Christoph Fussl

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

AimThe 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).MethodsA 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.ResultsInternational 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.ConclusionRecent 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.ZusammenfassungZielAktualisierung der DEGRO-Leitlinie von 2008 zur adjuvanten Strahlentherapie des regionalen Lymphabflusses bei Mammakarzinom und Ergänzung der allgemeinen Empfehlungen der interdisziplinären S3-Leitlinie der Deutschen Krebsgesellschaft von 2012 durch spezifisch radioonkologische Leitlinien zur Indikation, Zielvolumendefinition und Technik der postoperativen Radiotherapie.MethodenDie DEGRO-Expertengruppe Mammakarzinom führte eine systematische Literaturrecherche nach randomisierten Studien, Metaanalysen sowie internationalen Leitlinien durch, die nach 2008 publiziert wurden und sich an den Kriterien evidenzbasierter Medizin orientierten. Suchbegriffe waren „breast cancer“, „radiotherapy“ und „regional node irradiation“. Die Studien wurden sowohl auf ihre Ergebnisse als auch hinsichtlich der Unterschiede in den Zielvolumina analysiert und auf 3-D-Planungsschnittbilder mit CT-konturierten Lymphabflussgebieten projiziert.ErgebnisseDie Indikation zur regionalen Lymphabflussbestrahlung (RNI) wird in internationalen Leitlinien unterschiedlich gestellt. Bei Patientinnen mit 1–3 befallenen axillären Lymphknoten wurden nach RNI im Vergleich zur alleinigen Bestrahlung der Brust oder Brustwand Verbesserungen der lokoregionalen Kontrolle und des Überlebens beobachtet. Mehrere randomisierte Studien und eine Metaanalyse zeigten nach RNI (mit unterschiedlichen Zielvolumina) eine zwar geringe, jedoch signifikante Verbesserung des Überlebens. Bei positivem Sentinel-Lymphknoten (SN) ist die Lymphabflussbestrahlung einer axillären Lymphonodektomie (ALND) gleichwertig in der lokalen Tumorkontrolle, geht aber mit einer deutlich geringeren Lymphödemrate einher. Zur Frage, ob ein solch limitierter Lymphknotenbefall und selbst eine Mikrometastasierung langfristig einen Einfluss auf die Prognose haben, ist die Datenlage widersprüchlich.SchlussfolgerungDie restriktive Indikationsstellung zur Lymphabflussbestrahlung muss angesichts neuer Daten aus randomisierten Studien kritisch überdacht werden.

Boost IORT in Breast Cancer: Body of Evidence

The term IORT (intraoperative radiotherapy) is currently used for various techniques that show decisive differences in dose delivery. The largest evidence for boost IORT preceding whole breast irradiation (WBI) originates from intraoperative electron treatments with single doses around 10 Gy, providing outstandingly low local recurrence rates in any risk constellation also at long term analyses. Compared to other boost methods, an intraoperative treatment has evident advantages as follows. Precision. Direct visualisation of the tumour bed during surgery guarantees an accurate dose delivery. This fact has additionally gained importance in times of primary reconstruction techniques after lumpectomy to optimise cosmetic outcome. IORT is performed before breast tissue is mobilised for plastic purposes. Cosmesis. As a consequence of direct tissue exposure without distension by hematoma/seroma, IORT allows for small treatment volumes and complete skin sparing, both having a positive effect on late tissue tolerance and, hence, cosmetic appearance. Patient Comfort. Boost IORT marginally prolongs the surgical procedure, while significantly shortening postoperative radiotherapy. Its combination with a 3-week hypofractionated external beam radiotherapy to the whole breast (WBI) is presently tested in the HIOB trial (hypofractionated WBI preceded by IORT electron boost), a prospective multicenter trial of the International Society of Intraoperative Radiotherapy (ISIORT).

IOERT as anticipated tumor bed boost during breast-conserving surgery after neoadjuvant chemotherapy in locally advanced breast cancer--results of a case series after 5-year follow-up.

To evaluate retrospectively rates of local (LCR) and locoregional tumor control (LRCR) in patients with locally advanced breast cancer (LABC) who were treated with preoperative chemotherapy (primary systemic treatment, PST) followed by breast‐conserving surgery (BCS) and either intraoperative radiotherapy with electrons (IOERT) preceding whole‐breast irradiation (WBI) (Group 1) or with WBI followed by an external tumor bed boost (electrons or photons) instead of IOERT (Group 2). From 2002 to 2007, 83 patients with clinical Stage II or III breast cancer were enrolled in Group 1 and 26 in Group 2. All patients received PST followed by BCS and axillary lymph node dissection. IOERT boosts were applied by single doses of 9 Gy (90% reference isodose) versus external boosts of 12 Gy (median dose range, 6–16) in 2 Gy/fraction (ICRU). WBI in both groups was performed up to total doses of 51–57 Gy (1.7–1.8 Gy/fraction). The respective median follow‐up times for Groups 1 and 2 amount 59 months (range, 3–115) and 67.5 months (range, 13–120). Corresponding 6‐year rates for LCR, LRCR, metastasis‐free survival, disease‐specific survival and overall survival were 98.5, 97.2, 84.7, 89.2 and 86.4% for Group 1 and 88.1, 88.1, 74, 92 and 92% for Group 2, respectively, without any statistical significances. IOERT as boost modality during BCS in LABC after PST shows a trend to be superior in terms of LCR and LRCR in comparison with conventional boosts.

Intraoperative Tumor Bed Boost With Electrons in Breast Cancer of Clinical Stages I Through III: Updated 10-Year Results

PURPOSE To assess retrospectively the role of an anticipated intraoperative tumor electron radiation therapy (IOERT) as a bed boost during breast-conserving surgery followed by conventional whole breast irradiation (WBI). METHODS AND MATERIALS An unselected cohort of 770 breast cancer patients of all risk types was analyzed in terms of local control (LC) and survival outcome. Patients were treated by breast-conserving surgery, IOERT of 10 Gy, and WBI to total median doses of 54 Gy (range, 1.6-2). Patients were retrospectively analyzed for LC, locoregional control, metastasis-free survival (MFS), overall survival (OS), and breast cancer-specific survival (BCSS). RESULTS After a median follow-up of 121 months (range, 4-200), 21 (2.7%) in-breast recurrences (IBRs) were observed, 107 patients (14%) died and 106 (14%) developed metastases. Ten-year rates of LC, locoregional control, MFS, OS, and BCSS amounted to 97.2%, 96.5%, 86%, 85.7%, and 93.2 %, respectively. In multivariate analysis, HER2+ and triple-negative breast cancer subtype (TN) turned out to be significant negative predictors for IBRs (hazard ratios, 15.02 and 12.87, respectively; P < .05). Sorted by subtypes, 10-year LC rates were observed in 98.7% (range, 96.7%-99.5%) (luminal A), 98% (range, 94%-99.3%) (luminal B), 87.9% (range, 66.2%-96%) (HER2+), and 89% (range, 76.9%-94.9%) (TN), respectively. CONCLUSIONS After 10 years, boost IOERT maintains high LC rates in any risk setting.