Abstract Library

#4666 Merkel cell neuroendocrine carcinoma of the skin: High response rates to short course palliative radiotherapy – Typical clinical scenarios

Introduction: Merkel cell carcinomas (MCC) are a rare, aggressive skin neuroendocrine carcinomas, with peak incidence in the elderly. MCC often presents as a firm, red/purple painless nodule with a short history of increasing size. Surgery is considered the 1st line treatment but elderly patients, in particular, have comorbidities which may preclude radical surgery requiring reconstruction. In advanced MCC, immunotherapy (IO) is 1st line systemic treatment. Chemotherapy is used 2nd line or if contraindications for IO but can be challenging in an elderly population. There may be an emerging role for PRRT due to the presence of somatostatin receptors on MCC. Radiotherapy (RT) can be used for non-surgical candidates, or those with unresectable or metastatic disease. Adjuvant post-operative irradiation (PORT) may provide additional benefit in risk reduction and improves local control.

Conference:

Presenting Author:

Authors: Saunders E, Sizer B, Collins J, Skelly R, Srinivasan G,

Keywords: Merkel cell, skin, radiotherapy,

#3938 Brachytherapy in craniopharyngiomas: A systematic review and meta-analysis of long-term follow-up

Introduction: Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas (CPs). The potential benefits of brachytherapy for CPs have not yet been clarified. The purpose of this work was to conduct a meta-analysis to analyze the long-term efficacy and adverse reactions profile of brachytherapy for CPs.

Conference:

Presenting Author:

Authors: Zhang L, Guo W, Pan H,

Keywords: Brachytherapy, Craniopharyngiomas, Irradiation, Efficacy,

#3554 Stereotactic radiosurgery of brain metastases in large cell neuroendocrine carcinoma of the lung

Introduction: Stereotactic radiosurgery (SRS) is an established treatment of brain metastases (BM) in non-small cell lung cancer (NSCLC) whereas small cell lung cancer (SCLC) is usually treated with whole-brain irradiation (WBI). There is no consensus on treatment of BM in large cell neuroendocrine carcinoma of the lung (LCNEC).

Conference:

Presenting Author: Suppli M

Authors: Suppli M, Langer S, Persson G, Møller S,

Keywords: LCNEC, Radiosurgery, brain metastasis, radiotherapy,

#3396 Dose-response relationship after yttrium-90-radioembolization with glass microspheres in patients with neuro-endocrine tumor liver metastases

Introduction: In radioembolization, response is achieved through the irradiation and damaging of tumor DNA, while treatment toxicity is mainly related to healthy liver dose. Therefore, optimizing the dose in tumors while minimizing the healthy liver dose is deemed important. However, for hepatic metastases of neuroendocrine tumors, a dose-response relationship has not been established yet.

Conference:

Presenting Author: Ebbers S

Authors: Ebbers S, van Roekel C, Braat M, Barentsz M, Lam M,

Keywords: dose-response, neuroendocrine neoplasm, SIRT, 90y, radioembolization, liver metastasis,

#3270 Exploration of Ga-68 DOTA PET radiomics to predict the absorbed dose of Lu-177 DOTATATE® therapy of midgut neuroendocrine tumors

Introduction: Lu-177 DOTATATE® is a proficient systemic irradiation with heterogeneous individual consequences due to tumor burden, uptake and elimination. Current dosimetry protocols seem not accurate enough to predict efficacy or toxicity.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Courbon F

Authors: Brahmi S, Vallot D, Vija L, Dierickx L, Courbon F,

Keywords: midgut NET, Ga DOTA PET CT, LuPRRT, PET metrics, SUV, tumor absorbed dose,