique for breast-conserving radiotherapy

PURPOSE: To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. METHODS AND MATERIALS: Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. RESULTS: PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving > or =107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving > or =95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. Conclusion: The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity.     

Prone breast radiotherapy in early-stage breast cancer: a preliminary analysis

PURPOSE: Women with large breasts have marked dose inhomogeneity and often an inferior cosmetic outcome when treated with breast conservation compared to smaller-sized patients. We designed a prone breast board, which both minimizes breast separation and irradiated lung or heart volume. We report feasibility, cosmesis, and preliminary local control and survival for selected women with Stage 0-II breast cancer. MATERIALS AND METHODS: Fifty-six patients with clinical Stage 0-II breast cancer were treated with lumpectomy and breast irradiation utilizing a prototype prone breast board. A total of 59 breasts were treated. Indications for treatment in the prone position were large or pendulous breast size (n = 57), or a history of cardiopulmonary disease (n = 2). The median bra size was 41D (range, 34D-44EE). Cosmesis was evaluated on a 1-10 (worst-to-best) scale. RESULTS: Acute toxicity included skin erythema (80% of patients experienced Grade I or Grade II erythema), breast edema (72% of patients experienced mild edema), pruritus (20% of patients), and fatigue (20% of patients reported mild fatigue). One patient required a treatment break. The only late toxicity was related to long-term cosmesis. The mean overall cosmesis score for 53 patients was 9.37 (range, 8-10). Actuarial 3- and 5-year local control rates are 98%. Actuarial overall survival at 3 and 5 years are 98% and 94%. CONCLUSION: Our data indicate that treating selected women with prone breast radiotherapy is feasible and tolerated. The approach results in excellent cosmesis, and short-term outcome is comparable to traditional treatment techniques. This technique offers an innovative alternative to women who might not otherwise be considered candidates for breast conservation.     

Single fraction partial breast irradiation in prone position

The purpose of this work is to introduce a new treatment approach and technique for partial breast irradiation in only one session to patients in prone position by using a dedicated positioning device. The patients were treated on a home-made treatment table top that allows the breast to hang down. A particular immobilization system was introduced in order to assure the reproducibility of patient positioning between the CT acquisition session and the treatment session. The clinical target volume (CTV) was outlined according to surgical clips position and/or tumor location on preoperative mammography. Because of negligible movement due to respiration, only an additional margin of 3 mm was added to obtain the planning target volume (PTV). Based on radiobiological calculations, a dose of 21 Gy was prescribed to PTV. The tumor bed was treated with 3D-CRT technique by using 5 fields and rotating the table while the gantry was approximately 90 or 270 degrees. Thirty patients were enrolled for this study chosen in conformity to an approved clinical protocol. The average percentage of PTV volume enclosed in the 90% and 95% of prescribed dose were 99.9 and 98.6% respectively, while only 3.4% of PTV volume received more than 105% of prescribed dose. Dose to 3% of skin volume was, on average, 15.2 Gy. In 97% of patients, less than 50% of the ipsilateral breast received a dose greater than half the prescribed dose. Mean doses to lungs, heart and contralateral breast were negligible. With a median follow-up of 9 months, no important early toxicity was observed both for skin and breast tissue. The treatment of breast tumor bed in prone position in only one session by using the 3D-CRT is technically feasible and seems to be a promising alternative to other accelerated partial breast irradiation techniques.     

Phase I-II trial of prone accelerated intensity modulated radiation therapy to the breast to optimally spare normal tissue

PURPOSE: To report the clinical feasibility of a trial of accelerated whole-breast intensity modulated radiotherapy, with the patient in prone position, optimally to spare the heart and lung. PATIENTS AND METHODS: Patients with stages I or II breast cancer, excised by breast conserving surgery with negative margins, were eligible for this institutional review board-approved prospective trial. Computed tomography simulation was performed with the patient prone on a dedicated breast board, in the exact position used for treatment. A dose of 40.5 Gy, delivered at 2.7 Gy in 15 fractions, was prescribed to the index breast with an additional concomitant boost of 0.5 Gy delivered to the tumor bed, for a total dose of 48 Gy to the lumpectomy site. Physics constraints consisted of limiting 5% of the heart volume to receive > or = 18 Gy and < or = 10% of the ipsilateral lung volume to receive > or = 20 Gy. RESULTS: Between September 2003 and August 2005, 91 patients were enrolled on the study. Median length of follow-up was 12 months (range, 1 to 28 months). In all patients the technique was feasible and heart and lung sparing was achieved as prescribed by the protocol. Acute toxicities consisting mostly of reversible grades 1-2 skin dermatitis (67%) and fatigue (18%) occurred in 75 patients. One patient sustained a regional recurrence rapidly followed by distant metastases. CONCLUSION: Accelerated whole breast intensity modulated radiotherapy in the prone position is feasible and it permits a drastic reduction in the volume of lung and heart tissue exposed to significant radiation.     

Dosimetric and toxicity comparison between prone and supine position IMRT for endometrial cancer

PURPOSE: To determine the dosimetric and toxicity differences between prone and supine position intensity-modulate radiotherapy in endometrial cancer patients treated with adjuvant radiotherapy. METHODS: Forty-seven consecutive endometrial cancer patients treated with adjuvant RT were analyzed. Of these, 21 were treated in prone position and 26 in the supine position. Dose-volume histograms for normal tissue structures and targets were compared between the two groups. Acute and chronic toxicity were also compared between the cohorts. RESULTS: The percentage of volume receiving 10, 20, 30, 40, 45, and 50 Gy for small bowel was 89.5%, 69%, 33%, 12.2%, 5%, and 0% in the prone group and 87.5%, 62.7%, 26.4%, 8%, 4.3%, and 0% in the supine group, respectively. The difference was not statistically significant. The dose-volume histograms for bladder and rectum were also comparable, except for a slightly greater percentage of volume receiving 10 Gy (1.5%) and 20 Gy (5%) for the rectum in the prone group. Acute small bowel toxicities were Grade 1 in 7 patients and Grade 2 in 14 patients in the prone group vs. Grade 1 in 6 patients and Grade 2 in 19 patients in the supine group. Chronic toxicity was Grade 1 in 7 patients and Grade 3 in 1 patient in the prone group and Grade 1 in 5 patients in the supine group. CONCLUSION: These preliminary results suggest that no difference exists in the dose to the normal tissue and toxicity between prone and supine intensity-modulated radiotherapy for endometrial cancer. Longer follow-up and more outcome studies are needed to determine whether any differences exist between the two approaches.     

Dosimetric correlations of acute esophagitis in lung cancer patients treated with radiotherapy

PURPOSE: To evaluate the factors associated with acute esophagitis in lung cancer patients treated with thoracic radiotherapy. METHODS AND MATERIALS: We examined 35 patients with non-small-cell lung cancer (n = 27, 77%) and small-cell lung cancer (n = 8, 23%) treated with thoracic radiotherapy between February 2003 and November 2004. The median patient age was 70 years (range, 50-83 years). The disease stage was Stage I in 2 patients (6%), Stage II in 1 (3%), Stage IIIa in 10 (28%), Stage IIIb in 9 (26%), and Stage IV in 9 (26%); 4 patients (11%) had recurrent disease after surgery. A median dose of 60 Gy (range, 50-67 Gy) was given to the isocenter and delivered in single daily fractions of 1.8 or 2 Gy. With heterogeneity corrections, the median given dose to the isocenter was 60.3 Gy (range, 49.9-67.2 Gy). Of the 35 patients, 30 (86%) received concurrent chemotherapy consisting of a platinum agent, cisplatin or carboplatin, combined with paclitaxel in 18 patients (52%), irinotecan hydrochloride in 7 (20%), vincristine sulfate and etoposide in 2 (5%), vinorelbine ditartrate in 1 (3%), etoposide in 1 (3%), and docetaxel in 1 patient (3%). Three of these patients underwent induction therapy with cisplatin and irinotecan hydrochloride, administered before thoracic radiotherapy, and concurrent chemotherapy. Esophageal toxicity was graded according to the Radiation Therapy Oncology Group criteria. The following factors were analyzed with respect to their association with Grade 1 or worse esophagitis by univariate and multivariate analyses: age, gender, concurrent chemotherapy, chemotherapeutic agents, maximal esophageal dose, mean esophageal dose, and percentage of esophageal volume receiving >10 to >65 Gy in 5-Gy increments. RESULTS: Of the 35 patients, 25 (71%) developed acute esophagitis, with Grade 1 in 20 (57%) and Grade 2 in 5 (14%). None of the patients had Grade 3 or worse toxicity. The most significant correlation was between esophagitis and percentage of esophageal volume receiving >35 Gy on univariate (p = 0.002) and multivariate (p = 0.018) analyses. CONCLUSION: The percentage of esophageal volume receiving >35 Gy was the most statistically significant factor associated with mild acute esophagitis.     

Early Toxicity and Patient-Reported Cosmetic Outcomes in Patients Treated With Adjuvant Proton-Based Radiotherapy After Breast-Conserving Surgery

IntroductionTo evaluate the dosimetric data, early toxicity, and patient-reported cosmetic outcomes in breast cancer patients treated with adjuvant proton-based radiotherapy (RT) after breast-conserving surgery.Materials and MethodsWe performed a retrospective review of our institutional database to identify breast cancer patients treated with breast-conserving surgery followed by proton-based RT from 2015 to 2020. Patient-reported cosmetic outcomes were graded as excellent, good, fair, or poor. Early toxicity outcomes were graded by the treating physician during treatment. Dose-volume histograms were reviewed to obtain dosimetry data.ResultsWe identified 21 patients treated with adjuvant proton-based RT. Median whole breast dose delivered was 46.8 Gy (range, 40.0-50.4 Gy). Target volumes included the regional lymph nodes in 17 patients (81%). Seventeen patients (81%) received a lumpectomy boost. The median planning target volume V95 was 94% (range, 77%-100%), V100 71% (range, 60%-97%), V110 2% (range 0%-18%), and median max point dose was 115% (range, 105%-120%). The median ipsilateral breast V105 was 367.3 cc (range, 0-1172 cc) and V110 was 24.1 cc (range, 0-321.3 cc). Grade 2 and 3 dermatitis occurred in 62% and 14% of patients, respectively. Grade 2 and 3 pain was reported by 33% and 10% of patients, respectively. Median follow-up at the time of cosmetic evaluation was 27 months (range, 5-42 months). Four patients (21%) reported fair cosmetic outcome and 15 patients (79%) reported good or excellent cosmetic outcome. No poor cosmesis was reported.ConclusionAdjuvant proton-based radiotherapy after breast-conserving surgery is well tolerated with acceptable rates of acute toxicities and a high rate of good-to-excellent patient-reported cosmetic outcomes.     

Long-term clinical outcomes of whole-breast irradiation delivered in the prone position

PURPOSE: The aim of this study was to evaluate retrospectively the effectiveness and toxicity of post-lumpectomy whole-breast radiation therapy delivered with prone positioning. METHODS AND MATERIALS: Between September 1992 and August 2004, 245 women with 248 early-stage invasive or in situ breast cancers were treated using a prone breast board. Photon fields treated the whole breast to 46 to 50.4 Gy with standard fractionation. The target volume was clinically palpable breast tissue; no attempt was made to irradiate chest wall lymphatics. Tumor bed boosts were delivered in 85% of cases. Adjuvant chemotherapy and hormonal therapy were administered to 42% and 62% of patients, respectively. RESULTS: After a median follow-up of 4.9 years, the 5 year actuarial true local and elsewhere ipsilateral breast tumor recurrence rates were 4.8% and 1.3%, respectively. The 5-year actuarial rates of regional nodal recurrence and distant metastases were 1.6% and 7.4%. Actuarial disease-free, disease-specific, and overall survival rates at 5 years were 89.4%, 97.3%, and 93%, respectively. Treatment breaks were required by 2.4% of patients. Grade 3 acute dermatitis and edema were each limited to 2% of patients. Only 4.9% of patients complained of acute chest wall discomfort. Chronic Grade 2 to 3 skin and subcutaneous tissue toxicities were reported in 4.4% and 13.7% of patients, respectively. CONCLUSIONS: Prone position breast radiation results in similar long-term disease control with a favorable toxicity profile compared with standard supine tangents. The anatomic advantages of prone positioning may contribute to improving the therapeutic ratio of post-lumpectomy radiation by improving dose homogeneity and minimizing incidental cardiac and lung dose.     

适形放射治疗Ⅱ-Ⅲ期非小细胞肺癌初步报道

目的：研究三维适形放射治疗非小细胞肺癌(NSCLC)的疗效、副反应及患者的耐受性。方法：2000年10月～2001年7月，25例不能手术的Ⅱ-Ⅲ期非小细胞肺癌采用常规全纵隔或半纵隔 患侧肺门 原发病灶前后两野对穿外照射，照射肿瘤的剂量达8MV-X DT40～41．4Gy／20～23次／4～4．4周后，由CMS公司FOCUS2．6．1三维治疗计划系统设计、DVHs评价和优化适形治疗计划。计划靶区为临床靶区外放1．0～1．5cm，计划适形照射总剂量为25～30Gy，2．5～3Gy／次，1次／天，5天／周，肺作不均质密度校正，照射方法均为非共面野。按RTOG和WHO标准观察急性放射反应及近期疗效，评价患者的耐受性。结果：25例患者均顺利完成治疗，肿瘤中位剂量70．12Gy(62．45Gy～71．40Gy)。近期疗效为CR16．0％(4／25)，PR56．0％(14／25)，NC20．0％(5／25)，PD8．0％(2／25)，总有效率为72．0％(18／25)。根据RTOG分级，急性放射性食管炎1～2级24．0％(6／25)，3级4．0％(1／25)；急性放射性肺炎1～2级16．0％(4／25)，3级4．0％(1／25)；骨髓抑制1～2级16．0％(4／25)；心脏损伤1～2级12．0％(3／25)；随访至2002年7月，死亡7例，一年生存率75．15％。25例患者的中位随访期为14个月(6～18个月)，随访率为96％。结论：由于提高了分割量及总剂量，三维适形放射治疗不能手术的非小细胞肺癌可取得较好的近期疗效，并且经剂量-体积直方图(DVHs)优化治疗计划，减少了正常组织的照射剂量，使治疗能为患者耐受。由于样本较小，病例仍在进一步累积中，晚期并发症的发生率及远期疗效有待进一步观察。     

CT-targeted irradiation of the breast and internal mammary lymph nodes using a 5-field technique

PURPOSE: To develop an effective and resource-efficient radiotherapy technique to treat the breast and regional nodes, including the ipsilateral internal mammary nodes. METHODS AND MATERIALS: Eighty female patients who underwent MRI scans for a variety of indications had coronal, T1-weighted images of the chest performed to determine the position of the internal mammary chain (IMC). Based on these results, a 5-field treatment technique was developed that would include the breast, supraclavicular fossa, and ipsilateral IMC, while maintaining a low dose to the heart, lungs, and contralateral breast. This technique was implemented in a cohort of 13 patients. RESULTS: The lateral position of the right and left IMC were measured in three cephalo-caudad positions: at the clavicular heads, upper manubrium, and midsternum (at the 2nd/3rd rib interspace). The mean lateral separation between the right and left IMC chains at each level (and 95% confidence interval) at each level were 5.8 cm (4.67-7.00), 5.6 cm (4.49-6.73), and 5.9 cm (4.66-7.19), respectively. Treatment was delivered to 13 patients using a 5-field technique, with tangential photon fields for the breast, anterior and posterior supraclavicular/axillary field, and a matching anterior electron field. Three-dimensional treatment planning of a representative case confirmed adequate coverage of the planning target volume (PTV). The median dose to the whole heart was 10 Gy, and 20% of the ipsilateral lung received more than 20 Gy. Seven of the 13 patients treated experienced moist desquamation at the junction of the electron field and breast tangents, and 1 patient had persistent ulceration at 3 months' follow-up. CONCLUSION: The 5-field technique described in this paper provides good coverage to the breast and regional nodes with acceptable toxicity, and without requiring three-dimensional treatment planning or intensity-modulated radiotherapy techniques.     

Influence of patient positioning on dose-volume histogram and normal tissue complication probability for small bowel and bladder in patients receiving pelvic irradiation: a prospective study using a 3D planning system and a radiobiological model

Purpose: A prospective study was undertaken to evaluate the influence of patient positioning (prone position using a belly board vs. supine position) on the dose-volume histograms (DVHs) of organs of risk, and to analyze its possible clinical relevance using radiobiological models.

Methods and Materials: From November 1996 to August 1997 a computed tomography (CT) scan was done in the prone position using a belly board and in supine position in 20 consecutive patients receiving postoperative pelvic irradiation because of rectal cancer. Using a three-dimensional (3D) planning system (Helax, TMS®) the DVH for small bowel, bladder, a standard planning target volume (PTV) of postoperative irradiation of rectal cancer, the intersection of volume of PTV and small bowel (PTV ∩ V_SB), respectively, of PTV and bladder (PTV ∩ V_B) were defined in each axial CT slice. The normal tissue complication probability (NTCP) was determined by the radiobiological model of Lyman and Kutcher using the tolerance data of Emami. For evaluation of late toxicity /β ratio was 2.5; for evaluation of acute toxicity, it was 10. Total dose was 50.4 Gy (1.8 Gy/fraction) (ICRU 50).

Results: Using the prone position compared to the supine position, the median volume of PTV ∩ V_B was reduced by 18.5 cm³ (62%). Median dose (related to the reference dose) to the bladder was 44.5% (22.4 Gy) in prone and 66.05% (33.3 Gy) in supine position (p < 0.001). Median V_B within the 90% (45.4 Gy), 80% (40.3 Gy), 60% (30.2 Gy), and 40% (20.2 Gy) isodose was significantly lower in the prone position when compared to the supine position. Using the radiobiological models, however, there was no difference of NTCP between prone position or supine position. In the prone position, median volume of PTV ∩ V_SB was reduced by 32.5 cm³ (54%). The median dose to small bowel was 30.85% (15.4 Gy) in the prone position and 47.35% (23.9Gy) in the supine position (p < 0.001). Significant differences between prone and supine position were found for median V_SB within the 90% (45.4 Gy), 80% (40.3 Gy), 60% (30.2 Gy), and 40% (20.2 Gy) isodose. According to the method of Lyman, median NTCP of small bowel was significant lower in prone than in supine position.

Conclusion: The prone position with a standard belly board should be the standard positioning technique for patients receiving adjuvant postoperative radiation therapy following surgery of rectal cancer. Both irradiated volume and total dose to the organs of risk can be reduced significantly. As a consequence of this, radiation induced toxicity will be minimized.     

Intensity-modulated radiotherapy for resected mesothelioma: the Duke experience

PURPOSE: To assess the safety and efficacy of intensity-modulated radiotherapy (IMRT) after extrapleural pneumonectomy for malignant pleural mesothelioma. METHODS AND MATERIALS: Thirteen patients underwent IMRT after extrapleural pneumonectomy between July 2005 and February 2007 at Duke University Medical Center. The clinical target volume was defined as the entire ipsilateral hemithorax, chest wall incisions, including drain sites, and involved nodal stations. The dose prescribed to the planning target volume was 40-55 Gy (median, 45). Toxicity was graded using the modified Common Toxicity Criteria, and the lung dosimetric parameters from the subgroups with and without pneumonitis were compared. Local control and survival were assessed. RESULTS: The median follow-up after IMRT was 9.5 months. Of the 13 patients, 3 (23%) developed Grade 2 or greater acute pulmonary toxicity (during or within 30 days of IMRT). The median dosimetric parameters for those with and without symptomatic pneumonitis were a mean lung dose (MLD) of 7.9 vs. 7.5 Gy (p = 0.40), percentage of lung volume receiving 20 Gy (V(20)) of 0.2% vs. 2.3% (p = 0.51), and percentage of lung volume receiving 5 Gy (V(20)) of 92% vs. 66% (p = 0.36). One patient died of fatal pulmonary toxicity. This patient received a greater MLD (11.4 vs. 7.6 Gy) and had a greater V(20) (6.9% vs. 1.9%), and V(5) (92% vs. 66%) compared with the median of those without fatal pulmonary toxicity. Local and/or distant failure occurred in 6 patients (46%), and 6 patients (46%) were alive without evidence of recurrence at last follow-up. CONCLUSIONS: With limited follow-up, 45-Gy IMRT provides reasonable local control for mesothelioma after extrapleural pneumonectomy. However, treatment-related pulmonary toxicity remains a significant concern. Care should be taken to minimize the dose to the remaining lung to achieve an acceptable therapeutic ratio.     

Dose and volume reduction for normal lung using intensity-modulated radiotherapy for advanced-stage non-small-cell lung cancer

PURPOSE: To investigate dosimetric improvements with respect to tumor-dose conformity and normal tissue sparing using intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) for advanced-stage non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: Forty-one patients with Stage III-IV and recurrent NSCLC who previously underwent 3D-CRT were included. IMRT plans were designed to deliver 63 Gy to 95% of the planning target volume using nine equidistant coplanar 6-MV beams. Inverse planning was performed to minimize the volumes of normal lung, heart, esophagus, and spinal cord irradiated above their tolerance doses. Dose distributions and dosimetric indexes for the tumors and critical structures in both plans were computed and compared. RESULTS: Using IMRT, the median absolute reduction in the percentage of lung volume irradiated to >10 and >20 Gy was 7% and 10%, respectively. This corresponded to a decrease of >2 Gy in the total lung mean dose and of 10% in the risk of radiation pneumonitis. The volumes of the heart and esophagus irradiated to >40-50 Gy and normal thoracic tissue volume irradiated to >10-40 Gy were reduced using the IMRT plans. A marginal increase occurred in the spinal cord maximal dose and lung volume >5 Gy in the IMRT plans, which could be have resulted from the significant increase in monitor units and thus leakage dose in IMRT. CONCLUSION: IMRT planning significantly improved target coverage and reduced the volume of normal lung irradiated above low doses. The spread of low doses to normal tissues can be controlled in IMRT with appropriately selected planning parameters. The dosimetric benefits of IMRT for advanced-stage non-small-cell lung cancer must be evaluated further in clinical trials.