Department of Radiation Oncology, Klinikum rechts der isar, Technical University of Munich (TUM), Ismaninger Strasse 22, 81675, Munich, Germany.
Department of Radiation Sciences (DRS), Institute for Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany.
Radiat Oncol. 2021 May 1;16(1):82. doi: 10.1186/s13014-021-01811-8.
Positron emission tomography-(PET) has evolved as a powerful tool to guide treatment for prostate cancer (PC). The aim of this survey was to evaluate the acceptance and use of PET-especially with prostate-specific membrane antigen (PSMA) targeting tracers-in clinical routine for radiotherapy (RT) and the impact on target volume definition and dose prescription.
We developed an online survey, which we distributed via e-mail to members of the German Society of Radiation Oncology (DEGRO). The survey included questions on patterns of care of RT for PC with/without PET. For evaluation of doses we used the equivalent dose at fractionation of 2 Gy with α/β = 1.5 Gy [EQD2(1.5 Gy)].
From 109 participants, 78.9% have the possibility to use PET for RT planning. Most centers use PSMA-targeting tracers (98.8%). In 39.5%, PSMA-PET for biochemical relapse after prior surgery is initiated at PSA ≥ 0.5 ng/mL, while 30.2% will perform PET at ≥ 0.2 ng/mL (≥ 1.0 ng/mL: 16.3%, ≥ 2.0 ng/mL: 2.3%, regardless of PSA: 11.7%). In case of PET-positive local recurrence (LR) and pelvic lymph nodes (LNs), 97.7% and 96.5% of the participants will apply an escalated dose. The median total dose in EQD2(1.5 Gy) was 70.00 Gy (range: 56.89-85.71) for LR and 62.00 Gy (range: 52.61-80.00) for LNs. A total number of ≤ 3 (22.0%) or ≤ 5 (20.2%) distant lesions was most often described as applicable for the definition as oligometastatic PC.
PSMA-PET is widely used among German radiation oncologists. However, specific implications on treatment planning differ among physicians. Therefore, further trials and guidelines for PET-based RT are warranted.
正电子发射断层扫描（PET）已成为指导前列腺癌（PC）治疗的有力工具。本研究旨在评估 PET（尤其是针对前列腺特异性膜抗原（PSMA）的示踪剂）在临床常规放疗（RT）中的接受程度和使用情况，以及其对靶区定义和剂量处方的影响。
我们开发了一个在线调查，并通过电子邮件分发给德国放射肿瘤学会（DEGRO）的成员。该调查包括有关有/无 PET 的 PC 放疗护理模式的问题。为了评估剂量，我们使用 2 Gy 分割的等效剂量，α/β=1.5 Gy[EQD2(1.5 Gy)]。
在 109 名参与者中，78.9%有使用 PET 进行 RT 计划的可能性。大多数中心使用 PSMA 靶向示踪剂（98.8%）。在 39.5%的情况下，在 PSA≥0.5 ng/mL 时开始进行手术复发后的 PSMA-PET，而在 30.2%的情况下，将在 PSA≥0.2 ng/mL（≥1.0 ng/mL：16.3%，≥2.0 ng/mL：2.3%，PSA 不相关：11.7%）时进行 PET。对于 PET 阳性的局部复发（LR）和盆腔淋巴结（LNs），97.7%和 96.5%的参与者将应用递增剂量。LR 的 EQD2(1.5 Gy)总剂量中位数为 70.00 Gy（范围：56.89-85.71），LNs 为 62.00 Gy（范围：52.61-80.00）。大多数医生将≤3 个（22.0%）或≤5 个（20.2%）远处病变描述为适用于寡转移 PC 的定义。
PSMA-PET 在德国放射肿瘤学家中广泛使用。然而，治疗计划的具体影响在医生之间存在差异。因此，需要进一步的试验和基于 PET 的 RT 指南。
