Dose–response with stereotactic body radiotherapy for prostate cancer: A multi-institutional analysis of prostate-specific antigen kinetics and biochemical control

Levin-Epstein, Rebecca; Jiang, Naomi; Wang, Xiaoyan; Upadhyaya, Shrinivasa K.; Collins, Sean P.; Suy, Simeng; Aghdam, Nima; Mantz, C.A.; Katz, Alan J.; Miszczyk, Leszek; Napieralska, Aleksandra; Namysł-Kaletka, A.; Prionas, Nicolas D.; Bagshaw, H.P.; Buyyounouski, Mark K.; Cao, Minsong; Agazaryan, Nzhde; Dang, Alexander; Yuan, Ye; Kupelian, Patrick A.; Zaorsky, Nicholas G.; Spratt, Daniel E.; Mohamad, Osama; Feng, Felix Y.; Mahal, Brandon A.; Boutros, Paul C.; Kishan, Arun U.; Juarez, Jesus E.; Shabsovich, David; Jiang, Tommy; Kahlon, Sartajdeep; Patel, Ankur; Patel, Jay; Nickols, Nicholas G.; Steinberg, Michael L.; Fuller, Donald B.; Kishan, Amar U.

doi:10.1016/j.radonc.2020.09.053

Cited by 25 publications

(17 citation statements)

References 35 publications

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“…Previously reported studies have shown a faster PSA decline with SAbR as compared to other fractionations and on par with brachytherapy (24,(42)(43)(44)46). PSA nadir dose response trends have been shown to predict long-term biochemical control of PCa with follow-ups beyond 5 years (47).…”

Section: Discussionmentioning

confidence: 99%

“…The focus of this study is safety as the short follow-up precludes any conclusion regarding the BFFS, which in our study was 98.7% at the 2-, 3-, and 4-year follow-ups. Dose escalation in multiple studies has shown improved BFFS in patients treated with escalating SAbR doses of 40 Gy or higher in 5 fractions than with lower doses, showing a faster PSA decline with dose escalation (14,19,(42)(43)(44). These findings, while premature to conclude, are so far trending in a similar direction as reported in Zelefsky et al's 5-year outcomes of dose escalation, which reported BFFS trends of 83%, 85%, 90%, and 98% and lower PSA nadir values at 2 years of 0.7, 0.59, 0.46, and 0.48, respectively, in their 32.5, 35, 37.5, and 40 Gy in five fraction treatment arms, respectively, which was confirmed with declining rates of positive biopsy (14).…”

Section: Discussionmentioning

confidence: 99%

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Dose-Intensified Stereotactic Ablative Radiation for Localized Prostate Cancer

et al. 2022

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PurposeStereotactic ablative radiation (SAbR) has been increasingly used in prostate cancer (PCa) given its convenience and cost efficacy. Optimal doses remain poorly defined with limited prospective comparative trials and long-term safety/efficacy data at higher dose levels. We analyzed toxicity and outcomes for SAbR in men with localized PCa at escalated 45 Gy in 5 fractions.Methods and MaterialsThis study retrospectively analyzed men from 2015 to 2019 with PCa who received linear-accelerator-based SAbR to 45 Gy in 5 fractions, along with perirectal hydrogel spacer, fiducial placement, and MRI-based planning. Disease control outcomes were calculated from end of treatment. Minimally important difference (MID) assessing patient-reported quality of life was defined as greater than a one-half standard deviation increase in American Urological Association (AUA) symptom score after SAbR.ResultsTwo-hundred and forty-nine (249) low-, intermediate-, and high-risk PCa patients with median follow-up of 14.9 months for clinical toxicity were included. Acute urinary grade II toxicity occurred in 20.4% of patients. Acute grade II GI toxicity occurred in 7.3% of patients. For follow-up > 2 years (n = 69), late GU and GI grade ≥III toxicity occurred in 5.8% and 1.5% of patients, respectively. MID was evident in 31.8%, 23.4%, 35.8%, 37.0%, 33.3%, and 26.7% of patients at 3, 6, 12, 24, 36, and 48 months, respectively. The median follow-up for biochemical recurrence was 22.6 months with biochemical failure-free survival of 100% at 1 year (n = 226) and 98.7% for years 2 (n = 113) and 3 (n = 54).ConclusionsSAbR for PCa at 45 Gy in 5 fractions shows an encouraging safety profile. Prospective studies with longer follow-up are warranted to establish this dose regimen as standard of care for PCa.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Dose-Intensified Stereotactic Ablative Radiation for Localized Prostate Cancer

et al. 2022

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“…In contrast, a subset analysis of the pooled SBRT consortium failed to reveal an association between EQD 2 and time to BCR for any risk group [11]. A detailed comparison of bRFS in 1908 patients after 35 Gy/five fractions, 36.25 Gy/five fractions, 40 Gy/five fractions, and 38 Gy/four fractions found a difference in prostate ablation, without a clear difference in bRFS at 5-years [40]. However, at a median follow-up of 72.3 months, treatment with 40 Gy/five fractions was associated with improved long-term bRFS when compared against all other doses.…”

Section: Sbrt Dosementioning

confidence: 91%

“…Interestingly, LDRBT appears to achieve a greater degree of prostatic ablation compared to HDRBT with lower nPSA. However, this does not appear to translate into a meaningful difference in oncological outcomes (discussed in detail in Section 5 below) [40]. This offers another example of the decoupling of the extent of prostate tumor ablation and bRFS beyond a certain dose level when there is no difference in bRFS despite a steeper PSA decay slope and lower nadir PSA (nPSA).…”

Section: Hdrbt Vs Ldrbtmentioning

confidence: 99%

Ablative Radiotherapy in Prostate Cancer: Stereotactic Body Radiotherapy and High Dose Rate Brachytherapy

Martin

Lilleby

et al. 2020

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Prostate cancer (PCa) is the most common noncutaneous solid organ malignancy among men worldwide. Radiation therapy is a standard of care treatment option that has historically been delivered in the form of small daily doses of radiation over the span of multiple weeks. PCa appears to have a unique sensitivity to higher doses of radiation per fraction, rendering it susceptible to abbreviated forms of treatment. Stereotactic body radiation therapy (SBRT) and high-dose-rate brachytherapy (HDRBT) are both modern radiation modalities that allow the precise delivery of ablative doses of radiation to the prostate while maximally sparing sensitive surrounding normal structures. In this review, we highlight the evidence regarding the radiobiology, oncological outcomes, toxicity and dose/fractionation schemes of SBRT and HDRBT monotherapy in men with low-and intermediate-risk PCa.

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“…These findings are consistent with higher biological effective dosing, which is also found in brachytherapy. (29)(30)(31) There is emerging data which suggests an improvement in biochemical outcomes with SBRT dose escalation (10,32,33). Whereas most series have accomplished this with homogeneous dosing on robotic or gantry-based platforms, heterogeneous-dosing methods employing a virtual HDR-brachytherapy approach with ablative dosing, has been described, with favorable biochemical and quality of life results (34).…”

mentioning

confidence: 99%