DEGRO practical guideline for partial-breast irradiation.

PURPOSE: This consensus statement from the Breast Cancer Working Group of the German Society for Radiation Oncology (DEGRO) aims to define practical guidelines for accelerated partial-breast irradiation (APBI). METHODS: Recent recommendations for relevant aspects of APBI were summarized and a panel of experts reviewed all the relevant literature. Panel members of the DEGRO experts participated in a series of conferences, supplemented their clinical experience, performed a literature review, and formulated recommendations for implementing APBI in clinical routine, focusing on patient selection, target definition, and treatment technique. RESULTS: Appropriate patient selection, target definition for different APBI techniques, and basic rules for appropriate APBI techniques for clinical routine outside of clinical trials are described. Detailed recommendations for APBI in daily practice, including dose constraints, are given. CONCLUSION: Guidelines are mandatory to assure optimal results of APBI using different techniques.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017.

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer.

PURPOSE: Gold-marker-based image-guided radiation therapy (IGRT) of the prostate allows to correct for inter- and intrafraction motion and therefore to safely reduce margins for the prostate planning target volume (PTV). However, pelvic PTVs, when coadministered in a single plan (registered to gold markers [GM]), require reassessment of the margin concept since prostate movement is independent from the pelvic bony anatomy to which the lymphatics are usually referenced to. METHODS: We have therefore revisited prostate translational movement relative to the bony anatomy to obtain adequate margins for the pelvic PTVs compensating mismatch resulting from referencing pelvic target volumes to GMs in the prostate. Prostate movement was analyzed in a set of 28 patients (25 fractions each, totaling in 684 fractions) and the required margins calculated for the pelvic PTVs according to Van Herk's margin formula [Formula: see text]. RESULTS: The overall mean prostate movement relative to bony anatomy was 0.9 ± 3.1, 0.6 ± 3.4, and 0.0 ± 0.7 mm in anterior/posterior (A/P), inferior/superior (I/S) and left/right (L/R) direction, respectively. Calculated margins to compensate for the resulting mismatch to bony anatomy were 9/9/2 mm in A/P, I/S, and L/R direction and 10/11/6 mm if an additional residual error of 2 mm was assumed. CONCLUSION: GM-based IGRT for pelvic PTVs is feasible if margins are adapted accordingly. Margins could be reduced further if systematic errors which are introduced during the planning CT were eliminated.

Development and first use of a novel cylindrical ball bearing phantom for 9-DOF geometric calibrations of flat panel imaging devices used in image-guided ion beam therapy.

Image guidance during highly conformal radiotherapy requires accurate geometric calibration of the moving components of the imager. Due to limited manufacturing accuracy and gravity-induced flex, an x-ray imager's deviation from the nominal geometrical definition has to be corrected for. For this purpose a ball bearing phantom applicable for nine degrees of freedom (9-DOF) calibration of a novel cone-beam computed tomography (CBCT) scanner was designed and validated. In order to ensure accurate automated marker detection, as many uniformly distributed markers as possible should be used with a minimum projected inter-marker distance of 10 mm. Three different marker distributions on the phantom cylinder surface were simulated. First, a fixed number of markers are selected and their coordinates are randomly generated. Second, the quasi-random method is represented by setting a constraint on the marker distances in the projections. The third approach generates the ball coordinates helically based on the Golden ratio, ϕ. Projection images of the phantom incorporating the CBCT scanner's geometry were simulated and analysed with respect to uniform distribution and intra-marker distance. Based on the evaluations a phantom prototype was manufactured and validated by a series of flexmap calibration measurements and analyses. The simulation with randomly distributed markers as well as the quasi-random approach showed an insufficient uniformity of the distribution over the detector area. The best compromise between uniform distribution and a high packing fraction of balls is provided by the Golden section approach. A prototype was manufactured accordingly. The phantom was validated for 9-DOF geometric calibrations of the CBCT scanner with independently moveable source and detector arms. A novel flexmap calibration phantom intended for 9-DOF was developed. The ball bearing distribution based on the Golden section was found to be highly advantageous. The phantom showed satisfying results for calibrations of the CBCT scanner and provides the basis for further flexmap correction and reconstruction developments.

DEGRO practical guidelines for radiotherapy of breast cancer VI: therapy of locoregional breast cancer recurrences.

OBJECTIVE: To update the practical guidelines for radiotherapy of patients with locoregional breast cancer recurrences based on the current German interdisciplinary S3 guidelines 2012. METHODS: A comprehensive survey of the literature using the search phrases "locoregional breast cancer recurrence", "chest wall recurrence", "local recurrence", "regional recurrence", and "breast cancer" was performed, using the limits "clinical trials", "randomized trials", "meta-analysis", "systematic review", and "guidelines". CONCLUSIONS: Patients with isolated in-breast or regional breast cancer recurrences should be treated with curative intent. Mastectomy is the standard of care for patients with ipsilateral breast tumor recurrence. In a subset of patients, a second breast conservation followed by partial breast irradiation (PBI) is an appropriate alternative to mastectomy. If a second breast conservation is performed, additional irradiation should be mandatory. The largest reirradiation experience base exists for multicatheter brachytherapy; however, prospective clinical trials are needed to clearly define selection criteria, long-term local control, and toxicity. Following primary mastectomy, patients with resectable locoregional breast cancer recurrences should receive multimodality therapy including systemic therapy, surgery, and radiation +/- hyperthermia. This approach results in high local control rates and long-term survival is achieved in a subset of patients. In radiation-naive patients with unresectable locoregional recurrences, radiation therapy is mandatory. In previously irradiated patients with a high risk of a second local recurrence after surgical resection or in patients with unresectable recurrences, reirradiation should be strongly considered. Indication and dose concepts depend on the time interval to first radiotherapy, presence of late radiation effects, and concurrent or sequential systemic treatment. Combination with hyperthermia can further improve tumor control. In patients with isolated axillary or supraclavicular recurrence, durable disease control is best achieved with multimodality therapy including surgery and radiotherapy. Radiation therapy significantly improves local control and should be applied whenever feasible.

Collimator based tracking with an add-on multileaf collimator: Moduleaf.

Radiotherapy is one of the most important methods used for the treatment of cancer. Irradiating a moving target is also one of the most challenging tasks to accomplish in modern radiotherapy. We have developed a tracking system by modifying an add-on collimator, the Siemens Moduleaf, for realtime applications in radiotherapy. As the add-on collimator works nearly completely independently of the linear accelerator (LinAc), no modifications to the latter were necessary. The adaptations to the Moduleaf were mainly software-based. In order to reduce the complexity of the system, outdated electronic parts were replaced with newer components where practical.Verification was performed by measuring the latency of the system as well as the impact on applied dose to a predefined target volume, moving in the leaf's travel direction. Latency measurements in the software were accomplished by comparing the target and current positions of the leaves. For dose measurements, a Gafchromic EBT2 film was placed beneath the target 4D phantom, in between solid water plates and moved alongside with it. Comparing the dose distribution on the film with a moving target between 'tracking disabled' towards 'tracking enabled' functions resulted in penumbra widths of 23 mm to 4 mm for 0.1 Hz sinusoidal movements with an amplitude of 32 mm, respectively. The maximum speed was therefore 20 mm s(-1). Latency was measured to be less than 50 ms for the signal runtimes. Based on the results, a tracking-capable add-on collimator seems to be a useful tool for reducing the margins for the treatment of small, slow-moving targets.

Combined chemoradiotherapy with gemcitabine in patients with locally advanced inoperable transitional cell carcinoma of the urinary bladder and/or in patients ineligible for surgery: a phase I trial.

BACKGROUND: We conducted a phase I trial of gemcitabine (gem) with concurrent radiotherapy in patients with muscle-invasive bladder cancer (BC) ineligible for surgery or cisplatin or refusing organ loss. PATIENTS AND METHODS: Patients with urothelial cancer, cT2-T4, cN0-1, M0, ineligible for surgery due to local tumor extension, PS, age or co-morbidities or who refused surgery were included. After maximal transurethral resection, the treatment schedule included: twice-weekly i.v. infusion of gem [dose levels (DL) 1-6: 20, 27, 30, 33, 50 and 40 mg/m(2), respectively] for 30 min and concurrent radiotherapy (RT) to the bladder with 55.5 Gy. The primary end point was to determine the maximum-tolerated dose (MTD) and the dose recommended (RD) for further studies of this gem schedule. The secondary end point was late toxicity. The MTD was defined by dose-limiting toxicity (DLT) in 2 or more of 6 patients, discontinuation of RT and/or gem for >1 week in 2 or more of 6 patients due to grade (G) 3/4 acute and/or late toxicity in more than 2 of 18 patients. RESULTS: Thirty-five of 44 patients were assessable for toxicity and thus the primary end point. DLTs occurred in two of five patients at dose level 5: one G3 alanine aminotransferase elevation and one G3 fatigue. The MTD, therefore, was 50 mg/m(2) gem twice weekly. At DL 6 with 40 mg/m(2), the RD was established: only one of six patients developed G3 fatigue and diarrhea. Late toxicity was rare and of low grade (only G1-2). The 2-year locoregional failure rate was 32% (9/28); 10 of 28 patients (38%) were alive with an intact bladder and no evidence of recurrent disease, 9 patients developed distant metastases and 6 died of their disease. CONCLUSIONS: Gemcitabine in combination with RT is well tolerated in BC patients ineligible for surgery and/or cisplatin. The RD of gemcitabine for subsequent trials is 40 mg/m(2) twice weekly with concurrent radiation.

DEGRO practical guidelines: radiotherapy of breast cancer III--radiotherapy of the lymphatic pathways.

AIM: The purpose of this work is to update the practical guidelines for adjuvant radiotherapy of the regional lymphatics of breast cancer published in 2008 by the breast cancer expert panel of the German Society of Radiation Oncology (DEGRO). METHODS: A comprehensive survey of the literature concerning regional nodal irradiation (RNI) was performed using the following search terms: "breast cancer", "radiotherapy", "regional node irradiation". Recent randomized trials were analyzed for outcome as well as for differences in target definition. Field arrangements in the different studies were reproduced and superimposed on CT slices with individually contoured node areas. Moreover, data from recently published meta-analyses and guidelines of international breast cancer societies, yielding new aspects compared to 2008, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the German interdisciplinary S3 guidelines updated in 2012, this paper addresses indications, targeting, and techniques of radiotherapy of the lymphatic pathways after surgery for breast cancer. RESULTS: International guidelines reveal substantial differences regarding indications for RNI. Patients with 1-3 positive nodes seem to profit from RNI compared to whole breast (WBI) or chest wall irradiation alone, both with regard to locoregional control and disease-free survival. Irradiation of the regional lymphatics including axillary, supraclavicular, and internal mammary nodes provided a small but significant survival benefit in recent randomized trials and one meta-analysis. Lymph node irradiation yields comparable tumor control in comparison to axillary lymph node dissection (ALND), while reducing the rate of lymph edema. Data concerning the impact of 1-2 macroscopically affected sentinel node (SN) or microscopic metastases on prognosis are conflicting. CONCLUSION: Recent data suggest that the current restrictive use of RNI should be scrutinized because the risk-benefit relationship appears to shift towards an improvement of outcome.

DEGRO practical guidelines: radiotherapy of breast cancer II: radiotherapy of non-invasive neoplasia of the breast.

PURPOSE: To complement and update the 2007 practice guidelines of the breast cancer expert panel of the German Society of Radiation Oncology (DEGRO) for radiotherapy (RT) of breast cancer. Owing to its growing clinical relevance, in the current version, a separate paper is dedicated to non-invasive proliferating epithelial neoplasia of the breast. In addition to the more general statements of the German interdisciplinary S3 guidelines, this paper is especially focused on indication and technique of RT in addition to breast conserving surgery. METHODS: The DEGRO expert panel performed a comprehensive survey of the literature comprising recently published data from clinical controlled trials, systematic reviews as well as meta-analyses, referring to the criteria of evidence-based medicine yielding new aspects compared to 2005 and 2007. The literature search encompassed the period 2008 to September 2012 using databases of PubMed and Guidelines International Network (G-I-N). Search terms were "non invasive breast cancer", "ductal carcinoma in situ, "dcis", "borderline breast lesions", "lobular neoplasia", "radiotherapy" and "radiation therapy". In addition to the more general statements of the German interdisciplinary S3 guidelines, this paper is especially focused on indications of RT and decision making of non-invasive neoplasia of the breast after surgery, especially ductal carcinoma in situ. RESULTS: Among different non-invasive neoplasia of the breast only the subgroup of pure ductal carcinoma in situ (DCIS; synonym ductal intraepithelial neoplasia, DIN) is considered for further recurrence risk reduction treatment modalities after complete excision of DCIS, particularly RT following breast conserving surgery (BCS), in order to avoid a mastectomy. About half of recurrences are invasive cancers. Up to 50 % of all recurrences require salvage mastectomy. Randomized clinical trials and a huge number of mostly observational studies have unanimously demonstrated that RT significantly reduces recurrence risks of ipsilateral DCIS as well as invasive breast cancer independent of patient age in all subgroups. The recommended total dose is 50 Gy administered as whole breast irradiation (WBI) in single fractions of 1.8 or 2.0 Gy given on 5 days weekly. Retrospective data indicate a possible beneficial effect of an additional tumor bed boost for younger patients. Prospective clinical trials of different dose-volume concepts (hypofractionation, accelerated partial breast irradiation, boost radiotherapy) are still ongoing. CONCLUSION: Postoperative radiotherapy permits breast conservation for the majority of women by halving local recurrence as well as reducing progression rates into invasive cancer. New data confirmed this effect in all patient subsets-even in low risk subgroups (LoE 1a).

Image quality improvements of electronic portal imaging devices by multi-level gain calibration and temperature correction.

Amorphous silicon (aSi:H) flat panel detectors are prevalent in radiotherapy for megavoltage imaging tasks. Any clinical and dosimetrical application requires a well-defined dose response of the system to achieve meaningful results. Due to radiation damages, panels deteriorate and the linearity of pixel response to dose as well as the stability with regard to changing operating temperatures get worse with time. Using a single level gain correction can lead to an error of about 23% when irradiating a flood field image with 100 MU min(-1) on an old detector. A multi-level gain (MLG) correction is introduced, emending the nonlinearities and subpanel-related artifacts caused by insufficient radiation hardness of amplifiers in the read-out electronics. With rising temperature, offset values typically increase (up to 300 gray values) while the response at higher dose values per frame remain constant for a majority of pixels. To account for temperature-related image artifacts, two additional temperature correction methods have been developed. MLG in combination with temperature corrections can re-establish the aSi:H image quality to the performance required by reliable medical verification tools. Furthermore, the life span and recalibration intervals of these costly devices can be prolonged decisively.

DEGRO practical guidelines: radiotherapy of breast cancer I: radiotherapy following breast conserving therapy for invasive breast cancer.

BACKGROUND AND PURPOSE: The aim of the present paper is to update the practical guidelines for postoperative adjuvant radiotherapy of breast cancer published in 2007 by the breast cancer expert panel of the German Society for Radiooncology (Deutsche Gesellschaft für Radioonkologie, DEGRO). The present recommendations are based on a revision of the German interdisciplinary S-3 guidelines published in July 2012. METHODS: A comprehensive survey of the literature concerning radiotherapy following breast conserving therapy (BCT) was performed using the search terms "breast cancer", "radiotherapy", and "breast conserving therapy". Data from lately published meta-analyses, recent randomized trials, and guidelines of international breast cancer societies, yielding new aspects compared to 2007, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the DKG (Deutsche Krebsgesellschaft), this paper addresses indications, target definition, dosage, and technique of radiotherapy of the breast after conservative surgery for invasive breast cancer. RESULTS: Among numerous reports on the effect of radiotherapy during BCT published since the last recommendations, the recent EBCTCG report builds the largest meta-analysis so far available. In a 15 year follow-up on 10,801 patients, whole breast irradiation (WBI) halves the average annual rate of disease recurrence (RR 0.52, 0.48-0.56) and reduces the annual breast cancer death rate by about one sixth (RR 0.82, 0.75-0.90), with a similar proportional, but different absolute benefit in prognostic subgroups (EBCTCG 2011). Furthermore, there is growing evidence that risk-adapted dose augmentation strategies to the tumor bed as well as the implementation of high precision RT techniques (e.g., intraoperative radiotherapy) contribute substantially to a further reduction of local relapse rates. A main focus of ongoing research lies in partial breast irradiation strategies as well as WBI hypofractionation schedules. The potential of both in replacing normofractionated WBI has not yet been finally clarified. CONCLUSION: After breast conserving surgery, no subgroup even in low risk patients has yet been identified for whom radiotherapy can be safely omitted without compromising local control and, hence, cancer-specific survival. In most patients, this translates into an overall survival benefit.