BACKGROUND: Magnetic resonance imaging (MRI) is more often considered to guide, evaluate or select patients for partial breast irradiation (PBI) or minimally invasive therapy. Safe treatment margins around the MRI-visible lesion (MRI-GTV) are needed to account for surrounding subclinical occult disease. PURPOSE: To precisely compare MRI findings with histopathology, and to obtain detailed knowledge about type, rate, quantity and distance of occult disease around the MRI-GTV. METHODS AND MATERIALS: Patients undergoing MRI and breast-conserving therapy were prospectively included. The wide local excision specimens were subjected to detailed microscopic examination. The size of the invasive (index) tumor was compared with the MRI-GTV. The gross tumor volume (GTV) was defined as the pre-treatment visible lesion. Subclinical tumor foci were reconstructed at various distances to the MRI-GTV. RESULTS: Sixty-two patients (64 breasts) were included. The mean size difference between MRI-GTV and the index tumor was 1.3mm. Subclinical disease occurred in 52% and 25% of the specimens at distances ≥10mm and ≥20mm, respectively, from the MRI-GTV. CONCLUSIONS: For MRI-guided minimally invasive therapy, typical treatment margins of 10mm around the MRI-GTV may include occult disease in 52% of patients. When surgery achieves a 10mm tumor-free margin around the MRI-GTV, radiotherapy to the tumor bed may require clinical target volume margins >10mm in up to one-fourth of the patients.
BACKGROUND: Magnetic resonance imaging (MRI) is more often considered to guide, evaluate or select patients for partial breast irradiation (PBI) or minimally invasive therapy. Safe treatment margins around the MRI-visible lesion (MRI-GTV) are needed to account for surrounding subclinical occult disease. PURPOSE: To precisely compare MRI findings with histopathology, and to obtain detailed knowledge about type, rate, quantity and distance of occult disease around the MRI-GTV. METHODS AND MATERIALS: Patients undergoing MRI and breast-conserving therapy were prospectively included. The wide local excision specimens were subjected to detailed microscopic examination. The size of the invasive (index) tumor was compared with the MRI-GTV. The gross tumor volume (GTV) was defined as the pre-treatment visible lesion. Subclinical tumor foci were reconstructed at various distances to the MRI-GTV. RESULTS: Sixty-two patients (64 breasts) were included. The mean size difference between MRI-GTV and the index tumor was 1.3mm. Subclinical disease occurred in 52% and 25% of the specimens at distances ≥10mm and ≥20mm, respectively, from the MRI-GTV. CONCLUSIONS: For MRI-guided minimally invasive therapy, typical treatment margins of 10mm around the MRI-GTV may include occult disease in 52% of patients. When surgery achieves a 10mm tumor-free margin around the MRI-GTV, radiotherapy to the tumor bed may require clinical target volume margins >10mm in up to one-fourth of the patients.
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Authors: Suzanne C E Diepstraten; Helena M Verkooijen; Paul J van Diest; Wouter B Veldhuis; Arancha M Fernandez-Gallardo; Katya M Duvivier; Arjen J Witkamp; Thijs van Dalen; Willem P Th M Mali; Maurice A A J van den Bosch Journal: Cancer Imaging Date: 2011-12-28 Impact factor: 3.909
Authors: Mariska D DEN Hartogh; Marielle E P Philippens; Iris E VAN Dam; Catharina E Kleynen; Robbert J H A Tersteeg; Alexis N T J Kotte; Marco VAN Vulpen; Bram VAN Asselen; Desirée H J G VAN DEN Bongard Journal: Oncol Lett Date: 2015-09-14 Impact factor: 2.967
Authors: Mariska D den Hartogh; Marielle E P Philippens; Iris E van Dam; Catharina E Kleynen; Robbert J H A Tersteeg; Ruud M Pijnappel; Alexis N T J Kotte; Helena M Verkooijen; Maurice A A J van den Bosch; Marco van Vulpen; Bram van Asselen; Hjg Desirée van den Bongard Journal: Radiat Oncol Date: 2014-02-26 Impact factor: 3.481