BACKGROUND: To correlate dose and volume dosimetric parameters (D₉₀ and V₁₀₀) with biochemical control in advanced prostate cancer treated withhigh-dose rate brachytherapy (HDR-BT). METHODS: One hundred and eight patients received external beam radiotherapy (EBRT) to 35.75 Gy in 13 fractions followed by HDR-BT of 2 × 8.5 Gy. Kaplan-Meier freedom-from-biochemical relapse (FFbR; nadir+2 μg/L) fits were grouped by the first (Q1), second (Q2) and third (Q3) D₉₀ and V₁₀₀ quartiles. Groups were compared with the log-rank test. Univariate and multivariate Hazard Ratios (HR) for D₉₀ and V₁₀₀ and other co-variates (PSA, androgen deprivation therapy (ADT) were obtained using Cox's proportional hazard model. RESULTS:FFbR was significantly higher in patients whose D₉₀ and V₁₀₀ were at or above the second and third quartile (log rank p ≤ 0·04). In multivariate analysis D₉₀, V₁₀₀ were significant covariates for risk of relapse. CONCLUSIONS: Dichotomising the data using 6 levels of response (above and below Q1, Q2 and Q3) showed a progressive and continuous improvement in biochemical control of disease across the entire dose (and volume) range. The data show that a minimum D₉₀ of 108% of the prescribed dose should be the target to achieve.
RCT Entities:
BACKGROUND: To correlate dose and volume dosimetric parameters (D₉₀ and V₁₀₀) with biochemical control in advanced prostate cancer treated with high-dose rate brachytherapy (HDR-BT). METHODS: One hundred and eight patients received external beam radiotherapy (EBRT) to 35.75 Gy in 13 fractions followed by HDR-BT of 2 × 8.5 Gy. Kaplan-Meier freedom-from-biochemical relapse (FFbR; nadir+2 μg/L) fits were grouped by the first (Q1), second (Q2) and third (Q3) D₉₀ and V₁₀₀ quartiles. Groups were compared with the log-rank test. Univariate and multivariate Hazard Ratios (HR) for D₉₀ and V₁₀₀ and other co-variates (PSA, androgen deprivation therapy (ADT) were obtained using Cox's proportional hazard model. RESULTS:FFbR was significantly higher in patients whose D₉₀ and V₁₀₀ were at or above the second and third quartile (log rank p ≤ 0·04). In multivariate analysis D₉₀, V₁₀₀ were significant covariates for risk of relapse. CONCLUSIONS: Dichotomising the data using 6 levels of response (above and below Q1, Q2 and Q3) showed a progressive and continuous improvement in biochemical control of disease across the entire dose (and volume) range. The data show that a minimum D₉₀ of 108% of the prescribed dose should be the target to achieve.
Authors: Finbar Slevin; Sree Lakshmi Rodda; Peter Bownes; Louise Murray; David Bottomley; Clare Wilkinson; Ese Adiotomre; Bashar Al-Qaisieh; Emma Dugdale; Oliver Hulson; Joshua Mason; Jonathan Smith; Ann M Henry Journal: Clin Transl Radiat Oncol Date: 2019-10-14
Authors: Gabriel P Fonseca; Jacob G Johansen; Ryan L Smith; Luc Beaulieu; Sam Beddar; Gustavo Kertzscher; Frank Verhaegen; Kari Tanderup Journal: Phys Imaging Radiat Oncol Date: 2020-09-28
Authors: Joel Poder; Dylan Koprivec; Yashiv Dookie; Andrew Howie; Dean Cutajar; Antonio L Damato; Nicolas Côté; Marco Petasecca; Joseph Bucci; Anatoly Rosenfeld Journal: Med Phys Date: 2022-04-19 Impact factor: 4.506