Comparison of intraoperative ultrasound with postimplant computed tomography–dosimetric values at Day 1 and Day 30 after prostate brachytherapy

Ohashi, Toshio; Yorozu, Atsunori; Toya, Kazuhito; Saito, Shiro; Momma, Tetsuo; Nagata, Hirohiko; Kosugi, Michio; Shigematsu, Naoyuki; Kubo, Atsushi

doi:10.1016/j.brachy.2007.08.006

Cited by 41 publications

(25 citation statements)

References 24 publications

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“…In a series by Morris et al (6), D 90 values of !130 Gy at Day 0 or Day 30 were predictive of an increased risk of recurrence in the non-NADT subset. Because D 90 values change greatly from 0 to 30 days postimplant (16), this factor may have accounted for a variable threshold of the doseeresponse relationship (3, 6e8 (26). In our patient selection, patients with bulky disease or Gleason score 4 þ 3 are treated with BT and supplemental EBRT.…”

Section: Discussionmentioning

confidence: 98%

“…A VariSeed planning system, version 7.2 (Varian Medical Systems, Inc., Palo Alto, CA) was used for preplanning and intraoperative planning. The implant procedure and dose constraints have been previously described (15,16). Early in the study period, the preplanning method was used in the first 233 men (17.7%), and from December 2004 onward, the procedure was shifted to the real-time intraoperative planned approach (13).…”

Section: Implant Technique and Dosimetrymentioning

confidence: 99%

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Permanent prostate brachytherapy with or without supplemental external beam radiotherapy as practiced in Japan: Outcomes of 1300 patients

Yorozu¹,

Kuroiwa²,

Takahashi³

et al. 2015

Brachytherapy

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Section: Discussionmentioning

confidence: 98%

Section: Implant Technique and Dosimetrymentioning

confidence: 99%

Permanent prostate brachytherapy with or without supplemental external beam radiotherapy as practiced in Japan: Outcomes of 1300 patients

Yorozu¹,

Kuroiwa²,

Takahashi³

et al. 2015

Brachytherapy

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“…Ohashi et al . compared intra-operative TRUS based dosimetry with actual day 1 and day 30 coverage and found no difference between intra-operative and day 30 target coverage [20]. While this may eliminate the need for post-operative CT-based dosimetry in the future, a large proportion of centers have not yet adopted an intra-operative planning approach and, therefore, must continue to depend on post-implant CT-based dosimetry to evaluate the quality of their implants.…”

Section: Discussionmentioning

confidence: 99%

Clinical Investigations Case series analysis of post-brachytherapy prostate edema and its relevance to post-implant dosimetry. Post-implant prostate edema and dosimetry

Tejwani¹,

Bieniek²,

Puckett³

et al. 2012

jcb

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PurposeWe evaluated the post-operative pattern of prostate volume (PV) changes following prostate brachytherapy (PB) and analyzed variables which affect swelling.Material and methodsTwenty-nine patients treated with brachytherapy (14) or combined brachytherapy and external beam radiotherapy modality (15) underwent pre- and post-implant computed tomography (CT). Prostate volume measurements were done on post-operative days 1, 9, 30, and 60. An observer performed 139 prostate volume (PV) measurements. We analyzed the influence of pre-implant PV, number of needles and insertion attempts, number and activity of seeds, Gleason score, use of hormonal therapy and external beam radiation therapy on the extent of edema. We computed a volume correction factor (CF) to account for dosimetric changes between day 1 and day 30. Using the calculated CF, the dose received by 90% (D90) of the prostate on day 30 (D90Day30) was obtained by dividing day 1 (D90Day1) by the CF.ResultsThe mean PV recorded on post-operative day 1 was 67.7 cm3, 18.8 cm3 greater than average pre-op value (SD 15.6 cm3). Swelling returned to pre-implant volume by day 30. Seed activity, treatment modality, and Gleason score were significant variables. The calculated CF was 0.76. After assessment using the CF, the mean difference between estimated and actual D90Day30 was not significant.ConclusionsWe observed maximum prostate size on post-operative day 1, returning to pre-implant volume by day 30. This suggests that post-implant dosimetry should be obtained on or after post-operative day 30. If necessary, day 30 dosimetry can be estimated by dividing D90Day1 by a correction factor of 0.76.

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“…Waterman et al also reported that the probability of late rectal morbidity depends both on the dose and on the rectal surface area exposed to 100 Gy radiations [5]. These dose-volume thresholds of the rectal wall could not be adopted as intraoperative constraints for brachytherapy because of discrepancies in dose distribution between intraoperative ultrasound (US)-based and postoperative CT-based dosimetry [6-8]. To date, there appears to be no definitive agreement regarding rV100 constraints during interactive dose assessments.…”

Section: Introductionmentioning

confidence: 99%

“…To date, there appears to be no definitive agreement regarding rV100 constraints during interactive dose assessments. Some investigators have adopted presumptive rV100 constraints, such as 1.0 cc [9], while others have neglected to apply any safe range with rV100 [6]. …”

Section: Introductionmentioning

confidence: 99%

Narrow safety range of intraoperative rectal irradiation exposure volume for avoiding bleeding after seed implant brachytherapy

et al. 2012

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Background & PurposeRectal toxicity is less common after 125I seed implant brachytherapy for prostate cancer, and intraoperative rectal dose-volume constraints (the constraint) is still undetermined in pioneering studies. As our constraint failed to prevent grade 2 or 3 rectal bleeding (bled-pts) in 5.1% of patients, we retrospectively explored another constraint for the prevention of rectal bleeding.Materials and methodsThe study population consisted of 197 patients treated with the brachytherapy as monotherapy using real-time intraoperative transrectal ultrasound (US)-guided treatment at a prescribed dose of 145 Gy. Post-implant dosimetry was performed on Day 1 and Day 30 after implantation using computed tomography (CT) imaging. Rectal bleeding toxicity was classified by CTC-AE ver. 3.0 during a mean 29-month (range, 12-48 months) period after implantation. The differences in rV100s were compared among intraoperative, Day 1 and Day 30 dosimetry, and between that of patients with grade 2 or 3 rectal bleeding (the bled-pts) and of the others (the spared-pts). All patients were divided into groups based on provisional rV100s that were increased stepwise in 0.1-cc increments from 0 to 1.0 cc. The difference in the ratios of the bled-pts to the spared-pts was tested by chi-square tests, and their odds ratios were calculated (bled-OR). All statistical analyses were performed by t-tests.ResultsThe mean values of rV100us, rV100CT_1, and rV100CT_30 were 0.31 ± 0.43, 0.22 ± 0.36, and 0.59 ± 0.68 cc, respectively. These values temporarily decreased (p = 0.020) on Day 1 and increased (p = 0.000) on Day 30. There was no significant difference in rV100s between the bled-pts and spared-pts at any time of dosimetry. The maximum bled-OR was identified among patients with an rV100us value above 0.1 cc (p = 0.025; OR = 7.8; 95% CI, 1.4-145.8); an rV100CT_1 value above 0.3 cc (p = 0.014; OR = 16.2; 95% CI, 3.9-110.7), and an rV100CT_30 value above 0.5 cc (p = 0.019; OR = 6.3; 95% CI, 1.5-42.3).ConclusionBy retrospective analysis exploring rV100 as intraoperative rectal dose-volume thresholds in 125I seed implant brachytherapy for prostate cancer, it is proved that rV100 should be less than 0.1 cc for preventing rectal bleeding.

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Comparison of intraoperative ultrasound with postimplant computed tomography–dosimetric values at Day 1 and Day 30 after prostate brachytherapy

Cited by 41 publications

References 24 publications

Permanent prostate brachytherapy with or without supplemental external beam radiotherapy as practiced in Japan: Outcomes of 1300 patients

Permanent prostate brachytherapy with or without supplemental external beam radiotherapy as practiced in Japan: Outcomes of 1300 patients

Clinical Investigations Case series analysis of post-brachytherapy prostate edema and its relevance to post-implant dosimetry. Post-implant prostate edema and dosimetry

Narrow safety range of intraoperative rectal irradiation exposure volume for avoiding bleeding after seed implant brachytherapy

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