Neoadjuvant chemoradiotherapy in combination with deep regional hyperthermia followed by surgery for rectal cancer: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Combining chemoradiotherapy (CRT) with deep regional hyperthermia (HT) shows promise for enhancing clinical outcomes in selected rectal cancer patients. This study aimed to integrate the evidence and evaluate the efficacy of this combined treatment approach. MATERIALS AND METHODS: A systematic search of the PubMed, Scopus, and Mendeley databases was performed. This review was conducted according to the PRISMA guidelines. The quality of studies was evaluated using the Newcastle-Ottawa scale (NOS). Random-effects meta-analyses (DerSimonian and Laird) were performed. The primary outcome was pathological complete response (pCR), and secondary endpoints were overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and toxicity. RESULTS: In total, 12 studies were included, mostly of moderate quality. Patients with locally advanced rectal cancer (LARC; n = 760) and locally recurrent rectal cancer (LRRC; n = 22) were eligible. The pooled pCR rate was 19% (95% confidence interval [CI]: 16-22%) among all 782 patients and 19% (95%CI:16-23%) among 760 LARC patients. Due to significant study heterogeneity, survival outcomes were pooled by excluding LRRC patients. The pooled 5­year OS rate among 433 LARC patients was 87% (95%CI: 83-90%). The pooled 5­year DFS and LRFS in LARC patients were 75% (95%CI: 70-80%) and 95% (95%CI: 92-97%), respectively. There was a lack of consistent reporting of HT treatment parameters and toxicity symptoms among the studies. CONCLUSION: The collective clinical evidence showed that neoadjuvant CRT combined with HT in rectal cancer patients is feasible, with a 19% pCR rate and excellent survival outcomes in long term follow-up.

Regional hyperthermia for soft tissue sarcoma - a survey on current practice, controversies and consensus among 12 European centers.

PURPOSE: To analyze the current practice of regional hyperthermia (RHT) for soft tissue sarcoma (STS) at 12 European centers to provide an overview, find consensuses and identify controversies necessary for future guidelines and clinical trials. METHODS: In this cross-sectional survey study, a 27-item questionnaire assessing clinical subjects and procedural details on RHT for STS was distributed to 12 European cancer centers for RHT. RESULTS: We have identified seven controversies and five consensus points. Of 12 centers, 6 offer both, RHT with chemotherapy (CTX) or with radiotherapy (RT). Two centers only offer RHT with CTX and four centers only offer RHT with RT. All 12 centers apply RHT for localized, high-risk STS of the extremities, trunk wall and retroperitoneum. However, eight centers also use RHT in metastatic STS, five in palliative STS, eight for superficial STS and six for low-grade STS. Pretherapeutic imaging for RHT treatment planning is used by 10 centers, 9 centers set 40-43 °C as the intratumoral target temperature, and all centers use skin detectors or probes in body orifices for thermometry. DISCUSSION: There is disagreement regarding the integration of RHT in contemporary interdisciplinary care of STS patients. Many clinical controversies exist that require a standardized consensus guideline and innovative study ideas. At the same time, our data has shown that existing guidelines and decades of experience with the technique of RHT have mostly standardized procedural aspects. CONCLUSIONS: The provided results may serve as a basis for future guidelines and inform future clinical trials for RHT in STS patients.

Improving the safety of radiotherapy treatment processes via incident-driven FMEA feedback loops.

BACKGROUND: Failure mode and effects analysis (FMEA) is a valuable tool for radiotherapy risk assessment, yet its outputs might be unreliable due to failures not being identified or due to a lack of accurate error rates. PURPOSE: A novel incident reporting system (IRS) linked to an FMEA database was tested and evaluated. The study investigated whether the system was suitable for validating a previously performed analysis and whether it could provide accurate error rates to support the expert occurrence ratings of previously identified failure modes. METHODS: Twenty-three pre-identified failure modes of our external beam radiotherapy process, covering the process steps from patient admission to treatment delivery, were proffered on dedicated FMEA feedback and incident reporting terminals generated by the IRS. The clinical setting involved a computed tomography scanner, dosimetry, and five linacs. Incoming reports were used as basis to identify additional failure modes or confirm initial ones. The Kruskal-Wallis H test was applied to compare the risk priorities of the retrospective and prospective failure modes. Wald's sequential probability ratio test was used to investigate the correctness of the experts' occurrence ratings by means of the number of incoming reports. RESULTS: Over a 15-month period, 304 reports were submitted. There were 0.005 (confidence interval [CI], 0.0014-0.0082) reported incidents per imaging study and 0.0006 (CI, 0.0003-0.0009) reported incidents per treatment fraction. Sixteen additional failure modes could be identified, and their risk priorities did not differ from those of the initial failure modes (p = 0.954). One failure mode occurrence rating could be increased, whereas the other 22 occurrence ratings could not be disproved. CONCLUSIONS: Our approach is suitable for validating FMEAs and deducing additional failure modes on a continual basis. Accurate error rates can only be provided if a sufficient number of reports is available.

Accelerated partial breast irradiation using sole interstitial multicatheter brachytherapy compared with whole-breast irradiation with boost for early breast cancer: 10-year results of a GEC-ESTRO randomised, phase 3, non-inferiority trial.

BACKGROUND: Several randomised, phase 3 trials have investigated the value of different techniques of accelerated partial breast irradiation (APBI) for patients with early breast cancer after breast-conserving surgery compared with whole-breast irradiation. In a phase 3 randomised trial, we evaluated whether APBI using multicatheter brachytherapy is non-inferior compared with whole-breast irradiation. Here, we present the 10-year follow-up results. METHODS: We did a randomised, phase 3, non-inferiority trial at 16 hospitals and medical centres in Austria, Czech Republic, Germany, Hungary, Poland, Spain, and Switzerland. Patients aged 40 years or older with early invasive breast cancer or ductal carcinoma in situ treated with breast-conserving surgery were centrally randomly assigned (1:1) to receive either whole-breast irradiation or APBI using multicatheter brachytherapy. Whole-breast irradiation was delivered in 25 daily fractions of 50 Gy over 5 weeks, with a supplemental boost of 10 Gy to the tumour bed, and APBI was delivered as 30·1 Gy (seven fractions) and 32·0 Gy (eight fractions) of high-dose-rate brachytherapy in 5 days or as 50 Gy of pulsed-dose-rate brachytherapy over 5 treatment days. Neither patients nor investigators were masked to treatment allocation. The primary endpoint was ipsilateral local recurrence, analysed in the as-treated population; the non-inferiority margin for the recurrence rate difference (defined for 5-year results) was 3 percentage points. The trial is registered with ClinicalTrials.gov, NCT00402519; the trial is complete. FINDINGS: Between April 20, 2004, and July 30, 2009, 1328 female patients were randomly assigned to whole breast irradiation (n=673) or APBI (n=655), of whom 551 in the whole-breast irradiation group and 633 in the APBI group were eligible for analysis. At a median follow-up of 10·36 years (IQR 9·12-11·28), the 10-year local recurrence rates were 1·58% (95% CI 0·37 to 2·8) in the whole-breast irradiation group and 3·51% (1·99 to 5·03) in the APBI group. The difference in 10-year rates between the groups was 1·93% (95% CI -0·018 to 3·87; p=0·074). Adverse events were mostly grade 1 and 2, in 234 (60%) of 393 participants in the whole-breast irradiation group and 314 (67%) of 470 participants in the APBI group, at 7·5-year or 10-year follow-up, or both. Patients in the APBI group had a significantly lower incidence of treatment-related grade 3 late side-effects than those in the whole-breast irradiation group (17 [4%] of 393 for whole-breast irradiation vs seven [1%] of 470 for APBI; p=0·021; at 7·5-year or 10-year follow-up, or both). At 10 years, the most common type of grade 3 adverse event in both treatment groups was fibrosis (six [2%] of 313 patients for whole-breast irradiation and three [1%] of 375 patients for APBI, p=0·56). No grade 4 adverse events or treatment-related deaths have been observed. INTERPRETATION: Postoperative APBI using multicatheter brachytherapy after breast-conserving surgery in patients with early breast cancer is a valuable alternative to whole-breast irradiation in terms of treatment efficacy and is associated with fewer late side-effects. FUNDING: German Cancer Aid, Germany.

Prerequisites for the clinical implementation of a markerless SGRT-only workflow for the treatment of breast cancer patients.

PURPOSE: A markerless workflow for the treatment of breast cancer patients has been introduced and evaluated retrospectively. It includes surface-guided radiation therapy (SGRT)-only positioning for patients with small cone beam CT (CBCT) position corrections during the first five fractions. Prerequisites and the frequency of its clinical application were evaluated, as well as potential benefits in terms of treatment time and dose savings, the frequency of CBCT scans, and the accuracy of the positioning. METHODS: A group of 100 patients treated with the new workflow on two Versa HD linacs has been compared to a matched control group of patients treated with the former workflow, which included prepositioning with skin markings and lasers, SGRT and daily CBCT. The comparison was based on the evaluation of logfiles. RESULTS: Of the patients treated with the new workflow, 40% did not receive daily CBCT scans. This resulted in mean time savings of 97 s, 166 s and 239 s per fraction for the new workflow, for patients treated without daily CBCT and for SGRT-only fractions, respectively, when compared to the old workflow. Dose savings amounted to a weighted computed tomography dose index reduction of CTDIW = 2.56 cGy on average for normofractionated treatment and weekly CBCTs, while for patients not treated with daily CBCT, SGRT-based positioning accuracy was 5.2 mm for the mean translational magnitude, as evaluated by CBCT. CONCLUSION: For 40% of the patients, after five fractions with small CBCT corrections, the workflow could be changed to SGRT-only positioning with weekly CBCT. This leads to imaging dose and time savings and thus also reduced intrafraction motion, potentially increased patient throughput and patient comfort, while assuring appropriate positioning accuracy.

Low-dose radiotherapy of osteoarthritis: from biological findings to clinical effects-challenges for future studies.

Osteoarthritis (OA) is one of the most common and socioeconomically relevant diseases, with rising incidence and prevalence especially with regard to an ageing population in the Western world. Over the decades, the scientific perception of OA has shifted from a simple degeneration of cartilage and bone to a multifactorial disease involving various cell types and immunomodulatory factors. Despite a wide range of conventional treatment modalities available, a significant proportion of patients remain treatment refractory. Low-dose radiotherapy (LDRT) has been used for decades in the treatment of patients with inflammatory and/or degenerative diseases and has proven a viable option even in cohorts of patients with a rather poor prognosis. While its justification mainly derives from a vast body of empirical evidence, prospective randomized trials have until now failed to prove the effectiveness of LDRT. Nevertheless, over the decades, adaptions of LDRT treatment modalities have evolved using lower dosages with establishment of different treatment schedules for which definitive clinical proof is still pending. Preclinical research has revealed that the immune system is modulated by LDRT and very recently osteoimmunological mechanisms have been described. Future studies and investigations further elucidating the underlying mechanisms are an essential key to clarify the optimal patient stratification and treatment procedure, considering the patients' inflammatory status, age, and sex. The present review aims not only to present clinical and preclinical knowledge about the mechanistic and beneficial effects of LDRT, but also to emphasize topics that will need to be addressed in future studies. Further, a concise overview of the current status of the underlying radiobiological knowledge of LDRT for clinicians is given, while seeking to stimulate further translational research.

A patterns of care analysis of hyperthermia in combination with radio(chemo)therapy or chemotherapy in European clinical centers.

PURPOSE: The combination of hyperthermia (HT) with radio(chemo)therapy or chemotherapy (CT) is an established treatment strategy for specific indications. Its application in routine clinical practice in Europe depends on regulatory and local conditions. We conducted a survey among European clinical centers to determine current practice of HT. METHODS: A questionnaire with 22 questions was sent to 24 European HT centers. The questions were divided into two main categories. The first category assessed how many patients are treated with HT in combination with radio(chemo)therapy or CT for specific indications per year. The second category addressed which hyperthermia parameters are recorded. Analysis was performed using descriptive methods. RESULTS: The response rate was 71% (17/24) and 16 centers were included in this evaluation. Annually, these 16 centers treat approximately 637 patients using HT in combination with radio(chemo)therapy or CT. On average, 34% (range: 3-100%) of patients are treated in clinical study protocols. Temperature readings and the time interval between HT and radio(chemo)therapy or CT are recorded in 13 (81%) and 9 (56%) centers, respectively. The thermal dose quality parameter "cumulative equivalent minutes at 43 °C" (CEM43°C) is only evaluated in five (31%) centers for each HT session. With regard to treatment sequence, 8 (50%) centers administer HT before radio(chemo)therapy and the other 8 in the reverse order. CONCLUSION: There is a significant heterogeneity among European HT centers as to the indications treated and the recording of thermometric parameters. More evidence from clinical studies is necessary to achieve standardization of HT practice.

Hyperthermia in the treatment of high-risk soft tissue sarcomas: a systematic review.

BACKGROUND: The therapy of high-risk soft tissue sarcomas (STS) remains an interdisciplinary challenge. Regional hyperthermia (RHT) sparked interest as it has been shown to improve overall survival when added to perioperative chemotherapy (CTX). However, questions arise on how RHT should be optimally integrated into current multi-modal therapies. MATERIALS AND METHODS: We performed a systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies written in English and focused mainly on radiative RHT and superficial hyperthermia were evaluated and included. Studies including patients below the age of 18, with metastatic disease or review articles, were excluded. RESULTS: We identified 15 clinical reports from 1990 until July 2022. Three articles combined RHT + CTX, and twelve focused on combined RHT + radiotherapy (RT) or neoadjuvant chemoradiotherapy (CRT). Most treatments were based on invasive thermometry, and less on magnetic resonance imaging (MRI)-based, noninvasive thermometry for STS of the extremities. Perioperative chemotherapy was used for the combination of RHT and CTX, mostly Ifosfamide-based. The effectiveness of RT appeared to be increased by RHT, especially with two RHT sessions/week. The trimodal simultaneous approach of neoadjuvant RHT and CRT was also feasible. No significant toxicity of RHT was reported. CONCLUSIONS: The gathered data strengthen the beneficial role of RHT in the multimodal setting. Further expert consensus and clinical trials are required to determine the optimal integration of RHT in treating STS.

Region of interest optimization for radiation therapy of breast cancer.

PURPOSE: The goal of this study was to investigate how the choice of the region of interest (ROI) affects the registration results of surface imaging for daily positioning of breast cancer patients. METHODS: The AlignRT system (VisionRT, London) and the XVI Cone beam CT (CBCT; Elekta, Stockholm) installed on two Versa HD linacs (Elekta) were used in this study, which included 28 patients (160 fractions). In the clinical workflow, patients were prepositioned with AlignRT and then shifted in 6 degrees of freedom (DOF) according to the CBCT. A new reference capture was taken immediately afterward. Retrospectively, the surface capture resulting from prepositioning was registered to the latest reference capture. By varying the ROI used for registration, the surface-based results were optimized in terms of minimizing the deviation to the clinically applied CBCT shifts. Two sets of ROIs were used: one obtained by applying a variable margin to the breast surface, another by combining ROIs of anatomical structures, including the sternum and contralateral breast. RESULTS: Registration results showed significant differences from one ROI to another. Generally, the results improved with increasing ROI size, especially for rotational DOFs. ROIs, including the axilla or supraclavicular lymph drainage region, did not yield an improved registration result. On the other hand, an ROI comprising the breast surface, sternum, and a belt caudal to the breasts decreased the average magnitude of the translational and rotational deviations by 6.6% and 30.8% (p < 0.01), respectively, compared to the breast surface only results. CONCLUSION: The influence of the ROI choice on surface imaging registration results was analyzed and the surface-based shifts were compared to clinically applied CBCT shifts. An optimal ROI for the treatment of breast cancer patients, consisting of the breast surface, sternum, and a belt, was identified.

Low-dose radiation therapy for COVID-19 pneumopathy: what is the evidence?

In the current dismal situation of the COVID-19 pandemic, effective management of patients with pneumonia and acute respiratory distress syndrome is of vital importance. Due to the current lack of effective pharmacological concepts, this situation has caused interest in (re)considering historical reports on the treatment of patients with low-dose radiation therapy for pneumonia. Although these historical reports are of low-level evidence per se, hampering recommendations for decision-making in the clinical setting, they indicate effectiveness in the dose range between 0.3 and 1 Gy, similar to more recent dose concepts in the treatment of acute and chronic inflammatory/degenerative benign diseases with, e.g., a single dose per fraction of 0.5 Gy. This concise review aims to critically review the evidence for low-dose radiation treatment of COVID-19 pneumopathy and discuss whether it is worth investigating in the present clinical situation.

Low Dose Radiation Therapy, Particularly with 0.5 Gy, Improves Pain in Degenerative Joint Disease of the Fingers: Results of a Retrospective Analysis.

Low-dose radiation therapy (LDRT) has been successfully established for decades as an alternative analgesic treatment option for patients suffering from chronic degenerative and inflammatory diseases. In this study, 483 patients were undergoing LDRT for degenerative joint disease of the fingers and thumb at the University Hospital Erlangen between 2004 and 2019. Radiotherapy was applied according to the German guidelines for LDRT. Several impact factors on therapeutic success, such as the age and gender, the number of affected fingers, the single and cumulative dose, as well as the number of series, were investigated. In summary, 70% of the patients showed an improvement of their pain following LDRT. No significant impact was found for the factors age, gender, the number of series or the cumulative dosage. Patients with an involvement of the thumb showed a significantly worse outcome compared to patients with an isolated affection of the fingers. In this cohort, patients receiving a single dose of 0.5 Gy reported a significantly better outcome than patients receiving 1.0 Gy, strongly suggesting a reduction in the total dose. In summary, LDRT is a good alternative treatment option for patients suffering from degenerative and inflammatory joint disease of the fingers.

Tumour-Infiltrating Inflammatory Cells in Early Breast Cancer: An Underrated Prognostic and Predictive Factor?

The role of tumour-infiltrating inflammatory cells (TIICs) in the disease progression of hormone-receptor-positive breast cancer (HR+ BC) is largely unclear since it is generally regarded as the least immunogenic BC subtype. This study investigated the prognostic significance of CD1a+ dendritic cells, CD20+ B cells, CD45RO+ memory T cells and CD4+ T-helper cells in HR+ BC. One hundred and forty-six patients were treated for early stage, distant-metastases-free HR+ BC in an accelerated partial breast irradiation (APBI) phase II trial. Immunohistochemistry was used to double-stain two adjoining sets of tissue microarrays from pre-RT (radiotherapy) tumour resection samples for CD1a/CD20 and CD45RO/CD4. Cell densities of CD1a+, CD20+, CD45RO+ and CD4+ TIICs in the stromal and intraepithelial compartment were registered semiautomatically. High densities of CD20+ and CD4+ TIICs were strongly associated with reduced disease-free survival (DFS), while high stromal CD45RO+ TIIC densities were indicators of subsequent successful treatment. An immunoscore based on CD20+ and CD45RO+ TIIC densities identified three different risk groups (p < 0.001). Thus, contrary to current assumptions, intratumoural immune cell composition might be an important prognostic indicator and a possible contributing factor in the outcome of HR+ BC and should be the subject of further research. Specifically, B-cell infiltration entailed an increased relapse rate and could play an important role in disease progression.

Chemoradiotherapy with and without deep regional hyperthermia for squamous cell carcinoma of the anus.

PURPOSE: To compare results after chemoradiotherapy with and without deep regional hyperthermia in patients with anal cancer. METHODS: Between 2000 and 2015, a total of 112 consecutive patients with UICC stage I-IV anal cancer received chemoradiotherapy with 5­fluororuracil and mitomycin C (CRT). In case of insufficient tumor response 4-6 weeks after chemoradiotherapy, patients received an interstitial pulsed-dose-rate brachytherapy boost. Additionally, 50/112 patients received hyperthermia treatments (HCRT). RESULTS: Median follow-up was 41 (2-165) months. After 5 years follow-up, overall (95.8 vs. 74.5%, P = 0.045), disease-free (89.1 vs. 70.4%, P = 0.027), local recurrence-free (97.7 vs. 78.7%, P = 0.006), and colostomy-free survival rates (87.7 vs. 69.0%, P = 0.016) were better for the HCRT group. Disease-specific, regional failure-free, and distant metastasis-free survival rates showed no significant differences. The adjusted hazard ratios for death were 0.25 (95% CI, 0.07 to 0.92; P = 0.036) and for local recurrence 0.14 (95% CI, 0.02 to 1.09; P = 0.06), respectively. Grades 3-4 early toxicities were comparable with the exception of hematotoxicity, which was higher in the HCRT group (66 vs. 43%, P = 0.032). Incidences of late side effects were similar with the exception of a higher telangiectasia rate in the HCRT group (38.0 vs. 16.1%, P = 0.009). CONCLUSION: Additional regional hyperthermia improved overall survival, local control, and colostomy rates. Its potential beneficial role has to be confirmed in a prospective randomized setting. Therefore, the HyCAN trial has already been established by our group and is currently recruiting patients (Clinicaltrials.gov identifier: NCT02369939).

Quality-of-life results for accelerated partial breast irradiation with interstitial brachytherapy versus whole-breast irradiation in early breast cancer after breast-conserving surgery (GEC-ESTRO): 5-year results of a randomised, phase 3 trial.

BACKGROUND: Previous results from the GEC-ESTRO trial showed that accelerated partial breast irradiation (APBI) using multicatheter brachytherapy in the treatment of early breast cancer after breast-conserving surgery was non-inferior to whole-breast irradiation in terms of local control and overall survival. Here, we present 5-year results of patient-reported quality of life. METHODS: We did this randomised controlled phase 3 trial at 16 hospitals and medical centres in seven European countries. Patients aged 40 years or older with 0-IIA breast cancer were randomly assigned (1:1) after breast-conserving surgery (resection margins ≥2 mm) to receive either whole-breast irradiation of 50 Gy with a boost of 10 Gy or APBI using multicatheter brachytherapy. Randomisation was stratified by study centre, tumour type, and menopausal status, with a block size of ten and an automated dynamic algorithm. There was no masking of patients or investigators. The primary endpoint of the trial was ipsilateral local recurrence. Here, we present 5-year results of quality of life (a prespecified secondary endpoint). Quality-of-life questionnaires (European Organisation for Research and Treatment of Cancer QLQ-C30, breast cancer module QLQ-BR23) were completed before radiotherapy (baseline 1), immediately after radiotherapy (baseline 2), and during follow-up. We analysed the data according to treatment received (as-treated population). Recruitment was completed in 2009, and long-term follow-up is continuing. The trial is registered at ClinicalTrials.gov, number NCT00402519. FINDINGS: Between April 20, 2004, and July 30, 2009, 633 patients had accelerated partial breast irradiation and 551 patients had whole-breast irradiation. Quality-of-life questionnaires at baseline 1 were available for 334 (53%) of 663 patients in the APBI group and 314 (57%) of 551 patients in the whole-breast irradiation group; the response rate was similar during follow-up. Global health status (range 0-100) was stable in both groups: at baseline 1, APBI group mean score 65·5 (SD 20·6) versus whole-breast irradiation group 64·6 (19·6), p=0·37; at 5 years, APBI group 66·2 (22·2) versus whole-breast irradiation group 66·0 (21·8), p=0·94. The only moderate, significant difference (difference of 10-20 points) between the groups was found in the breast symptoms scale. Breast symptom scores were significantly higher (ie, worse) after whole-breast irradiation than after APBI at baseline 2 (difference of means 13·6, 95% CI 9·7-17·5; p<0·0001) and at 3-month follow-up (difference of means 12·7, 95% CI 9·8-15·6; p<0·0001). INTERPRETATION: APBI with multicatheter brachytherapy was not associated with worse quality of life compared with whole-breast irradiation. This finding supports APBI as an alternative treatment option after breast-conserving surgery for patients with early breast cancer. FUNDING: German Cancer Aid.

Late side-effects and cosmetic results of accelerated partial breast irradiation with interstitial brachytherapy versus whole-breast irradiation after breast-conserving surgery for low-risk invasive and in-situ carcinoma of the female breast: 5-year results of a randomised, controlled, phase 3 trial.

BACKGROUND: We previously confirmed the non-inferiority of accelerated partial breast irradiation (APBI) with interstitial brachytherapy in terms of local control and overall survival compared with whole-breast irradiation for patients with early-stage breast cancer who underwent breast-conserving surgery in a phase 3 randomised trial. Here, we present the 5-year late side-effects and cosmetic results of the trial. METHODS: We did this randomised, controlled, phase 3 trial at 16 centres in seven European countries. Women aged 40 years or older with stage 0-IIA breast cancer who underwent breast-conserving surgery with microscopically clear resection margins of at least 2 mm were randomly assigned 1:1, via an online interface, to receive either whole-breast irradiation of 50 Gy with a tumour-bed boost of 10 Gy or APBI with interstitial brachytherapy. Randomisation was stratified by study centre, menopausal status, and tumour type (invasive carcinoma vs ductal carcinoma in situ), with a block size of ten, according to an automated dynamic algorithm. Patients and investigators were not masked to treatment allocation. The primary endpoint of our initial analysis was ipsilateral local recurrence; here, we report the secondary endpoints of late side-effects and cosmesis. We analysed physician-scored late toxicities and patient-scored and physician-scored cosmetic results from the date of breast-conserving surgery to the date of onset of event. Analysis was done according to treatment received (as-treated population). This trial is registered with ClinicalTrials.gov, number NCT00402519. FINDINGS: Between April 20, 2004, and July 30, 2009, we randomly assigned 1328 women to receive either whole-breast irradiation (n=673) or APBI with interstitial brachytherapy (n=655); 1184 patients comprised the as-treated population (551 in the whole-breast irradiation group and 633 in the APBI group). At a median follow-up of 6·6 years (IQR 5·8-7·6), no patients had any grade 4 toxities, and three (<1%) of 484 patients in the APBI group and seven (2%) of 393 in the whole-breast irradiation group had grade 3 late skin toxicity (p=0·16). No patients in the APBI group and two (<1%) in the whole-breast irradiation group developed grade 3 late subcutaneous tissue toxicity (p=0·10). The cumulative incidence of any late side-effect of grade 2 or worse at 5 years was 27·0% (95% CI 23·0-30·9) in the whole-breast irradiation group versus 23·3% (19·9-26·8) in the APBI group (p=0·12). The cumulative incidence of grade 2-3 late skin toxicity at 5 years was 10·7% (95% CI 8·0-13·4) in the whole-breast irradiation group versus 6·9% (4·8-9·0) in the APBI group (difference -3·8%, 95% CI -7·2 to 0·4; p=0·020). The cumulative risk of grade 2-3 late subcutaneous tissue side-effects at 5 years was 9·7% (95% CI 7·1-12·3) in the whole-breast irradiation group versus 12·0% (9·4-14·7) in the APBI group (difference 2·4%; 95% CI -1·4 to 6·1; p=0·28). The cumulative incidence of grade 2-3 breast pain was 11·9% (95% CI 9·0-14·7) after whole-breast irradiation versus 8·4% (6·1-10·6) after APBI (difference -3·5%; 95% CI -7·1 to 0·1; p=0·074). At 5 years' follow-up, according to the patients' view, 413 (91%) of 454 patients had excellent to good cosmetic results in the whole-breast irradiation group versus 498 (92%) of 541 patients in the APBI group (p=0·62); when judged by the physicians, 408 (90%) of 454 patients and 503 (93%) of 542 patients, respectively, had excellent to good cosmetic results (p=0·12). No treatment-related deaths occurred, but six (15%) of 41 patients (three in each group) died from breast cancer, and 35 (85%) deaths (21 in the whole-breast irradiation group and 14 in the APBI group) were unrelated. INTERPRETATION: 5-year toxicity profiles and cosmetic results were similar in patients treated with breast-conserving surgery followed by either APBI with interstitial brachytherapy or conventional whole-breast irradiation, with significantly fewer grade 2-3 late skin side-effects after APBI with interstitial brachytherapy. These findings provide further clinical evidence for the routine use of interstitial multicatheter brachytherapy-based APBI in the treatment of patients with low-risk breast cancer who opt for breast conservation. FUNDING: German Cancer Aid.

5-year results of accelerated partial breast irradiation using sole interstitial multicatheter brachytherapy versus whole-breast irradiation with boost after breast-conserving surgery for low-risk invasive and in-situ carcinoma of the female breast: a randomised, phase 3, non-inferiority trial.

BACKGROUND: In a phase 3, randomised, non-inferiority trial, accelerated partial breast irradiation (APBI) for patients with stage 0, I, and IIA breast cancer who underwent breast-conserving treatment was compared with whole-breast irradiation. Here, we present 5-year follow-up results. METHODS: We did a phase 3, randomised, non-inferiority trial at 16 hospitals and medical centres in seven European countries. 1184 patients with low-risk invasive and ductal carcinoma in situ treated with breast-conserving surgery were centrally randomised to either whole-breast irradiation or APBI using multicatheter brachytherapy. The primary endpoint was local recurrence. Analysis was done according to treatment received. This trial is registered with ClinicalTrials.gov, number NCT00402519. FINDINGS: Between April 20, 2004, and July 30, 2009, 551 patients had whole-breast irradiation with tumour-bed boost and 633 patients received APBI using interstitial multicatheter brachytherapy. At 5-year follow-up, nine patients treated with APBI and five patients receiving whole-breast irradiation had a local recurrence; the cumulative incidence of local recurrence was 1.44% (95% CI 0.51-2.38) with APBI and 0.92% (0.12-1.73) with whole-breast irradiation (difference 0.52%, 95% CI -0.72 to 1.75; p=0.42). No grade 4 late side-effects were reported. The 5-year risk of grade 2-3 late side-effects to the skin was 3.2% with APBI versus 5.7% with whole-breast irradiation (p=0.08), and 5-year risk of grade 2-3 subcutaneous tissue late side-effects was 7.6% versus 6.3% (p=0.53). The risk of severe (grade 3) fibrosis at 5 years was 0.2% with whole-breast irradiation and 0% with APBI (p=0.46). INTERPRETATION: The difference between treatments was below the relevance margin of 3 percentage points. Therefore, adjuvant APBI using multicatheter brachytherapy after breast-conserving surgery in patients with early breast cancer is not inferior to adjuvant whole-breast irradiation with respect to 5-year local control, disease-free survival, and overall survival. FUNDING: German Cancer Aid.

Accelerated partial breast irradiation with external beam radiotherapy : First results of the German phase 2 trial.

BACKGROUND AND PURPOSE: To evaluate the feasibility and efficacy of external beam three-dimensional (3D) conformal accelerated partial breast irradiation (APBI) for selected patients with early breast cancer. PATIENTS AND METHODS: Between 2011 and 2016, 72 patients were recruited for this prospective phase 2 trial. Patients were eligible for APBI if they had histologically confirmed breast cancer or pure ductal carcinoma in situ (DCIS), a tumor diameter ≤3 cm, clear resection margins ≥2 mm, no axillary lymph node involvement, no distant metastases, tumor bed clips, and were aged ≥50 years. Patients were excluded if mammography showed a multicentric invasive growth pattern, or if they had residual diffuse microcalcifications postoperatively, an extensive intraductal component, or vessel invasion. Patients received 3D conformal external beam APBI with a total dose of 38 Gy in 10 fractions in 1-2 weeks. The trial had been registered at the German Clinical Trials Register, DRKS-ID: DRKS00004417. RESULTS: Median follow-up was 25.5 months (range 1-61 months). Local control was maintained in 71 of 72 patients. The 3­year local recurrence rate was 2.1% (95% confidence interval, CI: 0-6.1%). Early toxicity (grade 1 radiodermatitis) was seen in 34.7% (25/72). Late side effects ≥ grade 3 did not occur. Cosmetic results were rated as excellent/good in 96.7% (59/61). CONCLUSION: APBI with external beam radiotherapy techniques is feasible with low toxicity and, according to the results of the present and other studies, on the way to becoming a standard treatment option for a selected subgroup of patients.