IMRT allows treatment of pelvic nodes individualized by including sentinel nodes
Treatment of pelvic nodes individualized by inclusion of sentinel nodes can be easily integrated into an intensity-modulated radiation therapy (IMRT)-based treatment strategy, according to a new study conducted by a group of researchers from Tübingen and Munich in Germany. The target volume concept seems to correctly cover individual pelvic nodes, indicated by the absence of any nodal recurrence within 5 years of follow-up. The results of the study were presented at the 5th European Multidisciplinary Meeting for Urological Cancer (EMUC), November 15-17, 2013, in Marceille, France.
"Radiation treatment with long-term androgen deprivation has level 1 evidence as a treatment option for high-risk prostate cancer patients," commented lead author Dr. Arndt-Christian Müller of the Eberhard-Karls-Universität Tübingen. He explained that while standard target volumes for lymph node radiation exist, they do not account for the individual lymph drainage of different patients.
According to the researchers, these new data on individual inclusion of sentinel nodes into the target volumes for pelvic standard radiation IMRT suggest low toxicity with advanced treatment techniques. Müller explained that the absence of any nodal recurrence in the pelvis indicates that basing the target volume concept on sentinel nodes correctly covers individual pelvic lymph drainage.
Regarding the risk profile in this series, such as high risk defined in one third by Gleason score 8-10, outcome parameters were at least comparable to available data of the same treatment period. Thus, this sentinel node-based approach justifies further evaluation including current dose-escalation strategies in a larger prospective series.
"First, we conclude that treatment of pelvic nodes individualized by inclusion of sentinel nodes is feasible with IMRT. Second, the absence of any nodal pelvic recurrence within 5 years of follow-up indicates efficacy of this individualized treatment concept,” summarized Müller.
"We expect an improvement of PSA control and, with longer follow-up and higher patient numbers, a survival benefit for patients with individual inclusion of sentinel lymph nodes."
According to the authors, the results of the study could be followed up further by evaluating dose-escalated IMRT to prostate +/- sentinel node guided pelvic IMRT or by stratifying treatments after sentinel node biopsy with prostate only IMRT for node-negative patients and IMRT of prostate +/- sentinel node-guided IMRT in cases with affected pelvic nodes.