Interaction of 2-Gy Equivalent Dose and Margin Status in Perioperative High-Dose-Rate Brachytherapy

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• 作者：Rafael Martí ; nez-Monge M.D.<sup>*sup><sup> ; sup><sup>rmartinezm@unav.essup> ; Mauricio Cambeiro M.D.<sup>*sup> ; Marta Moreno M.D.<sup>*sup> ; Miren Gaztañ ; aga M.D.<sup>*sup> ; Mikel San Juliá ; n M.D.<sup>† ; sup> ; Juan Alcalde M.D.<sup>‡ ; sup> ; Matí ; as Jurado M.D.<sup>§ ; sup>
• 刊名：International Journal of Radiation Oncology*Biology*Physics
• 出版年：2011
• 出版时间：15 March 2011
• 年：2011
• 卷：79
• 期：4
• 页码：1158-1163
• 全文大小：205 K

文摘

ss=""h4"">Purpose

To determine patient, tumor, and treatment factors predictive of local control (LC) in a series of patients treated with either perioperative high-dose-rate brachytherapy (PHDRB) alone (Group 1) or with PHDRB combined with external-beam radiotherapy (EBRT) (Group 2).

ss=""h4"">Patient and Methods

Patients (n = 312) enrolled in several PHDRB prospective Phase I–II studies conducted at the Clínica Universidad de Navarra were analyzed. Treatment with PHDRB alone, mainly because of prior irradiation, was used in 126 patients to total doses of 32 Gy/8 b.i.d. or 40 Gy/10 b.i.d. treatments after R0 or R1 resections. Treatment with PHDRB plus EBRT was used in 186 patients to total doses of 16 Gy/4 b.i.d. or 24 Gy/6 b.i.d. treatments after R0 or R1 resections along with 45 Gy of EBRT with or without concomitant chemotherapy.

ss=""h4"">Results

No dose–margin interaction was observed in Group 1 patients. In Group 2 patients there was a significant interaction between margin status and 2-Gy equivalent (Eq2Gy) dose (p = 0.002): (1) patients with negative margins had 9-year LC of 95.7 % at Eq2Gy = 62.9Gy; (2) patients with close margins of >1 mm had 9-year LC of 92.4 % at Eq2Gy = 72.2Gy, and (3) patients with positive/close <1-mm margins had 9-year LC of 68.0 % at Eq2Gy = 72.2Gy.

ss=""h4"">Conclusions

Two-gray equivalent doses ≥70 Gy may compensate the effect of close margins ≥1 mm but do not counterbalance the detrimental effect of unfavorable (positive/close <1 mm) resection margins. No dose–margin interaction is observed in patients treated at lower Eq2Gy doses ≤50 Gy with PHDRB alone.