What is Salvage Radiotherapy, and what role does it play in treating prostate cancer?

Radiation therapy, specifically Salvage Radiotherapy (SRT), is a treatment method used after a radical prostatectomy (surgery to remove the prostate) for men with high-risk prostate cancer. It focuses radiation on the prostate fossa, the area where the prostate used to be. The aim is to eliminate any remaining cancer cells and prevent the cancer from returning.

What is biochemical failure, and why is it important in the context of prostate cancer treatment?

Biochemical failure (BCF) is defined as a rise in the Prostate-Specific Antigen (PSA) level after surgery, indicating that the cancer may have returned. PSA is a marker for prostate cancer; rising levels suggest that cancer cells are present in the body and are growing. The study examined the recurrence patterns in patients who experienced BCF after having Salvage Radiotherapy.

Where does prostate cancer tend to reappear after Salvage Radiotherapy?

The study found that the most common site for the recurrence of prostate cancer after Salvage Radiotherapy was in the bones (bone metastases). Other sites included the vesicourethral anastomosis (where the bladder and urethra were reconnected after surgery) and the lymph nodes. The findings highlight the spread of the cancer to multiple locations in the body.

What are pelvic lymph nodes, and why is it important to consider them when administering Salvage Radiotherapy?

The pelvic lymph nodes are glands that filter lymph fluid and can be sites of cancer spread. Including the pelvic lymph nodes in the radiation field of Salvage Radiotherapy means that the radiation targets the lymph nodes in addition to the prostate fossa. Since some cancer recurrences were found in the lymph nodes, expanding the radiation field may improve cancer control by targeting these areas where cancer cells might have spread.

What are the implications of the study's findings regarding the radiation field for high-risk prostate cancer patients?

The implication of the study's findings is that for some men with high-risk prostate cancer, broadening the area of radiation therapy to include the pelvic lymph nodes might be beneficial. The study's observation that lymph node recurrences were outside the traditional radiation zone suggests that expanding the radiation field could potentially improve cancer control. This approach aims to catch any stray cancer cells that may have spread to the pelvic lymph nodes, thus reducing the likelihood of cancer recurrence and potentially improving patient outcomes.

Illustration of prostate cancer treatment with radiation therapy and lymphatic system involvement

Beyond the Prostate: Rethinking Radiation Therapy for High-Risk Prostate Cancer

Kai Mendoza in Health & Wellness December 2025 • 4 min read.

"Is It Time to Expand the Treatment Zone to Improve Outcomes?"

In the fight against prostate cancer, radiation therapy after surgery (radical prostatectomy) plays a crucial role, especially for men categorized as high-risk. Traditionally, this radiation, known as salvage radiotherapy (SRT), has been narrowly targeted at the area where the prostate used to be (prostate fossa). The idea was simple: hit the most likely spot for cancer recurrence.

However, limiting the radiation field might be a problem. Some research suggests that the cancer can spread to nearby lymph nodes in the pelvis, even if initial tests don't show it. This raises a key question: should SRT be expanded to include these pelvic lymph nodes, casting a wider net to catch any stray cancer cells?

A recent study delved into this issue by examining recurrence patterns in men with high-risk prostate cancer who received SRT that included the pelvic lymph nodes. By understanding where the cancer tends to reappear, researchers hoped to shed light on whether a more comprehensive approach to radiation therapy could improve outcomes.

Where Does Prostate Cancer Reappear After Salvage Radiotherapy?

Illustration of prostate cancer treatment with radiation therapy and lymphatic system involvement

The study looked at data from 196 high-risk prostate cancer patients who underwent SRT after their prostate was removed. All patients had experienced biochemical failure (BCF), meaning their PSA levels (a marker for prostate cancer) started to rise again after surgery, indicating the possible return of cancer. After SRT, 80 of these patients experienced another BCF, and 59 of them underwent imaging to find out where the cancer was recurring.

What did the imaging reveal? Researchers found 24 recurrences in 16 patients. The most common site of recurrence was in the bones (13 bone metastases). Six recurrences were found at the site where the bladder and urethra were reconnected after surgery (vesicourethral anastomosis). Five recurrences occurred in the lymph nodes.

Bone Metastases: The most frequent site, highlighting the systemic nature of some prostate cancer recurrences.
Vesicourethral Anastomosis: Local recurrence at the surgical site, emphasizing the importance of adequate radiation coverage in this area.
Lymph Nodes: Regional spread, suggesting the potential benefit of including pelvic lymph nodes in the radiation field.

Importantly, when the researchers looked at the location of lymph node recurrences in relation to the radiation field, they made a key observation: No recurrences were found within the planned radiation area (in-field). Instead, the recurrences were either just outside the edge of the planned area or completely outside of it. This suggests that the radiation was effective where it was delivered, but it wasn't covering all the potential areas of spread.

The Implications: Should Radiation Therapy Target a Wider Area?

This study's findings suggest that for some men with high-risk prostate cancer, expanding the radiation field to include the pelvic lymph nodes might be a good idea. Since most lymph node recurrences occurred outside the traditional radiation zone, a more comprehensive approach could potentially improve cancer control.

However, it's not a one-size-fits-all situation. The study emphasizes the need to carefully select patients who might benefit most from this extended radiation field. Factors like the initial Gleason score (a measure of cancer aggressiveness) and pre-SRT PSA levels could help identify those at higher risk of lymph node involvement.

The authors conclude that while local recurrence at the anastomosis site remains a primary concern that might warrant dose escalation, elective pelvic nodal irradiation should be considered for selected individuals to optimize radiation therapy field.