A radiation badge survey for family members living with patients treated with a (103)Pd permanent breast seed implant

PURPOSE: Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a (103)Pd permanent breast seed implant as adjuvant radiotherapy after breast-conserving surgery. We report the dose received by family members living with these patients and compare measured doses with theoretical worst-case scenario estimates. METHODS AND MATERIALS: Exposure-rate measurements were taken at 1 m from the patient by using a calibrated low-energy survey meter. Landauer (Landauer Inc., Glenwood, IL) Luxel badges, with sensitivity of 0.01 mSv, were given to family members to wear after the implantation. Badge readings for 33 spouses and 28 other family members were used to estimate effective doses, and these were compared with theory. RESULTS: Average preimplantation planning target volume from computed tomography was 50.3 ml (range, 18.0-96.7 ml), and average preimplantation distance between the skin and the most anterior planning target volume margin was 0.57 cm. The average maximum exposure rate was measured to be 2.4 +/- 1.1 mR/h, and average measured dose to a spouse was 0.99 +/- 1.0 mSv. The calculated exposure rates and spousal doses using preimplantation computed tomography scan data overestimated those measured. Average measured family member dose (excluding spouses) was 0.20 +/- 0.58 mSv. CONCLUSIONS: Based on measured and calculated spousal doses, a permanent breast seed implant using (103)Pd is safe for the public. However, it is recommended that extra precautions in the way of a breast patch be used when patients with an implant will be in the vicinity of toddlers or pregnant women.     

Stage II adenocarcinoma of the endometrium: adjuvant radiotherapy and recurrence patterns

PURPOSE: Review patterns of recurrence for Stage II endometrial cancer in a community practice. METHODS AND MATERIALS: A retrospective review of patients with endometrial cancer diagnosed between 1985-2002. Patients were excluded for Stages I, III, or IV or treatment with preoperative pelvic radiation (external beam radiation therapy [EBRT]). RESULTS: Eighty-six patients with a mean follow-up of 70 months are reported. Higher risk patients were selected for adjuvant radiation with no apparent differences for those receiving only EBRT compared with EBRT with brachytherapy. Five-year actuarial vaginal, pelvic sidewall/nodal, and metastatic control rates were 100% and 100%, 96.9% and 100%, and 79% and 84.2% for patients receiving EBRT or EBRT with brachytherapy. Overall survival rates were 70.5% and 75.8%, and cause-specific survival rates were 78.8% and 82.9% for those receiving EBRT or EBRT with brachytherapy. A select group was observed and experienced one vaginal recurrence with overall and cause-specific survival rates of 100%. CONCLUSION: In higher risk patients with Stage II, adjuvant EBRT achieves excellent vaginal and pelvic sidewall/nodal control without apparent benefit from additional brachytherapy. Select patients may not require adjuvant treatment.     

Poor predictive value of intraoperative real-time dosimetry for prostate seed brachytherapy

PURPOSE: To identify dosimetric parameters predictive of a good prostate seed I(125) quality implant. We analyzed preimplant and postimplant realtime dosimetry in patients treated with intraoperative (IO) inverse planning. METHODS AND MATERIALS: We analyzed 127 consecutively treated patients with primarily low-risk prostate carcinoma who underwent prostate permanent seed I(125) brachytherapy using an IO planning approach. The implant was done using the three-dimensional transrectal ultrasound (PRE-TRUS)-guided IO interactive inverse preplanning system. The TRUS was repeated in the operating room after the implant procedure was complete (POST-TRUS). The prostate was recontoured and postimplant dosimetry was calculated. Each patient underwent computed tomography scan on Day 28 (CT-D28) to evaluate implant quality. Area under the receiver operating characteristic curves (AUROC) was evaluated for models predictive of a V100 of >/=90% and a D90 of >/=140 Gy on the basis of CT-D28 values. RESULTS: On CT-D28, 72.4% of patients had a V100 of >/=90% and 74.8% had a D90 of >/=140 Gy. AUROC for a V100 of >/=90% was 0.665 (p = 0.004) on PRE-TRUS and 0.619 (p = 0.039) on POST-TRUS. AUROC for D90 of >/=140 Gy was 0.602 (p = 0.086) on PRE-TRUS and 0.614 (p = 0.054) on POST-TRUS. Using PRE-TRUS V100 cutoff of >97% gives sensitivity of 88% and a false-positive rate of 63%. A POST-TRUS D90 cutoff of >170 Gy resulted in a sensitivity of 62% and a false-positive rate of 34%. CONCLUSIONS: Because of unacceptably high false-positive rates, IO preimplant and postimplant TRUS-based dosimetry are not accurate tools to predict for postimplant computed tomography-based dosimetry.     

Safety aspects of pulsed dose rate brachytherapy: analysis of errors in 1,300 treatment sessions

PURPOSE: To determine the safety of pulsed-dose-rate (PDR) brachytherapy by analyzing errors and technical failures during treatment. METHODS AND MATERIALS: More than 1,300 patients underwent treatment with PDR brachytherapy, using five PDR remote afterloaders. Most patients were treated with consecutive pulse schemes, also outside regular office hours. Tumors were located in the breast, esophagus, prostate, bladder, gynecology, anus/rectum, orbit, head/neck, with a miscellaneous group of small numbers, such as the lip, nose, and bile duct. Errors and technical failures were analyzed for 1,300 treatment sessions, for which nearly 20,000 pulses were delivered. For each tumor localization, the number and type of occurring errors were determined, as were which localizations were more error prone than others. RESULTS: By routinely using the built-in dummy check source, only 0.2% of all pulses showed an error during the phase of the pulse when the active source was outside the afterloader. Localizations treated using flexible catheters had greater error frequencies than those treated with straight needles or rigid applicators. Disturbed pulse frequencies were in the range of 0.6% for the anus/rectum on a classic version 1 afterloader to 14.9% for orbital tumors using a version 2 afterloader. Exceeding the planned overall treatment time by >10% was observed in only 1% of all treatments. Patients received their dose as originally planned in 98% of all treatments. CONCLUSIONS: According to the experience in our institute with 1,300 PDR treatments, we found that PDR is a safe brachytherapy treatment modality, both during and outside of office hours.     

直肠癌术后复发组织间插植放射治疗探讨

目的：探讨直肠癌术后复发的组织间插植放射治疗技术及疗效。方法：1996年2月～1998年10月本院治疗直肠癌Mile’s术后会阴部局部复发10例,其中伴阴道受侵3例。体外照射40～50Gy后行组织间插植高剂量率^192Ir后装治疗,施源管5～25根,剂量3～10Gy／次,总量26～30Gy。结果：CR3例,PR5例,PD2例。2例在治疗后出现局部复发,2例出现会阴部放射性溃疡,均为10Gy／次的患者。3年生存率60％（6／10）,其中2例带瘤生存。结论：组织问插植放射治疗是直肠癌术后复发的有效治疗方法,高剂量率放射治疗的分次剂量不宜过高,尤其是会阴皮肤及阴道受侵者。