Dosimetric evaluation of clinical target volume in the postimplant analysis of low-dose-rate brachytherapy for prostate cancer

Nasser, Nicola J.; Sappiatzer, J.; Wang, Yinkun; Borg, Jette; Saibishkumar, Elantholi P.

doi:10.1016/j.brachy.2014.08.044

Cited by 11 publications

(14 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We realized a HI of 0.42 on average, which is relatively high compared to values in recent literature, ranging from 0.29 to 0.41 . This indicates that our adaptive technique allows for sparse implantation reducing V

_{150}

and associated risks of urethral, bowel, and erectile toxicity as the technique provides the possibility to add remedial seeds if deemed necessary.…”

Section: Discussionmentioning

confidence: 49%

“…We compared our results to other large‐scale studies (>150 patients), reporting postimplant dosimetry. Techniques that relied on (intraoperative) preplanning showed an average postoperative D

_{90}

of 100−111%, a V

_{100}

of 89−94%, and a V

_{150}

of 56–61% . Intraoperative real‐time techniques showed a mean postoperative D

_{90}

of 105−126%, a V

_{100}

of 93−97%, and a V

_{150}

of 32–70% .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Cone-beam CT-based adaptive planning improves permanent prostate brachytherapy dosimetry: An analysis of 1266 patients

et al. 2017

View full text Add to dashboard Cite

Purpose: To evaluate adaptive planning for permanent prostate brachytherapy and to identify the prostate regions that needed adaptation. Methods and materials: After the implantation of stranded seeds, using real-time intraoperative planning, a transrectal ultrasound (TRUS)-scan was obtained and contoured. The positions of seeds were determined on a C-arm cone-beam computed tomography (CBCT)-scan. The CBCT-scan was registered to the TRUS-scan using fiducial gold markers. If dose coverage on the combined imagedataset was inadequate, an intraoperative adaptation was performed by placing remedial seeds. CBCT-based intraoperative dosimetry was analyzed for the prostate (D 90 , V 100 , and V 150 ) and the urethra (D 30 ). The effects of the adaptive dosimetry procedure for Day 30 were separately assessed. Results: We analyzed 1266 patients. In 17.4% of the procedures, an adaptation was performed. Without the dose contribution of the adaptation Day 30 V 100 would be < 95% for half of this group. On Day 0, the increase due to the adaptation was 11.8 AE 7.2% (1SD) for D 90 and 9.0 AE 6.4% for V 100 . On Day 30, we observed an increase in D 90 of 12.3 AE 6.0% and in V 100 of 4.2 AE 4.3%. For the total group, a D 90 of 119.6 AE 9.1% and V 100 of 97.7 AE 2.5% was achieved. Most remedial seeds were placed anteriorly near the base of the prostate. Conclusion: CBCT-based adaptive planning enables identification of implants needing adaptation and improves prostate dose coverage. Adaptations were predominantly performed near the anterior base of the prostate.

show abstract

_{150}

and associated risks of urethral, bowel, and erectile toxicity as the technique provides the possibility to add remedial seeds if deemed necessary.…”

Section: Discussionmentioning

confidence: 49%

“…We compared our results to other large‐scale studies (>150 patients), reporting postimplant dosimetry. Techniques that relied on (intraoperative) preplanning showed an average postoperative D

_{90}

of 100−111%, a V

_{100}

of 89−94%, and a V

_{150}

of 56–61% . Intraoperative real‐time techniques showed a mean postoperative D

_{90}

of 105−126%, a V

_{100}

of 93−97%, and a V

_{150}

of 32–70% .…”

Section: Discussionmentioning

confidence: 99%

Cone-beam CT-based adaptive planning improves permanent prostate brachytherapy dosimetry: An analysis of 1266 patients

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Several groups have previously shown that in I-125 seed brachytherapy, anterior prostate base receives a lower dose and apex receives a higher dose compared with pre-implant planned dose coverage [ 25 – 27 ]. Moreover, we have recently shown that the dose coverage of the clinical target volume of the prostate, defined as the prostate plus a 3 mm margin around it, is worse in patients with prostatic edema [ 28 ]. Clearly, seed loss in patients with prostatic edema would further worsen the dosimetry.…”

Section: Discussionmentioning

confidence: 99%

Original paper Evaluation of the dosimetric impact of loss and displacement of seeds in prostate low-dose-rate brachytherapy

Wang¹,

Nasser²,

Borg³

et al. 2015

jcb

Self Cite

View full text Add to dashboard Cite

PurposeTo analyze the seed loss and displacement and their dosimetric impact in prostate low-dose-rate (LDR) brachytherapy while utilizing the combination of loose and stranded seeds.Material and methodsTwo hundred and seventeen prostate cancer patients have been treated with LDR brachytherapy. Loose seeds were implanted in the prostate center and stranded seeds in the periphery of the gland. Patients were imaged with transrectal ultrasound before implant and with computerized tomography/magnetic resonance imaging (CT/MR) one month after implant. The seed loss and displacement had been analyzed. Their impact on prostate dosimetry had been examined. The seed distribution beyond the prostate inferior boundary had been studied.ResultsThe mean number of seeds per patient that were lost to lung, pelvis/abdomen, urine, or unknown destinations was 0.21, 0.13, 0.03, and 0.29, respectively. Overall, 40.1% of patients had seed loss. Seed migration to lung and pelvis/abdomen occurred in 15.5% and 10.5% of the patients, respectively. Documented seed loss to urine was found in 3% of the patients while 20% of patients had seed loss to unknown destinations. Prostate length difference between pre-plan and post-implant images was within 6 mm in more than 98% of cases. The difference in number of seeds inferior to prostate between pre-plan and post-implant dosimetry was within 7 seeds for 93% of patients. At time of implant, 98% of seeds, inferior to prostate, were within 5 mm and 100% within 15 mm, and in one month post-implant 83% within 9 mm and 96.3% within 15 mm. Prostate post-implant V100, D90, and rectal wall RV100 for patients without seed loss were 94.6%, 113.9%, and 0.98 cm3, respectively, as compared to 95.0%, 114.8%, and 0.95 cm3 for the group with seed loss.ConclusionsSeed loss and displacement have been observed to be frequent. No correlation between seed loss and displacement and post-plan dosimetry has been reported.

show abstract

“…Low-dose-rate (LDR) brachytherapy is an efficient treatment for low-risk, and selected patients with intermediate-risk disease as a single modality (2, 3), and is used in combination with external beam radiation for intermediate- and high-risk patients to achieve radiation dose escalation (4–8). LDR prostate brachytherapy is performed by permanently implanting radioactive seeds inside the prostate in a distribution that results in proper radiation coverage to the prostate and a margin around it (9, 10). The most used radionuclides in prostate LDR brachytherapy are 125 I with a radioactivity half-life of 59.4 days or 103 Pd with a half-life of 17 days (11).…”

Section: Introductionmentioning

confidence: 99%

Radiation safety of receptive anal intercourse with prostate cancer patients treated with low-dose-rate brachytherapy

et al. 2016

Self Cite

View full text Add to dashboard Cite

PURPOSE Prostate low-dose-rate (LDR) brachytherapy involves implantation of radioactive seeds permanently into the prostate gland. During receptive anal intercourse, the penis of the partner may come in close proximity to the implanted prostate gland. We estimate the potential intrarectal dose rates and suggest guidance on radiation precautions. METHODS AND MATERIALS One hundred two patients were included in the study. After implantation, with patients under anesthesia in the dorsal lithotomy position, a new set of ultrasound (US) images and a CT scan were obtained. The images were fused, radioactive seeds and US probe locations were determined on the CT, and prostate, bladder, and rectal contours were drawn on the US. Dose rates (cGy/h) were calculated for the portion of the US probe spanning the prostate for several dose-volume histogram parameters. RESULTS Twenty patients were treated with 125I and 82 patients with 103Pd. Average dose rates at Day 0 to the portion of the US probe spanning the prostate were 2.1 ± 1.3 cGy/h and 2.5 ± 0.8 cGy/h for patients treated with 125I and 103Pd, respectively. After 60 days, average calculated probe dose drops to 1.0 ± 0.6 cGy/h and 0.2 ± 0.1 cGy/h for 125I and 103Pd, respectively. CONCLUSIONS During the immediate weeks after prostate seed implant, the estimated intrarectal dose rates are higher in 103Pd compared to 125I. As 103Pd decays faster than 125I, 2 months after the implant, radiation exposure from 103Pd becomes lower than 125I. Receptive anal intercourse time should be kept as low as possible during 2 and 6 months after low-dose-rate brachytherapy of the prostate with 103Pd and 125I, respectively.

show abstract

Dosimetric evaluation of clinical target volume in the postimplant analysis of low-dose-rate brachytherapy for prostate cancer

Cited by 11 publications

References 25 publications

Cone-beam CT-based adaptive planning improves permanent prostate brachytherapy dosimetry: An analysis of 1266 patients

Cone-beam CT-based adaptive planning improves permanent prostate brachytherapy dosimetry: An analysis of 1266 patients

Original paper Evaluation of the dosimetric impact of loss and displacement of seeds in prostate low-dose-rate brachytherapy

Radiation safety of receptive anal intercourse with prostate cancer patients treated with low-dose-rate brachytherapy

Contact Info

Product

Resources

About