When facing a post prostatectomy biochemical failure (PSA only failure) the best way to treat is still not known. Preliminary data from Johns Hopkins
Despite this, it remains clear that results with salvage radiotherapy remain less than satisfactory. In response there have been investigations of expanding treatment to include the elective targeting of the pelvic lymph nodes in addition to the prostate bed. Currently most reports of radiation treatment of biochemical failure have limited the salvage radiotherapy to the prostate bed.
The question is now whether the expansion of radiation fields to include the pelvic lymph nodes can improve survival. Currently, the phase III RTOG 0534 trial is attempting to answer this question. The trial is prospectively randomizing patients to small versus large field radiotherapy, in addition to evaluating the role of a short course of androgen deprivation therapy.
This study continues to enroll patients, with about 60% of the targeted 1764 men in the trial. It will still take many more years before we get a good answer, if larger fields improve outcomes and if the potential risks of increased pelvic toxicity is warranted.
Duke and Virginia Commonwealth University did release data from an inter-institutional study which included 247 men. The data compared the experience of these two academic radiation oncology departments with an almost 100% preference for either targeting only the prostate bed (Duke) or including the pelvic lymph nodes (Virginia Commonwealth University).
The current analysis showed no significant improvement in biochemical PSA control rates with larger field radiotherapy in men treated with a pre-radiotherapy PSA <0.4 ng/mL. However, in men for whom salvage radiotherapy was initiated with a PSA ?0.4 ng/mL (n=139), the post-radiotherapy PSA progression rates were cut in half if the pelvic lymph nodes were included (HR 0.47, 0.24-0.93, p=0.03).Not surprisingly, the analysis also demonstrated outcomes with salvage radiotherapy were best when treatment was initiated at the lowest pre-radiotherapy PSA levels, and in men with Gleason scores of ?7.It is important to note that there are some statistical problems with this result. The issues included an unbalanced group of patients at each of the two institutions, largely an influence of upstream referral patterns from two different urology departments and there were not enough patients available for a propensity score matched-pair analysis.The data presented is intriguing, but we will need to be patient and continue recruiting patients for enrollment in this trial.References: 1. Trock BJ, Han M, Freedland SJ, et al. Prostate cancer-specific survival following salvage radiotherapy vs observation in men with biochemical recurrence after radical prostatectomy. JAMA. 2008;299: 2760-2769. 2. Cotter SE, Chen MH, Moul JW, et al. Salvage radiation in men after prostate-specific antigen failure and the risk of death. J Cancer. 2011;117:3925-3932. 3. Moghanaki D, Koontz BF, Karlin JD, et al. Elective Irradiation of Pelvic Lymph Nodes During Postprostatectomy Salvage Radiotherapy. J Cancer. 2012; Epub ahead of printJoel T. Nowak, M.A.,M.S.W. [/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]