ESTRO meets Asia 2024 - Abstract Book

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Invited Speaker

ESTRO meets Asia 2024

It is assumed that higher-risk disease requires higher conventionally fractionated radiation doses for comparable effectiveness. Physical whole-gland dose escalation to 80 Gy and higher, using conventional fractionation delivering 2 Gy per session, led to lower rates of biochemical failure and distant metastases and improved overall survival in patients with high-risk PCa. Unfortunately, the positive results of whole-gland dose escalation come often at the cost of increased toxicity. Furthermore local recurrences are still observed, mostly at the site of the primary tumor. Instead of escalating the dose to the whole prostate gland, increasing the radiation dose only to the intraprostatic tumor nodule(s), so called focal boosting, could be an ideal solution in patients with higher risk PCa, both in terms of toxicity and local control. Based on this principle, the phase III Focal Lesion Ablative Microboost in Prostate cancer (FLAME) trial showed that focal boosting to the intraprostatic tumor(s) up to 95 Gy in addition to EBRT to the whole prostate gland improved biochemical disease-free survival (bDFS) without significantly increasing toxicity or deteriorating quality of life (QoL) in patients with intermediate- or high-risk PCa. Both, the non-boosted standard and focal-boosted experimental group were treated by a conventionally fractionated, 35-session, scheme. By combining physical dose escalation, using the focal boost strategy, with biological dose escalation based on ultra hypofractionation, one could combine the advantages of both, especially in patients who are at higher risk of disease recurrence. The recently reported Hypflame phase 2 trials giving 5 fractions of 7 Gy on the prostate with isotoxic surdosage on the visible tumour up to 50 Gy also in 5 fractions show excellent 5 years bDFS of above 90%. There are currently several phase 3 trials ongoing comparing ultrahypofractionation with surdosage on the macroscopic tumour with moderate hypofractionation.

The session will provide an overview of the different dose/fractionation regimens and the underlying radiobiological assumptions.

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Role of pelvic nodal irradiation

Vedang Murthy

Radiation Oncology, Tata Memorial Centre, Mumbai, India

Abstract

This presentation evaluates the efficacy and feasibility of whole pelvic radiotherapy (WPRT) versus prostate-only radiotherapy (PORT) in patients with high-risk and very high-risk prostate cancer, considering modern imaging techniques and radiotherapy advancements. The presentation covers a comprehensive review of the role of WPRT in patients with negative nodes using conventional fractionation and stereotactic body radiotherapy (SBRT). It further discusses optimization strategies for WPRT in node-positive patients, utilizing PSMA PET CT to enhance targeting accuracy. Historical and recent clinical trial data are analyzed to compare treatment outcomes, particularly focusing on disease-free survival (DFS), biochemical failure-free survival (BFFS), and overall survival (OS) metrics. Advanced imaging and targeted radiotherapy techniques like IMRT and IGRT have played significant roles in improving treatment precision, potentially increasing DFS and reducing toxicity. The analysis also explores the impact of modern imaging on staging and treatment planning, particularly highlighting the utility of PSMA PET CT in node positive cases.

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