ESTRO 2021 Abstract Book

S1151

ESTRO 2021

PO-1400 Seminal vesicle adenocarcinoma: A systematic review of published literature V. Singla 1 , S. Goyal 1 , K. Periasamy 1 , R. Madan 1 , P. Vias 1 1 PGIMER, Radiotherapy, Chandigarh, India

Purpose or Objective Seminal vesicle tumors are rare, have variable pathology and poorly defined management guidelines. In this systematic review and individual patient data meta-analysis, we attempt to glean the patterns of presentation, treatment modalities and outcomes in pure seminal vesicle tumors. Materials and Methods A comprehensive EMBASE + MEDLINE search of all publications and conference abstracts between 1966 and 2021, using Emtree terms “seminal vesicle” AND “malignant neoplasm” was conducted. These were all hand- sorted through review of abstracts to eliminate primary prostate malignancies and those with epicentre in seminal vesicle but only pathologic or diagnostic details. The cross-references from selected articles gave additional cases which were added to the dataset. The initial results confined to the most common subset of adenocarcinoma are presented here Results Of the initially retrieved 313 entries using the specified Emtree terms, hand-sorting, elimination of diagnostic reports and inclusion of relevant cross-references, a total of 176 articles that reported treatment and outcomes were eligible for inclusion. Of these, 56 were adenocarcinomas (subtypes: adenocarcinoma NOS, papillary adenocarcinoma, tubular adenocarcinoma, adenocarcinoma in situ). The median age of this cohort was 47 years (range 19 years-92 years), with nearly 40% patients under 40 years at diagnosis. Most common presenting feature was hematospermia followed by hematuria and obstructive lower urinary tract symptoms. Most common MRI appearance was a large solid-cystic mass adjacent to prostate with variable adjacent structure invation. Four patients had metastatic disease at diagnosis. Treatment modalities included surgery in 27 patients (laparoscopic or robotic tumor excision in 12, total cystoprostatectomy with bilateral vesiculectomy with or without pelvic lymph node dissection performed in 10), chemotherapy in 13 patients (5FU+Platinum based) and radiotherapy in 11 patients (in neoadjuvant, radical, adjuvant and palliative settings). One patient refused any treatment. Complete treatment details were unavailable for 17 patients. Survival data was available for 19 patients. The available overall survival (OS) data range from 6 days to 6.5 years; 2 year OS was 31.8%. The available progression free survival (PFS) data range from 1 month to 6 years; 2 year PFS was 25%. Upfront radical surgery (but not extent of resection) and platinum-based chemotherapy correlated with 2 year OS. Conclusion Our findings suggest that adenocarcinoma seminal vesicle presents in young to middle aged adults and carries a poor prognosis. Patients who undergo radical surgeries and adjuvant chemotherapy may have encouraging outcomes. Role of radical or adjuvant radiation is unclear. Better understanding of disease behaviour with multidisciplinary discussion and enrolment of patients into rare tumor registries may help improvement of treatment decisions and disease outcomes. PO-1401 Lung metastasis from renal cell carcinoma: SBRT alone or in association with target therapy as a potential treatment option F. Zerbetto 1 , S. Foti 2 , C. Deantoni 1 , M. Pasetti 3 , A. Chiara 4 , T. Roberta 3 , S. Broggi 5 , N.G. Di Muzio 6 1 IRCCS San Raffaele Scientific Institute, Department of Radiotherapy, Milan, Italy; 2 IRCCS San Raffaele Scientific Institute, Department of Medical Oncology, Milan, Italy; 3 IRCCS San Raffaele Scientific Institute, (1) Department of Radiotherapy, Milan, Italy; 4 IRCCS San Raffaele Scientific Institute, Department of Radiotherapy, milan, Italy; 5 IRCCS San Raffaele Scientific Institute, Milan, Italy, Medical Physics, Milan, Italy; 6 Vita –Salute S. Raffaele University , (3) Department of Radiotherapy, Milan, Italy Purpose or Objective The introduction of new target therapy in metastatic renal cell carcinoma RCC has improved the prognosis of these patients (pts). Recently the role of robotic Stereotactic Body Radiotherapy (SBRT) in oligometastatic setting is emerging as a promising treatment option. Our aim is to evaluate toxicity and local control (LC) of SBRT with CyberKnife® (Accuray, Sunnyvales, CA-CK) in the management of lung metastasis (LM) from RCC as monotherapy or in combination with new target therapy. Materials and Methods From 02/2018 to 07/2020, 24 LM in 18 RCC pts were treated with CK in our Institute. Median maximum diameter of the lesions was 1.75 cm (0.6-5,9 cm). Maximum number of lesion treated for patient was three. Median prescribed dose was 45 (30-60) Gy in 1-5 fractions, at a median isodose of 80% (73-85%). The Biologically Effective Dose (BED), considering an alpha/beta ratio of 10 was 112.5 (48-120) Gy. Five patients underwent SBRT only, while in the other 12 pts radiation treatment was associated to immunotherapy (Nivolumab) or Thyrosine Kynase Inhibitors (TKY: Sunitinib, Pazopanib or Carbozatinib). Results Median follow-up was 9.4 months (3-31.6). No acute toxicity was registered. Only one patient presented G2 asymptomatic early-late radio-induced pneumonia computer tomography (CT) documented 16 weeks after the end of SBRT and subsequently solved with steroid therapy. In this case three LM were concomitant treated with SBRT and Nivolumab, for a cumulative PTV of 65,22 square cm. No other late toxicities were recorded. Six LM (25%) presented complete CT or 18F-FDG-PET/CT response, six LM (25%) were in partial response, while stable disease was observed in 12 LM (50%). In the six cases with complete response, five were treated with concurrently TKY (4 with Sunitinib and 1 with Pazopanib). No local progressive disease were observed. Conclusion In our experience robotic SBRT in LM from RCC cancer is a feasible treatment with excellent local short-term control. Apparently the concomitant use of immunotherapy or TKY doesn’t increase the toxicity, except in case of high volumes of treatment. Longer follow-up is necessary to verify the toxicity, the stability of the complete local response over time and to better evaluate if the early stable disease will become a complete