The imaging technology at the heart of the study is prostate-specific membrane antigen positron emission tomography, usually abbreviated PSMA PET. Unlike conventional CT or bone scans, which rely on anatomical changes to reveal tumours, PSMA PET exploits the fact that prostate cancer cells overproduce a surface protein called prostate-specific membrane antigen. A radioactive tracer, either gallium-68 labelled PSMA-11 or fluorine-18 labelled PSMA-1007 in this study, is injected into the bloodstream and binds to that protein, making even small clusters of cancer cells glow on the scan. In this cohort, scans were performed roughly an hour after tracer injection and jointly reviewed by an experienced nuclear medicine physician and a radiologist, with lesion locations confirmed on the accompanying CT component. This sensitivity allows detection of nodal recurrence at prostate-specific antigen, or PSA, levels far below those at which older imaging modalities become useful, opening a therapeutic window in which disease is still limited and potentially curable.

Armed with this detailed map of where the cancer had returned, the treating radiation oncologists did something that has become increasingly evidence-supported but had lacked long-term real-world validation: they delivered elective nodal radiotherapy, or ENRT. Rather than irradiating only the few lymph nodes visible on the PET scan, a strategy known as metastasis-directed therapy, ENRT treats the entire lymphatic drainage region at risk, including nodes that may harbour microscopic disease invisible to even the most sensitive scanner. Target volumes followed the Radiation Therapy Oncology Group atlas and, from 2020 onwards, the NRG Oncology consensus guidelines, adjusted according to the PSMA PET findings. In patients with disease extending above the pelvis, the elective field was stretched to include the paraaortic lymphatic pathways up to two centimetres above the highest PET-positive node. The prostate bed was routinely included in the treatment volume for patients who had not previously been irradiated there.

The technical execution reflected modern image-guided practice. In Innsbruck, patients initially received three-dimensional conformal radiotherapy before the centre switched to volumetric modulated arc therapy in 2017, while Munich used intensity-modulated or volumetric modulated arc therapy throughout. Daily or near-daily cone-beam CT verified patient positioning. All plans included a simultaneous integrated boost, meaning PET-positive lymph nodes received a higher radiation dose per fraction than the surrounding elective regions. In dose terms normalised to two-Gy fractions, the elective nodal regions received a median of 47.5 Gy, the prostate bed 66.0 Gy, locally recurrent disease 70.0 Gy, and PET-positive lymph nodes a median of 62.3 Gy, with doses adapted to respect the tolerance of nearby organs such as the bowel and bladder. Androgen deprivation therapy, which suppresses the testosterone that fuels prostate cancer growth, was recommended for all patients for 24 to 36 months and was actually given to 83.8 percent of the cohort.

The headline result is that this approach delivers durable disease control in routine clinical practice, not just in the carefully selected populations of clinical trials. Across the whole cohort, the five-year metastasis-free survival rate was 61.2 percent, meaning nearly two-thirds of these men remained free of distant spread five years after treatment. Biochemical progression-free survival, which tracks whether PSA remains suppressed, stood at 56.4 percent at five years, and overall survival reached 90.6 percent. Only 20 of the 179 patients died during follow-up, and just three of those had documented metastatic prostate cancer before death. For a population with nodal recurrence after prostatectomy, many of whom carried high-risk features such as grade 4 or 5 tumours, positive surgical margins, or disease extending beyond the pelvis, these figures represent a meaningful benchmark.

The most striking numbers emerged when the researchers separated two biologically distinct groups that are often lumped together. Some men experience a true biochemical recurrence, meaning their PSA fell to undetectable levels after surgery and only later began to rise. Others have PSA persistence, in which the marker never cleared after the operation, a sign that occult cancer cells were likely already disseminated at the time of surgery. Among the 104 men with true recurrence, five-year metastasis-free survival reached 74.3 percent and biochemical progression-free survival 62.3 percent, figures that closely approach the results of the randomised PEACE V-STORM trial, which reported four-year metastasis-free survival of 76 percent for elective nodal radiotherapy. By contrast, PSA persistence independently predicted worse outcomes in multivariable analysis, with more than double the risk of metastasis or death and nearly double the risk of biochemical progression, consistent with the idea that persistence marks more advanced, systemic disease.

The role of hormone therapy emerged as the other dominant prognostic factor. Men who received androgen deprivation therapy alongside their radiotherapy had a 64 percent lower risk of distant metastasis or death and a 74 percent lower risk of biochemical progression compared with those who did not, effect sizes that exceed those reported in meta-analyses of postoperative radiotherapy. The authors caution that this observational association cannot prove causation and may partly reflect the higher disease burden in patients with PET-detected nodal metastases, in whom combined modality treatment may simply be necessary. They also deliberately avoided analysing hormone therapy duration, because retrospectively grouping patients by the therapy actually completed rather than the intended duration invites statistical distortions known as immortal-time bias. The optimal duration of androgen suppression in this setting remains an open question for prospective trials.

Perhaps the most instructive finding concerns where the cancer returned when it did return. Among the 54 patients with imaging-confirmed recurrence, only 7.4 percent failed within the irradiated field, while 72.2 percent relapsed exclusively outside it and another 20.4 percent relapsed both inside and outside. This spatial pattern carries a double message. On one hand, it suggests the radiation targets were well designed, since true in-field failure was rare. On the other hand, the overwhelming predominance of out-of-field and distant relapse, including bone metastases in 20.7 percent of the entire cohort, points to microscopic disease lurking below the detection threshold of even PSMA PET, or to an inherently more aggressive systemic biology in these tumours. A negative PSMA PET scan, in other words, does not guarantee the absence of occult metastases, particularly in patients with high PSA levels at recurrence, and the authors argue that this limitation, not inadequate target coverage, is the main enemy to be fought.

The study is not without caveats, and the authors are candid about them. Its retrospective design introduces selection bias and limits causal inference, treatment varied between centres and eras, and the two institutions used different tracers and imaging protocols. Most importantly, toxicity was not systematically assessed and patient-reported quality of life was not collected, so the tolerability of this intensive combined approach cannot be reliably judged from these data. The multivariable models, built on data-driven variable selection, should be treated as exploratory. Nevertheless, the inclusion of higher-risk, less selected patients, including those with PSA persistence and paraaortic disease that the PEACE V-STORM trial excluded, is precisely what makes the results valuable as a real-world benchmark. Two ongoing phase III trials, GETUG-P12-OLIGOPELVIS 2 and POINTER-PC, are now testing whether adding elective nodal radiotherapy to hormone therapy improves survival and whether treating whole nodal regions outperforms targeting only visible nodes. Until those results mature, this bi-institutional analysis provides the strongest long-term signal yet that PSMA PET-guided elective nodal radiotherapy, combined with androgen deprivation, can convert nodal recurrence after prostatectomy from an ominous harbinger of metastatic disease into a controllable, and for many patients durably arrested, chapter of the illness.

Subject of Research: Long-term outcomes of PSMA PET/CT-guided salvage elective nodal radiotherapy for nodal prostate cancer recurrence after radical prostatectomy

Article Title: PSMA PET/CT-guided salvage elective nodal radiotherapy for nodal metastases after radical prostatectomy: a bi-institutional long-term outcome analysis

Article References: Vorbach, S. M., Seppi, T., Santo, G., Virgolini, I., Ganswindt, U., Keilholz, M., Brose, S. F., Casuscelli, J., Klimek, K., Werner, R. A., Schmidt-Hegemann, N.-S., Belka, C., Trapp, C., & Rogowski, P. (2026). PSMA PET/CT-guided salvage elective nodal radiotherapy for nodal metastases after radical prostatectomy: a bi-institutional long-term outcome analysis. European Journal of Nuclear Medicine and Molecular Imaging. https://doi.org/10.1007/s00259-026-08147-z

Image Credits: AI Generated

DOI: 10.1007/s00259-026-08147-z

Keywords: PSMA PET/CT, prostate cancer, elective nodal radiotherapy, radical prostatectomy, nodal metastases, salvage radiotherapy, androgen deprivation therapy, metastasis-free survival, biochemical recurrence, oligorecurrent disease, radiation oncology, molecular imaging

The clinical problem the researchers set out to solve is deceptively simple to state but notoriously difficult to quantify. After surgical removal of the prostate, the earliest sign that cancer has returned is a rise in prostate-specific antigen, or PSA, the blood protein that gives biochemical recurrence its name. Roughly one in three patients in the study cohort eventually experienced this endpoint. But PSA alone is a lagging indicator: by the time it climbs, micrometastatic disease may already be established, and the window for effective salvage radiotherapy or androgen deprivation may have narrowed. Existing tools such as the CAPRA-S score, which combines pathological findings from the surgical specimen with PSA and Gleason grade, are useful but fundamentally retrospective, because they depend on tissue that can only be examined after the operation. A genuinely preoperative predictor would allow surgeons and radiation oncologists to plan adjuvant treatment strategies while the patient is still on the operating table.

The technology at the heart of the study is a hybrid imaging platform that simultaneously captures two complementary views of the same tumour. The PET component relies on 18F-PSMA-1007, a fluorine-18 labelled radioligand that binds to prostate-specific membrane antigen, a transmembrane enzyme overexpressed on the surface of nearly all prostate cancer cells. Because the tracer carries a positron-emitting isotope, its accumulation within a lesion is directly proportional to PSMA expression, which in turn correlates with tumour aggressiveness, hypoxia, and metastatic potential. The MR component provides high-resolution soft-tissue contrast, allowing precise delineation of tumour boundaries within the prostate and assessment of extracapsular extension. Performing both acquisitions in a single session eliminates the registration errors that plague separately acquired scans and yields co-registered datasets in which every voxel carries both metabolic and morphological information.

From these co-registered datasets the researchers extracted quantitative imaging features, a practice known as radiomics. Two derived parameters proved especially powerful. The first, ADCmin-TBR, combines the minimum apparent diffusion coefficient measured on diffusion-weighted MRI with the tumour-to-background ratio of PET tracer uptake. ADC reflects how freely water molecules diffuse through tissue: densely packed, aggressively proliferating tumour cells restrict water movement, driving ADC values down. TBR, by contrast, captures the metabolic intensity of the lesion relative to surrounding tissue. By multiplying or otherwise combining these two quantities, ADCmin-TBR effectively encodes a lesion that is both densely cellular and metabolically voracious, the hallmark of a tumour primed to recur. The second parameter, TMR, integrates tumour volume characteristics with metabolic activity, capturing the overall disease burden visible on the hybrid scan.

To build the model, the team divided their 210 patients into a training cohort of 150 and an external validation cohort of 60 drawn from different centres. Rather than hand-picking candidate predictors, they employed least absolute shrinkage and selection operator regression, or LASSO, coupled to a Cox proportional hazards framework. LASSO works by penalising model complexity, shrinking the coefficients of weak predictors toward zero and effectively eliminating them, which guards against overfitting in datasets where the number of variables approaches the number of events. The researchers used ten-fold cross-validation with the one-standard-error rule, a conservative criterion that selects the simplest model within one standard error of the best-performing one. Only three predictors survived this stringent selection: ADCmin-TBR, TMR, and the PET/MR-derived T-stage, an imaging-based assessment of how far the tumour has extended beyond the prostate capsule.

The performance figures are impressive for a purely preoperative tool. Time-dependent areas under the receiver operating characteristic curve, which measure discrimination at specific follow-up horizons, ranged from 0.703 to 0.858 in the training cohort and from 0.766 to 0.846 in the external validation cohort across the one-to-three-year window. An AUC of 0.85 at three years means the model correctly ranks a randomly chosen recurring patient above a randomly chosen non-recurring patient in 85 of 100 such pairs. Calibration plots confirmed that predicted probabilities matched observed recurrence rates, and inverse probability of censoring weighted Brier scores accounted for patients whose follow-up ended before the endpoint could be observed. Decision-curve analysis, which quantifies the net clinical benefit of acting on a model’s predictions across a range of risk thresholds, showed positive net benefit across most clinically relevant thresholds, suggesting the model could genuinely inform treatment decisions rather than merely describe risk.

Perhaps the most consequential finding concerns how the PET/MR model relates to the established CAPRA-S score. On its own, the imaging model did not significantly outperform CAPRA-S in raw discrimination, as DeLong tests revealed no statistically significant differences in AUC. But discrimination is not the only measure of a prognostic tool’s worth. When the researchers formally tested whether adding the PET/MR model to CAPRA-S improved the statistical fit of the combined model, the answer was a clear yes. Likelihood-ratio tests showed significant improvement at both two and three years in the derivation cohort, with p-values below 0.001, and at three years in the external validation cohort, with a p-value of 0.031. In practical terms, this means the imaging model captures prognostic information that the pathological score cannot, offering genuinely incremental value precisely at the longer follow-up horizons that matter most for treatment planning.

The team also confronted the messy realities of real-world oncology data through sensitivity analyses. Two potential confounders loomed large: persistent postoperative PSA, which may reflect incomplete tumour resection rather than true recurrence, and secondary treatments such as salvage radiotherapy initiated before biochemical recurrence was documented, which can artificially delay the observed endpoint. Reassuringly, the two imaging-derived predictors, ADCmin-TBR and TMR, remained directionally stable across all sensitivity analyses, suggesting their prognostic signal is robust to these distortions. The PET/MR T-stage effect, however, was attenuated after treatment censoring, a finding the authors interpret as evidence that imaging-based staging may partly capture disease biology that secondary treatment subsequently modifies. This nuance underscores why the researchers caution that prospective validation is required before the model can guide secondary-treatment decisions in routine practice.

The implications of the study extend well beyond the statistics. If a preoperative PET/MR scan can identify patients at high risk of recurrence, surgeons could tailor the extent of lymph node dissection, radiation oncologists could escalate or de-escalate adjuvant therapy, and patients could be stratified into trials of intensified systemic treatment. The fluorine-18 label of PSMA-1007 also carries practical advantages over gallium-68 based tracers, including a longer half-life of roughly 110 minutes that permits central radiopharmacy production and wider distribution, potentially making the approach scalable beyond specialised academic centres. Previous work has already established that high PSMA expression correlates with early PSA recurrence and that PET-based tumour segmentation predicts survival in the recurrent setting, but this study is among the first to combine metabolic, diffusion, and staging information from a single hybrid examination into an externally validated preoperative model.

Challenges remain before the model reaches the clinic. The retrospective design, the modest validation cohort of 60 patients, and the predominance of Chinese centres all warrant broader prospective testing across diverse populations. Radiomic features are also sensitive to scanner vendor, acquisition protocol, and reconstruction parameters, so multicentre harmonisation will be essential. Yet the direction of travel is unmistakable. Medicine is steadily moving from reactive diagnosis toward predictive, imaging-driven risk stratification, and this study demonstrates that a single preoperative hybrid scan can carry enough quantitative information to forecast the trajectory of prostate cancer years before PSA betrays the first sign of relapse. For patients facing the anxious arithmetic of post-surgical surveillance, that prospect transforms a routine PET/MR examination into something far more powerful: a crystal ball built from physics, chemistry, and statistics, refined by data from 210 patients and validated across three hospitals.

Subject of Research: Preoperative 18F-PSMA-1007 PET/MR prognostic modelling for predicting biochemical recurrence after radical prostatectomy in prostate cancer

Article Title: Development and validation of a preoperative 18F-PSMA-1007 PET/MR prognostic model for predicting biochemical recurrence in prostate cancer: a multicentre study

Article References: Hu, J., Chunyu, H., Yang, Y., Song, Y., Cheng, C., Tang, H., Chen, X., Cheng, R., Dai, J., Meng, H., Zuo, C., Zhao, J., & Li, B. (2026). Development and validation of a preoperative 18F-PSMA-1007 PET/MR prognostic model for predicting biochemical recurrence in prostate cancer: a multicentre study. European Journal of Nuclear Medicine and Molecular Imaging. https://doi.org/10.1007/s00259-026-08179-5

Image Credits: AI Generated

DOI: 10.1007/s00259-026-08179-5

Keywords: prostate cancer, PSMA PET, 18F-PSMA-1007, PET/MR, biochemical recurrence, radical prostatectomy, prognostic model, radiomics, CAPRA-S, LASSO-Cox regression, multicentre study, molecular imaging

The study, led by Indri Desiati and May-Britt Tessem of the Norwegian University of Science and Technology together with colleagues at Oslo University Hospital and St. Olavs Hospital, focused on 223 men drawn from two independent cohorts: 136 patients from Trondheim and 87 from Oslo. Each patient provided a serum sample before surgery, and the researchers measured the levels of proteins involved in inflammation and immuno-oncology using the Olink platform, a proximity extension assay technology capable of quantifying hundreds of proteins from tiny volumes of blood with high sensitivity and specificity. Thirty-four proteins overlapped between the inflammation and immuno-oncology panels and were analyzed across the combined cohort.

The clinical questions at the heart of the study are among the most consequential in prostate cancer management. Biochemical recurrence was defined as a PSA level of 0.2 nanograms per milliliter or higher following surgery, a signal that prostate tissue, or possibly residual or metastatic cancer cells, is once again producing the enzyme. PSA persistence, defined as a PSA level of 0.1 nanograms per milliliter or higher, indicates that PSA never fully fell after the operation, often hinting that cancerous tissue remained in the body. Both outcomes mark turning points at which patients and clinicians must decide whether additional treatment, such as radiotherapy or androgen deprivation therapy, is warranted.

Among the 34 immune proteins measured, one stood out with striking consistency. Interleukin 18, or IL18, a cytokine known to stimulate antitumor immune activity and promote the development of cytotoxic T lymphocytes and natural killer cells, was consistently lower in patients who later experienced recurrence or PSA persistence compared with those who remained disease-free. Reduced IL18 before surgery, the authors suggest, may reflect weakened antitumor immune surveillance already in place before the tumor was removed, leaving patients biologically vulnerable to regrowth.

The PSA persistence group told an even more distinctive immunological story. Patients whose PSA never dropped to undetectable levels showed lower levels of TNFSF12, also known as TWEAK, along with reduced CCL19, a chemokine that helps guide immune cells into lymphoid tissues, and lower CD244, a receptor involved in natural killer and T cell function. Perhaps most intriguingly, the researchers observed a broader trend toward reduced protein levels across the entire panel in the persistence group in both cohorts, a pattern consistent with what oncologists call an immune-desert profile, in which the tumor environment is largely devoid of active immune cell infiltration and activity.

To translate these observations into practical risk prediction, the team built protein-based classification models using partial least squares discriminant analysis with fivefold cross-validation and recursive feature elimination, then compared their performance against models built from standard clinical parameters including age, pre-surgical PSA, biopsy Gleason Grade Group, clinical tumor stage, and PI-RADS MRI scoring. The protein signatures outperformed the clinical models in both cohorts. In Trondheim, the protein model achieved an area under the receiver operating characteristic curve, or AUC, of 0.73 for recurrence compared with 0.64 for the clinical model, and 0.83 for PSA persistence compared with 0.81. In Oslo the gap was even wider: AUC values of 0.77 versus 0.54 for recurrence and 0.89 versus 0.63 for persistence.

When the researchers combined the immune protein data with clinical parameters, discrimination improved further still. The combined models reached an AUC of 0.75 for recurrence in Trondheim and 0.75 in Oslo, while for PSA persistence the combined models achieved AUC values of 0.91 in Trondheim and 0.88 in Oslo. These numbers, while requiring validation in larger independent cohorts, indicate that a simple pre-surgical blood test capturing immune signaling could meaningfully sharpen the risk picture that clinicians currently assemble from imaging, biopsy grading, and PSA measurements alone.

The technical rigor of the study strengthens confidence in its conclusions. Group comparisons were performed using one-way analysis of variance with false discovery rate correction to guard against spurious findings, and prognostic associations were evaluated with Cox proportional hazards models for recurrence and logistic regression for PSA persistence. Analyzing two geographically and administratively separate cohorts provided an internal replication of the key findings, particularly the consistent reduction of IL18 in patients destined for recurrence or persistence, and the immune-desert pattern in the persistence group.

Beyond its immediate predictive value, the study carries broader implications for the immunobiology of prostate cancer. Prostate cancer has traditionally been considered a relatively cold tumor, less responsive to the checkpoint inhibitor immunotherapies that have transformed the treatment of melanoma and lung cancer. The observation that specific, measurable immune states, one inflamed and one suppressed, are already detectable in peripheral blood before surgery suggests that systemic immune contexture plays a role in determining which tumors evade control. If confirmed, immune-proteomic profiling could help identify patients who might benefit from immunotherapeutic strategies or more aggressive adjuvant treatment, and could enrich clinical trials designed around immune biomarkers.

The authors emphasize that their findings support the potential of pre-surgical serum immune-proteomic profiling for risk stratification and treatment planning, pending further validation in larger independent cohorts. The work was funded by the Norwegian Cancer Society and the Central Norway Regional Health Authority, and the serum samples were provided through hospital biobanks with ethics approval and written informed consent from all participants. For the roughly 1.4 million men diagnosed with prostate cancer worldwide each year, the prospect of a routine blood test performed before surgery that reveals not only the tumor’s characteristics but the body’s immunological readiness to fight it represents a compelling step toward truly individualized cancer care. As proteomic technologies grow faster and cheaper, the immune fingerprint in a vial of blood may become as standard a part of the surgical workup as the MRI scan itself.

Subject of Research: Pre-surgical serum immune-proteomic biomarkers predicting recurrence after prostate cancer surgery

Article Title: Pre-surgical immune-proteomic profiles in serum identify inflamed and suppressed immune states associated with biochemical recurrence and PSA persistence in prostate cancer

Article References: Desiati, I., Bozorgpana, S., Ramberg, H., Berge, V., Tasken, K. A., Giskeødegård, G. F., Bathen, T. F., & Tessem, M.-B. (2026). Pre-surgical immune-proteomic profiles in serum identify inflamed and suppressed immune states associated with biochemical recurrence and PSA persistence in prostate cancer. Clinical Proteomics. https://doi.org/10.1186/s12014-026-09634-z

Image Credits: AI Generated

DOI: 10.1186/s12014-026-09634-z

Keywords: prostate cancer, biochemical recurrence, PSA persistence, immune biomarkers, serum proteomics, IL18, Olink, radical prostatectomy, risk stratification, immune-desert profile, TNFSF12, CCL19