Initial efficacy results of RTOG 0319: three-dimensional conformal radiation therapy (3D-CRT) confined to the region of the lumpectomy cavity for stage I/ II breast carcinoma

Prospective study of once-daily accelerated partial breast irradiation using 3-dimensional conformal external beam radiotherapy for Japanese women: 12-year outcomes, toxicity, and cosmesis

BACKGROUND

To analyze in a prospective study the long-term safety and efficacy of 3-dimensional conformal radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) for Japanese women with early breast cancer.

METHODS

Breast cancer patients with pathological tumor size ≤ 3 cm, age ≥ 20 years, lumpectomy with at least a 5 mm margin, and ≤ 3 positive axillary nodes were eligible. APBI was delivered by 3D-CRT at a dose of 38.5 Gy in 10 fractions over 10 days. The primary endpoints were the frequency and severity of acute and late radiation toxicities, and secondary endpoints were local control, survival, and cosmesis. The sample size was determined based on the incidence of ≥ grade 3 acute and late radiation toxicities, which required 71 enrollments.

RESULTS

Between 2008 and 2010, 73 patients enrolled in this trial. Twelve patients (16%) had 1-3 lymph node metastases. At a median follow-up of 12.6 years (range: 2.7-13.9 years), there were no cases of grade ≥ 3 acute or late toxicity. There were 4 ipsilateral breast tumor recurrence (IBTR) events: 12-year IBTR incidence was 4.4%. The difference in the incidence of IBTR between node-negative and node-positive patients was marginal (1.9% vs. 16.7%, p = 0.055). The majority of patients (94.4% at 2 years, 89.3% at 10 years after enrollment) had excellent/good cosmesis.

CONCLUSIONS

APBI delivered with 3D-CRT is a feasible treatment option for Asian females, but it was indicated that node-positive status might increase IBTR risk.

A systematic review on the techniques, long-term outcomes, and complications of partial breast irradiation after breast-conserving surgery for early-stage breast cancer

To evaluate the efficacy and safety of four techniques of partial breast irradiation (PBI) including interstitial brachytherapy (ISBT), balloon-based brachytherapy (BBT), Intraoperative radiotherapy (IORT) and three-dimensional conformal radiotherapy (3DCRT) in the treatment for early-stage breast cancer patients after breast-conserving surgery. A systematic search was performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed, Embase, Cochrane Library and Web of Science databases. The inclusion criteria were clinical trials and observational studies that reported on outcome measures of principal PBI techniques. The methodological quality of the included research data was assessed using bias risk assessment tool with the Methodological Index for Non-Randomized Studies (MINORS), and the research information were analyzed using data analysis software. Clinical studies were collected from the earliest available date until September 2023. Fifty-one studies were included, with a total sample size of 7708. The results of network meta-analysis (NMA) showed that ISBT can lower the local recurrence (SUCRA: 73.8%). In terms of reducing distant metastasis, 3DCRT may be the best choice (SUCRA: 52.5%). And IORT has the highest 5-year overall survival (SUCRA: 90%). Furthermore, ISBT also has the advantages of lowest risk with fat necrosis (SUCRA: 72.5%), infection (SUCRA: 78.3%) and breast pain (SUCRA: 86.2%). BBT may be the optimal solution for fibrosis (SUCRA: 76.9%) and hyperpigmentation (SUCRA: 66.7%). 3DCRT has lower incidence of telangiectasia (SUCRA: 56.7%) and better cosmetic result (SUCRA: 85%). Postoperative PBI treatment using ISBT after breast-conserving surgery in patients with early-stage breast cancer may be a more valuable choice based on the treatment efficacy and is associated with fewer late side-effects. Large-scale, prospective, long-term studies are warranted to clarify the role of different PBI techniques in selected patients.

Five-Year Outcomes of a Phase 1/2 Trial of Accelerated Partial Breast Irradiation Using Proton Therapy for Women With Stage 0-IIA Breast Cancer

Purpose

We report the results of a phase 1/2 trial of external beam partial breast radiation using proton therapy.

Methods and Materials

Eligible patients included stage 0-IIA breast cancer pTis-T2, N0, and size ≤3 cm. Proton beam radiation was used to deliver 3.85 Gy twice daily to 38.5 Gy. The phase 1 portion determined feasibility based on criteria of successful plan creation, treatment delivery, and acute toxicity grade ≥3 in ≤20% of patients. The phase 2 portion had efficacy goals of acute toxicity grade ≥3 in ≤20% of patients and observing physician-rated cosmesis of excellent or good >85% of patients at 2 years.

Results

From April 2013 to March 2015, there were 12 patients enrolled onto the phase 1 portion, and the preplanned analysis of feasibility was met in all 4 required criteria. From July 2015 through December 2019 there were 28 patients with 29 treated breasts (1 bilateral) enrolled onto the phase 2 portion of the trial out of 45 originally planned. The trial was closed to accrual because of the coronavirus pandemic and not reopened. Thirty-eight breasts were treated with double-scattering and 3 pencil-beam scanning protons. The median follow-up of the 40 patients is 5.4 years (range, 2.3-8.6 years). There was 1 local recurrence. There was no grade ≥3 acute or late toxicity. At baseline all patients had physician-rated cosmesis good or excellent but at 2 years was excellent in 56%, good in 19%, and fair in 25%.

Conclusions

Proton-accelerated partial breast irradiation delivered with a twice-daily fractionation was feasible and associated with very low acute and long-term toxicity. However, the trial did not meet goals for cosmesis outcomes and was closed prematurely. Future study is needed to determine whether pencil-beam scanning protons or different fractionation could improve these outcomes.

Comparison of adverse events in partial- or whole breast radiotherapy: investigation of cosmesis, toxicities and quality of life in a meta-analysis of randomized trials

PURPOSE/OBJECTIVE

Adjuvant whole breast radiotherapy and systemic therapy are part of the current evidence-based treatment protocols for early breast cancer, after breast-conserving surgery. Numerous randomized trials have investigated the therapeutic effects of partial breast irradiation (PBI) compared to whole breast irradiation (WBI), limiting the treated breast tissue. These trials were designed to achieve equal control of the disease with possible reduction in adverse events, improvements in cosmesis and quality of life (QoL). In this meta-analysis, we aimed to investigate the differences between PBI and WBI in side effects and QoL.

MATERIAL/METHODS

We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect-sizes for available acute and late adverse events. Additionally, we evaluated cosmetic outcomes as well as general and breast-specific QoL using the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

Sixteen studies were identified (n = 19,085 patients). PBI was associated with a lower prevalence in any grade 1 + acute toxicity and grade 2 + skin toxicity (OR = 0.12; 95% CI 0.09-0.18; p < 0.001); (OR = 0.16; 95% CI 0.07-0.41; p < 0.001). There was neither a significant difference in late adverse events between the two treatments, nor in any unfavorable cosmetic outcomes, rated by either medical professionals or patients. PBI-technique using EBRT with twice-daily fractionation schedules resulted in worse cosmesis rated by patients (n = 3215; OR = 2.08; 95% CI 1.22-3.54; p = 0.007) compared to WBI. Maximum once-daily EBRT schedules (n = 2071; OR = 0.60; 95% CI 0.45-0.79; p < 0.001) and IORT (p = 0.042) resulted in better cosmetic results grade by medical professionals. Functional- and symptom-based QoL in the C30-scale was not different between PBI and WBI. Breast-specific QoL was superior after PBI in the subdomains of "systemic therapy side effects" as well as "breast-" and "arm symptoms".

CONCLUSION

The analysis of multiple randomized trials demonstrate a superiority of PBI in acute toxicity as well breast-specific quality of life, when compared with WBI. Overall, late toxicities and cosmetic results were similar. PBI-technique with a fractionation of twice-daily schedules resulted in worse cosmesis rated by patients.

A prospective Phase III trial evaluating patient self-reported pain and cosmesis in accelerated partial breast irradiation utilizing 3-D versus intensity-modulated radiotherapy

Purpose/Objective

The primary objective is to examine patient self‐assessment of breast pain and cosmesis between three‐dimensional (3D‐CRT) versus intensity‐modulated radiotherapy (IMRT). The secondary objective is to evaluate any relationship of treatment planning conformality of both cohorts to patient‐assessed pain. Assessments were performed at interim 12, 24, 36, and 48 months with a final 5‐year assessment.

Materials/Methods

In total, 656 patients (3D‐CRT n = 328; IMRT n = 328) were randomly assigned to either IMRT or 3D‐CRT accelerated partial breast radiotherapy to 38.5 Gy in 10 BID 3.85 Gy fractions.

Results

Median follow‐up was 3 years. Multivariate analysis showed that pain severity significantly decreased from baseline to the 12‐month follow‐up visit (<0.001 for both 3D‐CRT and IMRT) in each cohort. There was significantly less pain at 2 (p = 0.002) and 3 years (0.045) in the IMRT arm versus the 3D‐CRT arm when compared to the baseline pain level. There was no difference in patient‐assessed cosmesis at any follow‐up point; however, although MD‐assessed cosmesis showed no difference from years 1 to 4, there was significantly better cosmesis for 3D‐CRT versus IMRT (p = 0.047) at 5 years. There was a significant correlation between a maximum pain score and an increase in the CI₁₀₀ (indicating less conformity) in the IMRT cohort (p < 0.01) and in the IMRT subgroup when the CI₁₀₀ was ≤0.37 cohort arm (p = 0.01).

Conclusion

In the analysis of our primary objective we found that at 2 years, IMRT resulted in more interval improvement in breast pain after baseline when compared to patients treated with 3D‐CRT planning. As seen in our secondary analysis, this may be due to the ability of IMRT to achieve higher conformality (as evidenced by lower CI values) resulting in less fibrosis. There were no differences in patient‐assessed cosmesis or MD‐assessed cosmesis for years 1–4; however, physician‐assessed 5‐year cosmesis was better with 3D‐CRT.

Accelerated partial breast irradiation with 3-dimensional conformal and image-guided intensity-modulated radiotherapy following breast conserving surgery - 7-Year results of a phase II trial

Purpose

To present the 7-year results of accelerated partial breast irradiation (APBI) using three-dimensional conformal (3D-CRT) and image-guided intensity-modulated radiotherapy (IG-IMRT) following breast-conserving surgery (BCS).

Patients and methods

Between 2006 and 2014, 104 patients were treated with APBI given by means of 3D-CRT using 3–5 non-coplanar, isocentric wedged fields, or IG-IMRT using kV-CBCT. The total dose of APBI was 36.9 Gy (9 × 4.1 Gy) using twice-a-day fractionation. Survival results, side effects and cosmetic results were assessed.

Results

At a median follow-up of 90 months three (2.9%) local recurrences, one (0.9%) regional recurrence and two (1.9%) distant metastases were observed. The 7-year local (LRFS), recurrence free survival was 98.9%. The 7-year disease-free (DFS), metastases free (MFS) and overall survival (OS) was 94.8%, 97.9% and 94.8%, respectively. Late side effects included G1 skin toxicity in 15 (14.4%), G1, G2, and G3 fibrosis in 26 (25%), 3 (2.9%) and 1 (0.9%) patients respectively. Asymptomatic (G1) fat necrosis occurred in 10 (9.6%) patients. No ≥ G2 or higher late side effects occurred with IMRT. The rate of excellent/good and fair/poor cosmetic results was 93.2% and 6.8%, respectively.

Conclusion

7-year results of APBI with 3D-CRT and IG-IMRT are encouraging. Toxicity profile and local tumor control are comparable to other series using multicatheter interstitial brachytherapy. Therefore, these external beam APBI techniques are valid alternatives to whole breast irradiation and brachytherapy based APBI.

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Phase II APBI trial using 3D-CRT or IG-IMRT.

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Twice-a-day fractionation, with a total dose of 36.9 Gy (9 × 4.1Gy).

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No Grade 2 or worst late side effects with IG-IMRT at median follow up of 90 months.

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These APBI techniques are valid alternatives to WBI or brachytherapy based APBI.

Who are the optimal candidates for partial breast irradiation?

At the 2017 St. Gallen International Expert Consensus Conference on the Primary Therapy for Early Breast Cancer, the consensus panel recognized "partial breast irradiation as an option for women meeting the low-risk criteria put forward by the American Society for Radiation Oncology/European Society for Radiotherapy and Oncology (ASTRO/ESTRO) guideline," although acknowledging that there was less evidence for this approach. Partial breast irradiation is defined as irradiation localized to the surgical resection cavity only as opposed to the entire breast. Accelerated partial breast irradiation (APBI) involves intensive treatment in a short time period. The methods vary, and three available APBI options are brachytherapy, external beam and intra-operative irradiation. The long-term follow-up results from two large-scale, well-designed phase III randomized clinical trials have been released. However, further discussion of the optimal treatment candidates and delivery method is needed before the clinical application of APBI as a mainstream breast conservation treatment.

Long-Term Results of Partial Breast Irradiation After Breast-Conserving Surgery for Early Stage Breast Cancer: A Prospective Phase II Trial in China

Background

Partial breast radiotherapy (PBI) has emerged as an option after breast-conserving surgery for early stage breast cancer patients.

Methods

A total of 55 patients with early stage breast cancer between 2009 and 2013 were enrolled in this single-institutional phase II prospective clinical trial. All patients received adjuvant PBI-IMRT after lumpectomy, with the prescription of 48 Gy in 12 fractions at 4 Gy per fraction, 5 days a week. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), the other endpoints were a regional nodal failure (RNF), distant metastasis (DM) rate, disease-free survival (DFS), and overall survival (OS). These endpoints were used to evaluate clinical outcomes. The cosmetic effects and the late toxicity were assessed according to Harvard standard scale and CTCAE 3.0, respectively.

Results

In our cohorts, the median age was 45.60 years old (range 31-65 years) and 29.09% of these patients were post-menopause (n = 16). Most patients were T1 stage (65.45%) or N0 stage (70.91%). 80% of patients were ER-positive, 67.27% PR positive, and 61.82% HER2 negative. At the median follow-up of 9.25 years, RNF was 0% and IBTR occurred in only one patient (1.82%) to the chest wall. Except for one patient (1.82%) had DM to lung and pleura and died from disease progression, the remaining patients were alive at the end of the 10-year follow-up. The 10-year DFS and OS were 94.55 and 98.18%. One patient (1.82%) was diagnosed with endometrial cancer after PBI. Except for 9 patients who declined the cosmetic assessment, the rest of the 46 patients (83.64%) were all rated as good and well-satisfied with the appearance of the irradiated breast. No breast retraction and fibrosis were observed in any of the patients. Additionally, only 4 patients experienced grade 1 late toxicity (7.28%). None had grade 3 or higher late toxicity.

Conclusion

This is the first study to report the 10-year results of PBI after breast-conserving surgery in Chinese patients. Our study suggested that PBI had durable local control and maintained good cosmetic outcomes with minimal late toxicity at long term follow up for the early stage breast cancer patients.

Phase 2 Trial of Accelerated Partial Breast Irradiation (APBI) Using Noninvasive Image Guided Breast Brachytherapy (NIBB)

PURPOSE

Noninvasive image guided breast brachytherapy (NIBB) is a novel approach to delivery of accelerated partial breast irradiation (APBI) that may hold advantages over established techniques. NIBB is not invasive but maintains a high level of precision by using breast immobilization via breast compression and image guidance; it therefore does not require large planning tumor volume margins. We present the primary outcomes of this prospective phase 2 study (BrUOG Br-251).

METHODS AND MATERIALS

Eligible patients with early-stage breast cancer underwent NIBB APBI using a dose 34 Gy in 10 fractions delivered daily or twice a day. Treatment was delivered using an Ir-192 high-dose-rate source via specialized applicators. Two orthogonal treatment axes were used for each fraction. The primary endpoints were late toxicity and cosmesis assessed at 2 and 5 years. Toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. Cosmesis was assessed using the NRG/Radiation Therapy Oncology Group scale. Ipsilateral breast tumor recurrence was defined as any recurrence or new primary in the treated breast.

RESULTS

Forty patients underwent protocol treatment. Median patient age was 68 years (50-92 years). Mean tumor size was 1.1 cm (0.3-3.0 cm). Among the cohort, 62.5% had invasive carcinoma and 37.5% had ductal carcinoma in situ. Thirty-nine percent elected to receive hormone therapy. No grade ≥3 late toxicities were observed at any time point. Grade 2 toxicity was 5% and 10% at 2 and 5 years, respectively. Telangiectasia grade 1 and 2 occurred in 27.5% and 5%, respectively. Breast separation of >7 cm was associated with telangiectasia (P < .01). The rate of good to excellent cosmetic outcome was 95% at 2 years and 100% at 5 years. With a median follow-up of 68 months, the actuarial 5-year freedom from ipsilateral breast tumor recurrence was 93.3% (±4.8%), and overall survival was 93.7% (±4.4%).

CONCLUSIONS

NIBB to deliver APBI is well tolerated with a low incidence of significant late toxicity and has favorable cosmetic outcomes. Continued evaluation of the NIBB APBI technique in a larger cohort is warranted.

Implementation of Stereotactic Accelerated Partial Breast Irradiation Using Cyber-Knife - Technical Considerations and Early Experiences of a Phase II Clinical Study

To report the implementation, dosimetric results of and early experiences with stereotactic accelerated partial breast irradiation (SAPBI) following breast conserving surgery (BCS) for postmenopausal low-risk St I-II invasive breast cancer (IBC) patients. Between November 2018 and August 2019, 27 patients were registered in our phase II prospective study. SAPBI was performed with Cyber-Knife (CK) M6 machine, in 4 daily fractions of 6.25 Gy to a total dose of 25 Gy. Respiratory movements were followed with implanted gold markers and Synchrony system. Corrections for patient displacement and respiratory movement during treatment were performed with the robotic arm. Early side effects, cosmetic results, and dosimetric parameters were assessed. The average volume of the surgical cavity, clinical target volume (CTV), and planning target volume (PTV_EVAL) were 8.1 cm³ (range: 1.75–27.3 cm³), 55.3 cm³ (range: 26.2–103.5 cm³), and 75.7 cm³ (range: 40–135.4 cm³), respectively. The mean value of the PTV_eval/whole breast volume ratio was 0.09 (range: 0.04–0.19). No grade 2 or worst acute side-effect was detected. Grade 1 (G1) erythema occurred in 6 (22.2%) patients, while G1 oedema was reported by 3 (11.1%) cases. G1 pain was observed in 1 (3.4%) patient. Cosmetic result were excellent in 17 (62.9%) and good in 10 (37.1%) patients. SAPBI with CK is a suitable and practicable technique for the delivery of APBI after BCS for low-risk, St. I-II. IBC. Our early findings are encouraging, CK-SAPBI performed with four daily fractions is convenient and perfectly tolerated by the patients.

Single-Institution Phase 1/2 Prospective Clinical Trial of Single-Fraction, High-Gradient Adjuvant Partial-Breast Irradiation for Hormone Sensitive Stage 0-I Breast Cancer

PURPOSE

We sought to evaluate the feasibility and tolerability of a novel accelerated partial breast irradiation regimen delivered in a single fraction postoperatively.

METHODS AND MATERIALS

We enrolled 50 patients with low-risk, hormone-sensitive breast cancer from 2015 to 2018 on a prospective phase 1/2 trial to receive single-fraction, high-gradient partial-breast irradiation (SFHGPBI) 2 to 8 weeks after lumpectomy for node-negative, invasive, or in situ breast cancer. The high gradient was achieved by prescribing 20 Gy to the surgical bed and 5 Gy to the breast tissue within 1 cm of the surgical bed simultaneously in 1 fraction using external beam.

RESULTS

The median age was 65 (range, 52-84). Ten patients (20%) had small-volume ductal carcinoma in situ while the remainder had stage I disease. At a median follow-up of 25 months, we evaluated toxicity, patient- and physician-reported cosmesis, patient-reported quality of life (QOL), and initial tumor control. There was no Common Terminology Criteria for Adverse Events v4.0 grade 3+ toxicity. Only 34% of patients experienced grade 1 erythema. Good-to-excellent pretreatment cosmesis was present in 100% and 98% per physicians and patients, respectively, and did not change post-SFHGPBI. Quantitative cosmesis by percentage of breast retraction assessment significantly improved over time during the post-SFHGPBI period per mixed repeated measures modeling (P = .0026). QOL per European Organization for Research and Treatment of Cancer QOL Questionnaires C30 and BR-23 did not decline other than temporarily in the systemic therapy effects and hair loss domains, both of which returned to pretreatment values. There was 1 noninvasive in-breast recurrence in a separate untreated quadrant 18 months post-SFHGPBI and 1 isolated axillary recurrence 30 months post-SFHGPBI, both salvaged successfully. There were no distant recurrences or cancer-related deaths observed.

CONCLUSIONS

Accelerated partial-breast irradiation delivered in a single fraction postoperatively using external beam techniques is a novel, feasible, well-tolerated regimen. SFHGPBI does not adversely affect cosmesis or QOL as reported by both physicians and patients. Initial tumor control rates are excellent, with longer follow-up required to confirm efficacy.

Accelerated partial breast irradiation-Redefining the treatment target for women with early stage breast cancer

Following breast conserving surgery, the standard of care has been to deliver adjuvant radiation therapy directed to the whole breast (WBI) over a period of 3-7 weeks. Over the past decade, increasing data have supported the concept that treatment to the whole breast may not be required in selected patients, allowing for the emergence of partial breast irradiation (PBI). Multiple randomized trials with 5-10 years of follow-up have been published documenting the safety and efficacy associated with PBI using multiple techniques. Questions that remain to be answered include (a) what is the optimal PBI technique for each clinical scenario, (b) are there additional patients that can be effectively managed with PBI approaches, and (c) are there different techniques/dose schedules that allow for further reduction in treatment duration and/or toxicities? Partial breast irradiation represents a standard approach for appropriately selected patients. PBI provides comparable clinical outcomes to WBI while allowing for a reduction in the duration treatment and the potential for reduced toxicities. Future studies may also help to better define which patients require no radiation, PBI, hypofractionated WBI or conventional WBI, based upon patient, clinical, pathologic features as well as potentially using tumor genetics.

Ten daily fractions for partial breast irradiation. Long-term results of a prospective phase II trial

Partial breast irradiation (PBI) is an effective adjuvant treatment after breast conservative surgery for selected early-stage breast cancer patients. However, the best fractionation scheme is not well defined. Hereby, we report the 5-year clinical outcome and toxicity of a phase II prospective study of a novel regimen to deliver PBI, which consists in 40 Gy delivered in 10 daily fractions. Patients with early-stage (pT1-pT2, pN0-pN1a, M0) invasive breast cancer were enrolled after conservative surgery. The minimum age at diagnosis was 60 years old. PBI was delivered with 3D-conformal radiotherapy technique with a total dose of 40 Gy, fractionated in 10 daily fractions (4 Gy/fraction). Eighty patients were enrolled. The median follow-up was 67 months. Five-year local control (LC), disease-free survival (DFS), and overall survival (OS) were 95%, 91%, and 96%, respectively. Grade I and II subcutaneous fibrosis were documented in 23% and 5% of cases. No grade III late toxicity was observed. PBI delivered in 40 Gy in 10 daily fractions provided good clinical results and was a valid radiotherapy option for early-stage breast cancer patients.

Accelerated partial breast radiotherapy: a review of the literature and future directions

Breast conservation therapy exemplifies the tailoring of medicine in the care of patients with cancer. Akin to improvements in surgical approaches, accelerated partial breast irradiation (APBI) tailors the treatment volume and duration to the needs of well selected patients. Here, we examine the evidence supporting APBI as well as the lessons in patient selection, dose and delivery techniques. Examination of historical techniques and their associated outcomes will support more correct patient selection and treatment delivery in an era where we await the reports of several large prospective trials.

Preliminary toxicity results using partial breast 3D-CRT with once daily hypo-fractionation and deep inspiratory breath hold

BACKGROUND

To evaluate the clinical outcomes of patients treated with 3D conformal Hypo-fractionated, deep Inspiratory breath-hold (DIBH), Partial breast radiotherapy, termed "HIP." HIP was implemented to merge the schedule of once-daily breast hypofractionation with partial breast treatment.

METHODS

We identified 38 breast cancers in 37 patients from 2013 to 2014 treated at our institution with HIP following lumpectomy for early stage breast cancer. Patients received a hypo-fractionated course (≤ 20 fractions) of once daily radiation to the partial breast (lumpectomy cavity + margin) utilizing DIBH regardless of laterality. Clinical and treatment-related characteristics were obtained, including target volume and organ at risk (OAR) dosimetric characteristics. Patients were followed clinically and with at least yearly mammograms for up to 36 months (range 5-36 months). Acute and late toxicity was scored using the Common Terminology Criteria for Adverse Events (CTCAE) v4.03.

RESULTS

Patients received a median dose of 42.56 Gy in 16 Fractions (Fx) (range 40.05-53.2 Gy; and 15-20 Fx). OAR doses were low, with a mean heart dose of 0.37 Gy, an ipsilateral lung V20 mean of 4%, and a contralateral lung V5 of 1%. Acute toxicity (≤ grade 2) was present in 79% (n = 30) of the cases, with dermatitis being the most common finding (63%). Late grade 1-2 toxicity was present in 42% (n = 16) of the cases, with hyperpigmentation being the most common finding (n = 9). There were no severe acute or late toxicities (≥ grade 3). At a median follow up of 21 months, there were no local, regional, or distant failures.

CONCLUSIONS

We report limited toxicity in this low risk cohort of patients with early stage breast cancer treated with HIP, a unique and logical combination of 3-D conformal external beam radiotherapy, moderate hypo-fractionation, and DIBH.

Advancements and Personalization of Breast Cancer Treatment Strategies in Radiation Therapy

Significant technologic advances in radiation treatment delivery now allow for more personalized delivery considerations which incorporate individual patient characteristics (such as tumor location and patient anatomy) and more precise delivery in the breast conservation or post-mastectomy setting. The combined advancements with other treatment modalities (i.e., systemic therapy, surgical management) have had direct effects on local-regional management and outcomes such that currently, local-regional relapses after definitive treatment for localized disease are now rarely experienced. Recent advances in the radiation therapy field have come from careful patient selection for a variety of three-dimensional treatment delivery techniques and alternatives to conventional tangential radiation. These advances have been demonstrated to diminished acute/long-term toxicity, minimized dose to surrounding normal tissue structures such as the heart and lung, and ultimately result in an improvement in the therapeutic ratio for radiation treatment. This chapter discusses recent radiation innovations and appropriate patient selection for their application, for a more personalized approach to radiation therapy for breast cancer patients.

Long-term cosmesis following a novel schedule of accelerated partial breast radiation in selected early stage breast cancer: result of a prospective clinical trial

PURPOSE

There is controversy regarding the cosmetic outcome after accelerated partial breast radiation (APBR). We report the cosmetic outcome from a single-arm prospective clinical trial of APBR delivered using intensity-modulated radiation therapy (IMRT) in elderly patients with stage I breast cancer (BC), using a novel fractionation schedule.

MATERIALS AND METHODS

Forty-two patients aged ≥65, with Stage I BC who underwent breast-conserving surgery were enrolled in a phase I/II study evaluating a 2-week course of APBR. Thirty eligible patients received 40 Gy in 4 Gy daily fractions. Cosmetic outcome was assessed subjectively by physician/patient and objectively by using a computer program (BCCT.core) before APBR, during, and after completion of the treatment.

RESULTS

The median age was 72 years, the median tumor size was 0.8 cm, and the median follow-up was 50.5 months. The 5-year locoregional control in this cohort was 97% and overall survival 87%. At the last follow-up, patients and physicians rated cosmesis as 'excellent' or 'good' in 100% and 91 %, respectively. The BCCT.core program scored the cosmesis as 'excellent' or 'good' in 87% of the patients at baseline and 81% at the last follow-up. The median V50 (20 Gy) of the whole breast volume (WBV) was 37.2%, with the median WBV V100 (40 Gy) of 10.9%.

CONCLUSION

An excellent rate of tumor control was observed in this prospective trial. By using multiple assessment techniques, we are showing acceptable cosmesis, supporting the use of IMRT planned APBR with daily schedule in elderly patients with early stage BC.

Cost-effectiveness Analysis Comparing Conventional, Hypofractionated, and Intraoperative Radiotherapy for Early-Stage Breast Cancer

Background

Early-stage breast cancer is among the most prevalent and costly malignancies treated in the American health care system. Adjuvant radiotherapy after lumpectomy represents a substantial portion of breast cancer expenditures. The relative value of novel radiotherapeutic approaches such as intraoperative radiotherapy (IORT) and hypofractionated whole breast irradiation (HF-WBI) compared with conventionally fractionated whole breast irradiation (CF-WBI) is unknown. Therefore, we used prospectively collected outcomes from randomized clinical trials (RCTs) to compare the cost-effectiveness of these approaches.

Methods

We constructed a decision-analytic model that followed women who were treated with lumpectomy for early-stage breast cancer. Recurrence, mortality, complication rates, and utilities (five-year radiation-associated quality of life scores), were extracted from RCTs. Costs were based on Medicare reimbursement rates. Cost-effectiveness from societal and health care sector perspectives was estimated considering two scenarios-the first assumes that radiation-associated disutility persists five years after treatment, and the second assumes that disutility discontinues. Lifetime outcomes were summarized using incremental cost-effectiveness ratios (ICERs). Deterministic and probabilistic sensitivity analyses evaluated the robustness of the results.

Results

HF-WBI dominated CF-WBI (ie, resulted in higher quality-adjusted life-years [QALYs] and lower cost) in all scenarios. HF-WBI also had a greater likelihood of cost-effectiveness compared with IORT; under a societal perspective that assumes that radiation-associated disutility persists, HF-WBI results in an ICER of $17 024 per QALY compared with IORT with a probability of cost-effectiveness of 80% at the $100 000 per QALY willingness-to-pay threshold. If radiation-associated disutility is assumed to discontinue, the ICER is lower ($11 461/QALY), resulting in an even higher (83%) probability of relative cost-effectiveness. The ICER was most sensitive to the probability of metastasis and treatment cost.

Conclusions

For women with early-stage breast cancer requiring adjuvant radiotherapy, HF-WBI is cost-effective compared with CF-WBI and IORT.

A Single Institution Retrospective Comparison Study of Locoregional Recurrence After Accelerated Partial Breast Irradiation Using External Beam Fractionation Compared with Whole Breast Irradiation with 8 Years of Follow-Up

BACKGROUND

Accelerated partial breast irradiation (APBI) was developed to address disadvantages of overall treatment time and potentially unnecessary radiation associated with whole breast irradiation (WBI). We report updated results of our single institution study using an external beam APBI regimen with a median follow-up of 8 years.

METHODS

A total of 290 APBI patients with AJCC Stage 0-II breast cancer were compared with 290 WBI patients with matched tumor characteristics. Toxicities were scored based on the Common Terminology Criteria for Adverse Events (CTCAE v3.0). Cox regression models were used to predict likelihood of freedom from ipsilateral failure.

RESULTS

Median follow-up was 8 years in the APBI group and 7.5 years in the WBI group. In the APBI group, there were 18 (6.2%) ipsilateral breast tumor recurrence (IBTR), 13 (72%) had elsewhere failures (EF), and 5 (28%) had local failures (LF) with a median time to failure of 64.1 months. In the WBI group, there were three (1.0%) IBTR; one (33%) was an EF and two (67%) were LF with a median time to failure of 91 months. APBI was 4.6 times more likely (hazard ratio 4.57, 95% confidence interval 1.3-16.2, p = 0.02) to have an IBTR than WBI after adjusting for age, tumor size, histology, grade, and estrogen receptor status. Fatigue, erythema, and desquamation toxicities were significantly less in the APBI group then the WBI group.

CONCLUSIONS

IBTR rates were higher in external beam APBI group compared with WBI, but APBI had fewer toxicities. Clinicians must weigh the risks and benefits of APBI when making a recommendation for partial breast irradiation after lumpectomy.

Projected Improvements in Accelerated Partial Breast Irradiation Using a Novel Breast Stereotactic Radiotherapy Device: A Dosimetric Analysis

Accelerated partial breast irradiation has caused higher than expected rates of poor cosmesis. At our institution, a novel breast stereotactic radiotherapy device has demonstrated dosimetric distributions similar to those in brachytherapy. This study analyzed comparative dose distributions achieved with the device and intensity-modulated radiation therapy accelerated partial breast irradiation. Nine patients underwent computed tomography simulation in the prone position using device-specific immobilization on an institutional review board–approved protocol. Accelerated partial breast irradiation target volumes (planning target volume_10mm) were created per the National Surgical Adjuvant Breast and Bowel Project B-39 protocol. Additional breast stereotactic radiotherapy volumes using smaller margins (planning target volume_3mm) were created based on improved immobilization. Intensity-modulated radiation therapy and breast stereotactic radiotherapy accelerated partial breast irradiation plans were separately generated for appropriate volumes. Plans were evaluated based on established dosimetric surrogates of poor cosmetic outcomes. Wilcoxon rank sum tests were utilized to contrast volumes of critical structures receiving a percentage of total dose (Vx). The breast stereotactic radiotherapy device consistently reduced dose to all normal structures with equivalent target coverage. The ipsilateral breast V20-100 was significantly reduced (P < .05) using planning target volume_10mm, with substantial further reductions when targeting planning target volume_3mm. Doses to the chest wall, ipsilateral lung, and breast skin were also significantly lessened. The breast stereotactic radiotherapy device’s uniform dosimetric improvements over intensity-modulated accelerated partial breast irradiation in this series indicate a potential to improve outcomes. Clinical trials investigating this benefit have begun accrual.

Seven fractions to deliver partial breast irradiation: the toxicity is Low

Purpose

To assess toxicity and clinical outcome, in breast cancer patients treated with external beam partial breast irradiation (PBI) consisting of 35 Gy in 7 daily fractions (5 Gy/fraction).

Materials and Methods

Patients affected by early-stage breast cancer were enrolled in this phase II trial. Patients had to be 60 years old or over and treated with breast conservative surgery for early stage invasive carcinoma.

Results

Seventy-three patients were analyzed. Median follow-up was 40 months. The proposed schedule was well tolerated. No Grade 3 toxicity was documented. Late toxicity was assessable for all the treated patients. Two patients (2.7%) developed Grade 2 pain 6 months after PBI. Four patients (5%) developed asymptomatic fat necrosis. Grade 2 fibrosis was observed in 5 patients (6.7%). No correlation was found between early and late toxicity and the type of adjuvant systemic therapy (no therapy vs. hormonal therapy vs. chemotherapy). No statistical correlation between dosimetric parameters and toxicity was found. Patients who developed Grade 2 radiation fibrosis had not higher radiation volumes to the untreated normal breast than those without fibrosis. Cosmesis was judged good/excellent in the majority of the cases (93%). One patient relapsed locally, and one developed distant metastases, corresponding to a 5-year local control and distant metastases-free survival of 98% and 96.7%, respectively.

Conclusions

35 Gy in 7 daily fractions is an effective and well-tolerated regimen to deliver PBI.

High-dose-rate interstitial brachytherapy for accelerated partial breast irradiation - trial results of Azerbaijan National Center of Oncology

Purpose

To describe early results of two cohorts of patients with low and intermediate risk of early breast cancer treated with accelerated partial breast irradiation (APBI) using different schedules of multicatheter brachytherapy.

Material and methods

Patients with early stage breast cancer after breast conserving surgery were enrolled for a prospective analysis. The APBI, using multicatheter brachytherapy, was delivered either eight times 4 Gy in five days with a planned total dose of 32 Gy, or seven times 5 Gy in four days with a planned total dose of 35 Gy. Primary endpoints were side effects.

Results

Forty-eight patients were enrolled between 2012 and 2014. Patients characteristics were as follow: median age of patients was 55 years, early breast cancer was defined according GEC-ESTRO recommendations. With a median follow-up period of 37 months, no significant differences regarding late side effects and cosmesis between two cohorts of patients were documented. In total, cosmesis was excellent in 13/48 (27.1%) patients, good in 34/48 (70.8%) patients, and moderate in 1/48 patient (2.1%).

Conclusions

Accelerated partial breast irradiation using multicatheter brachytherapy with 32 Gy/8 fractions and 35 Gy/7 fractions for early breast cancer seems to be similar in terms of late side effects. According to our findings, APBI was also feasible for intermediate-risk of early breast cancer patients.

Effects of online cone-beam computed tomography with active breath control in determining planning target volume during accelerated partial breast irradiation

PURPOSE

To test if active breath control during cone-beam computed tomography (CBCT) could improve planning target volume during accelerated partial breast radiotherapy for breast cancer.

METHODS

Patients who were more than 40 years old, underwent breast-conserving dissection and planned for accelerated partial breast irradiation, and with postoperative staging limited to T1-2 N0 M0, or postoperative staging T2 lesion no larger than 3cm with a negative surgical margin greater than 2mm were enrolled. Patients with lobular carcinoma or extensive ductal carcinoma in situ were excluded. CBCT images were obtained pre-correction, post-correction and post-treatment. Set-up errors were recorded at left-right, anterior-posterior and superior-inferior directions. The differences between these CBCT images, as well as calculated radiation doses, were compared between patients with active breath control or free breathing.

RESULTS

Forty patients were enrolled, among them 25 had active breath control. A total of 836 CBCT images were obtained for analysis. CBCT significantly reduced planning target volume. However, active breath control did not show significant benefit in decreasing planning target volume margin and the doses of organ-at-risk when compared to free breathing.

CONCLUSION

CBCT, but not active breath control, could reduce planning target volume during accelerated partial breast irradiation.

NRG Oncology-Radiation Therapy Oncology Group Study 1014: 1-Year Toxicity Report From a Phase 2 Study of Repeat Breast-Preserving Surgery and 3-Dimensional Conformal Partial-Breast Reirradiation for In-Breast Recurrence

PURPOSE

To determine the associated toxicity, tolerance, and safety of partial-breast reirradiation.

METHODS AND MATERIALS

Eligibility criteria included in-breast recurrence occurring >1 year after whole-breast irradiation, <3 cm, unifocal, and resected with negative margins. Partial-breast reirradiation was targeted to the surgical cavity plus 1.5 cm; a prescription dose of 45 Gy in 1.5 Gy twice daily for 30 treatments was used. The primary objective was to evaluate the rate of grade ≥3 treatment-related skin, fibrosis, and/or breast pain adverse events (AEs), occurring ≤1 year from re-treatment completion. A rate of ≥13% for these AEs in a cohort of 55 patients was determined to be unacceptable (86% power, 1-sided α = 0.07).

RESULTS

Between 2010 and 2013, 65 patients were accrued, and the first 55 eligible and with 1 year follow-up were analyzed. Median age was 68 years. Twenty-two patients had ductal carcinoma in situ, and 33 had invasive disease: 19 ≤1 cm, 13 >1 to ≤2 cm, and 1 >2 cm. All patients were clinically node negative. Systemic therapy was delivered in 51%. All treatment plans underwent quality review for contouring accuracy and dosimetric compliance. All treatment plans scored acceptable for tumor volume contouring and tumor volume dose-volume analysis. Only 4 (7%) scored unacceptable for organs at risk contouring and organs at risk dose-volume analysis. Treatment-related skin, fibrosis, and/or breast pain AEs were recorded as grade 1 in 64% and grade 2 in 7%, with only 1 (<2%) grade ≥3 and identified as grade 3 fibrosis of deep connective tissue.

CONCLUSION

Partial-breast reirradiation with 3-dimensional conformal radiation therapy after second lumpectomy for patients experiencing in-breast failures after whole-breast irradiation is safe and feasible, with acceptable treatment quality achieved. Skin, fibrosis, and breast pain toxicity was acceptable, and grade 3 toxicity was rare.

A novel schedule of accelerated partial breast radiation using intensity-modulated radiation therapy in elderly patients: survival and toxicity analysis of a prospective clinical trial

Purpose

Several accelerated partial breast radiation (APBR) techniques have been investigated in patients with early-stage breast cancer (BC); however, the optimal treatment delivery techniques remain unclear. We evaluated the feasibility and toxicity of APBR delivered using intensity-modulated radiation therapy (IMRT) in elderly patients with stage I BC, using a novel fractionation schedule.

Materials and Methods

Forty-two patients aged ≥65 years, with stage I BC who underwent breast conserving surgery were enrolled in a phase I/II study evaluating APBR using IMRT. Forty eligible patients received 40 Gy in 4 Gy daily fractions. Patients were assessed for treatment related toxicities, and cosmesis, before APBR, during, and after completion of the treatment.

Results

The median age was 73 years, median tumor size 0.8 cm and the median follow-up was 54 months. The 5-year locoregional control was 97.5% and overall survival 90%. Erythema and skin pigmentation was the most common acute adverse event, reported by 27 patients (69%). Twenty-six patients (65%) reported mild pain, rated 1-4/10. This improved at last follow-up to only 2 (15%). Overall the patient and physician reported worst late toxicities were lower than the baseline and at last follow-up, patients and physicians rated cosmesis as excellent/good in 93% and 86 %, respectively.

Conclusion

In this prospective trial, we observed an excellent rate of tumor control with daily APBR. The acceptable toxicity profile and cosmetic results of this study support the use of IMRT planned APBR with daily schedule in elderly patients with early stage BC.

Association between access to accelerated partial breast irradiation and use of adjuvant radiotherapy

BACKGROUND

The current study was performed to determine whether access to facilities performing accelerated partial breast irradiation (APBI) is associated with differences in the use of adjuvant radiotherapy (RT).

METHODS

Using the National Cancer Data Base, the authors performed a retrospective study of women aged ≥50 years who were diagnosed with early-stage breast cancer between 2004 and 2013 and treated with breast-conserving surgery (BCS). Facilities performing APBI in ≥10% of their eligible patients within a given year were defined as APBI facilities whereas those not performing APBI were defined as non-APBI facilities. All other facilities were excluded. The authors identified independent factors associated with RT use using multivariable logistic regression with clustering in the overall sample as well as in subsets of patients with standard-risk invasive cancer, low-risk invasive cancer, and ductal carcinoma in situ.

RESULTS

Among 222,544 patients, 76.6% underwent BCS plus RT and 23.4% underwent BCS alone. The likelihood of RT receipt in the overall sample did not appear to differ significantly between APBI and non-APBI facilities (adjusted odds ratio [AOR], 1.02; P = .61). Subgroup multivariable analysis demonstrated that among patients with standard-risk invasive cancer, there was no association between evaluation at an APBI facility and receipt of RT (AOR, 0.98; P = .69). However, patients with low-risk invasive cancer were found to be significantly more likely to receive RT (54.4% vs 59.5%; AOR, 1.22 [P<.001]), whereas patients with ductal carcinoma in situ were less likely to receive RT (56.9% vs 55.3%; AOR, 0.89 [P = .04]) at APBI facilities.

CONCLUSIONS

Patients who were eligible for observation were more likely to receive RT in APBI facilities but no difference was observed among patients with standard-risk invasive cancer who would most benefit from RT. Cancer 2017;123:502-511. © 2016 American Cancer Society.

Long-Term Update of NRG Oncology RTOG 0319: A Phase 1 and 2 Trial to Evaluate 3-Dimensional Conformal Radiation Therapy Confined to the Region of the Lumpectomy Cavity for Stage I and II Breast Carcinoma

PURPOSE

NRG Oncology RTOG 0319 was the first cooperative group trial in the United States to evaluate 3-dimensional conformal radiation therapy (3D-CRT) accelerated partial breast irradiation (APBI). This report updates secondary endpoints of toxicity and efficacy.

METHODS AND MATERIALS

Patients with stage I or II invasive breast cancer (tumor size ≤3 cm, ≤3 positive lymph nodes, negative margins) were eligible for 3D-CRT APBI: 38.5 Gy in 10 twice-daily fractions. Patient characteristics and treatment details have previously been reported. Adverse events were graded with CTCAE v3.0 (National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0). This analysis updates the rates of ipsilateral breast recurrence (IBR), contralateral breast recurrence, ipsilateral node recurrence (INR), metastatic sites (distant metastases [DM]), mastectomy, disease-free survival, mastectomy-free survival, and overall survival.

RESULTS

Of 58 enrolled patients, 52 were eligible, with a median age of 61 years; 94% had stage I cancer and 83% had estrogen receptor positive disease. The median follow-up period was 8 years (minimum-maximum, 1.7-9.0 years). The 7-year estimate of isolated IBR (no DM) was 5.9%. The 7-year estimates of all IBRs, INR, mastectomy rate, and DM were 7.7%, 5.8%, 7.7%, and 7.7%, respectively. All 4 IBRs were invasive, of which 3 had a component within the planning target volume. The patterns of failure were as follows: 3 IBRs, 1 INR, 2 DM, 1 INR plus DM, and 1 IBR plus INR plus DM. The 7-year estimates of mastectomy-free survival, disease-free survival, and overall survival were 71.2%, 71.2%, and 78.8%, respectively. Thirteen patients died: 3 of breast cancer and 10 of other causes. Grade 3 (G3) treatment-related adverse events were reported by 4 patients (7.7%). No G3 pain or pulmonary or cardiac toxicities were reported.

CONCLUSIONS

This phase 1 and 2 trial of 3D-CRT APBI continues to show durable tumor control and minimal G3 toxicity, comparable to other APBI techniques. Mature phase 3 results will determine the appropriateness and limitations of this noninvasive APBI technique.

Preoperative Accelerated Partial Breast Irradiation for Early-Stage Breast Cancer: Preliminary Results of a Prospective, Phase 2 Trial

PURPOSE

To assess the feasibility of utilizing 3-dimensional conformal accelerated partial-breast irradiation (APBI) in the preoperative setting followed by standard breast-conserving therapy.

PATIENTS AND METHODS

This was a prospective trial testing the feasibility of preoperative APBI followed by lumpectomy for patients with early-stage invasive ductal breast cancer. Eligible patients had T1-T2 (<3 cm), N0 tumors. Patients received 38.5 Gy in 3.85-Gy fractions delivered twice daily. Surgery was performed >21 days after radiation therapy. Adjuvant therapy was given as per standard of care.

RESULTS

Twenty-seven patients completed treatment. With a median follow-up of 3.6 years (range, 0.5-5 years), there have been no local or regional failures. A complete pathologic response according to hematoxylin and eosin stains was seen in 4 patients (15%). There were 4 grade 3 seromas. Patient-reported cosmetic outcome was rated as good to excellent in 79% of patients after treatment.

CONCLUSIONS

Preoperative 3-dimensional conformal radiation therapy-APBI is feasible and well tolerated in select patients with early-stage breast cancer, with no reported local recurrences and good to excellent cosmetic results. The pathologic response rates associated with this nonablative APBI dose regimen are particularly encouraging and support further exploration of this paradigm.

Implementation of image-guided intensity-modulated accelerated partial breast irradiation : Three-year results of a phase II clinical study

PURPOSE

To report 3‑year results of accelerated partial breast irradiation (APBI) using image-guided intensity-modulated radiotherapy (IG-IMRT) following breast conserving surgery (BCS) for low-risk early invasive breast cancer.

PATIENTS AND METHODS

Between July 2011 and March 2014, 60 patients with low-risk early invasive breast cancer underwent BCS and were enrolled in this phase II prospective study. The total dose was 36.9 Gy (9 fractions of 4.1 Gy, two fractions/day). Patient setup errors were detected in LAT, LONG and VERT directions. Local tumour control, survival results, early and late side effects and cosmetic outcome were assessed.

RESULTS

At a median follow-up of 39 months, all patients were alive and neither locoregional nor distant failure occurred. One contralateral breast cancer and two new primary malignancies outside the breast were observed. No grade (G) 3-4 acute toxicity was detected. G1 and G2 erythema occurred in 21 (35%) and 2 (3.3%) patients, respectively; while G1 oedema was observed in 23 (38.8%) cases. G1 and G2 pain was reported by 6 (10%) and 2 (3.3%) patients, respectively. Among the late radiation side effects, G1 pigmentation or telangiectasia, G1 fibrosis and G1 asymptomatic fat necrosis occurred in 10 (16.7%), 7 (11.7%) and 3 (5%) patients, respectively. No ≥ G2 late toxicity was detected. Cosmetic outcome was excellent in 43 (71.7%) and good in 17 (28.3%) patients.

CONCLUSION

IG-IMRT is a reproducible and feasible technique for delivery of external beam APBI following BCS for treatment of low-risk, early-stage invasive breast carcinoma. In order to avoid toxicity, image guidance performed before each radiation fraction is necessary to minimize the PTV. Three-year results are promising, early and late radiation side-effects are minimal, and cosmetic results are excellent to good.

Over-irradiation

Decreasing the burden of radiation therapy (RT) for breast cancer includes, next to complete omission, several ways to tailor the extent of RT. Possible options for this include lowering of the total dose, such as selective omission of the boost, hypofractionated RT to shorten the duration of treatment, the selective introduction of partial breast irradiation and anatomy based target volume contouring to decrease the size of the irradiated volumes. Elective regional nodal irradiation showed in several randomised trials and meta-analyses to significantly impact on local-regional control, disease-free survival, breast cancer mortality and overall survival. The generalisability of these results remains complex in the light of the decreasing use of axillary lymph node dissection, the use of more effective adjuvant systemic therapy, the increasing use of primary systemic therapy and continuously improving RT techniques. In general, the use of RT compensates for the decreasing extent of surgery to the breast and the axillary lymph nodes, eliminating residual tumour cells while maintaining better aesthetic and functional results. In some occasions, however, the indications for the extent of RT have to be based on limited pathological staging information. Research is ongoing to individualise RT more on the basis of biological factors including gene expression profiles. When considering age, treatment decisions should rather be based on biological instead of formal age. The aim of this review article is to put current evidence into the right perspective, and to search for an appropriate appreciation of the balance between efficacy and side effects of local-regional RT.

Accelerated partial breast irradiation: advances and controversies

The management of localized breast cancer has changed dramatically over the past three to four decades. Breast-conserving therapy, which involved lumpectomy followed by adjuvant irradiation, is now widely considered the standard of care in women with early-stage breast cancer. Accelerated partial breast irradiation (APBI), which involves focal irradiation of the lumpectomy cavity over a short period of time, has developed over the past two decades as an alternative to whole breast irradiation (WBI). Multiple APBI modalities have been developed including brachytherapy, external beam irradiation, and intraoperative irradiation. These new techniques have provided early-stage breast cancer patients with shorter treatment duration and more focused irradiation, delivering very high biological doses to the region at a high risk of failures over a much shorter treatment course as compared with conventional radiotherapy. However, the advantages of APBI over conventional radiotherapy are controversial, including a higher risk of complications reported in retrospective literature and shorter follow-up duration in the intraoperative APBI trials. Nevertheless, APBI presents a valuable alternative to WBI for a selected population of women with early-stage breast cancer.

WBRT vs. APBI: an interim report of patient satisfaction and outcomes

PURPOSE

To determine differences in patient's reported quality of life and self-reported breast cosmesis between whole breast radiation therapy (WBRT) and accelerated partial breast irradiation (APBI) via single and multi-lumen high-dose-rate (HDR) brachytherapy for women with early stage breast cancer.

MATERIAL AND METHODS

Patient information was retrospectively reviewed and survey data were prospectively collected for women treated between 2004 to 2014 (APBI) and 2012 to 2014 (WBRT). Criteria for APBI treatments were ER+ (after 2010), N0 (after 2010), T < 3 cm, and post-menopausal. All patients were given a survey with modified FACIT (Functional Assessment of Chronic Illness Therapy) breast quality of life questions to rate their amount of pain, self-consciousness, low energy, presence of lymphedema, and breast cosmesis.

RESULTS

242 APBI patients and 59 WBRT patients were identified. In the WBRT cohort, 34 women met departmental criteria for APBI treatment (WBRT who were APBI eligible). The FACIT survey was completed by 80 women treated with APBI (33%; mean follow-up time of 14 months), and 26 women treated with WBRT who were APBI eligible (76%; mean follow-up time of 26 months). During the first year post-treatment, low energy (p = 0.009), self-consciousness (p = 0.0004), and lymphedema (p = 0.0002) scores were significantly lower in the APBI cohort when compared to women treated with WBRT who were APBI eligible. During the second year post-treatment, women treated with APBI reported significantly better breast cosmesis (p = 0.04). The single-lumen balloon (score = 6.3/10) was found to be associated with worse cosmesis compared to the multi-lumen balloons (Mammosite ML and Contura; score = 8.2/10; p = 0.002). There were no significant differences in rates of recurrence between balloons or treatments (p > 0.05).

CONCLUSIONS

APBI treated patients reported higher cosmetic satisfaction than patients in the matched WBRT cohort. Quality of life scores tended to improve over time. Multi-lumen catheters provided superior cosmetic results compared to single-lumen catheters.

Comparison of Mammographic Changes Across Three Different Fractionation Schedules for Early-Stage Breast Cancer

PURPOSE

As the use of hypofractionated breast radiation therapy (RT) increases, so will the need for long-term data on post-RT mammographic changes. The purpose of the present study was to longitudinally compare the incidence of common mammographic sequelae seen after breast conserving surgery and RT in patients treated with accelerated partial breast irradiation (APBI), hypofractionated whole breast irradiation (HWBI), and conventionally fractionated whole breast irradiation (WBI).

METHODS AND MATERIALS

Patients treated with either APBI or HWBI after breast conserving therapy and with ≥3 mammograms of the treated breast were identified. They were matched 1:1 by age ±5 years to patients treated with WBI. The mammograms were evaluated for common post-RT breast findings by a mammographer who was unaware of the treatment. The outcomes were analyzed using a cumulative logistic regression model; P<.05 indicated statistically significance.

RESULTS

Of 89 patients treated with RT from 2006 to 2011, 29 had received APBI, 30 had received HWBI, and 30 had received WBI. Their median age was 60 years (range 33-83). A total of 605 mammograms were evaluated, with a median follow-up of 48 months. The treatment technique did not affect the severity of architectural distortion when the groups were evaluated longitudinally. The likelihood of finding skin thickening decreased with increasing follow-up duration (odds ratio 0.6; P<.001) adjusted for fractionation schemes. No differences were seen with respect to changes in skin thickening, fluid collections, or calcifications among the treatment groups, after adjustment for the follow-up time. The clinical characteristics, including age, race, T stage, and chemotherapy use, were not linked to the likelihood of finding several mammographic phenomena over time.

CONCLUSIONS

Although specific post-treatment imaging findings evolved over time, RT fractionation did not alter the relative incidence or severity of architectural distortion, skin thickening, fluid collections, or calcifications. These findings will be useful to both radiologists and radiation oncologists when counseling patients regarding follow-up studies after RT.

The Influence of Treatment Position (Prone vs. Supine) on Clip Displacement, Seroma, Tumor Bed and Partial Breast Target Volumes: Comparative Study

To analyse the displacement of surgical clips in prone (Pr) position and assess the consequences on target volumes and integral dose of partial breast irradiation (PBI). 30 post-lumpectomy breast cancer patients underwent CT imaging in supine (Su) and Pr. Clip displacements were measured by the distances from the clips to a common fix bony reference point. On each dataset, the tumour bed (TB = clips ± seroma), clinical target volume (CTV = TB + 1.5 cm) and planning target volumes (PTV = CTV + 1 cm) for PBI were determined and the volume pairs were compared. Furthermore estimation of integral dose ratio (IDR) within the breast from tangential treatment was performed as the ratio of the irradiated breast volume and the volume encompassing all clips. Clips close to the chest wall (CW) in Su showed significantly less displacement in Pr. The mean volumes of seroma, CTV and PTV were significantly higher in Pr than in Su. The PTV volume difference (Pr-Su) was significantly higher in patients with presence of seroma, deep clips and TB location in the superior-internal-quadrant (SIQ) and at the junction of superior quadrants (jSQ). In a multivariate analysis two factors remained significant: seroma and TB localization in SIQ-jSQ. The IDR was significantly larger in Su than in Pr (7.6 vs. 4.1 p < 0.01). Clip displacements varied considerably with respect to their relative position to the CW. In selected patients Pr position potentially leads to a significant increase in target volumes of PBI. Tangential beam arrangement for PBI should be avoided, not only in Su but in Pr as well in case of clip-based target volume definition.

Reducing the Human Burden of Breast Cancer: Advanced Radiation Therapy Yields Improved Treatment Outcomes

Radiation therapy is an important modality in the treatment of patients with breast cancer. While its efficacy in the treatment of breast cancer was known shortly after the discovery of x-rays, significant advances in radiation delivery over the past 20 years have resulted in improved patient outcomes. With the development of improved systemic therapy, optimizing local control has become increasingly important and has been shown to improve survival. Better understanding of the magnitude of treatment benefit, as well as patient and biological factors that confer an increased recurrence risk, have allowed radiation oncologists to better tailor treatment decisions to individual patients. Furthermore, significant technological advances have occurred that have reduced the acute and long-term toxicity of radiation treatment. These advances continue to reduce the human burden of breast cancer. It is important for radiation oncologists and nonradiation oncologists to understand these advances, so that patients are appropriately educated about the risks and benefits of this important treatment modality.

Intraoperative Radiotherapy Versus Whole-Breast External Beam Radiotherapy in Early-Stage Breast Cancer: A Systematic Review and Meta-Analysis

There has not been a clear answer about the efficacy of intraoperative radiotherapy (IORT) for women with early-stage breast cancer.The aim of this meta-analysis was to summarize the available evidence comparing the efficacy and safety of IORT with those of whole-breast external beam radiotherapy (EBRT) for women with early-stage breast cancer.MEDLINE, EMBASE, the Web of Science, and the Cochrane Library were searched up to October 2014. Two authors independently conducted the literature selection and data extraction.Studies that compared IORT with whole-breast EBRT were included in the systematic review. IORT was defined as a single dose of irradiation to the tumor bed during breast-conserving surgery rather than whole-breast irradiation.Qualities of RCTs were evaluated according to the PEDro scale. Qualities of non-RCTs were evaluated according to the Methodological Index for Non-Randomized Studies (MINORS). The risk ratios (RRs) of ipsilateral breast tumor recurrence, overall mortality, breast cancer mortality, non-breast cancer mortality, and distant metastasis were pooled using a random-effects model.Four studies with 5415 patients were included in this meta-analysis, including 2 randomized controlled trials (RCTs) and 2 non-RCTs. Ipsilateral breast tumor recurrence was significantly higher in patients with IORT compared to those with whole-breast EBRT (RR 2.83, 95% CI 1.23-6.51), but with significant heterogeneity (I = 58.5%, P = 0.065). Comparing IORT with whole-breast EBRT, the pooled RRs for overall mortality, breast cancer mortality, non-breast cancer mortality, and distant metastasis were 0.88 (95% CI: 0.66-1.17), 1.20 (95% CI: 0.77-1.86), 0.76 (95% CI: 0.44-1.31), and 0.95 (95% CI: 0.61-1.49), respectively.IORT had a significantly higher risk of ipsilateral breast tumor recurrence than whole-breast EBRT. Overall mortality did not differ significantly. IORT should be used in conjunction with the prudent selection of suitable patients. It is imperative to identify women with a low risk of local recurrence.

Long-term cosmetic outcomes and toxicities of proton beam therapy compared with photon-based 3-dimensional conformal accelerated partial-breast irradiation: a phase 1 trial

PURPOSE

To present long-term outcomes of a prospective feasibility trial using either protons or 3-dimensional conformal photon-based (accelerated partial-breast irradiation [APBI]) techniques.

METHODS AND MATERIALS

From October 2003 to April 2006, 98 evaluable patients with stage I breast cancer were treated with APBI (32 Gy in 8 fractions given twice daily) on a prospective clinical trial: 19 with proton beam therapy (PBT) and 79 with photons or mixed photons/electrons. Median follow-up was 82.5 months (range, 2-104 months). Toxicity and patient satisfaction evaluations were performed at each visit.

RESULTS

At 7 years, the physician rating of overall cosmesis was good or excellent for 62% of PBT patients, compared with 94% for photon patients (P=.03). Skin toxicities were more common for the PBT group: telangiectasia, 69% and 16% (P=.0013); pigmentation changes, 54% and 22% (P=.02); and other late skin toxicities, 62% and 18% (P=.029) for PBT and photons, respectively. There were no significant differences between the groups in the incidences of breast pain, edema, fibrosis, fat necrosis, skin desquamation, and rib pain or fracture. Patient-reported cosmetic outcomes at 7 years were good or excellent for 92% and 96% of PBT and photon patients, respectively (P=.95). Overall patient satisfaction was 93% for the entire cohort. The 7-year local failure rate for all patients was 6%, with 3 local recurrences in the PBT group (7-year rate, 11%) and 2 in photon-treated patients (4%) (P=.22).

CONCLUSIONS

Local failure rates of 3-dimensional APBI and PBT were similar in this study. However, PBT, as delivered in this study, led to higher rates of long-term telangiectasia, skin color changes, and skin toxicities. We recommend the use of multiple fields and treatment of all fields per treatment session or the use of scanning techniques to minimize skin toxicity.

Accelerated partial breast irradiation with intensity-modulated radiotherapy is feasible for chinese breast cancer patients

PURPOSE

Several accelerated partial breast irradiation (APBI) techniques are being investigated in patients with early-stage breast cancer. The present study evaluated the feasibility, early toxicity, initial efficacy, and cosmetic outcomes of accelerated partial breast intensity-modulated radiotherapy (IMRT) for Chinese female patients with early-stage breast cancer after breast-conserving surgery.

METHODS

A total of 38 patients met the inclusion criteria and an accelerated partial breast intensity-modulated radiotherapy (APBI-IMRT) plan was designed for each patient. The prescription dose was 34 Gy in 10 fractions, 3.4 Gy per fraction, twice a day, in intervals of more than 6 hours.

RESULTS

Of the 38 patients, six patients did not meet the planning criteria. The remaining 32 patients received APBI-IMRT with a mean target volume conformity index of 0.67 and a dose homogeneity index of 1.06. The median follow-up time was 53 months and no local recurrence or distant metastasis was detected. The most common acute toxicities observed within 3 months after radiotherapy were erythema, breast edema, pigmentation, and pain in the irradiated location, among which 43.8%, 12.5%, 31.3%, and 28.1% were grade 1 toxicities, respectively. The most common late toxicities occurring after 3 months until the end of the follow-up period were breast edema, pigmentation, pain in the irradiated location, and subcutaneous fibrosis, among which 6.2%, 28.1%, 21.9%, and 37.5% were grade 1 toxicities, respectively. Thirty-one patients (96.8%) had fine or excellent cosmetic outcomes, and only one patient had a poor cosmetic outcome.

CONCLUSION

It is feasible for Chinese females to receive APBI-IMRT after breast conserving surgery. The radiotherapeutic toxicity is acceptable, and both the initial efficacy and cosmetic outcomes are good.

Accelerated partial breast irradiation

Local therapies to treat newly diagnosed breast cancer include a lumpectomy with radiation therapy or a mastectomy. The 20-year data from studies about the safety and efficacy of lumpectomy with full-breast radiation therapy support the safety of this regimen and its role to decrease the risk of ipsilateral recurrence and increase long-term survivorship of women with breast cancer. Accelerated partial breast irradiation (APBI) provides radiation therapy to the tumor bed but spares the remaining breast tissue. APBI accelerates the time required to complete the therapy regimen, with a range of one intraoperative session to five consecutive days compared to five to seven weeks. Several techniques exist to administer APBI, including the insertion of a balloon into the lumpectomy space. Of interest is the widespread use of APBI in community and academic settings that has preceded outcomes of large, randomized clinical trials. Because of selection bias in a number of small, single-institution, nonrandomized studies, published data are of limited value to ensure APBI as a standard of care.

A Phase I/II Trial to Evaluate the Technical Feasibility of Partial Breast Irradiation with Three-Dimensional Conformal Radiation Therapy in Korean Women with Stage I Breast Carcinoma: An Initial Report of the Korean Radiation Therapy Oncology Group (KROG) Study 0804

PURPOSE

This prospective study was designed to verify the technical feasibility of partial breast irradiation in breast cancer patients with small breasts, which are commonly encountered in Korean women.

MATERIALS AND METHODS

A total of 40 Gy, administered in 10 fractions on consecutive days (one fraction per day), was prescribed to the isocenters of the fields using three-dimensional conformal radiotherapy (3-DCRT). For all patients, treatment planning and dose parameters strictly adhered to the constraints set forth in the Radiation Therapy Oncology Group (RTOG) 0319 protocol. This study was designed such that if fewer than five of the first 42 evaluable patients received unacceptable scores, the treatment would be considered reproducible.

RESULTS

Ten treatment plans (23.8%) were determined to have major variations. There was no major variation in planning target volume (PTV) coverage. The ipsilateral and contralateral breast dose limitations were not met in four (9.5%) and four cases (9.5%), respectively. Major variations in ipsilateral and contralateral lung dose limitations were observed in two cases (4.8%). Major variations in the heart and thyroid dose limitations were observed in one (2.4%) and one case (2.4%), respectively. In multivariate analysis, a ratio of PTV to ipsilateral breast volume (PTV/IB) > 0.16 was the only significant factor that statistically affected major variations.

CONCLUSION

We concluded that partial breast irradiation using 3-DCRT could not be reproduced in Korean breast cancer patients, particularly small-volumed breast surrogated as PTV/IB > 0.16. The dominant cause was the major variation in surrounding normal breast tissues.

Current role of modern radiotherapy techniques in the management of breast cancer

Breast cancer is the most common type of malignancy in females. Advances in systemic therapies and radiotherapy (RT) provided long survival rates in breast cancer patients. RT has a major role in the management of breast cancer. During the past 15 years several developments took place in the field of imaging and irradiation techniques, intensity modulated RT, hypofractionation and partial-breast irradiation. Currently, improvements in the RT technology allow us a subsequent decrease in the treatment-related complications such as fibrosis and long-term cardiac toxicity while improving the loco-regional control rates and cosmetic results. Thus, it is crucial that modern radiotherapy techniques should be carried out with maximum care and efficiency. Several randomized trials provided evidence for the feasibility of modern radiotherapy techniques in the management of breast cancer. However, the role of modern radiotherapy techniques in the management of breast cancer will continue to be defined by the mature results of randomized trials. Current review will provide an up-to-date evidence based data on the role of modern radiotherapy techniques in the management of breast cancer.