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[6] Vinogradskiy et a. 2012; Prescribing radiation dose to lung cancer patients based on personalized toxicity estimates. J Thorac Oncol. 7(11):1676-82. SP-0453 Functional-imaging guided dose-escalation U. Nestle 1 1 Kliniken Maria Hilf GmbH, Department of Radiation Oncology, Mönchengladbach, Germany Abstract text Functional Imaging, especially Positron Emission Tomography (PET) has been extensively explored in lung cancer. Due to the bad prognosis of the disease and the high risk of normal tissue damage in the chest, this has led to discussion and modification of target volume concepts. Furthermore, Imaging based dose escalation strategies have been developed and are being explored prospectively. Current ceoncepts and recent results of prospective trials will be outlined and discussed. SP-0454 New trends in the management of SCLC U. Ricardi 1 1 University of Torino, Department of Oncology, Torino, Italy Abstract text Small cell lung cancer (SCLC) is staged as either limited disease (LD), potentially curable, or extensive disease (ED). LD is treated with concurrent chemotherapy and thoracic radiotherapy, followed by prophylactic cranial irradiation (PCI, 25 Gy/10 fractions). Being concurrent chemoradiotherapy the standard of care in LD-SCLC, there are sill some uncertainties regarding the optimal radiotherapy schedule and dose, even if results of CONVERT trial show that there are no significant differences in survival and no major differences in toxicity between twice-daily (45 Gy in 30 BID 1.5 Gy fractions) and once-daily radiotherapy (66 Gy in 33 once daily fractions of 2 Gy). The conventional approach to ED-SCLC is mailny chemotherapy only, with radiotherapy reserved for site- specific palliation. Recent reports suggest increasing indications for radiotherapy in ED. In ED-SCLC patients with residual intrathoracic disease after first-line chemotherapy, the addition of thoracic radiotherapy reduces the risk of intrathoracic recurrence, and improves 2-year survival. It will be certainly important to identify, based on some prognosticators, patients who benefit more. The administration of PCI to patients affected with ED-SCLC showing response to chemotherapy is now recommended, due to overall survival benefit; however, because of the absence of brain imaging before enrolment and variations in chemotherapeutic regimens and irradiation doses, concerns have been raised about these findings, with some groups considering PCI not essential and therefore suggesting just a periodic MRI examination during follow- up of ED-SCLC patients with any response to initial chemotherapy and a confirmed absence of brain metastases. In spite of the evidence in favour of PCI in SCLC (randomised controlled trials and a meta-analysis strongly suggesting improved survival), its indication should be considered also in light of its potential contribution to neurotoxicity. Even if randomised trials have shown that neurocognitive functions seem to be moderately altered after PCI compared with no PCI, current areas of active research are investigating whole brain irradiation (WBI) with hippocampal-sparing as a potential way to reduce the risk of neurocognitive decline related to PCI, based on the positive results of a Phase II trial (RTOG 0933) of WBI in brain metastases. A small prospective study of

hippocampal-sparing PCI in SCLC suggests a potential benefit of such an approach in limiting the neuropsychological sequelae of brain irradiation, but with a risk of failures in the spared regions. These findings have generated several studies prospectively assessing PCI with or without hippocampal sparing, both in Europe and North America. In most of these trials, neurocognitive function is the primary endpoint. Indications for radiotherapy in the management of LD and ED will be addressed in the presentation, including new directions in SCLC treatment, represented by immunotherapy and emerging targeted therapy approaches (with potential biomarkers to direct therapy). SP-0455 How to manage SCLC cancer patients with brain metastases? C. Le Pechoux 1 , P. Gustin 1 , A. Botticella 1 , A. Levy 1 1 Institut Gustave Roussy, Radiation Oncology, Villejuif, France Abstract text Because small-cell lung cancer (SCLC) often metastasizes to the brain, cerebral imaging should be part of the initial assessment of all SCLC patients. The rate of symptomatic metastases at the time of diagnosis is around 15%, The detection of BMs varies according to imaging modality: in patients with newly diagnosed SCLC, BMs can be detected in 10% patients using CT and in up to 24% using MRI. Intracranial metastases will eventually occur in more than 50% of patients with SCLC during the course of their disease. Even in patients with clinical complete remission after treatment for “limited disease”, about half of them will develop brain relapse. Prophylactic cranial irradiation was therefore introduced in the early 1980s as a treatment that could prevent the development of BMs for SCLC patients. However, even after PCI patients may relapse in the brain (33% at 3 years in the meta analysis, 32.4% at 1 year in patients with extra-cranial metastatic disease having brain MRI every 3 months). Furthermore, the frequency of brain failure seems to be rising as a consequence of earlier detection, imaging modality and longer survival after primary diagnosis. Whole-brain radiotherapy (WBRT) with steroids is generally the preferred treatment as there are usually multiple BMs, and it gives symptomatic improvement in more than 50% of patients. Response rate to chemotherapy is 22 to 33%. The intracranial RR seems higher in patients receiving both WBI and chemotherapy as compared to chemotherapy alone as shown in a randomized trial (57% vs. 22%, P < 0.001); time to progression in the brain was also significantly longer in the combined-modality group, but with no impact on overall survival. Stereotactic radiotherapy rather than surgery may be an option in selected patients especially in patients with previous WBRT. Despite good response to radiotherapy and chemotherapy, management of the BMs continues to be difficult. There have been too few trials addressing SCLC patients with BMs as their survival is dismal.

Debate: This house believes that active surveillance is a good option for the management of low risk prostate cancer patients

SP-0456 This house believes that active surveillance is a good option for the management of low risk prostate cancer patients R. Valdagni 1 1 Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program and Radiation Oncology 1, Milan, Italy