From the Guidelines
Radiation therapy is a recommended treatment option for localized prostate cancer, particularly for intermediate and high-risk disease, with a typical external beam radiation therapy (EBRT) regimen involving 76-78 Gy delivered in 38-39 fractions over 7-8 weeks, often with 4-6 months of androgen deprivation therapy (ADT) 1.
Key Considerations
- The decision to use radiation therapy should be based on the patient's risk category, with intermediate and high-risk patients being the most likely to benefit from this treatment option.
- The use of intensity-modulated radiation therapy (IMRT) and daily image-guided radiation therapy (IGRT) can help minimize side effects and improve treatment accuracy.
- Patients with low-risk prostate cancer may not require radiation therapy, and active surveillance may be a suitable alternative.
- Radiation therapy can also be used after prostatectomy for patients with adverse pathological features or rising PSA (biochemical recurrence).
Radiation Doses and Fractions
- For intermediate-risk prostate cancer, a typical EBRT regimen involves 76-78 Gy delivered in 38-39 fractions over 7-8 weeks.
- For high-risk patients, similar radiation doses plus longer-term ADT (18-36 months) may be recommended.
- For metastatic disease, radiation may be used palliatively to control symptoms or in oligometastatic disease.
Side Effects and Considerations
- Patients should be informed about potential side effects including urinary symptoms, erectile dysfunction, and bowel changes.
- The use of ADT can increase the risk of erectile dysfunction, and patients should be counseled about this potential side effect.
- Radiation therapy can be delivered safely and effectively in community practice, and is a viable alternative to surgical therapy.
Guideline Recommendations
- The AUA/ASTRO/SUO guideline recommends radical prostatectomy or radiotherapy plus ADT as standard treatment options for patients with intermediate risk localized prostate cancer 1.
- Clinicians should inform patients that favorable intermediate risk prostate cancer can be treated with radiation alone, but the evidence basis is less robust than for combining radiotherapy with ADT.
- Active surveillance may be offered to select patients with favorable intermediate risk localized prostate cancer, but patients should be informed that this comes with a higher risk of developing metastases compared to definitive treatment.
From the FDA Drug Label
ZOLADEX is indicated for use in combination with flutamide for the management of locally confined Stage T2b-T4 (Stage B2-C) carcinoma of the prostate. Treatment with ZOLADEX and flutamide should start 8 weeks prior to initiating radiation therapy and continue during radiation therapy The effects of hormonal treatment combined with radiation were studied in 466 patients (231 ZOLADEX + flutamide + radiation, 235 radiation alone) with bulky primary tumors confined to the prostate (stage B2) or extending beyond the capsule (stage C), with or without pelvic node involvement.
The radiation indications for prostate cancer are for locally confined Stage T2b-T4 (Stage B2-C) carcinoma of the prostate.
- The treatment should start 8 weeks prior to initiating radiation therapy and continue during radiation therapy.
- ZOLADEX is used in combination with flutamide for this indication 2, 2, 2.
From the Research
Radiation Indications for Prostate Cancer
The indications for radiation therapy in prostate cancer are based on the risk of disease progression or recurrence. The main factors used to stratify risk include clinical stage, pathologic grade, prostate-specific antigen level, and comorbidity-adjusted life expectancy 3.
- For low-risk prostate cancer, radiation therapy options include:
- Image-guided intensity modulated radiotherapy
- Brachytherapy for eligible patients 4
- For intermediate-risk prostate cancer, radiation therapy options include:
- Intensity modulated radiotherapy combined with 4-6 months of androgen deprivation therapy
- Intensity modulated radiotherapy alone or combined with brachytherapy for patients unsuitable for androgen deprivation therapy 4
- For high-risk prostate cancer, radiation therapy options include:
- Intensity modulated radiotherapy with long-term (≥2 years) androgen deprivation therapy 4
- Radical prostatectomy followed by adjuvant radiation therapy for patients with adverse pathologic features or biochemical recurrence 5
- Salvage radiation therapy for patients with local recurrence after radiation 5
Role of Radiotherapy in Localized and Locally Advanced Prostate Cancer
Radiotherapy plays a crucial role in the management of localized and locally advanced prostate cancer. The choice of radiation therapy depends on the individual patient's risk factors and treatment goals. External beam radiotherapy is considered the gold standard, and intensity modulated radiotherapy is the preferred technique 4.
- Post-operative irradiation may be proposed to patients with adverse pathologic features or biochemical recurrence after radical prostatectomy 4, 5
- Neoadjuvant radiotherapy may be considered for patients with high-risk localized prostate cancer, although further study is needed 5
- Salvage prostatectomy may be effective for treating local recurrence after radiation, but is associated with significant surgical morbidity 5