This trial was a randomized, multicenter, phase 3 trial that included patients with a persistently detectable or initially undetectable and rising PSA of between 0.1 and 2.0 after prostatectomy. Patients had pT2 or pT3 disease, Gleason score of 9 or less, and good performance status. These patients were randomized to prostate bed radiation therapy to 64.8 Gy-70.2 Gy at 1.8 Gy per fraction daily alone, or the same regimen plus short-term ADT or prostate bed radiation plus lymph node radiation to 45 Gy at 1.8 Gy per fraction and then a cone down to the PTV for 19.8-25.2 Gy plus ADT.

Authors looked at a primary end point of freedom from progression, defined as biochemical failure per the Phoenix definition, clinical failure, or death. 1716 were eligible for the final evaluation and at the interim analysis, the Haybittle-Peto boundary for 5-year freedom from progression was exceeded when group 1 was compared with group 3 (p<0.0001). The difference between groups 2 and 3 did not exceed the boundary (p=0·0063). The 5-year freedom from progression rates in all patients were 70.9%, 81.3%, and 87.4% in groups 1, 2, and 3 respectively. Adverse events were more common in group 3, but late toxicities were similar between the three groups.

The authors conclude that the addition of ADT to salvage prostate bed radiation improves outcomes, and the addition of pelvic lymph node irradiation further improves outcomes without any significant differences in late toxicities.

Reference (Pub-Med Link): Pollack, A., Karrison, T. G., Balogh, A. G., et al. (2022). The addition of androgen deprivation therapy and pelvic lymph node treatment to prostate bed salvage radiotherapy (NRG Oncology/RTOG 0534 SPPORT): an international, multicentre, randomised phase 3 trial. Lancet (London, England), 399(10338), 1886–1901. https://doi.org/10.1016/S0140-6736(21)01790-6

Key Institution: Multi-Center, International

Keywords: Prostate

This systematic review and meta-analysis of 7 studies evaluated overall survival following WBRT with or without SRS boost and SRS for SCLC brain metastases. Survival after SRS was not inferior to WBRT. Median OS after first-line SRS was estimated at 8.7 months. At 12 months, local and distant brain control rates were 78% and 58%, which are comparable with rates seen in other histologies. These findings also held true among patients who had not received prior PCI. In summary, among select patients, survival and intracranial disease control after SRS appear comparable to those treated with WBRT.

Reference (Pub-Med Link): Gaebe, K., Li, A. Y., Park, A., Parmar, A., et al. (2022). Stereotactic radiosurgery versus whole brain radiotherapy in patients with intracranial metastatic disease and small-cell lung cancer: a systematic review and meta-analysis. The Lancet. Oncology, 23(7), 931–939. https://doi.org/10.1016/S1470-2045(22)00271-6

Key Institution: University of Toronto

Keywords: Brain, metastasis

This is a retrospective review of 220 patients treated with definitive SBRT for non-metastatic prostate cancer treated to either the prostate alone (n = 118) or the prostate plus pelvic lymph nodes (n = 102). Dose to the prostate was 36.25 Gy in 5 Fx, with SIB to 25 Gy in 5 Fx for those receiving pelvic LN coverage. LN coverage was associated with increased G2 GI toxicity (29.4% vs 14.7%, p=0.008) and late G2 urinary toxicity (45.6% vs 25%, p=0.003). There was one case of G3 urinary obstruction in the prostate only group, and both groups had similar rates of late G3 toxicities (2.5% urinary toxicity, 1% GI). Though incidence of severe toxicity was low for Prostate SBRT with SIB to pelvic lymph nodes, there was a significant increase in acute GI and late GU toxicity. This retrospective study supports the notion that SIB coverage of pelvic lymph nodes is feasible, with an associated risk of increased low-grade toxicities.

Reference (Pub-Med Link): Murthy, V., Adsul, K., Maitre, P., et al. (2022). Acute and Late Adverse Effects of Prostate-Only or Pelvic Stereotactic Radiation Therapy in Prostate Cancer: A Comparative Study. International Journal of Radiation Oncology, Biology, Physics, 114(2), 275–282. https://doi.org/10.1016/j.ijrobp.2022.05.050

Key Institution: Tata Memorial Hospital, Mumbai, India
Keywords: Prostate

The oligometastatic paradigm hypothesizes that patients with a limited number of metastases may achieve long term disease control if all sites of disease can be ablated. Although there have been several retrospective studies, there is limited randomized data. This article reports the long-term update of the SABR COMET trial which randomized patients with oligometastatic disease, defined as a controlled primary malignancy with 1-5 metastatic lesions, to palliative standard of care vs standard of care plus the addition of SABR. Between 2012 and 2016, 99 patients were randomly assigned at 10 centers internationally. The most common primary tumor types were breast (n 5 18), lung (n 5 18), colorectal (n 5 18), and prostate (n 5 16). Median follow-up was 51 months. The 5-year OS rate was 17.7% in arm 1 (95% CI, 6% to 34%) versus 42.3% in arm 2 (95% CI, 28% to 56%; stratified log-rank P5.006). The 5-year PFS rate was not reached in arm 1 (3.2%; 95% CI, 0% to 14% at 4 years with last patient censored) and 17.3% in arm 2 (95% CI, 8% to 30%; P 5 .001). There were no new grade 2-5 adverse events and no differences in QOL between arms. At a median follow up of 51 months, there was a large statistically significant difference in overall survival, 5-yr OS (17.7% vs 42.3%) with the addition of SABR. There were no new safety concerns and there was no significant detriment on QOL. These promising results, pending confirmation in phase III randomized studies, support the expanded use of SABR/SBRT for patients with oligometastatic disease.

(Open Access)

Reference (PubMed Link): Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: Long-term results of the sabr-comet phase ii randomized trial. J Clin Oncol 2020:Jco2000818.

Key Institution: Multi-Institutional
Keywords: Oligometastases, SBRT, COMET trial

Several dosimetric studies and retrospective studies have suggested that proton beam therapy could reduce normal tissue toxicity compared with IMRT. However, proton beam therapy is substantially more expensive, and there is insufficient evidence that proton beam therapy leads to clinically meaningful differences in patient outcomes. In this single-institution randomized trial, the authors compared proton beam therapy and IMRT for locally advanced esophageal cancer. The authors found that proton beam therapy significantly reduced the total toxicity burden (TTB) and rate of post-operative complications compared with IMRT with similar rates of PFS and OS at 3 years. Remarkably, the postoperative complication score was 7.6 times higher for patients treated with IMRT. Interestingly, there were no significant differences in quality of life between the arms. This study provides the first randomized evidence that proton beam therapy can improve patient outcomes over IMRT. However, the primary endpoint of TTB has not been previously validated, and it is unclear that an improvement in TTB can economically justify routine use of proton beam therapy for esophageal cancer. The currently ongoing NRG-GI006 trial will help to evaluate the findings of this trial in a larger multi-institutional setting.

Reference (PubMed Link): Lin SH, Hobbs BP, Verma V, et al. Randomized phase iib trial of proton beam therapy versus intensity-modulated radiation therapy for locally advanced esophageal cancer. J Clin Oncol 2020;38:1569-1579.

Key Institution: Multi-Institutional
Keywords: Locally advanced esophageal cancer, proton beam therapy, total toxicity burden, NCT01512589