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.     

High-dose simultaneously integrated breast boost using intensity-modulated radiotherapy and inverse optimization

PURPOSE: Recently a Phase III randomized trial has started comparing a boost of 16 Gy as part of whole-breast irradiation to a high boost of 26 Gy in young women. Our main aim was to develop an efficient simultaneously integrated boost (SIB) technique for the high-dose arm of the trial. METHODS AND MATERIALS: Treatment planning was performed for 5 left-sided and 5 right-sided tumors. A tangential field intensity-modulated radiotherapy technique added to a sequentially planned 3-field boost (SEQ) was compared with a simultaneously planned technique (SIB) using inverse optimization. Normalized total dose (NTD)-corrected dose volume histogram parameters were calculated and compared. RESULTS: The intended NTD was produced by 31 fractions of 1.66 Gy to the whole breast and 2.38 Gy to the boost volume. The average volume of the PTV-breast and PTV-boost receiving more than 95% of the prescribed dose was 97% or more for both techniques. Also, the mean lung dose and mean heart dose did not differ much between the techniques, with on average 3.5 Gy and 2.6 Gy for the SEQ and 3.8 Gy and 2.6 Gy for the SIB, respectively. However, the SIB resulted in a significantly more conformal irradiation of the PTV-boost. The volume of the PTV-breast, excluding the PTV-boost, receiving a dose higher than 95% of the boost dose could be reduced considerably using the SIB as compared with the SEQ from 129 cc (range, 48-262 cc) to 58 cc (range, 30-102 cc). CONCLUSIONS: A high-dose simultaneously integrated breast boost technique has been developed. The unwanted excessive dose to the breast was significantly reduced.     

Simultaneous integrated boost in breast conserving treatment of breast cancer: A dosimetric comparison of helical tomotherapy and three-dimensional conformal radiotherapy

Background and purpose

To evaluate the dosimetry of helical tomotherapy (HT) and three-dimensional conformal radiotherapy (3D-CRT) in breast cancer patients undergoing whole breast radiation with simultaneous integrated boost (SIB) of the tumor bed.

Material and methods

Thirteen patients with breast cancer treated by lumpectomy and requiring whole breast radiotherapy with tumor bed boost were planned using both HT and 3D-CRT using the field-in-field technique. The whole breast and tumor bed were prescribed 50.68 Gy and 64.4 Gy, respectively, in 28 fractions. Dosimetries for both techniques were compared.

Results

Coverage of the whole breast was adequate with both techniques (V_95% = 96.22% vs. 96.25%, with HT and 3D-CRT, respectively; p = 0.64). Adequate tumor bed coverage was also achieved, although it was significantly lower with HT (V_95% = 97.18% vs. 99.72%; p < 0.001). Overdose of the breast volume outside the tumor bed was significantly lower with HT (V_54.23Gy = 12.47% vs. 30.83%; p < 0.001). Ipsilateral lung V_20Gy (6.34% vs. 10.17%; p < 0.001), V_5Gy (16.54% vs. 18.53%; p < 0.05) and mean dose (4.05 Gy vs. 6.36 Gy; p < 0.001) were significantly lower with HT. In patients with left-sided tumors, heart V_30Gy (0.03% vs. 1.14%; p < 0.05) and mean dose (1.35 Gy vs. 2.22 Gy; p < 0.01) were significantly lower with HT, but not V_5Gy. Contralateral breast V_5Gy (0.27% vs. 0.00%; p < 0.01) and maximum dose were significantly increased with HT.

Conclusions

In breast cancer treated with SIB, both HT and 3D-CRT provided adequate target volume coverage and low heart doses. Tumor bed coverage was slightly lower with HT, but HT avoided unnecessary breast overdosage while improving ipsilateral lung dosimetry.     

Minimising contralateral breast dose in post-mastectomy intensity-modulated radiotherapy by incorporating conformal electron irradiation

Purpose

To assess the potential benefit of incorporating conformal electron irradiation in intensity-modulated radiotherapy (IMRT) for loco-regional post-mastectomy RT.

Patients and methods

Ten consecutive patients that underwent left-sided mastectomy were selected for this comparative planning study. Three-dimensional conformal radiotherapy (3D-CRT) photon-electron dose plans were compared to photon-only IMRT (IMRT_p) and photon IMRT with conformal electron irradiation (IMRT_p/e). The planning target volume (PTV) was prescribed 50 Gy and included the chest wall and the internal mammary and supra-clavicular lymph node regions. It was attempted to minimise dose delivered to heart, lungs and contralateral breast (CB), while maintaining adequate PTV coverage.

Results

All plans complied with objectives for PTV coverage. IMRT_p/e eliminated volumes receiving ?70 Gy (V70) that were present in 3D-CRT at the junction of photon and electron beams. Both IMRT strategies reduced heart V30 significantly below 3D-CRT levels. Mean heart dose with IMRT_p/e was the lowest and was equal to that with 3D-CRT. Minimising heart dose with IMRT_p resulted in irradiated CB volumes much larger than that with 3D-CRT. With IMRT_p/e, CB dose was only slightly increased when compared to 3D-CRT. Mean lung dose values were similar for IMRT and 3D-CRT. With IMRT, lung V20 was smaller, whereas V5 values for heart, lung and CB were higher than those with 3D-CRT.

Conclusions

Incorporation of conformal electron irradiation in post-mastectomy IMRT_p/e enables a heart dose reduction which can only be obtained with IMRT_p when allowing large irradiated volumes in the contralateral breast.     

前列腺癌同步加量放疗dIMRT和RapidArc比较研究

目的 前列腺大分割照射与盆腔常规分割预防照射相结合的同步加量放疗可提高前列腺癌临床疗效,本研究比较固定野动态调强(dynamic intensity modulated radiotherapy,dIMRT)与快速旋转调强(RapidArc)在前列腺癌同步加量放疗中的剂量分布、治疗效率和执行精度的差异,为临床应用提供参考.方法 选取2013-01-04-2013-12-31在中山大学肿瘤防治中心行放疗的10例前列腺癌高危风险患者,靶区包括前列腺、精囊和盆腔淋巴结.以相同的剂量目标和优化参数分别设计9野dIMRT、单弧和双弧RapidArc同步加量治疗计划,分别用9F、1ARC和2ARC表示.比较分析3种计划的靶区剂量学特点,直肠、膀胱、小肠和双侧股骨头等危及器官的受照剂量及体积,机器跳数,治疗时间以及剂量验证通过率.结果 对于PTV1,9F的D2％为(69.37±0.89) Gy,D50％为(66.92±0.63) Gy,HI为0.09±0.02,CI为0.83±0.05;1ARC的D2％为(71.13±1.21) Gy,D50％为(68.50±0.76) Gy,HI为0.12±0.02,CI为0.74±0.07;9F均优于1ARC,差异均有统计学意义,P＜0.05;9F与2ARC的各参数差异均无统计学意义,P＞0.05.对于PTV2,9F的V5％为(99.45±0.78)％,优于1ARC的(99.35±1.28)％,差异有统计学意义,P＜0.05;9F与2ARC各参数的差异均无统计学意义,P＞0.05.对于膀胱Dmean,3组计划差异无统计学意义,P＞0.05;对于直肠V67.5Gy,9F与2ARC的差异无统计学意义,P＞0.05;对于左右股骨头Dmean,1ARC和2ARC低于9F,差异有统计学意义,P＜0.05;各OAR其余评价指标9F均低于1ARC和2ARC,差异均有统计学意义,P＜0.05.1ARC和2ARC相比于9F机器跳数平均减少了70.0％和67.2％,治疗时间平均缩短了81.7％和61.0％.9F、1ARC和2ARC的3％/3 mm标准的γ通过率分别为97.8％、98.9％和99.4％,差异均具有统计学意义,P＜0.05.结论 相比于dIMRT,RapidArc可显著提高治疗效率,其双弧计划具有相仿的靶区覆盖,但对膀胱、直肠和小肠的保护更差,dIMRT更适用于前列腺癌同步加量放射治疗.     

Five year outcomes of hypofractionated simultaneous integrated boost irradiation in breast conserving therapy; patterns of recurrence

In 2005, we introduced hypofractionated 3-dimensional conformal radiotherapy with a simultaneous integrated boost (3D-CRT-SIB) technique after breast conserving surgery. In a consecutive series of 752 consecutive female invasive breast cancer patients (stages I-III) the 5-year actuarial rate for local control was 98.9%. This new technique gives excellent 5-year local control.     

乳腺癌保乳术后同步加量IMRT前瞻性研究

目的 前瞻性评估乳腺癌保乳术后瘤床同步加量IMRT的疗效和不良反应。     

Three-dimensional conformal hypofractionated simultaneous integrated boost in breast conserving therapy: Results on local control and survival

Purpose

To report on local control and survival after breast conserving therapy (BCT) including three-dimensional conformal simultaneous integrated boost irradiation (3D-CRT-SIB) and on the influence of age on outcome.

Patient and methods

For this study, 752 consecutive female breast cancer patients (stages I–III), treated with 3D-CRT-SIB at the University Medical Center Groningen from 2005 to 2008, were retrospectively identified. Median age was 58.4 (range 26–84) years. The SIB fractionation used was: 28 × 1.8 Gy (whole breast) and 28 × 2.3 Gy or 2.4 Gy (tumour bed). Next to outcome, we estimated the effect of age on the recurrence-free period (RFP) by multivariate Cox regression survival analysis.

Results

Median follow-up was 41 (range 3–65) months. Local control was 99.6% at 3 years (6 ipsilateral recurrences). The 3-year locoregional control, RFP and overall survival (OS) rates were 99.2%, 95.5%, and 97.1%, respectively. In multivariate analysis, tumours >2 cm (hazard ratio (HR) 3.11; 95% confidence interval (CI) 1.57–6.17) and triple negativity (HR 3.03; 95% CI 1.37–6.67) and not age were associated with impaired RFP.

Conclusions

At 3 years, the 3D-CRT-SIB technique in BCT results in excellent local control and OS. Age was not a risk factor for any recurrence.     

乳腺癌保乳术后同步推量放疗与常规放疗近期疗效的临床研究

目的 探讨早期乳腺癌保乳术后不同放疗方式的疗效及危及器官受照射体积。方法选取本院2012年6月至2012年12月接受保乳术的早期乳癌患者70例,其中35例行瘤床同步推量放疗（SIB组）,其余35例患者行常规放疗（CRT组）。观察两组患者的放疗反应（急性和晚期皮肤反应、骨髓抑制情况、咽部及消化道反应）,比较两组的美容效果、治疗时间及肿瘤的局部控制情况。应用三维治疗计划系统比较SIB与CRT计划下危及器官的受照射体积。结果 SIB组的急性和晚期皮肤反应的总发生率均高于CRT组,差异有统计学意义（P＜0.05）;SIB组的美容优良率为82.9％（29／35）,而CRT组的美容优良率为77.1％（27／35）,差异无统计学意义（P＞0.05）;SIB组的平均住院时间为（39.74±1.55）天,CRT组为（45.60±2.35）天,SIB组在放射治疗住院时间短于CRT组,差异有统计学意义（P＜0.05）;SIB组较CRT组降低了肺V20,差异有统计学意义（P＜0.05）。至随访截止日期,所有患者均生存,两组局部控制率的差异无统计学意义（P＞0.05）。结论 SIB相比于CRT在早期乳腺癌保乳术后有相当的美容效果及局部控制率。SIB缩短治疗时间,降低了肺受到20 Gy剂量照射时的体积,可推广应用于乳腺癌保乳术后的患者。     

乳腺癌保乳术后同步加量调强放疗的临床疗效

目的:探讨乳腺癌保乳术后同步加量调强放疗的疗效、不良反应及美容效果。方法:2008年~2010年收治乳腺癌保乳术后患者78例,其中38例行瘤床同步加量调强放疗（A组）,剂量分割方案为全乳50Gy/25次（2Gy/次）,瘤床同步加量至60Gy/25次（2.4Gy/次）,总疗程33~35天;40例行常规分割调强放疗（B组）,剂量分割方案为全乳50Gy/25次,后续瘤床推量10Gy/5次（2Gy/次）,总疗程40~42天。应用Kaplan-Meier法生存分析,Log-rank法检验差异。结果:中位随访时间为73个月,随访率为100%。两组5年总生存率均为100%。A组和B组5年局部无复发生存率、无病生存率分别为97.4%、97.5%（P=0.978）;97.4%、95.0%（P=0.589)。A组和B组1、2级急性皮肤反应发生率分别为57.9%、52.5%(P＝0.632); 13.2%、12.5%(P＝0.931);A组和B组的1级皮肤及皮下组织晚期反应发生率分别为15.8%、15.0%（P=0.932）;1级白细胞减少发生率分别为7.9%、10.0%（P=0.745）。A组和B组在放疗前、放疗后3、5年美容效果优良率分别为86.8%、87.5%（P=0.931）;84.2%、85.0%（P=0.932）;81.6%、82.5%（P=0.916）。结论:保乳术后同步加量调强放疗的疗效与常规分割调强放疗相似,美容效果及不良反应相当。     

鼻咽癌旋转调强与固定野调强同步加量计划比较研究

目的 比较旋转调强技术与常规固定野调强技术在鼻咽癌计划中对靶区及危及器官剂量学差异.方法 选取10例同步加量放疗鼻咽癌患者,通过瓦里安Eclipse 8.6计划系统分别制定旋转调强放疗(IMAT)计划和固定野调强放疗(IMRT)计划,运用剂量体积直方图评价两种计划的靶区(PTV、PTV1、PTV2)及危及器官剂量参数、机器跳数(MU)和治疗时间(T).结果 IMAT和IMRT计划的PTV、PTV1、PTV2适形指数均不同,分别为0.71和0.75(Z=-2.32,P＜0.05)、0.54和0.59(Z=-2.56,P＜0.05)、0.71和0.78(Z=-2.52,P＜0.05);均匀指数均相似,分别为10.5和11.2(Z=-0.84,P＞0.05)、13.1和17.1(Z=-1.68,P＞0.05)、14.1和13.3(Z=-1.01,P＞0.05).IMAT和IMRT计划的脑干平均剂量相似,分别为(3512.8±406.2)cGy和(3384.3±361.3)cGy(Z=-1.82,P＞0.05),最大剂量也相似,分别为(5528.1±192.9)cGy和(5727.5±356.3)cGy(Z=-1.12,P＞0.05);脊髓最大剂量不同,分别为(4186.1±8 8.7)cGy和(4390.2±74.9)cGy(Z=-2.38,P＜0.05).两种计划中双侧腮腺平均剂量、腮腺33%体积受照剂量(D33)、D50、D60均相似(P值均＞0.05),正常组织[定义为全身(body)减去PTV,即B-P]受照500 cGy体积占总B-P体积百分比(V5)、V10均也相似(P值均＞0.05),但V15、V20、V25、V30、V35、V40、V45、V50均不同(P值均＜0.05).两种计划的MU不同,MUIMRT=1308±213,MUIMAT=606±96(Z=-2.52,P＜0.05).结论 IMAT计划靶区剂量覆盖与IMRT计划相当,适形度好于IMRT计划;危及器官受照剂量相当,B-P受照剂量明显降低;可减少机器跳数和治疗时间.     

Concomitant intensity modulated boost during whole breast hypofractionated radiotherapy - A feasibility and toxicity study

Background

Breast cancer sensitivity to large fraction size may be enhanced using hypofractionated concomitant boost radiotherapy (CBRT), thereby shortening overall treatment time. This ethics approved, prospective single cohort feasibility study was designed to evaluate the dosimetry and toxicity of CBRT using an intensity-modulated radiotherapy (IMRT) technique, compared with a standard sequential boost technique (SBT).

Methods

Fifteen women (11 right-sided; 4 left-sided) received 42.4 Gy to the whole breast and an additional 10.08 Gy to the tumor bed in 16 daily fractions, using IMRT and standard dose constraints. Each patient was replanned with the SBT, using mixed photon-electrons. Clinical target volume (CTV), dose evaluation volume (DEV), and organs at risk (OAR) dose distributions were compared with the SBT. Toxicity and treatment times were prospectively recorded.

Results

All 15 CBRT plans achieved the desired CTV (V_49.9Gy ? 99%) and DEV (V_49.9Gy ? 95%), coverage of the boost, compared with only 10 (66.7%, p = 0.03), and 12 (80%, p = 0.125) SBT plans, respectively. Ipsilateral lung (p < 0.0001), and heart (right-sided, p = 0.001; left-sided, p = 0.13) doses were lower. Grade 3 acute toxicity occurred in 1 (6.7%) patient. At 1 year, two (13.3%) additional patients had overall grade 2 late toxicity, compared with baseline. No grade 3-4 late toxicity was observed.

Conclusions

CBRT using IMRT improved boost coverage and lowered OAR doses, compared with SBT. Toxicities were acceptable using a daily boost of 3.28 Gy. While resource utilization was greater, overall treatment time was reduced.     

同期推量调强放射治疗脑转移瘤临床分析

目的：探讨脑转移瘤患者采用同期推量调强放疗的近期疗效和毒副作用。方法：120例患者随机分为研究组即同期推量调强放疗组（SIB）和对照组即全脑放疗联合三维适形放疗组（WBRT＋3D—CRT）,每组60例。结果：放疗结束时影像学检查疗效：研究组和对照组完全缓解率（CR）分别为70．0％和46．7％,有显著性差异（P=0．010）。总有效率研究组和对照组分别为90．9％和81．7％,无显著性差异（P=0．191）。1年生存率研究组和对照组分别为68．3％和45．O％,有显著性差异（P=0．007）。急性不良反应发生率研究组和对照组分别为21．7％和18．3％,无显著性差异（P=0．648）。平均住院时间研究组和对照组分别为24天和44天,有显著性差异（P=0．000）。结论：同期推量调强放疗治疗脑转移瘤疗效好,能够改善患者生活质量,延长生存期,毒副作用无增加,而且缩短了治疗疗程。值得临床推广应用。     

Four-week course of radiation for breast cancer using hypofractionated intensity modulated radiation therapy with an incorporated boost

PURPOSE: Standard radiation for early breast cancer requires daily treatment for 6 to 7 weeks. This is an inconvenience to many women, and for some a barrier for breast conservation. We present the acute toxicity of a 4-week course of hypofractionated radiation. METHODS AND MATERIALS: A total of 75 patients completed radiation on a Phase II trial approved by the hospital institutional review board. Eligibility criteria were broad to include any patient normally eligible for standard radiation: age >or=18 years, invasive or in situ cancer, American Joint Committee on Cancer Stage 0 to II, breast-conserving surgery, and any systemic therapy not given concurrently. The median age was 52 years (range, 31-81 years). Of the patients, 15% had ductal carcinoma in situ, 67% T1, and 19% T2; 71% were N0, 17% N1, and 12% NX. Chemotherapy was given before radiation in 44%. Using photon intensity-modulated radiation therapy and incorporated electron beam boost, the whole breast received 45 Gy and the lumpectomy bed 56 Gy in 20 treatments over 4 weeks. RESULTS: The maximum acute skin toxicity by the end of treatment was Grade 0 in 9 patients (12%), Grade 1 in 49 (65%) and Grade 2 in 17 (23%). There was no Grade 3 or higher skin toxicity. After radiation, all Grade 2 toxicity had resolved by 6 weeks. Hematologic toxicity was Grade 0 in most patients except for Grade 1 neutropenia in 2 patients, and Grade 1 anemia in 11 patients. There were no significant differences in baseline vs. 6-week posttreatment patient-reported or physician-reported cosmetic scores. CONCLUSIONS: This 4-week course of postoperative radiation using intensity-modulated radiation therapy is feasible and is associated with acceptable acute skin toxicity and quality of life. Long-term follow-up data are needed. This radiation schedule may represent an alternative both to longer 6-week to 7-week standard whole-breast radiation and more radically shortened 1-week, partial-breast treatment schedules.     

Differences in breast tissue oxygenation following radiotherapy

Tissue perfusion and oxygenation changes following radiotherapy may result from and/or contribute to the toxicity of treatment. Breast tissue oxygenation levels were determined in the treated and non-treated breast 1 year after radiotherapy for breast conserving treatment. Transcutaneous oxygenation varied between subjects in both treated and non-treated breast. Subjects without diabetes mellitus (n = 16) had an average oxygenation level of 64.8 ± 19.9 mmHg in the irradiated breast and an average of 72.3 ± 18.1 mmHg (p = 0.018) at the corresponding location in the control breast. Patients with diabetes (n = 4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast. This study suggests oxygenation levels in normal tissues vary between patients and may respond differently after radiotherapy.