STEREOTACTIC BODY RADIATION THERAPY FOR ISOLATED NODAL RECURRENCES OF PROSTATE CANCER

Aim: To evaluate the feasibility, tolerability and preliminary outcomes of stereotactic body radiation therapy in patients with nodal recurrences of prostate cancer. Patients and Methods: Between May 2006 and July 2009, 12 patients (10 with isolated nodal recurrences and 2 with multiple adjacent adenopathy) underwent stereotactic body radiation therapy delivered by a linear accelerator (Linac 2100, Varian). The patient age ranged from 51 and 87 (median, 70) years. Primary treatment was radical prostatectomy in 7 patients, prostatectomy and postoperative radiotherapy in 2 patients and exclusive radiotherapy, androgen deprivation and radiotherapy with rescue prostatectomy in 3 patients. The initial disease category according to the National Comprehensive Cancer Network 2011 was defined as intermediate, high, very high and metastatic (pNl) in 1, 2, 5 and 3 patients, respectively (1 unknown). At the time of radiation therapy, 3 patients did not receive androgen deprivation, 7 patients received some forms of androgen deprivation and the remaining 2 patients were hormone-resistant. Ten patients underwent super(11)C-choline positron-emission tomography/computed tomography ( super(11)C-choline PET/CT) examination, while the remaining 2 patients underwent a magnetic resonance imaging (MRI) and a CT scan, respectively, for the diagnosis of the recurrence and in order to exclude the presence of other sites of disease. All patients had a CT scan with contrast centering; 10 mm were added to the macroscopic disease or gross tumor volume (GTV) to create the planning target volume (PTV). Ten patients received a total dose of 30 Gy/3 daily fractions for lesions of dimensions between 1.2 and 2 cm (pelvic disease). Two patients received 35 Gy/5 fractions and 27 Gy/3 fractions, respectively, because of the large size of the adenopathy (5 cm) and its critical location near the bone marrow (para-aortic lymph nodes). Results: There was no report of acute and late toxicity. The mean follow- up was 38 (range, 18-58) months. Eight patients had a complete response to radiotherapy with negative imaging exams ( super(11)C-choline PET/CT, MRI and CT) with 3 of them never having received neoadjuvant or concomitant/adjuvant hormonal therapy; 3 patients had stable disease/partial response, and the remaining patient had progressive disease in the irradiated field. Clinical progression was observed in 9 patients after a mean time of 11 (range, 5-24) months from the completion of the stereot