Whole-breast irradiation with or without a boost for patients treated with breast-conserving surgery for early breast cancer: 20-year follow-up of a randomised phase 3 trial

On the need of in vivo verifications as quality control for intraoperative electron radiotherapy in breast cancer

INTRODUCTION

Intraoperative electron radiotherapy (IOERT) is a technique aiming to deliver radiotherapy during oncological surgery. In breast IOERT, the applicator and shielding disc placement are correlated with organs at risk (OAR) irradiation, in vivo verification of these parameters is scarcely reported. The aim of our study is to report and analyze possible causes of the misalignment using radiochromic films and compare our results to others reported in the bibliography.

METHODS

From November 2019 to April 2023, in vivo verifications were performed for 33 patients. IOERT was performed using a LIAC 10 MeV (Sordina, Italy) electron accelerator. We attached a radiochromic film to the upper side of the polytetrafluoroethylene cover of the shielding disc. The percentage of the irradiation area outside the disc was recorded and various parameters (applicator angulations, prescription depth, tumor location and breast size) were analyzed to find possible correlations.

RESULTS

For 29 patients, 20 Gy were prescribed while 10 Gy were prescribed to 4 patients. The average irradiated area outside the disc was 19% (0-56%) corresponding to a surface of 4.5 cm2 (0-17.4 cm2). The applicator of 5 cm was used for most of the patients. The mean prescription depth was 1.4 cm (0.5-2.5 cm). We found no correlation between the analyzed parameters and misalignment.

CONCLUSION

This study confirms the presence and magnitude of the misalignments. We strongly recommend in vivo verifications as a quality check during IOERT procedures. The misalignment has no correlation with tumor localization parameters, so the solution could be based on technical improvements of the applicator.

Timing of genetic testing in BRCA1/2 and PALB2-Associated breast cancer: Preoperative result disclosure increases uptake of risk-reducing mastectomy and reduces unnecessary exposure to radiotherapy

INTRODUCTION

The impact of timing of genetic testing on uptake of risk reducing mastectomy (RRM) in affected female BRCA1/2 or PALB2 carriers remains an area of evolving interest, particularly with the introduction of mainstream genetic testing initiatives.

METHODS

Women with stage I-III breast cancer and a confirmed germline pathogenic variant in BRCA1/2 or PALB2 between 2000 and 2023 were identified from an institutional genetics database. Uptake of RRM was evaluated according to disclosure of genetic testing results before or after index surgery for a first diagnosis of breast cancer.

RESULTS

The cohort included 287 female BRCA1/2 or PALB2 carriers with a median age of 44 years (IQR, 36-52). Overall, 155 (54 %) carriers received genetic testing results before and 132 (46 %) after index breast surgery. Receipt of genetic testing results before surgery was associated with a higher rate of index bilateral mastectomy (58.7 % vs. 7.6 %, p < 0.001) and a commensurate decrease in adjuvant radiation (41.9 % vs. 74.2 %, p < 0.001). At a median follow up of 4.4 years after genetic testing, 219 (76.3 %) affected carriers had undergone bilateral RRM, including 83.9 % with preoperative knowledge and 67.4 % of patients with postoperative knowledge of their germline pathogenic variant (log rank, p < 0.001). On multivariate regression, disclosure of genetic testing results before index breast surgery was independently associated with long-term uptake of bilateral mastectomy (HR 1.69, 95 % CI 1.21-2.38).

CONCLUSION

Genetic testing results delivered prior to index breast surgery increase uptake of bilateral RRM in affected BRCA1/2 and PALB2 carriers. Efforts to mainstream genetic testing would help optimize surgical decision-making.

Impact of radiation therapy for breast cancer with involved surgical margin after immediate breast reconstruction: A multi-institutional observational study

INTRODUCTION

Involved surgical margins are risk factors for local recurrence and re-excision is often difficult, particularly in patients with breast cancer undergoing immediate breast reconstruction (IBR). However, the magnitude of the effect of radiation therapy on preventing local recurrence for breast cancers with involved margins has not been sufficiently assessed.

MATERIALS AND METHODS

We retrospectively assessed sites of involved surgical margins and local recurrence after mastectomy with IBR in patients with early breast cancer between 2008 and 2016. The effect of postoperative radiation therapy was evaluated in patients with involved margins, adjusted for nuclear grade, lymphatic invasion, surgical procedures, and primary systemic therapy.

RESULTS

A total of 274 (5.8 %) out of 4726 patients who underwent mastectomy with IBR had involved surgical margins: 133, 68, 88, and 26 had involvement of the skin, deep margin, lateral margins, and nipple, respectively (including duplicates). Radiation therapy was administered to 54 patients with involved margins. In patients with involved margins, 7-year cumulative incidences of local recurrence were 1.9 % and 12.6 % with and without radiation therapy, respectively (adjusted hazard ratio, 0.17; 95 % CI, 0.04-0.80). Local recurrence occurred in 28 patients, and the sites were skin, subcutaneous tissue, muscle, and nipple-areola complex in 7, 17, 1, and 3 patients, respectively. Among them, 23 (82.1 %) were associated with involved margin sites.

CONCLUSIONS

Radiation therapy meaningfully reduced the incidence of local recurrence in patients with breast cancer with margin involvement after mastectomy with IBR. Most local recurrences occurred at involved margin-related sites.

A meta-analysis of randomized controlled trials comparing breast-conserving surgery and mastectomy in terms of patient survival rate and quality of life in breast cancer

The study aimed to assess the effects of breast-conserving surgery (BCS) versus mastectomy on survival and quality of life in Stages I, II, and III breast cancer, providing solid evidence for clinical decisions. We conducted a meta-analysis of randomized controlled trials on breast cancer treatments, searching databases such as PubMed and the Cochrane Library to compare BCS, and mastectomy's effects on survival and quality of life. A combined total of 16 734 patients in the control group and 17 435 patients in the experimental group were included in this analysis. This meta-analysis used RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) software for analysis. Our meta-analysis of 34 169 patients from 11 studies showed that BCS significantly reduced the overall recurrence rate at a median follow-up of 29 months, with a mean difference of 1.27 and a 95% confidence interval of 1.19-1.36, strongly supporting its effectiveness (P < .00001). Furthermore, our analysis found no significant increase in 5-year local recurrence rates for BCS versus mastectomy, indicating its long-term effectiveness with a mean difference of 1.13 (95% confidence interval: [1.03, 1.24], P = .01). Additionally, there was a notable decrease in tissue ischaemic necrosis among patients who had received BCS, with a mean difference of 0.37 (95% confidence interval: [0.33, 0.42], P < .00001), underscoring its benefits and long-term viability. BCS resulted in fewer cases of tissue ischaemic necrosis and higher body image scores compared with mastectomy, suggesting that it is a preferable option for better cosmetic outcomes and potentially favourable effects on prognosis and quality of life.

Hypofractionated radiotherapy with simultaneous tumor bed boost (Hi-RISE) in breast cancer patients receiving upfront breast-conserving surgery: study protocol for a phase III randomized controlled trial

BACKGROUND

The effectiveness and safety of moderately hypofractionated radiotherapy (HFRT) in patients undergoing breast-conserving surgery (BCS) has been demonstrated in several pivotal randomized trials. However, the feasibility of applying simultaneous integrated boost (SIB) to the tumor bed and regional node irradiation (RNI) using modern radiotherapy techniques with HFRT needs further evaluation.

METHODS

This prospective, multi-center, randomized controlled, non-inferiority phase III trial aims to determine the non-inferiority of HFRT combined with SIB (HFRTsib) compared with conventional fractionated radiotherapy with sequential boost (CFRTseq) in terms of five-year locoregional control rate in breast cancer patients undergoing upfront BCS. A total of 2904 participants will be recruited and randomized in a 1:1 ratio into the HFRTsib and CFRTseq groups. All patients will receive whole breast irradiation, and those with positive axillary nodes will receive additional RNI, including internal mammary irradiation. The prescribed dose for the HFRTsib group will be 40 Gy in 15 fractions, combined with a SIB of 48 Gy in 15 fractions to the tumor bed. The CFRTseq group will receive 50 Gy in 25 fractions, with a sequential boost of 10 Gy in 5 fractions to the tumor bed.

DISCUSSION

This trial intends to assess the effectiveness and safety of SIB combined with HFRT in early breast cancer patients following BCS. The primary endpoint is locoregional control, and the results of this trial are expected to offer crucial evidence for utilizing HFRT in breast cancer patients after BCS.

TRIAL REGISTRATION

This trial was registered at ClincalTrials.gov (NCT04025164) on July 18, 2019.

Hypofractionated whole breast IMRT with HDR brachytherapy boost in early-stage breast cancer: Long-term results from a single-center

INTRODUCTION/OBJECTIVES

The addition of a boost to the lumpectomy bed after whole-breast (WB) radiotherapy plays a key role in the treatment of patients with breast cancer (BC). The clinical benefits of a boost with high-dose-rate brachytherapy (HDR-BT) after conventional fractionation is supported by a large body of evidence. However, few studies have described its outcomes after a hypofractionated scheme.

MATERIALS AND METHODS

We included all patients treated with adjuvant WB-IMRT in 15 sessions followed by a single-session HDR-BT boost with local anesthesia on an outpatient basis.

RESULTS

Between 2009 and 2017, 638 patients with early-stage BC were treated according to the aforementioned protocol after breast-conserving surgery. Median follow-up was 6 years (4-11). Despite the low incidence of side effects and their slightness, we did identify an impact of breast volume on the risk of acute radiodermatitis, fibrosis, pain and edema. However, we did not identify any relationship between the volume in cubic centimeters of the BT-implant with acute or long-term side effects. 2.2% patients had an actual local relapse, 2.4% a 2nd primary in the same breast and 2.39% were diagnosed with contralateral BC. Event-free survival at 11 years was 85.5% with an overall survival of 95.7%.

CONCLUSION

Adjuvant hypofractionated whole-breast IMRT followed by a single dose HDR-BT boost has a low incidence of acute and chronic toxicity and excellent oncological outcomes. However, it may be worthwhile to intensify self-care protocols and surveillance in women with large breasts who may be at increased risk of side effects.

The Japanese breast cancer society clinical practice guidelines for radiation treatment of breast cancer, 2022 edition

The Breast Cancer Clinical Practice Guidelines, organized by the Japanese Breast Cancer Society (JBCS), were published in 2022. We present the English version of the Radiation Therapy (RT) section of the guidelines. The JBCS formed a task force to update the 2018 version of the JBCS Clinical Practice Guidelines. The Background Questions (BQs) contain the standard treatments for breast cancer in clinical practice, whereas the Clinical Questions (CQs) address daily clinical questions that remain controversial. Future Research Questions (FRQs) explore the subjects that are considered important issues, despite there being insufficient data for inclusion as CQs. The task force selected the 12 BQs, 8 CQs, and 6 FRQs for the RT section. For each CQ, systematic literature reviews and meta-analyses were conducted according to the Minds Manual for Guideline Development 2020, version 3.0. The recommendations, strength of recommendation, and strength of evidence for each CQ were determined based on systematic reviews and meta-analyses, and finalized by voting at the recommendation decision meeting.

Impact on the Transcriptome of Proton Beam Irradiation Targeted at Healthy Cardiac Tissue of Mice

Proton beam therapy is considered a step forward with respect to electromagnetic radiation, thanks to the reduction in the dose delivered. Among unwanted effects to healthy tissue, cardiovascular complications are a known long-term radiotherapy complication. The transcriptional response of cardiac tissue from xenografted BALB/c nude mice obtained at 3 and 10 days after proton irradiation covering both the tumor region and the underlying healthy tissue was analyzed as a function of dose and time. Three doses were used: 2 Gy, 6 Gy, and 9 Gy. The intermediate dose had caused the greatest impact at 3 days after irradiation: at 2 Gy, 219 genes were differently expressed, many of them represented by zinc finger proteins; at 6 Gy, there were 1109, with a predominance of genes involved in energy metabolism and responses to stimuli; and at 9 Gy, there were 105, mainly represented by zinc finger proteins and molecules involved in the regulation of cardiac function. After 10 days, no significant effects were detected, suggesting that cellular repair mechanisms had defused the potential alterations in gene expression. The nonlinear dose-response curve indicates a need to update the models built on photons to improve accuracy in health risk prediction. Our data also suggest a possible role for zinc finger protein genes as markers of proton therapy efficacy.

Major complications after intraoperative radiotherapy with low-energy x-rays in early breast cancer

PURPOSE

To describe and analyze major local complications after intraoperative radiotherapy (IORT) with low-energy x‑rays during breast-conserving surgery (BCS) in early breast cancer.

METHODS

Ten women out of 408 who were treated with IORT between 2002 and 2017 and subsequently developed a severe local complication requiring surgical intervention were retrospectively identified and analyzed. Demographic, clinical, and surgical parameters as well as complication characteristics and treatment methods were evaluated.

RESULTS

At initial presentation, eight patients (80%) showed redness, six (60%) seroma, six (60%) wound infection, six (60%) suture dehiscence, and four (40%) induration of the former surgical area. Hematoma and necrosis were observed in one case (10%) each. Time interval until appearance of the first symptoms ranged from directly postoperative until 15 years postoperatively (median 3.1 months). Initial treatment modalities comprised antibiotic therapy (n = 8/80%) and transcutaneous aspiration of seroma (n = 3/30%). In the majority of patients, smaller surgical interventions (excision of a necrotic area/fistula [n = 6/60%] or secondary suture [n = 5/50%]) were sufficient to overcome the complication, yet larger interventions such as complex flap surgery and mastectomy were necessary in one patient each.

CONCLUSION

IORT is an efficient and safe treatment method as < 2.5% of all IORT patients experienced major local complications. However, it seems to pose the risk of causing severe local complications that may require lengthy and burdensome treatment. Thorough preoperative counseling, implementation of recommended intraoperative precautions, and high vigilance for first symptoms of complications during follow-up appointments are necessary measures.

Pre- and Postoperative Antioxidant Use, Aryl Hydrocarbon Receptor (AhR) Activation and Clinical Outcome in Different Treatment Groups of Breast Cancer Patients

BACKGROUND

Cancer patients often use antioxidants that may interact with adjuvant treatments. The purpose was to investigate pre- and postoperative antioxidant use in relation to clinicopathological characteristics and prognosis in different breast cancer treatment groups.

METHODS AND PATIENTS

Pre- and postoperative antioxidant (vitamin A, C, E, carotenoids, or Q10) or multivitamin use was self-reported by patients from Lund (n = 1855) and Helsingborg (n=478), Sweden. Patients were followed for up to 15 years. Clinical data were obtained from patient charts. The aryl hydrocarbon receptor (AhR) was evaluated in tumor tissue arrays from 915 patients from Lund and with Western blot in MCF-7 and MDA-MB-231 cells.

RESULTS

About 10% of patients used antioxidants. Nuclear AhR (AhRnuc) positivity was twice as common in preoperative antioxidant users compared to non-users. In mechanistic studies vitamin C increased AhR levels and its downstream target CYP1B1, indicating AhR activation. There were significant interactions between tumor AhRnuc status and preoperative antioxidant use in relation to clinical outcome. In all patients, antioxidant use (other than multivitamins) at both visits was associated with poorer prognosis, while use only at the follow-up visit was associated with better prognosis, compared with no use at either visit.

CONCLUSION

The clinical impact of antioxidants depended on antioxidant type, timing of use, and tumor AhR activation. Antioxidants may influence clinical outcome by activation of the master regulator AhR in addition to interference with free radicals. Further studies are needed to identify breast patients that might improve or worsen their prognosis when using antioxidants postoperatively.

Breast Conserving Therapy for Patients With Prior Cosmetic Implant-Based Breast Augmentation: Outcomes and Comparison Against a Matched Cohort

INTRODUCTION

Controversy exists regarding potential increased toxic effects in patients with cosmetic implant-based augmentation (CIBA) who receive radiation therapy. We evaluated acute and chronic toxic effects associated with radiation therapy in women with prior CIBA treated with whole-breast irradiation (WBI) as part of breast conserving therapy (BCT) and compared these results against a cohort of patients without prior breast augmentation who received similar therapy.

METHODS

A retrospective review was performed to identify patients with a prior history of CIBA who subsequently underwent BCT with WBI. The control group consisted of consecutively treated patients without prior CIBA who also underwent BCT with WBI. Analyses included a comparison of baseline and treatment-associated factors between the augmentation and control groups, evaluation of toxic effects between both groups, and multivariable analysis of factors associated with the receipt of additional surgery following radiation.

RESULTS

Thirty-six patients with prior CIBA and 135 consecutively treated patients without CIBA were identified. Patients with prior CIBA were treated from 2006 through 2019, and patients without CIBA were treated from 2016 through 2019, though treatment characteristics and median follow-up time were similar between the two groups. Patients with prior CIBA were significantly less likely to experience acute moist desquamation (0% vs. 18%; P = .005). There were otherwise no statistically significant differences in acute (≤ 6 months) or chronic (> 6 months) toxic effects between the two groups. Rates of excellent/good chronic cosmetic outcome were 89% for the CIBA group and 97% in the control group (P = .094). On multivariable analysis, patients without prior CIBA (OR = 0.04; CI = 0.01-0.13; P < .001) and patients treated with moderately hypofractionated irradiation (OR = 0.08; CI = 0.02-0.23; P < .001) were significantly less likely to undergo additional surgery following receipt of WBI. Two patients experienced implant loss following radiation therapy.

CONCLUSIONS

WBI as part of BCT in patients with prior implant-based breast augmentation appears safe and is associated with favorable cosmetic outcomes. There was an increased need for additional surgery in patients with prior CIBA, but rates of acute and chronic toxic effects appeared similar to those in nonaugmented patients.

Traditional Clinicopathological Biomarkers Still Determine Disease-Free and Overall Survival in Invasive Breast Cancer Patients: A Pilot Study

Background: Molecular classification, tumor diameter, Ki67 expression, and brachytherapy administration still act as the most potent potential predictors of breast cancer recurrence and overall survival. Methods: Over the period of 23 months, we included in the study 92 invasive breast cancer (IBrC) patients initially diagnosed at the Clinical Ward of Breast Cancer and Reconstructive Surgery, Oncology Center in Bydgoszcz, Poland. The probability of disease-free survival (DFS) and overall survival (OS) in relation to potential prognostic factors for the patients were determined using a Kaplan-Meier analysis, and univariate and multivariate Cox regression analyses evaluated the predictive factors of IBrC patients. The investigation of the potential prognostic model's accuracy was analyzed using the ROC curve. Results: Patients with tumor size < 2 cm, Ki67 expression < 20%, luminal-A molecular subtype, and extra-dose brachytherapy boost administration displayed the most favorable prognosis according to breast cancer disease-free survival and overall survival. The estimated 5 year probability of DFS and OS rates in women with tumor diameter < 2 cm were 89% and 90%, respectively. In tumor diameter > 2 cm, the estimated 5 year probability of DFS was 73% and OS was 76%. Interestingly, the tumor diameter of 1.6 cm with a specificity of 60.5% and a sensitivity of 75% occurred as the best threshold point to differentiate patients with cancer recurrence from those without cancer progression. Conclusions: Our study provides essential information on the clinicopathological profile and future outcomes of early stage IBrC patients. Furthermore, the tumor diameter cut-off value of 1.6 cm discriminating between disease recurrence and those without disease progression patients represents an innovative direction for further research.

Computational Model Based on Optical Coherence Tomography (OCT) Skin Scanning to Identify and Quantify Acute Radiation Dermatitis (ARD): A Prospective Diagnostic Study

BACKGROUND

Acute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD.

OBJECTIVE

Our main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies.

METHODS

We conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT).

RESULTS

A total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P<.05) and a decrease after 3 months (P=.032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime.

CONCLUSION

An OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.

Decision regret of cancer patients after radiotherapy: results from a cross-sectional observational study at a large tertiary cancer center in Germany

PURPOSE

The decision-making process regarding cancer treatment is emotionally challenging for patients and families, harboring the risk of decision regret. We aimed to explore prevalence and determinants of decision regret following radiotherapy.

METHODS

This cross-sectional observational study was conducted at a tertiary cancer center to assess decision regret following radiotherapy. The study employed the German version of the Ottawa Decision Regret Scale (DRS) which was validated in the study population. Decision regret was categorized as absent (0 points), mild (1-25 points), and strong (> 25 points). Various psychosocial outcome measures were collected using validated questionnaires to identify factors that may be associated with decision regret.

RESULTS

Out of 320 eligible patients, 212 participated, with 207 completing the DRS. Median age at start of radiotherapy was 64 years [interquartile range (IQR), 56-72], genders were balanced (105 female, 102 male), and the most common cancer types were breast (n = 84; 41%), prostate (n = 57; 28%), and head-and-neck cancer (n = 19; 9%). Radiotherapy was applied with curative intention in 188 patients (91%). Median time between last radiotherapy fraction and questionnaire completion was 23 months (IQR, 1-38). DRS comprehensibility was rated as good or very good by 98% (196 of 201) of patients. Decision regret was reported by 43% (n = 90) as absent, 38% (n = 78) as mild, and 18% (n = 38) as strong. In the multiple regression analysis, poor Eastern Cooperative Oncology Group performance status, low social support, and dissatisfaction with care were independent risk factors for higher decision regret after radiotherapy.

CONCLUSIONS

The German version of the DRS could be used to assess decision regret in a diverse cohort of cancer patients undergoing radiotherapy. Decision regret was prevalent in a considerable proportion of patients. Further studies are necessary to validate these findings and obtain causal factors associated with decision regret after radiotherapy.

Radiotherapy for breast cancer

In early breast cancer, adjuvant moderately hypofractionated regimens are recommended for both whole breast, partial breast and locoregional irradiation which abbreviates the overall treatment time, as argued in this review. Gating is recommended as well as the use of a simultaneous integrated boost when indicated. A tangential field set-up is standard, however, for challenging cases volumetric modulated arc therapy techniques, or referral for proton therapy, may be considered. In the metastatic setting, stereotactic radiotherapy is a promising treatment option for oligometastatic disease.

Practice of Tumor Bed Boost in Patients after Oncoplastic Breast-Conserving Surgery

The practice of boost to the tumor bed after treatment with oncoplastic breast-conserving surgery (BCS) remains variable. Using a survey, the present study evaluated the current practice of tumor bed boost administered in women after oncoplastic BCS. Actively practicing radiation oncologists across India were sent a questionnaire on the practice of adjuvant whole-breast radiotherapy and tumor bed boost after oncoplastic BCS via email and encouraged to participate. Of the 54 radiation oncologists who participated, most (98.1%) used a linear accelerator for radiotherapy. Hypofractionation was preferred by 59.26%, standard fractionation by 7.41%, and the remaining selected the fractionation strategy based on various patient factors. In addition, 83.33% participants reported that they always planned tumor boost, 51.85% preferred photons for the boost, and 75.93% administered sequential boost. The most common dose for the boost was 12.5 Gy in five fractions (40.74%). Most participants (77.78%) revealed that they used a combination of methods for identifying the tumor bed. With respect to clip placement, most surgeons (96%) at the participants' centers placed ≥ 4 clips at the tumor site, with both the base and margins being preferred by surgeons (81.48%) for placement. Finally, 12.96% participants revealed that the surgeons always involved them during surgical planning, whereas 7.4% participants reported that they always included the surgeons during radiotherapy planning, suggesting that radiation oncologists and oncoplastic surgeons do not involve each other during surgical and radiotherapy planning, possibly leading to suboptimal treatment. This may be attributed to the absence of guidelines regarding boost practices after oncoplastic BCS.

Interplay of Oncoplastic Reconstruction and Adjuvant Radiation Therapy in Breast Cancer

Purpose

Oncoplastic breast surgery (OBS) combines breast cancer tumor removal with the cosmetic benefits of plastic surgery at the time of breast-conserving surgery. Potential advantages of OBS include wider surgical margins around the tumor bed, while the natural shape and appearance of the breast are maintained more than standard lumpectomy procedures. However, limited information is available regarding the potential effect on adjuvant radiation treatment planning.

Materials and Methods

Women with localized breast cancer undergoing lumpectomy with immediate OBS and adjuvant radiation therapy between 2014 and 2019 were reviewed. OBS was performed using volume displacement techniques and patients received whole-breast irradiation with 3-dimensional conformal radiation therapy.

Results

Volume of additional ipsilateral breast tissue removed during OBS ranged from 21 to 2086 cm3 (median, 304 cm3), 29% of patients had >500 cm3 of tissue removed. Surgical margins were positive in 12.5% and were not affected by volume of breast tissue removed (445 vs 439 cm3). Patients with surgical clips more often received a lumpectomy bed boost (75.9% vs 50.0%), boost volumes were on average 157 cm3 with clips versus 205 cm3 without clips. Mean V105 was comparable in patients with >500 cm3 tissue removed and irradiated breast volume >1000 cm3, while higher absolute volumes were found in patients with >26 cm posterior separation (58.0 cm3 vs 102.7 cm3; P = .07). No meaningful difference was observed in Dmax or radiation coverage (95% of the volume receiving 95% of the prescription dose) for patients with >26 cm posterior separation, >500 cm3 of breast tissue removed, or irradiated breast volume >1000 cm3.

Conclusions

Radiation dosimetry plans for patients undergoing oncoplastic surgery were acceptable and no significant radiation or surgical advantage was gained in patients with more tissue removed. Our study stresses the importance of clear communication between surgeons and radiation oncologists about sufficient marking of the lumpectomy cavity, using practices that minimize the need for re-excisions and minimize lumpectomy cavity disruption during rearrangement.

Toxicity of external beam accelerated partial-breast irradiation (APBI) in adjuvant therapy of early-stage breast cancer: prospective randomized study

BACKGROUND

Accelerated partial breast irradiation (APBI) is an alternative breast-conserving therapy approach where radiation is delivered in less time compared to whole breast irradiation (WBI), resulting in improved patient convenience, less toxicity, and cost savings. This prospective randomized study compares the external beam APBI with commonly used moderate hypofractionated WBI in terms of feasibility, safety, tolerance, and cosmetic effects.

METHODS

Early breast cancer patients after partial mastectomy were equally randomized into two arms- external APBI and moderate hypofractionated WBI. External beam technique using available technical innovations commonly used in targeted hypofractionated radiotherapy to minimize irradiated volumes was used (cone beam computed tomography navigation to clips in the tumor bed, deep inspiration breath hold technique, volumetric modulated arc therapy dose application, using flattening filter free beams and the six degrees of freedom robotic treatment couch). Cosmetics results and toxicity were evaluated using questionnaires, CTCAE criteria, and photo documentation.

RESULTS

The analysis of 84 patients with a median age of 64 years showed significantly fewer acute adverse events in the APBI arm regarding skin reactions, local and general symptoms during a median follow-up of 37 months (range 21-45 months). A significant difference in favor of the APBI arm in grade ≥ 2 late skin toxicity was observed (p = 0.026). Late toxicity in the breast area (deformation, edema, fibrosis, and pain), affecting the quality of life and cosmetic effect, occurred in 61% and 17% of patients in WBI and APBI arms, respectively. The cosmetic effect was more favorable in the APBI arm, especially 6 to 12 months after the radiotherapy.

CONCLUSION

External APBI demonstrated better feasibility and less toxicity than the standard regimen in the adjuvant setting for treating early breast cancer patients. The presented study confirmed the level of evidence for establishing the external APBI in daily clinical practice.

TRIAL REGISTRATION

NCT06007118.

Target volumes comparison between postoperative simulation magnetic resonance imaging and preoperative diagnostic magnetic resonance imaging for prone breast radiotherapy after breast-conserving surgery

BACKGROUND

This study investigated the differences in target volumes between preoperative magnetic resonance imaging (MRIpre) and postoperative MRI (MRIpost) for breast radiotherapy after breast-conserving surgery (BCS) using deformable image registration (DIR).

METHODS AND MATERIALS

Seventeen eligible patients who underwent whole-breast irradiation in the prone position after BCS were enrolled. On MRIpre, the gross tumor volume (GTV) was delineated as GTVpre, which was then expanded by 10 mm to represent the preoperative lumpectomy cavity (LC), denoted as LCpre. The LC was expanded to the clinical target volume (CTV) and planning target volume (PTV) on the MRIpre and MRIpost, denoted as CTVpre, CTVpost, PTVpre, and PTVpost, respectively. The MIM software system was used to register the MRIpre and MRIpost using DIR. Differences were evaluated regarding target volume, distance between the centers of mass (dCOM), conformity index (CI), and degree of inclusion (DI). The relationship between CILC /CIPTV and the clinical factors was also assessed.

RESULTS

Significant differences were observed in LC and PTV volumes between MRIpre and MRIpost (p < 0.0001). LCpre was 0.85 cm3 larger than LCpost, while PTVpre was 29.38 cm3 smaller than PTVpost. The dCOM between LCpre and LCpost was 1.371 cm, while that between PTVpre and PTVpost reduced to 1.348 cm. There were statistically significant increases in CI and DI for LCpost-LCpre and PTVpost-PTVpre (CI = 0.221, 0.470; DI = 0.472, 0.635). No obvious linear correlations (p > 0.05) were found between CI and GTV, primary tumor volume-to-breast volume ratio, distance from the primary tumor to the nipple and chest wall, and body mass index.

CONCLUSIONS

Despite using DIR technology, the spatial correspondence of target volumes between MRIpre and MRIpost was suboptimal. Therefore, relying solely on preoperative diagnostic MRI with DIR for postoperative LC delineation is not recommended.

The Effect of Wire Versus Magnetic Seed Localization on Lumpectomy Cavity Size

PURPOSE

Our purpose was to assess whether an association exists between surgical localization technique and lumpectomy cavity size on radiation therapy planning computed tomography (CT) scan.

METHODS AND MATERIALS

A single-institution retrospective review was conducted of women undergoing breast conserving surgery with wire or magnetic seed guided lumpectomy followed by adjuvant radiation therapy from 2018 to 2021. Patients of a surgeon only performing 1 localization technique or undergoing bracketed localization were excluded. The primary outcome was lumpectomy cavity size on simulation CT. Confounding due to imbalance in patient and tumor factors was addressed with overlap weights derived from a propensity score analysis and used in a weighted multivariable analysis. Secondary outcomes included positive margins, total pathologic volume, boost delivery, and boost modality.

RESULTS

Of 617 women who received lumpectomy during the study period, 387 were included in final analysis. Tumors of patients undergoing seed localization were more likely unifocal, assessable by ultrasound, and smaller. Seed use rates ranged from 27.7% to 70.7% per surgeon. There was no difference in positive margins (6.4 vs 5.4%, P = .79) or second surgeries (9.4 vs 8.1%, P = .79) between groups. Close margin rates were similar for ductal carcinoma in situ (P = .35) and invasive carcinoma (P = .97). In unadjusted bivariable analyses, wire localization was associated with larger total pathology volume (P = .004), but localization technique showed no association with CT cavity volume (P = .15). After adjusting for potentially confounding variables, multivariable analysis failed to show an association between localization technique and either CT cavity (P = .35) or total path volume (P = .08). There was no difference in indicated-boost delivery (P = .15) or electron boost (P = .14) by localization technique.

CONCLUSIONS

There was no significant difference in CT cavity size by localization technique, suggesting choice between surgical techniques does not impede radiation therapy boost delivery.

Effect of Delayed Oncoplastic Reduction Mammoplasty on Radiation Treatment Delay Following Breast-Conserving Surgery for Breast Cancer

BACKGROUND

The purpose of this study was to evaluate the delay in initiating adjuvant radiation therapy (RT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer who underwent oncoplastic reduction mammoplasty (ORM) following BCS compared with a matched cohort of patients who did not undergo ORM between BCS and RT.

METHODS

Medical records of 112 women (56 ORMs and 56 matched non-ORMs) with carcinoma in situ or early-stage breast cancer treated with BCS were reviewed. ORM was performed in a delayed manner following BCS, allowing confirmation of negative surgical margins. Time to RT was defined as time from last oncologic surgery to start of RT.

RESULTS

The median follow-up time was 6.8 years for the ORM cohort and 6.7 years for the control non-ORM cohort. Patients who underwent ORM following BCS experienced a significant delay in initiating RT (>8 weeks) than matched patients not undergoing ORM (66% vs. 34%; p < 0.001). Wound complications occurred in 44.6% (n = 25) of patients in the ORM cohort, which were mostly minor, including delayed wound healing and/or infection (39%). There was no significant difference in local recurrence between patients in the non-ORM and ORM cohorts (p = 0.32).

CONCLUSIONS

This study demonstrates that ORM following BCS has the potential to delay RT >8 weeks, largely as a result of increased risk of wound complications; however, this delay did not impact local control. ORM can be safely considered for appropriately selected patients with breast cancer.

Large scale experience of two ultrahypofractionated 5 fractions regimes after breast conserving surgery from a single centre

PURPOSE

Ultra-hypofractionation breast radiotherapy is a safe alternative to moderate hypofractionation. This study reports the results of two ultrahypofractionated regimens used in clinical practice in a high-volume radiotherapy center in terms of efficacy and of tolerance.

METHODS

we included all patients treated in an adjuvant setting with five fractions after breast conserving surgery (BCS), for a histologically-confirmed invasive or in situ breast carcinoma. Radiotherapy regimens after BCS were either a 5-week schedule with 5 weekly fractions of 5,7 Gy or a one-week schedule with 5 daily fractions of 5,2 Gy. Adverse events were recorded and local-relapse free survival (LRFS), locoregional-relapse free survival (LRRFS), metastasis-free survival (MFS), for breast-cancer specific survival (BCSS) and overall survival (OS) were evaluated.

RESULTS

Between December 2014 and December 2022, 396 patients (400 breasts) were treated with ultrahypofractionated radiotherapy. Five-year LRFS was 98.8% (95% confidence interval: 97.1%-100%), and 5-year OS was 96.0% (95%CI: 92.6-99.5%). Age was statistically associated with OS in univariate analysis (HR: 1.16, 95%CI: 1.04-1.42, p = .01). Four patients (1.0%) experienced acute grade 3 radiation-induced adverse events, and 8 patients (2.3%) acute grade 2 toxicities. Twenty-three patients (5.8%) experienced late toxicity, all of them being graded as grade 1. The use of the 5.7 Gy-weekly-fraction regimen and the delivery of a tumor bed boost were significantly associated with acute radiodermatitis (p < .01; p = .02; respectively) and late fibrosis (p < .01; p = .049; respectively).

CONCLUSIONS

ultrahypofractionated radiotherapy was associated with an excellent tumor control rate in our 'real-life' cohort with low-risk breast cancer patients. However, delivery of a tumor bed boost and using weekly 5.7-Gy fractions were associated with an increased risk of acute and late cutaneous toxicities.

Locoregional Therapy: From Mastectomy to Reconstruction, Targeted Surgery, and Ultra-Hypofractionated Radiotherapy

Background

The past 3 decades have seen an unprecedented shift toward treatment de-escalation in surgical therapy of breast cancer.

Summary

Radical mastectomy has been replaced by breast-conserving and oncoplastic approaches in most patients, and full axillary lymph node dissection by less radical staging procedures, such as sentinel lymph node biopsy and targeted axillary dissection. Further, attempts have been made to spare healthy tissue while increasing the probability of removing the tumor with clear margins, thus improving cosmetic results and minimizing the risk of local recurrence. In this context, modern probe-guided localization techniques have been introduced to guide surgical excision. This progress was accompanied by the development of targeted systemic therapies. At the same time, radiotherapy for breast cancer has undergone significant changes. The use of hypofractionation has decreased the typical length of a treatment course from 5-6 weeks to 1-3 weeks. Partial breast irradiation is now a valid option for de-escalation in patients with low-risk features. Axillary radiotherapy achieves similar recurrence rates and decreases the risk of lymphedema in patients with limited sentinel node involvement.

Key Messages

Taken together, these advances are important steps toward individualization of locoregional management strategies. This highlights the importance of interdisciplinary approaches for de-escalation of locoregional therapies.

Risk of developing subsequent primary lung cancer after receiving radiation for breast cancer

Background

Radiotherapy (RT) is integral to breast cancer treatment, especially in the current era that emphasizes breast conservation. The aim of our study was to determine the incidence of subsequent primary lung cancer after RT exposure for breast cancer over a time span of 3 decades to quantify this risk over time as modern oncologic treatment continues to evolve.

Methods

The SEER (Surveillance, Epidemiology, and End Results) database was queried from 1988 to 2014 for patients diagnosed with nonmetastatic breast cancer. Patients who subsequently developed primary lung cancer were identified. Multivariable regression modeling was performed to identify independent factors associated with the development of lung cancer stratified by follow up intervals of 5 to 9 years, 10 to 15 years, and >15 years after breast cancer diagnosis.

Results

Of the 612,746 patients who met our inclusion criteria, 319,014 (52%) were irradiated. primary lung cancer developed in 5556 patients (1.74%) in the RT group versus 4935 patients (1.68%) in the non-RT group. In a multivariable model stratified by follow-up duration, the overall HR of developing subsequent ipsilateral lung cancer in the RT group was 1.14 (P = .036) after 5 to 9 years of follow-up, 1.28 (P = .002) after 10 to 15 years of follow-up, and 1.30 (P = .014) after >15 years of follow-up. The HR of contralateral lung cancer was not increased at any time interval.

Conclusions

The increased risk of developing a primary lung cancer secondary to RT exposure for breast cancer is much lower than previously published. Modern RT techniques may have contributed to the improved risk profile, and this updated study is important for counseling and surveillance of breast cancer patients.

Thermally boosted interstitial high-dose-rate brachytherapy in high-risk early-stage breast cancer conserving therapy - large cohort long-term results

Background

Early-stage high-risk breast cancer (BC) is standardly treated with breast-conserving therapy (BCT), combined with systemic therapy and radiotherapy (RT) ± tumor bed boost, e.g., with interstitial high-dose-rate brachytherapy (HDR-BT). To improve local recurrence rate (LRR), BT radiosensitization (thermal boost, TB) with interstitial microwave hyperthermia (MWHT) may be an option. The paper aims to report a retrospective single-institutional study on 5- and 10-year local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), overall survival (OS), cosmetic outcome (CO), and late toxicity (fibrosis, fat necrosis) after thermally enhanced HDR-BT boost to the BC tumor bed.

Materials and methods

In 2006-2018, 557 early-stage (I-IIIA) high-risk BC patients were treated with BCT. If indicated, they were administered systemic therapy, then referred for 40.0-50.0 Gy whole breast irradiation (WBI) and 10 Gy interstitial HDR-BT boost (group A). Eligible patients had a single MWHT session preceding BT (group B). Based on present risk factors (RF), medium-risk (1-2 RF) and high-risk subgroups (≥ 3 RF) were formed. Patients were standardly checked, and control mammography (MMG) was performed yearly. Breast cosmesis (Harvard scale) and fibrosis were recorded. LC, DMFS, DFS, and OS were statistically analyzed.

Results

Out of 557 patients aged 57 years (26-84), 364 (63.4%) had interstitial HDR-BT boost (group A), and 193 (34.6%) were preheated with MWHT (group B). Patients in group B had a higher clinical stage and had more RFs. The median follow-up was 65.9. Estimated 5-year and 10-year LC resulted in 98.5% and 97.5%, respectively. There was no difference in LC, DMFS, DFS, and OS between groups A and B and between extracted high-risk subgroups A and B. Five- and ten-year OS probability was 95.4% and 88.0%, respectively, with no difference between groups A and B. Harvard criteria-based CO assessment revealed good/excellent cosmesis in 74.9-79.1%. Tumor bed hardening was present in 40.1-42.2%. Asymptomatic fat necrosis-related macrocalcifications were detected in 15.6%, more frequently in group B (p = 0.016).

Conclusions

Thermally boosted or not, HDR-BT was locally highly effective as part of combined treatment. Five- and ten-year LC, DMFS, DFS, and OS were high and equally distributed between the groups, although TB was prescribed in more advanced one with more RFs. TB did not influence CO and fibrosis. TB added to late toxicity regarding asymptomatic fat necrosis detected on MMG.

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.

Single-Institution Prospective Evaluation of Moderately Hypofractionated Whole-Breast Radiation Therapy With Simultaneous Integrated Boost With or Without Lymphatic Drainage Irradiation After Breast-Conserving Surgery

Purpose

We report treatment outcomes for patients who received adjuvant moderate hypofractionated whole-breast radiation therapy with simultaneous integrated boost (SIB-mhWBRT) after breast-conserving surgery.

Methods and Materials

SIB-mhWBRT for patients with breast cancer was introduced in our department in July 2017. This prospective evaluation includes 424 consecutive patients treated with SIB-mhWBRT for stage I-III invasive breast cancer (n = 391) and/or ductal carcinoma in situ (n = 33) until December 2021. SIB-mhWBRT was applied with 40 Gy in 15 daily fractions over 3 weeks according to the START B trial, with an SIB dose to the tumor bed of 48 Gy according to Radiation Therapy Oncology Group 1005/UK-IMPORT-HIGH, delivered as 3-dinemsional conformal radiation therapy (RT; n = 402), intensity modulated RT (n = 4), or volumetric modulated arc therapy (n = 18). The mean patient age was 60 years (range, 27-88). Since May 2018, patients with indications for lymphatic pathway RT were included (n = 62). Baseline parameters and follow-up data were recorded and reported, including objective assessment of treatment-related outcomes and subjective patient-reported outcome measures (PROMs).

Results

Mean/median follow-up was 29/33 months (range, 2-60). Acute toxicity grade 0, 1, 2, and 3 was observed in 25.0%, 61.4%, 13.3%, and 0%, respectively, at the completion of RT. Data of 281, 266, 243, 172, and 58 patients were available for 6-month and 1-, 2-, 3-, and 4-year follow-up, respectively. Grade 2 late effects were identified in 8.5%, 6.0%, 4.9%, 2.2%, and 10.2% and grade 3 in 2.8%, 1.1%, 1.2%, 0%, and 0% of patients at 6-month and 1-, 2-, 3-, and 4-year follow-up, respectively. Medical treatment of breast edema was the only grade 3 late effect observed. PROM cosmesis results were evaluated as excellent-good, fair, and poor in 97.2%, 2.5%, and 0.4%; 96.5%, 3.1%, and 0.4%; 97.4%, 2.2%, and 0.4%; 97.5%, 2.5%, and 0%; and 96.5%, 3.5%, and 0.0% at 6 months and 1, 2, 3, and 4 years post-RT, respectively. For all patients, the 3-year overall, cancer-specific, and disease-free survival rates were 98.2%, 99.1%, and 95.9%, respectively. Three-year risk of any locoregional recurrence was 0.6%. No mortality or relapse was observed in patients with ductal carcinoma in situ.

Conclusions

SIB-mhWBRT demonstrated very favorable side effect profiles and cosmesis/PROMs. Three-year results demonstrate excellent locoregional control. This short-term regimen offers substantial patient comfort and improves institutional efficacy.

Case Report: Bilateral targeted intraoperative radiotherapy: a safe and effective alternative for synchronous bilateral breast cancer

Background

The incidence of bilateral breast cancer (BBC) ranges from 1.4% to 11.8%. BBC irradiation is a challenge in current clinical practice due to the large target volume that must be irradiated while minimizing the dose to critical organs. Supine or prone breast techniques can be used, with the latter providing better organ sparing; both, however, result in lengthy treatment times. The use of Intra-operative radiotherapy (IORT) in breast cancer patients who choose breast conservation has been highlighted in previous studies, but there is a scarcity of literature analyzing the utility and applicability of IORT in BBC. This case series aims to highlight the applicability of administering bilateral IORT in patients with BBC.

Case reports

Five patients with bilateral early-stage breast cancer (or DCIS) were treated with breast-conserving surgery followed by bilateral IORT. Of the 10 breast cancers, 8 were diagnosed as either DCIS or IDC, while the other 2 were diagnosed as invasive lobular carcinoma and invasive carcinoma, respectively. During surgery, all patients received bilateral IORT. Furthermore, 1 patient received external beam radiation therapy after her final pathology revealed grade 3 DCIS. The IORT procedure was well tolerated by all five patients, and all patients received aromatase inhibitors as adjuvant therapy. Additionally, none of these patients showed evidence of disease after a 36-month median follow-up.

Conclusion

Our findings demonstrate the successful use of IORT for BCS in patients with BBC. Furthermore, none of the patients in our study experienced any complications, suggesting the feasibility of the use of IORT in BBC. Considering the benefits of improved patient compliance and a reduced number of multiple visits, IORT may serve as an excellent patient-centered alternative for BBC. Future studies are recommended to reinforce the applicability of IORT in patients with BBC.

A Comprehensive Primer on Radiation Oncology for Non-Radiation Oncologists

Background: Multidisciplinary management is crucial in cancer diagnosis and treatment. Multidisciplinary teams include specialists in surgery, medical therapies, and radiation therapy (RT), each playing unique roles in oncology care. One significant aspect is RT, guided by radiation oncologists (ROs). This paper serves as a detailed primer for non-oncologists, medical students, or non-clinical investigators, educating them on contemporary RT practices. Methods: This report follows the process of RT planning and execution. Starting from the decision-making in multidisciplinary teams to the completion of RT and subsequent patient follow-up, it aims to offer non-oncologists an understanding of the RO's work in a comprehensive manner. Results: The first step in RT is a planning session that includes obtaining a CT scan of the area to be treated, known as the CT simulation. The patients are imaged in the exact position in which they will receive treatment. The second step, which is the primary source of uncertainty, involves the delineation of treatment targets and organs at risk (OAR). The objective is to ensure precise irradiation of the target volume while sparing the OARs as much as possible. Various radiation modalities, such as external beam therapy with electrons, photons, or particles (including protons and carbon ions), as well as brachytherapy, are utilized. Within these modalities, several techniques, such as three-dimensional conformal RT, intensity-modulated RT, volumetric modulated arc therapy, scattering beam proton therapy, and intensity-modulated proton therapy, are employed to achieve optimal treatment outcomes. The RT plan development is an iterative process involving medical physicists, dosimetrists, and ROs. The complexity and time required vary, ranging from an hour to a week. Once approved, RT begins, with image-guided RT being standard practice for patient alignment. The RO manages acute toxicities during treatment and prepares a summary upon completion. There is a considerable variance in practices, with some ROs offering lifelong follow-up and managing potential late effects of treatment. Conclusions: Comprehension of RT clinical effects by non-oncologists providers significantly elevates long-term patient care quality. Hence, educating non-oncologists enhances care for RT patients, underlining this report's importance.

Implementation of a Breast Intraoperative Oncoplastic Form to Aid Management of Oncoplastic Surgery

INTRODUCTION

Oncoplastic breast conservation surgery (BCS) uses concurrent reduction and/or mastopexy with lumpectomy to improve aesthetic outcomes. However, tissue rearrangement can shift the original tumor location site in relation to external breast landmarks, resulting in difficulties during re-excision for a positive margin and accurate radiation targeting. We developed the Breast Intraoperative Oncoplastic (BIO) form to help depict the location of the tumor and breast reduction specimen. This study seeks to assess physician perspectives of the implementation outcomes.

METHODS

From February 2021 to April 2021, the BIO form was used in 11 oncoplastic BCS cases at a single institution. With institutional review board approval, surgical oncologists (SOs), plastic surgeons (PSs), and radiation oncologists (ROs) were administered a 12-question validated survey on Acceptability of Intervention Measure (AIM), Intervention Appropriateness Measure (IAM), and Feasibility of Intervention Measure (FIM), using a 5-point Likert scale during initial implementation and at 6-month reassessment.

RESULTS

Twelve physicians completed the survey initially (4 SOs, 4 PSs, and 4 ROs). The mean scores for Acceptability of Intervention Measure, Intervention Appropriateness Measure, and Feasibility of Intervention Measure were high (4.44, 4.56, and 4.56, respectively). Twelve completed the second survey (5 SOs, 3 PSs, and 4 ROs). The mean scores were marginally lower (4.06, 4.21, and 4.25). There were no significant differences when stratified by number of years in practice or specialty. Free text comments showed that 75% of physicians found the form helpful in oncoplastic BCS.

CONCLUSIONS

The data indicate high feasibility, acceptability, and appropriateness of the BIO form. Results of this study suggest multidisciplinary benefits of implementing the BIO form in oncoplastic BCS.

A Comparison Between Sequential Conventional and Hypofractionated Boost Following Whole-Breast Radiotherapy: A Propensity Score-Matched Analysis

BACKGROUND

The majority of local relapses after breast conservation therapy occur in the proximity of the primary lesion. Studies have shown that boost radiotherapy (RT) following conventional whole-breast radiotherapy (WBRT) of 50 Gy in five weeks improves outcomes. Boost RT also increases the risk of moderate skin reactions and fibrosis. The ideal boost RT dose and timing (sequential versus simultaneous) after hypofractionated radiotherapy schedules remain unclear. This retrospective propensity score-matched analysis assessed the outcome of sequential hypofractionated boost compared to conventional fractionated boost.

METHODS

The study was approved by the Institutional Review Board of the Regional Cancer Centre, Thiruvananthapuram, India. Patients with stage I-III breast cancer who have received adjuvant radiotherapy with a sequential boost of either hypofractionated RT (8 Gy in three fractions) or conventional fractionated RT (10 Gy in five fractions) after conservative breast surgery were identified from the radiotherapy planning records and included in this study. A 1:1 case matching was performed using a propensity score incorporating four known prognostic factors, namely, clinical and pathological composite stage, tumor grade, tumor biology (based on estrogen and/or progesterone and HER2 neu expression), and boost technique, which may have an impact on acute toxicity to make the two boost groups more homogenous.

RESULTS

After propensity score matching (PSM), there were a total of 166 patients, with 83 patients each in both conventional and hypofractionated boost RT groups. The median follow-up period was 30.7 months. At two years, locoregional recurrence-free survival (LRFS) was 98.8% in both groups. Disease-free survival (DFS) at two years for the hypofractionated group and conventional group was 91.5% and 96.3% (hazard ratio (HR): 2.5, 95% confidence interval (CI): 0.664-9.4, p = 0.161), respectively, with no statistically significant difference. Patients with grade 3 tumors who received hypofractionated boost had a statistically significant increased risk of recurrence (DFS: 88.9% versus 100%, HR: 60.559, 95% CI: 0.138-26613.2, p = 0.011). The overall survival (OS) at two years was 100% in both groups. There was no difference in acute skin toxicity between the two groups.

CONCLUSION

The present interim analysis shows similar locoregional recurrence-free survival, overall survival, and disease-free survival and acute skin toxicity for hypofractionated boost RT of 8 Gy in three fractions compared to the conventional boost of 10 Gy in five fractions. Hypofractionated boost is a feasible alternative option following hypofractionated whole-breast radiotherapy for women with breast conservation treatment. However, longer follow-up is required before forming definite conclusions.

[Breast cancer radiation therapy: Current questions in 2023]

Radiation therapy is a corner stone of breast cancer treatment as it has been shown postoperatively that it improves local control and overall survival. In recent years, multidisciplinary therapeutic strategies have evolved considerably for early-stage breast cancer, both surgically and in terms of systemic treatments or radiation therapy. Each of these developments affects other treatment components and open up new questions allowing even more personalized treatments. Essentially normofractionated a few years ago, breast radiation therapy is today very largely moderately or even ultra hypofractionated. De-escalation of the surgery of the axilla has changed the indications for lymph node radiation therapy keeping similar efficacy with reduced toxicity. Indications for radiation therapy after neoadjuvant chemotherapy remain based on pre-chemotherapy staging pending the results of ongoing randomized studies. The addition of a boost to the tumor bed significantly reduces the risk of local recurrence, but the magnitude of this benefit decreases with increasing age. The main risk factors for local recurrence are young age, the associated extended ductal in situ component, hormone receptor negative and high-grade status. The results of the simultaneous integrated boost (SIB) seem similar with normo- or moderately hypofractionated radiation therapy regimen.

[Adjuvant radiation therapy for breast cancer]

Adjuvant radiotherapy is an integral part of multimodal therapy for early breast cancer. It contributes to the reduction of local recurrences across all disease stages. (Moderate) hypofractionated whole-breast irradiation is the standard of care. In low-risk situations, partial breast irradiation can be an option. The indication for adjuvant radiotherapy after mastectomy or additional irradiation of regional lymph nodes depends on the patient's individual risk profile. Long-term results of treatment and further development of irradiation techniques now allow shorter, individualized and well-tolerated treatments with the aim of therapy de-escalation.

Treatment of Early Breast Cancer: The 18th St. Gallen International Breast Cancer Consensus Conference against the Background of Current German Treatment Recommendations

This year's 18th St. Gallen (SG) consensus conference on the treatment of early breast cancer (SGBCC: St. Gallen International Breast Cancer Conference) focused on practice-oriented questions. The individual situation and risk-benefit assessment were discussed in great detail. As in previous years, a German working group of leading breast cancer experts presented the results of the international SGBCC 2023 against the background of German treatment recommendations - especially the updated treatment recommendations of the Arbeitsgemeinschaft Gynäkologische Onkologie e. V. (AGO) - for everyday clinical practice in Germany. The German treatment recommendations of AGO are based on the current evidence. The comparison with the clinical approach in Germany has proven useful, as the SGBCC panel consists of experts from different countries and disciplines. That is why country-specific characteristics can be incorporated into the SGBCC recommendations.

Comparison of helical and TomoDirect techniques with simultaneous integrated boost in early breast cancer patients

Background

The aim of the study was to perform dosimetric comparisons of helical (H) and TomoDirect (TD) plans for whole-breast irradiation (WBI) with simultaneous integrated boost (SIB) in early-stage breast cancer patients undergoing breast conserving surgery.

Materials and methods

Fifty patients, 25 with left-side and 25 with right-side tumors, were determined for a treatment planning system for a total dose of 50.4Gy in 1.8Gy per fraction to WBI, with a SIB of 2.3Gy per fraction delivered to the tumor bed. The planning target volume (PTV) doses and the conformity (CI) and homogeneity indices (HI) for PTVbreast and PTVboost, as well as organ-at-risk (OAR) doses and treatment times, were compared between the H and TD plans.

Results

All plans met the PTV coverage criteria for the H plan, except for mean V107 of PTVbreast for TD plan. The H plan yielded better homogeneity and conformity of dose distribution compared to the TD plan. The ipsilateral mean lung doses were not significantly different between the two plans. The TD plans is advantageous for mean doses to the heart, contralateral breast and lung, spinal cord, and esophagus than the H plans. In both the H and TD plans, the right-sided breast patients had lower heart dose parameters than the left-sided breast patients. The TD plan is superior to the H plan in sparing the contralateral breast and lung by decreasing low-dose volumes.

Conclusions

While the OAR dose advantages of TD are appealing, shorter treatment times or improved dose homogeneity and conformity for target volume may be advantageous for H plan.

Tumor Bed Boost Radiotherapy in the Conservative Treatment of Breast Cancer: A Review of Intra-Operative Techniques and Outcomes

Conservative surgery is the preferred treatment in the management of breast cancer followed by adjuvant whole-breast irradiation. Since the tumor bed is the main site of relapse, boost doses are conveniently administered according to risk factors for local relapse to increase the efficacy of the treatment. The benefit of a radiation boost is well established and it can be performed by several techniques like brachytherapy, external radiation or intraoperative radiotherapy. Greater precision in localizing the tumor cavity, immediacy and increased biological response are the main advantages of intraoperative boost irradiation. This modality of treatment can be performed by means of mobile electron accelerators or low-photon X-ray devices. There is a lot of research and some published series analyzing the results of the use of an intraoperative boost as an adjuvant treatment, after neoadjuvant systemic therapy and in combination with some reconstructive surgeries. This review discusses advantages of intraoperative radiotherapy and presents the main results of a boost in terms of local control, survival, tolerance and cosmesis.

Mapping the location of local and regional recurrences according to breast cancer surgery and radiation therapy: Results from EORTC 22922/10925

The purpose of this study is to evaluate the influence of the extent of surgery and radiation therapy (RT) on the rates and sites of local (LR) and regional recurrences (RR) in the EORTC 22922/10925 trial.

PATIENTS AND METHODS

All data were extracted from the trial's individual patients' case report forms (CRF) and analysed with a median follow-up of 15.7 years. Cumulative incidence curves were produced for LR and RR accounting for competing risks: an exploratory analysis of the effect of the extent of surgical and radiation treatments on LR rate was conducted using the Fine & Gray model accounting for competing risks and adjusted for baseline patient and disease characteristics. The significance level was set at 5%, 2-sided. Frequency tables were used to describe the spatial location of LR and RR.

RESULTS

Out of 4004 patients included in the trial, 282 (7%) patients experienced LR and 165 (4.1%) RR, respectively. Cumulative incidence rate of LR at 15 years was lower after mastectomy (3.1%) compared to BCS + RT (7.3%) (F&G: HR (Hazard Ratio) = 0.421, 95%CI = 0.282-0.628, p-value < 0.0001). LR were similar up to 3 years for both mastectomy and BCS but continued to occur at a steady rate for BCS + RT, only. The spatial location of the recurrence was related to the locoregional therapy applied and the absolute gain of RT correlated to stage of disease and extent of surgery.

CONCLUSIONS

The extent of locoregional therapies impacts significantly on LR and RR rates and spatial location.

A single-institution retrospective analysis of intraoperative radiation boost during breast-conservation treatment for breast cancer

BACKGROUND

As part of a breast-conservation strategy for breast cancer, there are presently no data from randomized controlled studies on the use of intraoperative radiation (IORT) as a tumor bed boost. The effectiveness and safety of IORT as a boost therapy at a tertiary cancer center were retrospectively reviewed in this study.

METHODS

Patients had breast-conserving surgery from 2012 to 2016 that included staging of the axillary lymph nodes, a single dose of 20 Gy IORT with 50-kV photons, whole-breast irradiation (WBI), and (neo-)adjuvant systemic treatment (if applicable). During the follow-up patients were monitored for the assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 4.03). Results included ipsilateral (IBTR), contralateral (CBE), and distant metastasis-free (DMFS) breast progression-free survival, as well as overall survival (OS).

RESULTS

The 68 patients had a median follow-up of 91.5 months (with a range of 9-125). Most patients (n = 51) had T1 disease and were clinically node negative. Only a small number of individuals had triple negative or high-grade illness. The majority of patients had sentinel node biopsy, and three (4.4%) had to have their tumors removed again since their original margins were positive. Finally, there were no distinct tumor bed margins. Neoadjuvant chemotherapy was administered to ten (14.7%). The median duration from BCS to WBI was 54.5 days, and conventionally fractionated WBI was used to accomplish WBI most frequently (n = 57, 96.6%). IORT was administered in a single 20 Gy dosage. 50 Gy was the median WBI dosage (range 40.05-50.4 Gy). There were no grade 4 adverse events for any patients in. Toxicities following surgery were minimal. There were only one patient with grade 3 toxicity (radiation dermatitis) to observe. Five tumor bed recurrences and two contralateral breast incident each occurred.

CONCLUSION

This work adds to the preliminary evidence already in the literature and supports the use of IORT in boost settings. When randomized trials like TARGIT-B are eventually published, these hopeful findings should be prospectively evaluated.

Experience with intraoperative radiation therapy in an urban cancer center

BACKGROUND/OBJECTIVE

Intra-operative radiation therapy (IORT) is a newer partial breast irradiation technique that has been well studied in 2 large randomized trials, the TARGIT-A and ELIOT trials. We initiated our IORT program in 2018 in the context of a registry trial, and aim to report our early results thus far.

METHODS

We instituted an IORT practice using Intrabeam® low energy 50kVp x-rays for selected breast cancer cases in 2018. Patients were enrolled on our institutional registry protocol which allowed for IORT in ER + patients with grade 1-2 DCIS ≤ 2.5 cm or invasive disease ≤ 3.5 cm in patients of at least 45 years of age.

RESULTS

Between January 2018 and December 2021, 181 patients with clinical stage 0-IIA ER + breast cancer were evaluated. One hundred sixty-seven patients ultimately received IORT to 172 sites. The majority of patients received IORT at the time of initial diagnosis and surgery (160/167; 95.8%). Re-excision post IORT occurred in 16/167 patients (9.6%) due to positive margins. Adjuvant RT to the whole breast +/- LN was ultimately given to 23/167 (13.8%) patients mainly due to positive sentinel LN found on final pathology (12/23; 52%); other reasons were close margins for DCIS (3/23; 13%), tumor size (3/23; 4.3%), and multifactorial (5/23; 17.4%). Five patients (3%) had post-operative complications of wound dehiscence. There were 3 local recurrences (1.6%) at a median follow-up of 27.9 months (range: 0.7- 54.8 months).

CONCLUSIONS

IORT has been proven to be a safe and patient-centered form of local adjuvant RT for our population, in whom compliance with a longer course of external beam radiation can be an issue. Long term efficacy remains to be evaluated through continued follow up. In the era of COVID-19 and beyond, IORT has been an increasingly attractive option, as it greatly minimizes toxicities and patient visits to the clinic.

TRIAL REGISTRATION

All patients were prospectively enrolled on an institutional review board-approved registry trial (IRB number: 2018-9409).

Accelerated subsequent lung cancer after post-operative radiotherapy for breast cancer

BACKGROUND

Post-operative whole breast radiotherapy for breast cancer (BC) may increase the risk of subsequent lung cancer (LC). The impact of radiotherapy intensification (boost) has not been specifically explored in this context. We investigated the role of radiation modalities on the development of subsequent LC among our patients treated by radiotherapy for localized BC.

METHODS

All patients with a diagnosis of LC between 2000 and 2020 with a history of prior localized BC treated by surgery and post-operative radiotherapy were retrospectively reviewed. Primary endpoint was time to first diagnosis of LC after BC treatment with radiotherapy (RT).

RESULTS

From 98 patients who developed subsequent LC after primary BC treated with post-operative RT, 38% of patients (n = 37) received an additional RT boost, and 46% (n = 45) received hormonal treatment post radiation. A total of 61% (n = 60) were smokers. With regards to LC characteristics, adenocarcinoma was the most frequent histology (68%, n = 66); 36% (n = 35) harbored at least 1 molecular alteration, 57% (n = 20) of them being amenable to targeted therapy. Median time to first diagnosis of LC was 6 years [1.7-28.4 yrs] in the whole cohort. In the subgroup of patients treated with boost this time was reduced to 4 years [1.8-20.8 years] compared to 8 years for patients without boost [1.7-28.4 yrs] (p = 0.007). Boost, smoking usage, endocrine therapy, and age <50 yrs old at BC radiation remained independent factors associated with shorter time to first diagnosis of LC after BC treatment.

DISCUSSION

We report for the first time the potential impact of boost -part of BC radiation treatment- for BC on the risk of subsequent LC. The impact of low dose radiation on lung parenchyma could explain this phenomenon, but the underlying physiopathology is still under investigation. This work highlights the need for clinicians to identify patients at risk of developing faster subsequent thoracic malignancy after BC radiation, for implementing personalized surveillance.

The Efficacy of Low-Kilovoltage X-Rays Intraoperative Radiation as Boost for Breast Cancer: A Systematic Review and Meta-Analysis

Background

Intraoperative radiotherapy (IORT) is a novel promising technology that may replace external beam radiation therapy (EBRT) as boost for patients receiving breast-conserving surgery. To better evaluate the efficacy of IORT using low-kilovoltage (low-kV) X-rays as boost, we presented this meta-analysis according to the PRISMA checklist.

Methods

Studies reported survival outcomes of intraoperative radiation using low-kilovoltage X-rays system (Intrabeam®, Carl Zeiss Meditec, Dublin, CA, USA) as boost were identified through electronic bibliographic database: PUBMED. The meta-analysis module in Stata (16.0) is used to pool the studies. A Poisson regression model is used to predict a 5-year local recurrence rate.

Results

Twelve studies including 3006 cases were included in the final analysis, with a median follow-up of 55 months weighted by sample size. The pooled local recurrence rate is 0.39% per person-year (95% CI: 0.15%-0.71%), with a low degree of heterogeneity (I² = 0%). The predicted 5-year local recurrence rate was 3.45%. No difference in pooled local recurrence rate was found between non-neoadjuvant patients studies and neoadjuvant patients studies (0.41% per person-year vs. 0.58% per person-year, P = 0.580).

Conclusions

This study shows that low-kV IORT is an effective method as boost in breast cancer patients, with a low pooled local recurrence rate and low predicted 5-year local recurrence rate. Besides, no difference in the local recurrence rate was found between non-neoadjuvant patients studies and neoadjuvant patients studies. Low-kV IORT boost may be a promising alternative to EBRT boost in the future, which is being tested in the ongoing TARGIT-B trial.

Acute skin toxicity of ultra-hypofractionated whole breast radiotherapy with simultaneous integrated boost for early breast cancer

Background

Whole-breast irradiation (WBI) after breast conserving surgery (BCS) is indicated to improve loco-regional control and survival. Former studies showed that addition of tumor bed boost in all age groups significantly improved local control although no apparent impact on overall survival but with an increased risk of worse cosmetic outcome. Even though shortened regimens in 3 weeks are considered the standard, recent studies have shown the non-inferiority of a treatment regimen of 5 fractions in one-week in both locoregional control and toxicity profile, although simultaneous integrated boost (SIB) in this setting has been scarcely studied.

Materials and Methods

From March-2020 to March-2022, 383 patients with early breast cancer diagnosis and a median age of 56 years-old (range 30-99)were included in a prospective registry of ultra-hypofractionated WBI up to a total dose of 26 Gy in 5.2 Gy/fraction with a SIB of 29 Gy in 5.8 Gy/fraction in 272 patients (71%), 30-31 Gy in 6-6.2 Gy/fraction in 111 patients (29%) with close/focally affected margins. Radiation treatment was delivered by conformal 3-D technique in 366 patients (95%), VMAT in 16patients (4%) and conformal 3-D with deep inspiration breath hold (DIBH) in 4patients (1%). Ninety-three per cent of patients received endocrine therapy and 43% systemic or targeted chemotherapy. Development of acute skin complications was retrospectively reviewed.

Results

With a median follow-up of 18 months (range 7-31), all patients are alive without evidence of local, regional or distant relapse. Acute tolerance was acceptable, with null o mild toxicity: 182 (48%) and 15 (4%) patients developed skin toxicity grade 1 and 2 respectively; 9 (2%) and 2 (0.5%) patients breast edema grade 1and 2 respectively. No other acute toxicities were observed. We also evaluated development of early delayed complications and observed grade 1 breast edema in 6 patients (2%); grade 1 hyperpigmentation in 20 patients (5%); and grade 1 and 2 breast induration underneath boost region in 10(3%) and 2 patients (0.5%) respectively. We found a statistically significant correlation between the median PTV_WBI and presence of skin toxicity (p = 0.028) as well as a significant correlation between late hyperpigmentation with the median PTV_BOOST (p = 0.007) and the ratio PTV_BOOST/PTV_WBI (p = 0.042).

Conclusion

Ultra-hypofractionated WBI + SIB in 5 fractions over one-week is feasible and well tolerated, although longer follow-up is necessary to confirm these results.

Dose-escalated simultaneous integrated boost radiotherapy in early breast cancer (IMPORT HIGH): a multicentre, phase 3, non-inferiority, open-label, randomised controlled trial

BACKGROUND

A tumour-bed boost delivered after whole-breast radiotherapy increases local cancer-control rates but requires more patient visits and can increase breast hardness. IMPORT HIGH tested simultaneous integrated boost against sequential boost with the aim of reducing treatment duration while maintaining excellent local control and similar or reduced toxicity.

METHODS

IMPORT HIGH is a phase 3, non-inferiority, open-label, randomised controlled trial that recruited women after breast-conserving surgery for pT1-3pN0-3aM0 invasive carcinoma from radiotherapy and referral centres in the UK. Patients were randomly allocated to receive one of three treatments in a 1:1:1 ratio, with computer-generated random permuted blocks used to stratify patients by centre. The control group received 40 Gy in 15 fractions to the whole breast and 16 Gy in 8 fractions sequential photon tumour-bed boost. Test group 1 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 48 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. Test group 2 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 53 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. The boost clinical target volume was the clip-defined tumour bed. Patients and clinicians were not masked to treatment allocation. The primary endpoint was ipsilateral breast tumour relapse (IBTR) analysed by intention to treat; assuming 5% 5-year incidence with the control group, non-inferiority was predefined as 3% or less absolute excess in the test groups (upper limit of two-sided 95% CI). Adverse events were assessed by clinicians, patients, and photographs. This trial is registered with the ISRCTN registry, ISRCTN47437448, and is closed to new participants.

FINDINGS

Between March 4, 2009, and Sept 16, 2015, 2617 patients were recruited. 871 individuals were assigned to the control group, 874 to test group 1, and 872 to test group 2. Median boost clinical target volume was 13 cm3 (IQR 7 to 22). At a median follow-up of 74 months there were 76 IBTR events (20 for the control group, 21 for test group 1, and 35 for test group 2). 5-year IBTR incidence was 1·9% (95% CI 1·2 to 3·1) for the control group, 2·0% (1·2 to 3·2) for test group 1, and 3·2% (2·2 to 4·7) for test group 2. The estimated absolute differences versus the control group were 0·1% (-0·8 to 1·7) for test group 1 and 1·4% (0·03 to 3·8) for test group 2. The upper confidence limit for test group 1 versus the control group indicated non-inferiority for 48 Gy. Cumulative 5-year incidence of clinician-reported moderate or marked breast induration was 11·5% for the control group, 10·6% for test group 1 (p=0·40 vs control group), and 15·5% for test group 2 (p=0·015 vs control group).

INTERPRETATION

In all groups 5-year IBTR incidence was lower than the 5% originally expected regardless of boost sequencing. Dose-escalation is not advantageous. 5-year moderate or marked adverse event rates were low using small boost volumes. Simultaneous integrated boost in IMPORT HIGH was safe and reduced patient visits.

FUNDING

Cancer Research UK.

Objective, Clinician- and Patient-Reported Evaluation of Late Toxicity Following Adjuvant Radiation for Early Breast Cancer: Long-Term Follow-Up Results of a Randomised Series

Background and Purpose: This study aimed to differentially assess the frequency and severity of late radiation-induced toxicity following adjuvant whole-breast irradiation for early breast cancer with conventional fractionation (CF) and moderate hypofractionation (mHF). Materials and Methods: Patients recruited in a previous randomised controlled trial comparing acute toxicity between CF and mHF without disease recurrence were included in a post hoc analysis. Spectrophotometric and ultrasonographic examinations were performed for an objective evaluation and subsequent comparison of long-term skin toxicity. Furthermore, patient- and clinician-reported outcomes were recorded. Results: Sixty-four patients with a median age of 58 (37-81) years were included. The median follow-up was 57 (37-73) months. A total of 55% underwent CF and 45% mHF. A total of 52% received a sequential boost to the tumour bed. A significant decrease in mean L* (p = 0.011) and an increase in a* (p = 0.040) and b* values (p < 0.001) were observed, indicating hyperpigmentation. In comparison with the non-irradiated breast, there was a significant increase in both cutis (+14%; p < 0.001) and subcutis (+17%; p = 0.011) thickness, significantly more pronounced in CF patients (p = 0.049). In CF patients only, a sequential boost significantly increased the local cutis thickness and oedema compared to non-boost regions in the same breast (p = 0.001 and p < 0.001, respectively). Conclusions: mHF objectively resulted in reduced long-term skin toxicity compared to CF. A sequential boost increased the local fibrosis rate in CF, but not in mHF. This might explain the subjectively reported better cosmetic outcomes in patients receiving mHF and reinforces the rationale for favouring mHF as the standard of care.

Comparison of intraoperative radiotherapy as a boost vs. simultaneously integrated boosts after breast-conserving therapy for breast cancer

Background

Currently, there are no data from randomized trials on the use of intraoperative radiotherapy (IORT) as a tumor bed boost in women at high risk of local recurrence. The aim of this retrospective analysis was to compare the toxicity and oncological outcome of IORT or simultaneous integrated boost (SIB) with conventional external beam radiotherapy (WBI) after breast conserving surgery (BCS).

Methods

Between 2009 and 2019, patients were treated with a single dose of 20 Gy IORT with 50 kV photons, followed by WBI 50 Gy in 25 or 40.05 in 15 fractions or WBI 50 Gy with SIB up to 58.80-61.60 Gy in 25-28 fractions. Toxicity was compared after propensity score matching. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method.

Results

A 1:1 propensity-score matching resulted in an IORT + WBI and SIB + WBI cohort of 60 patients, respectively. The median follow-up for IORT + WBI was 43.5 vs. 32 months in the SIB + WBI cohort. Most women had a pT1c tumor: IORT group 33 (55%) vs. 31 (51.7%) SIB group (p = 0.972). The luminal-B immunophenotype was most frequently diagnosed in the IORT group 43 (71.6%) vs. 35 (58.3%) in the SIB group (p = 0.283). The most reported acute adverse event in both groups was radiodermatitis. In the IORT cohort, radiodermatitis was grade 1: 23 (38.3%), grade 2: 26 (43.3%), and grade 3: 6 (10%) vs. SIB cohort grade 1: 3 (5.1%), grade 2: 21 (35%), and grade 3: 7 (11.6%) without a meaningful difference (p = 0.309). Fatigue occurred more frequently in the IORT group (grade 1: 21.7% vs. 6.7%; p = 0.041). In addition, intramammary lymphedema grade 1 occurred significantly more often in the IORT group (11.7% vs. 1.7%; p = 0.026). Both groups showed comparable late toxicity. The 3- and 5-year local control (LC) rates were each 98% in the SIB group vs. 98% and 93% in the IORT group (LS: log rank p = 0.717).

Conclusion

Tumor bed boost using IORT and SIB techniques after BCS shows excellent local control and comparable late toxicity, while IORT application exhibits a moderate increase in acute toxicity. These data should be validated by the expected publication of the prospective randomized TARGIT-B study.

A phase II randomized clinical trial to assess toxicity and quality of life of breast cancer patients with hypofractionated versus conventional fractionation radiotherapy with regional nodal irradiation in the context of COVID-19 crisis

Purpose

This study, conducted during the COVID-19 crisis, primarily aimed to compare the acute toxicity between conventional fractionated radiation therapy (CF-RT) with hypofractionated radiation therapy (HF-RT) among patients who underwent breast-conserving surgery or mastectomy in whom breast or chest wall and regional nodal irradiation (RNI) were indicated. The secondary endpoints were both acute and subacute toxicity, cosmesis, quality of life, and lymphedema features.

Methods

In this open and non-inferiority randomized trial, patients (n = 86) were randomly allocated 2:1 in the CF-RT arm (n = 33; 50 Gy/25 fractions ± sequential boost [10 Gy/5 fractions]) versus the HF-RT arm (n = 53; 40 Gy/15 fractions ± concomitant boost [8 Gy/15 fractions]). Toxic effects and cosmesis evaluation used the Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE) and the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/Radiation Therapy Oncology Group (RTOG) scale. For the patient-reported quality of life (QoL), the European Organisation for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-C30) and the breast cancer-specific supplementary questionnaire (QLQ-BR23) were used. Lymphedema was assessed by comparing volume differences between the affected and contralateral arms using the Casley-Smith formula.

Results

Grade 2 and grade 3 dermatitis were lower with HF-RT than with CF-RT (28% vs. 52%, and 0% vs. 6%, respectively; p = 0.022). HF-RT had a lower rate of grade 2 hyperpigmentation (23% vs. 55%; p = 0.005), compared to CF-RT. No other differences in overall rates of physician-assessed grade 2 or higher and grade 3 or higher acute toxicity between HF-RT and CF-RT were registered. There was no statistical difference between groups regarding cosmesis, lymphedema rate (13% vs. 12% HF-RT vs. CF-RT; p = 1.000), and functional and symptom scales, during both the irradiation period and after 6 months of the end of treatment. The results revealed that the subset of patients up to 65 years or older did not show a statistical difference between both arm fractionation schedules (p > 0.05) regarding skin rash, fibrosis, and lymphedema.

Conclusion

HF-RT was non-inferior to CF-RT, and moderate hypofractionation showed lower rates of acute toxicity, with no changes in quality-of-life outcomes.

Clinical trial registration

ClinicalTrials.gov, identifier NCT40155531.

Effect of pre-operative radiation therapy on surgical outcome in retroperitoneal sarcoma

Background

A high rate of locoregional recurrence is one of the major difficulties in successful treatment of retroperitoneal sarcoma (RPS). Although pre-operative radiation therapy (RT) is considered a potential way to improve local recurrence, concerns about the associated treatment toxicity and risk of peri-operative complications need to be addressed. Hence, this study investigates the safety of pre-operative RT (preRTx) for RPS.

Methods

A cohort of 198 patients with RPS who had undergone both surgery and RT was analyzed for peri-operative complications. They were divided into three groups according to the RT scheme: (1) preRTx group, (2) post-operative RT without tissue expander, and (3) post-operative RT with tissue expander.

Results

The preRTx was overall well tolerated and did not affect the R2 resection rate, operative time, and severe post-operative complications. However, the preRTx group was associated with higher incidence of post-operative transfusion and admission to intensive care unit (p = 0.013 and p = 0.036, respectively), where preRTx was an independent risk factor only for the post-operative transfusion (p = 0.009) in multivariate analysis. The median radiation dose was the highest in preRTx group, although no significant difference was demonstrated in overall survival and local recurrence rate.

Conclusion

This study suggests that the preRTx does not add significant post-operative morbidity to the patients with RPS. In addition, radiation dose elevation is achievable with the pre-operative RT. However, a meticulous intra-operative bleeding control is recommended in those patients, and further high-quality trials are warranted to evaluate the long-term oncological outcomes.