Intensity-Modulated Radiation Therapy with Stereotactic Body Radiation Therapy Boost for Unfavorable Prostate Cancer: The Georgetown University Experience

Abstract

Purpose/objective(s)Stereotactic body radiation therapy (SBRT) is emerging as a minimally invasive alternative to brachytherapy to deliver highly conformal, dose-­escalated radiation therapy (RT) to the prostate. SBRT alone may not adequately cover the tumor extensions outside the prostate commonly seen in unfavorable prostate cancer. External beam radiation therapy (EBRT) with high dose rate brachytherapy boost is a proven effective therapy for unfavorable prostate cancer. This study reports on early prostate-specific antigen and prostate cancer-specific quality of life (QOL) outcomes in a cohort of unfavorable patients treated with intensity-modulated radiation therapy (IMRT) and SBRT boost.Materials/methodsProstate cancer patients treated with SBRT (19.5 Gy in three fractions) followed by fiducial-guided IMRT (45–50.4 Gy) from March 2008 to September 2012 were included in this retrospective review of prospectively collected data. Biochemical failure was assessed using the Phoenix definition. Patients completed the expanded prostate cancer index composite (EPIC)-26 at baseline, 1 month after the completion of RT, every 3 months for the first year, then every 6 months for a minimum of 2 years.ResultsOne hundred eight patients (4 low-, 45 intermediate-, and 59 high-risk) with median age of 74 years completed treatment, with median follow-up of 4.4 years. Sixty-four percent of the patients received androgen deprivation therapy prior to the initiation of RT. The 3-year actuarial biochemical control rates were 100 and 89.8% for intermediate- and high-risk patients, respectively. At the initiation of RT, 9 and 5% of men felt their urinary and bowel function was a moderate to big problem, respectively. Mean EPIC urinary and bowel function and bother scores exhibited transient declines, with subsequent return to near baseline. At 2 years posttreatment, 13.7 and 5% of men felt their urinary and bowel function was a moderate to big problem, respectively.ConclusionAt 3-year follow-up, biochemical control was favorable. Acute urinary and bowel symptoms were comparable to conventionally fractionated IMRT and brachytherapy. Patients recovered to near their baseline urinary and bowel function by 2 years posttreatment. A combination of IMRT with SBRT boost is well tolerated with minimal impact on prostate cancer-specific QOL.

Hypofractionated stereotactic boost in intermediate risk prostate carcinoma: Preliminary results of a multicenter phase II trial (CKNO-PRO)

“…One other strength of our series is the absence of ADT to preserve potency and QoL and to avoid metabolic dysfunction. In a retrospective series of 108 patients (45 with an intermediate-risk cancer), the majority of them received ADT [ 21 ]. Patients were treated with SBRT (19.5 Gy in three fractions) followed by fiducial-guided IMRT (45–50.4 Gy).…”

“…Erectile dysfunction was not assessed. At 2 years 13.7% and 5% of men complained from moderate to severe urinary and bowel dysfunctions respectively [ 21 ]. Another series reported results of SBRT as a boost after pelvic EBR in patients with high-risk prostate carcinoma.…”

Intensity-Modulated Radiation Therapy with Stereotactic Body Radiation Therapy Boost for Unfavorable Prostate Cancer: A Report on 3-Year Toxicity

“…In an effort to maximize the benefit of administering high doses per fraction and patient acceptance, we have examined the use of stereotactic body radiation therapy (SBRT) as a prostatic boost to image-guided intensity-modulated radiation therapy (IMRT) for the treatment of patients with unfavorable clinically localized prostate cancer. Previously, we reported early outcomes of this treatment modality, with a 3-year biochemical-free survival rate of 100% for intermediate-risk and 89.8% for high-risk disease ( 19 ). Similarly, we reported that such a therapy conferred minimal impact on long-term quality of life (QOL) ( 19 ).…”

Predictors of multidomain decline in health‐related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer

“…Volume delineation of the prostate and seminal vesicles was defined using registration of the pretreatment magnetic resonance image (MRI) with the pretreatment CT simulation. Treatment‐planning details of prostate SBRT alone as well as external‐beam radiotherapy (EBRT) plus SBRT boost (intensity‐modulated radiotherapy [IMRT] plus SBRT boost) have been previously described . The prescribed dose was 35 to 36.25 grays (Gy) in 5 fractions for SBRT.…”

“…Treatment-planning details of prostate SBRT alone as well as external-beam radiotherapy (EBRT) plus SBRT boost (intensity-modulated radiotherapy [IMRT] plus SBRT boost) have been previously described. 14,15 The prescribed dose was 35 to 36.25 grays (Gy) in 5 fractions for SBRT. Certain patients with higher risk disease received IMRT plus SBRT boost, with the prescribed dose including IMRT at 45 to 50.4 Gy in 1.8-Gy fractions plus SBRT at 19.5 Gy in 3 fractions.…”