https://orcid.org/0000-0002-7109-509X

Colombia

https://orcid.org/0000-0002-7109-509X

Colombia

Colombia

Colombia

Clínica Los Nogales

Colombia

experienced biochemical recurrence following radical prostatectomy and were treated with salvage

SBRT to the prostatectomy bed and pelvic lymph node areas at Clínica Los Nogales (Bogotá, Colombia)

between March and October 2023. Toxicities were assessed using CTCAE v5.0, and health-related

quality of life (HRQOL) was evaluated using the EPIC-26 questionnaire. Grade 1 genitourinary (GU)

toxicity occurred in 50% of patients and grade 2 in 29.3%, with no grade ≥3 GU toxicity reported.

Gastrointestinal (GI) toxicity was reported as grade 1 in 20.7% and grade 2 in 12% of patients, with no

grade ≥3 GI events. Prior to SBRT, 17% of patients had preserved sexual function, and 31% had full

urinary continence. These findings suggest that salvage SBRT including ENI is feasible and well

tolerated, with low rates of acute toxicity. The greatest HRQOL impact was observed in the sexual

domain, highlighting the importance of early detection of biochemical recurrence to guide treatment

Correspondencia: Radioterapiapapers@gmail.com

La literatura existente sobre radioterapia estereotáxica corporal (SBRT) de rescate se ha enfocado

principalmente en los resultados de toxicidad y eficacia restringidos a la fosa prostática, sin estudios

previos que evalúen sistemáticamente la irradiación nodal electiva (ENI) en este contexto. El objetivo

principal de este estudio fue evaluar la incidencia de toxicidades genitourinarias (GU) y

Nogales (Bogotá, Colombia) entre marzo y octubre de 2023. Según la escala CTCAE v5.0, el 50% de

los pacientes presentó toxicidad GU grado 1 y el 29,3% toxicidad grado 2; no se observaron eventos

grado 3. En cuanto a la toxicidad GI, el 20,7% presentó grado 1 y el 12% grado 2, sin toxicidades de

grado 3. Antes del tratamiento, el 17% de los pacientes conservaba funcionalidad sexual y el 31% reportó

continencia urinaria completa. La SBRT dirigida al lecho prostático y áreas nodales como terapia de

rescate puede administrarse de forma segura, mostrando tasas bajas de toxicidad aguda sin

complicaciones mayores. Estos resultados refuerzan la viabilidad y tolerabilidad de la SBRT en este

escenario, destacando la importancia del diagnóstico temprano de la recaída bioquímica para optimizar

el tratamiento y de ser posible, evitar la necesidad de terapia hormonal.

The estimated incidence rate of prostate cancer in Colombia ranges from 20 to 30 cases per 100,000

men, 30–60% of patients will develop recurrent disease after any local therapy in prostate cancer, (1,2).

The rationale for using SBRT in patients with prostate cancer is the low α/β value of about 1.5 Gy (3,4.)

The organs at risk in close proximity to the prostate like the bladder, rectum or urethra for instance have

a higher α/β value of 3–6 (5). Therefore, using a larger fraction dose is expected to improve the

therapeutic ratio and consequently the probability of tumor control.

greater demand for radiotherapy. According to the Department of Health in England, there is a 2.3%

annual growth in demand for radiotherapy. Radiotherapy is a highly cost-effective treatment. It

represents only 5% of the national expenditure on cancer treatment in England and is the second most

effective cancer treatment after surgery.

Of all cancer patients who are cured, 40-50% have received radiotherapy as part of their curative

treatment, and 16% of all cancer patients cured are completely attributable to radiotherapy, according to

a report by the National Radiotherapy Implementation Group (NRIG) of England (9).

In developing countries, the only alternative available to the shortage of radiotherapy equipment is

extreme hypofractionation to increase installed capacity due to lack of access. Extending the adoption

of SBRT in LATAM can provide a path forward to increase access to radiotherapy .(8)

delivery. The use of hypofractionated radiotherapy has advantages for the patient by reducing

transportation costs, lodging expenses, and costs of work incapacity for the labor system. For the

radiotherapy center, it reduces patient absenteeism during treatment and improves patient adherence.

(10)

That is why this study was developed to evaluate the Toxicity profile and patient-reported outcomes

following salvage Sbrt to pelvic lymphnode and prostate bed after prostatectomy.

health-related quality of life (HRQOL).

Materials and Methods

This single-institution, prospective cohort study included 62 patients diagnosed with adenocarcinoma

of the prostate who experienced biochemical relapse after radical prostatectomy. All patients had a

prostate-specific antigen (PSA) level ≥ 0.1 ng/mL and an Eastern Cooperative Oncology Group (ECOG)

performance status of 0-1. Patients were treated with stereotactic body radiotherapy (SBRT) targeting

the prostatectomy bed and pelvic lymph node areas as salvage therapy at Clínica Los Nogales in Bogotá,

Colombia, between March and October 2023. Androgen deprivation therapy (ADT) was administered

at the discretion of the treating physician. This study was approved by the Institutional Review Board

● Men with adenocarcinoma of the prostate who experienced biochemical recurrence or

● Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.

● Signed informed consent.

an every-other-day regimen.

A extreme hypofractionation or SBRT schedule was used, with a total dose of 30 Gy administered in 5

fractions to the prostate bed or positive lymph nodes in PET PSMA (if the patient has PSMA PET )

and 25 Gy to pelvic (ganglia) nodal regions. Bladder filling and bowel preparation (enemas) were

advised for treatment planning.The treatment was planned with a CT scan using a supine position with

immobilization and fusion with PET in case of positive lesions ( devices, and a multi-leaf collimator

was used.)

The clinical target volume (CTV1) encompassed the prostate bed, while the clinical target volume

(CTV2) included the pelvic lymph nodes.Pelvic nodal regions were contoured following established

global guidelines NRG/RTOG , with the upper boundary of the pelvic contour delineated at the

Acute toxicities were evaluated in the first 90 days after the beginning of radiation therapy, were scored

weekly during radiation therapy in morbility consultation and at 3 months after the initiation of radiation

therapy, The first control was in the final consultation once the radiotherapy ended, the second control

was after 60 days and the last control was carried out after completing the 90 days of completion of

treatment by telephone contact for all patients. Toxicity assessments were performed at baseline and at

each follow-up visit using the EPIC26 short form

reported mildly affected quality of life due to mild urinary symptoms, of whom 70% (12 patients) had

pre-existing incontinence before radiotherapy. Figure 1.

Additionally, 20.6% (12 patients) reported a moderately affected quality of life, with 83.3% (10 patients)

experiencing urinary symptoms prior to treatment. Finally, 13.8% (8 patients) had a severely affected

quality of life in the incontinence domain, entirely attributable to surgery, as all of them had incontinence

before undergoing ultrahypofractionated radiotherapy.

It is concluded that SBRT treatment to the prostatectomy bed and pelvic lymph nodes may have

Based on the latest data, only 37% of them actually required ADT treatment, meaning that 62% of the

cohort underwent unnecessary ADT.

Given the known adverse effects of ADT—particularly on sexual function—overtreatment poses a

significant concern. Notably, when patients were referred at a PSA of 0.1 or lower for ultra-early salvage

therapy, 100% were successfully treated without requiring ADT. These findings underscore the critical

importance of early referral to minimize unnecessary exposure to ADT-related toxicities.

With this abbreviated treatment regimen, urinary toxicity typically manifests after treatment completion.

and epithelial desquamation. This exposes isotonic tissue to hypertonic urine, triggering inflammation

and overactive bladder symptoms (15).

In conventional (prolonged) radiotherapy regimens, bladder filling capacity becomes progressively

compromised, often starting as early as the third week of treatment. This is primarily due to detrusor

muscle hyperactivity, which induces involuntary contractions even at low bladder volumes (15).

Consequently, reproducibility of bladder filling across treatment sessions is significantly impaired once

radiation-induced overactive bladder symptoms emerge.

In contrast, this ultra-short treatment schedule circumvents this issue, as urinary toxicity typically arises

after treatment completion, thereby preserving consistent bladder filling throughout the therapeutic

course.

Stereotactic Body radiotherapy (SBRT) targeting the prostatectomy bed and pelvic lymph node areas

as salvage therapy can be safely administered

Our results revealed low rates of acute genitourinary and gastrointestinal toxicity with no grade > 3

complications observed. These findings reinforce the feasibility and tolerability of SABR to bed tumor

and lymph nodes .

limitations retrospective, longer observation is essential to assess late complications Continued patient

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7. The addition of androgen deprivation therapy and pelvic lymph node treatment to prostate bed

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15. V. David, A. A. Kahokehr, J. Lee, D. I. Watson, J. Leung, and M. E. O’Callaghan,“Incidence of