Postoperative management of keloids: Low-dose-rate and high-dose-rate brachytherapy

PurposeWe report the experience of the Radiation Oncology Department of the European Institute of Oncology in Milan, Italy, on the adjuvant low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy. Brachytherapy might be useful to improve keloids recurrence rate or reduce keloids treatment side effects instead of external beam radiotherapy.Methods and MaterialsData on 70 consecutive patients treated after complete keloid surgical excision were retrospectively analyzed. First 38 patients and 46 keloids were treated with adjuvant LDR brachytherapy and the following 39 patients and 50 keloids underwent HDR treatment. Median delivered dose of LDR therapy was 16 Gy; HDR median dose was 12 Gy. Sixty-four keloids (66.7%) were symptomatic at diagnosis with pain, itching, or stress.ResultsFourteen relapses over 46 treated keloids (30.4%) were observed in the LDR group and 19 of 50 keloids (38%) in the HDR group (p = 0.521). Recurrence rate was significantly higher in males (p = 0.009), in patients younger than 44 years (p < 0.0001), for arms, neck, and chest wall anatomic sites (p = 0.0001) and for symptomatic keloids (p = 0.017). Aesthetic outcome was better in case of larger keloids (>8 cm) (p = 0.064). Symptomatic relief was achieved in 92% of HDR patients and only 68% of LDR patients (p = 0.032).ConclusionsPostoperative brachytherapy is an effective treatment for keloids. In our study, LDR and HDR treatments resulted in similar recurrence rate. Better symptomatic relief was reported in case of HDR treatment compared with the LDR regimen.     

Brachytherapy provides comparable outcomes and improved cost-effectiveness in the treatment of low/intermediate prostate cancer

PurposeTo evaluate the cost-effectiveness and outcomes of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy compared with intensity-modulated radiation therapy (IMRT) in patients with low/intermediate risk of prostate cancer.Methods and MaterialsOne thousand three hundred twenty-eight patients with low or intermediate risk of prostate cancer were treated with LDR (n = 207), HDR with four fractions (n = 252), or IMRT (n = 869) between January 1992 and December 2008. LDR patients were treated with palladium seeds to a median dose of 120 Gy, whereas HDR patients were treated to a median dose 38.0 Gy (four fractions). IMRT patients received 42–44 fractions with a median dose of 75.6 Gy. Clinical outcomes were compared, including biochemical failure, cause-specific survival, and overall survival.ResultsOverall, no differences in 5-year biochemical control (BC) or cause-specific survival were noted among treatment modalities. The calculated reimbursement for LDR brachytherapy, HDR brachytherapy with four fractions, and IMRT was $9,938; $17,514; and $29,356, respectively. HDR and LDR brachytherapy were statistically less costly to Medicare and the institution than IMRT (p < 0.001), and LDR brachytherapy was less costly than HDR brachytherapy (p = 0.01 and p < 0.001). Incremental cost-effectiveness ratios for cost to Medicare for BC with IMRT were $4045 and $2754 per percent of BC for LDR and HDR brachytherapy, respectively. Incremental cost-effectiveness ratio using institutional cost comparing IMRT with LDR and HDR brachytherapy was $4962 and $4824 per 1% improvement in BC.ConclusionsIn this study of patients with low and intermediate risk of prostate cancer, comparable outcomes at 5 years were noted between modalities with increased costs associated with IMRT.     

An age-corrected matched-pair study of erectile function in patients treated with dose-escalated adaptive image-guided intensity-modulated radiation therapy vs. high-dose-rate brachytherapy for prostate cancer

PurposeTo compare erectile dysfunction (ED) after adaptive dose-escalated image-guided intensity-modulated radiotherapy (IG-IMRT) and high-dose-rate interstitial brachytherapy (HDR) monotherapy.Methods and MaterialsLow- and intermediate-risk prostate cancer patients treated with IG-IMRT or HDR were matched on pretreatment ED, age, Gleason score, T-stage, and prostate specific antigen. Patients who received androgen deprivation therapy were excluded. ED was graded by Common Terminology Criteria for Adverse Events v4. Actuarial rates of ED were computed by the Kaplan–Meier method.ResultsThere were 384 patients with median followup of 2.0 years (0.5–6.1) for IG-IMRT and 2.0 years (0.5–8.7) for HDR. The median IG-IMRT dose was 75.6 Gy and HDR dose 38 Gy in four fractions. For patients with no pretreatment ED, actuarial rates of requiring intervention (Grade ≥2 ED) at 3 years were 31% for IG-IMRT and 19% for HDR (p = 0.23), and impotence despite medical intervention (Grade 3) were 0% for IG-IMRT and 6% for HDR (p = 0.06). For patients with Grade 1 pretreatment ED, Grade ≥2 ED at 3 years were 47% for IG-IMRT and 34% for HDR (p = 0.79), and Grade 3 ED were 15% in both groups (p = 0.59). For patients with Grade 2 pretreatment ED, Grade 3 ED at 3 years were 22% for IG-IMRT and 37% for HDR (p = 0.70). No variables were predictive of Grade ≥2 ED following treatment.ConclusionsRates of ED requiring medical intervention for both IG-IMRT and HDR are low and equivalent. Even patients with ED before treatment are likely to maintain potency with medication use at 3 years following treatment.     

Long-term outcomes with high-dose-rate brachytherapy for the management of base of tongue cancer

PurposeTo report the long-term results of a prospective, nonrandomized clinical trial using high-dose-rate (HDR) brachytherapy (BT) for the management of base of the tongue (BOT) tumors.Methods and MaterialsBetween January 1992 and June 2011, 60 patients (mean age, 57 years; range, 36–78 years) with T1–T4 and N0-3 carcinoma of BOT were treated. Fifty-six patients (93%) had advanced (Stage III-IV) disease. HDR BT boost (mean dose, 17 Gy; range, 12–30 Gy) was delivered after 50–70 Gy (mean 62 Gy) locoregional external beam irradiation. Seventeen patients (28%) received radiochemotherapy (RCT) with cisplatin.ResultsThe 5-year actuarial rate of local tumor control, locoregional tumor control, overall survival (OS), and cancer-specific survival (CSS) was 57%, 50%, 47%, and 61%, respectively. OS was significantly better in patients (n = 17) receiving RCT (69% vs. 39%; p = 0.005). Delayed soft-tissue ulceration occurred in seven patients (12%). Only one patient (<2%) developed osteoradionecrosis. In univariate analysis, the tumor size (T1–T2–T3 vs. T4) was found to have a significant effect on CSS (p = 0.043), whereas the nodal status (N0 vs. N+) affected locoregional tumor control (p = 0.042), OS (p = 0.002), and CSS (p = 0.015). Low histologic grade (1–2) was associated with better CSS (p = 0.020), whereas RCT significantly improved OS (p = 0.012).ConclusionsExternal beam irradiation combined with interstitial HDR BT boost results in good local tumor control with an acceptable rate of late side effects in patients with BOT carcinoma. RCT improves OS. Our results are similar to those reported with traditional low-dose-rate BT implants.     

Impact of experience and technical changes on acute urinary and rectal morbidity in low-dose prostate brachytherapy using loose seeds real-time implantation

PurposeTo assess the impact of experience and technical changes on morbidity during the first year after permanent prostate brachytherapy.Methods and MaterialsFrom July 2003 to May 2010, 150 patients with prostate cancer underwent low-dose iodine-125 prostate brachytherapy as a monotherapy by the same medical team (one urologist and one radiation oncologist). Patients were divided into three periods: P1 (n = 64), P2 (n = 45), and P3 (n = 41) according to technical changes: use of an automatic stepper from P2, use of a high-frequency ultrasound probe in P3. Urinary toxicity was analyzed according to the incidence of acute urinary retention (AUR), Delta International Prostate Symptom Score (Δ IPSS) defined as IPPS maximal ? IPSS at baseline, and proportion of patients with Δ IPSS ≥5 and IPSS total >15. The Radiation Therapy Oncology Group classification was used to evaluate the rectal morbidity.ResultsThe incidence of AUR (6% overall) decreased significantly with time: 12.5% (8/64) during P1, 2.2% (1/45) in P2, and 0% in P3 (p = 0.014). Mean Δ IPSS (11.6) remained stable during the three periods. Patients with Δ IPSS ≥5 and IPSS total >15 were 58.7%, 58.1%, and 56.1% for P1, P2, and P3 (p = 0.96), respectively. Grade 1 and 2 proctitis were observed in 15.3% and 9.3% of the patients without any significant difference between the three periods.ConclusionThe incidence of AUR decreased significantly with time. This was probably because of the experience of the practitioner and the use of an automatic stepper that allowed reducing prostatic traumatism. Experience and technical changes did not seem to affect rectal morbidity.     

Improved rectal dosimetry with the use of SpaceOAR during high-dose-rate brachytherapy

PurposeHydrogel spacers have been suggested to limit rectal radiation dose with improvements in clinical outcomes in patients undergoing external beam radiation treatment for prostate cancer. No studies to date have assessed the utility and dosimetric effect of SpaceOAR (Augmenix, Inc, Waltham, MA), the only Food and Drug Administration–approved hydrogel rectal spacer, for high-dose-rate (HDR) brachytherapy.MethodsEighteen consecutive patients scheduled for HDR brachytherapy in the treatment of prostate cancer underwent transperineal ultrasound-guided placement of 10 cc of SpaceOAR hydrogel following catheter implantation. Treatment plans were generated using an inverse planning simulated annealing algorithm. Rectal dosimetry for these 18 patients was compared with the 36 preceding patients treated with HDR brachytherapy without SpaceOAR.ResultsFifty-four plans were analyzed. There was no difference in age, pretreatment prostate-specific antigen, Gleason score, clinical stage, prostate volume, or contoured rectal volume between those who received SpaceOAR and those who did not. Patients who received SpaceOAR hydrogel had significantly lower dose to the rectum as measured by percent of contoured organ at risk (median, V₈₀ < 0.005% vs. 0.010%, p = 0.003; V₇₅ < 0.005% vs. 0.14%, p < 0.0005; V₇₀ 0.09% vs. 0.88%, p < 0.0005; V₆₀ = 1.16% vs. 3.08%, p < 0.0005); similar results were seen for rectal volume in cubic centimeters. One patient who received SpaceOAR developed a perineal abscess 1 month after treatment.ConclusionsTransperineal insertion of SpaceOAR hydrogel at the time of HDR brachytherapy is feasible and decreases rectal radiation dose. Further investigation is needed to assess the clinical impact of this dosimetric improvement and potential toxicity reduction.     

Computed tomography versus magnetic resonance imaging in high-dose-rate prostate brachytherapy planning: The impact on patient-reported health-related quality of life

PurposeHigh-dose-rate (HDR) prostate brachytherapy uses volumetric imaging for treatment planning. Our institution transitioned from computed tomography (CT)-based planning to MRI-based planning with the hypothesis that improved visualization could reduce treatment-related toxicity. This study aimed to compare the patient-reported health-related quality of life (hrQOL) and physician-graded toxicity outcomes of CT-based and MRI-based HDR prostate brachytherapy.MethodsFrom 2016 to 2019, 122 patients with low- or intermediate-risk prostate cancer were treated with HDR brachytherapy as monotherapy. Patients underwent CT only or CT and MRI imaging for treatment planning and were grouped per treatment planning imaging modality. Patient-reported hrQOL in the genitourinary (GU), gastrointestinal (GI), and sexual domains was assessed using International Prostate Symptom Score and Expanded Prostate Cancer Index Composite Short Form-26 questionnaires. Baseline characteristics, changes in hrQOL scores, and physician-graded toxicities were compared between groups.ResultsThe median follow-up was 18 months. Patient-reported GU, GI, and sexual scores worsened after treatment but returned toward baseline over time. The CT cohort had a lower baseline mean International Prostate Symptom Score (5.8 vs. 7.8, p = 0.03). The other patient-reported GU and GI scores did not differ between groups. Overall, sexual scores were similar between the CT and MRI cohorts (p = 0.08) but favored the MRI cohort at later follow-up with a smaller decrease in Expanded Prostate Cancer Index Composite Short Form-26 sexual score from baseline at 18 months (4.9 vs. 19.8, p = 0.05). Maximum physician-graded GU, GI, and sexual toxicity rates of grade ≥2 were 68%, 3%, and 53%, respectively, with no difference between the cohorts (p = 0.31).ConclusionOur study shows that CT- and MRI-based HDR brachytherapy results in similar rates of GU and GI toxicity. MRI-based planning may result in improved erectile function recovery compared with CT-based planning.     

3T multiparametric MRI–guided high-dose-rate combined intracavitary and interstitial adaptive brachytherapy for the treatment of cervical cancer with a novel split-ring applicator

PurposeTo evaluate the role of 3T-MRI–guided adaptive high-dose-rate (HDR) combined intracavitary and interstitial brachytherapy for cervical cancer using a novel intracavitary split-ring (ICSR) applicator adapter.Methods and MaterialsWe retrospectively reviewed all HDR brachytherapy cases from 2013 to 2015 using an ICSR applicator. Initial optimization was performed using 3T multiparametric MRI (mpMRI) series with an applicator in place. The mpMRI series were discretionarily acquired before subsequent fractions for possible target adaptation. When necessary, interstitial needles (ISNs) were inserted through a novel ICSR adapter or freehand. Dosimetric parameters, clinical outcomes, and toxicities were compared between groups.ResultsSeventeen patients were included, with a mean followup of 32 months. An mpMRI series preceded each initial fraction and 52.9% of patients underwent ≥1 additional pretreatment mpMRI. Among these subsequent fractions, the high-risk clinical target volume was reduced in 80% vs. 41% without pretreatment mpMRI. Five patients had ISN placement (seven insertions) to improve extracervical target coverage. Mean D₉₀ (Gy) per fraction to the high-risk clinical target volume and intermediate-risk clinical target volume with and without an ISN were 7.51 ± 1.07 vs. 6.14 ± 0.52 (p = 0.028) and 6.35 ± 0.75 vs. 5.21 ± 0.49 (p = 0.007), respectively. Mean fractional D_2cc (Gy) for organs at risk was comparable. No Grades 3–4 toxicity was reported. Disease-free survival and local control for the ICSR-ISN and ICSR-alone groups were 29.8 months/80.0% and 31.2 months/83.3%, respectively.ConclusionsThe mpMRI acquisition with ICSR applicator in place immediately before HDR brachytherapy for cervical cancer guided successful adaptive treatment optimization and delivery. Our initial experience with a novel interstitial adapter for the split-ring applicator demonstrated excellent target coverage without compromising organs at risk, resulting in good local control and disease-free survival.     

Dose to the bladder neck is not correlated with urinary toxicity in patients with prostate cancer treated with HDR brachytherapy boost

PurposeThe purpose of this study was to evaluate whether the dose to bladder neck (BN) is a predictor of acute and late urinary toxicity after high-dose-rate brachytherapy (HDRB) boost for prostate cancer.Methods and MaterialsBetween 2014 and 2016, patients with prostate cancer treated at our institution with external beam radiation therapy and 15 Gy single-fraction HDRB boost for intermediate- and high-risk disease according to D'Amico definition were reviewed. Intraoperative CT scan–based inverse planning and ultrasound-based inverse planning were performed in 173 and 136 patients, respectively. The following structures were prospectively contoured: prostate, urethra, rectum, bladder, and the BN defined as 5 mm around the urethra between the catheter balloon and the prostatic urethra. Dose to the BN was reported only, no constraint was applied. Acute and late urinary toxicity were assessed using the International Prostate Symptom Score (IPSS) and the Common Terminology Criteria for Adverse Events v.4.0. Clinical and dosimetry factors associated with urinary toxicity were analyzed using generalized linear models.ResultsA total of 309 patients with median age of 71 years (range 50–89) were included. Median followup was 25 months (range 0–39 months). Using D'Amico definition, 71% of the patients had intermediate-risk disease, whereas 29% had high-risk disease. The mean pretreatment prostate-specific antigen value was 9.65 ng/mL. The mean pretreatment, after 6 weeks and over 6 months IPSSs were 8.34, 12.14, and 10.02, respectively. Urinary obstruction was reported in 14 cases (4.5%). Pretreatment IPSS (p = 0.003) and prostate volume (p = 0.024) were significantly associated with acute and late urinary toxicity. The dose for the most exposed 2 cc (D_2cc) of BN was not correlated with acute (p = 0.798) or late urinary toxicity (p = 0.859). BN D_2cc was not correlated with urinary obstruction (p = 0.272), but bladder V₇₅ was (p = 0.021).ConclusionsHigh pretreatment IPSS, large prostate volume and bladder V₇₅ were the only predictors of acute and late urinary toxicity after HDRB boost in our study. Although BN D_2cc was associated with acute and late urinary toxicity after low-dose-rate brachytherapy, no correlation was found after HDRB. A prospective study comparing dose to the BN in HDRB monotherapy would validate the impact of BN dose on acute and late urinary toxicity.     

Patient assessment of lower urinary tract symptoms using the international prostate symptom score following low-dose-rate prostate brachytherapy

PurposeTo correlate changes in urinary patient-reported outcomes including the International Prostate Symptom Score (IPSS), acute urinary retention and urethral stricture with urethral dose in those treated with low dose rate (LDR) prostate brachytherapy.Materials and MethodsPatients treated with prostate LDR between 2012 and 2019 (n=117) completed IPSS urinary symptom assessments prior to treatment and at each follow-up. CT simulation was obtained with urinary catheter 1-month post-implant for dosimetric analysis. 113 patients with pre- and ≥1 post-LDR IPSS score available were analyzed. Urethral dosimetric parameters including U75, U100, U125, U150 and U200 were abstracted from post-implant dosimetry and assessed for association with urinary toxicity using bivariate logistic regression and Spearman correlation. Outcomes included clinically significant change (CSC, defined as 4 or more points or 25% rise above baseline) in IPSS score at 6 and 12 months, acute urinary retention (AUR), and urethral stricture (US).Results89 (79%) patients were treated with LDR monotherapy (145 Gy) and 24 (21%) with LDR boost (110 Gy) with external beam radiation therapy. Twenty (18%) had baseline IPSS ≥15. Median IPSS scores were: baseline 6 (3−12; n=113), 1-month 17 (10−25; n=110), 6 months 12 (7−18; n=77), 1 year 8 (5−14; n=52). CSC-6 was observed in 59 (77%), CSC-12 in 26 (50%), AUR in 12 (11%), and US in 4 (4%). No association was identified between urethral dose parameters and CSC-6, CSC-12, AUR, or US. No correlation between urethral dose and IPSS at 6- and 12-months was identified. The IPSS ≥15 group exhibited lower rates of CSC-12 (13% v. 57%, p=0.05) but not CSC-6 (55% v. 80%, p=0.12).ConclusionsWe did not find a relationship between urethral dose and IPSS elevation, AUR or US. We did identify a significantly lower change in IPSS at 12 months for those with baseline IPSS ≥15 compared to those with low baseline scores.     

Optimization for high-dose-rate brachytherapy of cervical cancer with adaptive simulated annealing and gradient descent

PurposeTo validate an in-house optimization program that uses adaptive simulated annealing (ASA) and gradient descent (GD) algorithms and investigate features of physical dose and generalized equivalent uniform dose (gEUD)–based objective functions in high-dose-rate (HDR) brachytherapy for cervical cancer.MethodsEight Syed/Neblett template-based cervical cancer HDR interstitial brachytherapy cases were used for this study. Brachytherapy treatment plans were first generated using inverse planning simulated annealing (IPSA). Using the same dwell positions designated in IPSA, plans were then optimized with both physical dose and gEUD-based objective functions, using both ASA and GD algorithms. Comparisons were made between plans both qualitatively and based on dose–volume parameters, evaluating each optimization method and objective function. A hybrid objective function was also designed and implemented in the in-house program.ResultsThe ASA plans are higher on bladder V_75% and D_2cc (p = 0.034) and lower on rectum V_75% and D_2cc (p = 0.034) than the IPSA plans. The ASA and GD plans are not significantly different. The gEUD-based plans have higher homogeneity index (p = 0.034), lower overdose index (p = 0.005), and lower rectum gEUD and normal tissue complication probability (p = 0.005) than the physical dose-based plans. The hybrid function can produce a plan with dosimetric parameters between the physical dose-based and gEUD-based plans. The optimized plans with the same objective value and dose–volume histogram could have different dose distributions.ConclusionsOur optimization program based on ASA and GD algorithms is flexible on objective functions, optimization parameters, and can generate optimized plans comparable with IPSA.     

Phase II trial of image-based high-dose-rate interstitial brachytherapy for previously irradiated gynecologic cancer

PurposeTo report the disease-free Grade ≥3 complication-free survival of a Phase II protocol of reirradiation with high-dose-rate (HDR) interstitial brachytherapy (ITB) in previously irradiated gynecologic cancer.Methods and MaterialsFifteen patients with previously irradiated cervical (n = 6), endometrial (n = 6), and vulvovaginal tumors (n = 3) were treated with HDR-ITB alone to a median dose of 38 Gy in 8 b.i.d. fractions over 4 consecutive days. Prior treatments included surgery (n = 12; 80%), external irradiation (n = 15; 100%), and brachytherapy (n = 9; 60%). Average clinical target volume Size was 60.9 cc (range, 14.8–165.3 cc), and median time to reirradiation was 3.9 years (range, 0.4–22.7 years).ResultsWith a median followup of 2.8 years (range, 1.2–9.2 years), 3 patients (20.0%) developed Grade ≥3 toxicity consisting of Grade 3 intestinal obstruction (n = 1), Grade 4 rectovesical fistula (n = 1), and Grade 5 intestinal obstruction (n = 1). Six patients remain alive and without evidence of disease at last followup. Two patients are alive with disease progression, and 7 patients have died, 4 of them from disease progression and 3 from other causes. The 2-year disease-free Grade ≥3 complication-free survival was 40%.ConclusionsHDR-ITB alone is a reasonable salvage treatment option in a significant number of patients with previously irradiated gynecologic tumors.     

Upfront radiotherapy with brachytherapy for medically inoperable and unresectable patients with high-risk endometrial cancer

ObjectivesComprehensive surgery with adjuvant therapy is standard of care for high-risk endometrial cancers, whereas upfront radiotherapy with brachytherapy is indicated for inoperable/unresectable patients, irrespective of risk. We evaluated outcomes for inoperable/unresectable patients with high-risk endometrial cancer (HREC: stage III and/or grade 3) and low-risk endometrial cancer (LREC: stage I/II and grade 1/2) treated with upfront radiotherapy.MethodsTwenty-nine patients with inoperable/unresectable endometrial cancer were treated with upfront radiotherapy at an academic medical center from 2012 to 2019. Cancer-specific survival (CSS), overall survival (OS), and recurrence rates between patients with HREC and LREC were compared.ResultsMedian follow-up was 17.0 months (range 3.7–54.0). Twenty cancers were stage I + II and nine were stage III. Twenty-one cancers were grade 1 + 2 and eight were grade 3. Thirteen patients (45%) had HREC. Twenty-five patients received radiotherapy/chemoradiotherapy for primary treatment, while 4 patients received chemoradiotherapy before surgery. All patients underwent high dose rate brachytherapy (HDR) with 7 receiving HDR alone and 22 receiving external beam radiation and HDR. Two-year CSS was 100% for both HREC and LREC patients (log-rank p = 0.32). There was no OS difference between HREC and LREC patients (2-year: 73% vs. 77%; log-rank p = 0.33). Four HREC and 1 LREC patients recurred with one local recurrence in each group. There were no acute grade ≥3 and two late grade ≥3 gastrointestinal/genitourinary toxicities.ConclusionsUpfront radiotherapy for inoperable/unresectable HREC patients was well tolerated with high local control and CSS rates. Upfront radiotherapy with brachytherapy remains important even for high-risk inoperable and unresectable endometrial cancer patients.     

Efficacy of high-dose-rate interstitial brachytherapy in patients with oral tongue carcinoma

PurposeTo evaluate the results of high-dose-rate (HDR)-interstitial brachytherapy (ISBT) in oral tongue carcinomas.Methods and MaterialsBetween September 1999 and August 2007, 50 patients were treated for oral tongue carcinoma with HDR-ISBT. The patient's mean age was 58 years. Forty-two patients were in T1–2 stage and 8 patients were in T3 stage; 16 patients were in N+ stage and 34 patients in N0 stage. Exclusive ISBT was given to 17 patients (34%) in T1–2 N0 stage and complementary to external beam radiotherapy (EBRT) to 33 patients (66%). A perioperative technique was performed on 14 patients. The median total dose was 44 Gy when HDR was used alone (4 Gy per fraction) and 18 Gy when complementary to 50 Gy EBRT (3 Gy per fraction).ResultsThe median followup was 44 months. Actuarial disease-free survival rates at 3 and 5 years were 81% and 74%, respectively. Local failure developed in 7 patients. Actuarial local control (LC) rates were 87% and 79% at 3 and 5 years in T1–2 stage 94.5% and 91% and T3 stage 43% and 43% (with salvage surgery). Exclusive HDR cases showed LC in 100% of the cases, and the combined group (EBRT + HDR) showed LC in 80% and 69% of the cases at 3 and 5 years (p = 0.044). Soft-tissue necrosis developed in 16% and bone necrosis in 4% of the cases.ConclusionsHDR brachytherapy is an effective method for the treatment of oral tongue carcinoma in low-risk cases. Doses per fraction between 3 and 4 Gy yield LC and complication rates similar to low-dose rate. The perioperative technique promises encouraging results.     

Is stereotactic CyberKnife radiotherapy or multicatheter HDR brachytherapy the better option dosimetrically for accelerated partial breast irradiation?

ObjectiveTo compare dosimetrically the stereotactic CyberKnife (CK) therapy and multicatheter high-dose-rate (HDR) brachytherapy (BT) for accelerated partial breast irradiation (APBI).MethodsTreatment plans of 25 patients treated with CK were selected, and additional plans using multicatheter HDR BT were created on the same CT images. The prescribed dose was 6.25/25 Gy in both plans to the target volume (PTV). The dose-volume parameters were calculated for both techniques and compared.ResultsThe D90 total dose of the PTV was significantly lower with CK than with HDR BT, D90 was 25.7 Gy, and 27.0 Gy (p < 0.001). However, CK plans were more conformal than BT, COIN was 0.87, and 0.81 (p = 0.0030). The V50 of the non-target breast was higher with CK than with BT: 10.5% and 3.3% (p = 0.0010), while there was no difference in the dose of the contralateral breast and contralateral lung. Dose to skin, ipsilateral lung, and ribs were higher with CK than with BT: D₁ was 20.6 Gy vs. 11.5 Gy (p = 0.0018) to skin, 11.4 Gy vs. 9.6 Gy (p = 0.0272) to ipsilateral lung and 18.5 Gy vs. 12.3 Gy (p = 0.0013) to ribs, while D_0.1 to heart was lower, 3.0 Gy vs. 3.2 Gy (p = 0.0476), respectively.ConclusionsMulticatheter HDR BT yields more advantageous plans than stereotactic CyberKnife treatment in accelerated partial breast irradiation, except in terms of dose conformality and the dose to the heart. There was no difference in the dose of the contralateral breast and lung.     

The one hundred most cited publications in prostate brachytherapy

PurposeThe aim of this study is to identify the leaders in research on prostate brachytherapy through a bibliometric analysis of the top 100 most cited publications in the field.Methods and materialsA broad search was performed with the term “prostate brachytherapy” using the Web of Science database to generate wide-ranging results that were reviewed by reading the abstracts and, if necessary, the articles to select the top 100 most cited publications.ResultsThe median of the total citation count was 187 (range 132–1464). The median citation per year index (citations/year since publication) was 13.5 (range 6.3–379.0). In all publications, the first author was also the corresponding author. The top publishing countries of the first author included the United States (n = 78), Canada (n = 6), the UK (n = 5), and Germany (n = 4). The journal with the most publications was the International Journal of Radiation Oncology Biology Physics (n = 38). There were 27 more publications on low-dose-rate (LDR) than on high-dose-rate (HDR) (43 vs 16) among the top 100. HDR publications had only one first author that had three articles in comparison to LDR publications, which had four first authors, each with three articles on LDR. The United States was the leading country in 43.8% of HDR publications (n = 7) and 88.4% of LDR publications (n = 38).ConclusionsOur bibliometric analysis of the top 100 most cited publications clearly demonstrates the North American dominance in the publications of prostate brachytherapy, especially in LDR. However, European first authors were more frequent in HDR publications.     

A comparative dosimetric analysis of virtual stereotactic body radiotherapy to high-dose-rate monotherapy for intermediate-risk prostate cancer

PurposeStereotactic body radiotherapy (SBRT) is being used with increasing frequency as definitive treatment of early stage prostate cancer. Much of the justification for its adoption was derived from earlier clinical results using high-dose-rate (HDR) brachytherapy. We determine whether HDR's dosimetry can be achieved by virtual SBRT.Methods and MaterialsPatients with intermediate-risk prostate cancer on a prospective trial evaluating the efficacy of HDR monotherapy treated to dose of 9.5 Gy × 4 fractions were used for this study. A total of 5 patients were used in this analysis. Virtual SBRT plans were developed to reproduce the planning target volume (PTV) HDR dose distributions. Both normal tissue– and PTV-prioritized plans were generated.ResultsFrom the normal tissue–prioritized plan, HDR and virtual SBRT achieved similar PTV V₁₀₀ (93.8% vs. 93.1%, p = 0.20) and V₁₅₀ (40.3% vs. 42.9%, p = 0.69) coverage. However, the PTV V₂₀₀ was not attainable with SBRT (15.2% vs. 0.0%, p < 0.001). The rectal D_max was significantly lower with HDR (94.2% vs. 99.42%, p = 0.05). The rectal D_{2 cc} was also lower (60.8% vs. 71.1%, p = 0.07). Difference in D_{1 cc} urethral dose was not significantly different (87.7% vs. 75.2%, p = 0.33). Comparing the PTV-prioritized plans, the rectal D_max (94.2% vs. 111.1%, p = 0.05) and mean dose (27.1% vs. 33.3%, p = 0.03) were significantly higher using SBRT, and the rectal D_{2 cc} was higher using SBRT (60.8% vs. 81.8%, p = 0.07).ConclusionsHDR achieves significantly higher intraprostatic doses while achieving a lower maximum rectal dose compared with our virtual SBRT treatment planning. Future studies should compare clinical outcomes and toxicity between these modalities.     

Prolonged hormonal therapy and external beam radiation independently increase the risk of Persistent Hypogonadism in men treated with prostate brachytherapy

PurposeTo identify variables that predict persistent hypogonadism and castration in patients with prostate cancer (PCa) treated with brachytherapy (BT).Materials and MethodsA retrospective analysis was performed on 1,053 patients receiving BT ± external beam radiation therapy (EBRT) ± hormone therapy (HT) for NCCN low, intermediate, or high-risk PCa between 1990 and 2011. Patients were categorized as not receiving HT (n = 438, 41.6%), ≤6 months (n = 317, 31.1%) or > 6 months (n = 298, 28.3%) of HT. 572 (54.3%) received BT alone, and 481 had combination therapy. The five- and 10-year freedom from persistent hypogonadism (T < 280 ng/dL) and castration (T < 50 ng/dL) for each group was evaluated with Kaplan-Meier estimates. Multivariable cox proportional hazards models were used to compare the risk of persistent hypogonadism and castration at a median followup of 6.5 years (posttreatment to final T) (IQR: 4.3–9.1 years; range: 1.0–19.2 years).ResultsThe 5-year freedom from hypogonadism rates were 92.4%, 88.9%, and 87.0% for patients with no HT, ≤ 6 months and >6 months of HT, respectively (10-year rates: 66.7%, 55.3%, 40.5%); p < 0.01. The 5-year freedom from castration rates were 99.2%, 98.0%, and 98.4%, respectively (10-year rates: 97.9%, 95.5%, 90.9%); p = 0.078. Number of months of HT (HR = 1.04, p = 0.030) and BT with EBRT vs. BT alone (HR = 1.56, p = 0.010) significantly increased the risk of persistent hypogonadism. Number of months of HT was the only variable which increased the risk of persistent castration (HR = 1.09, p = 0.014).ConclusionsThe addition of EBRT to BT is an independent risk factor for persistent hypogonadism. Prolonged HT additionally increases the risk of persistent hypogonadism and castration.     

Dosimetric comparison of multichannel with one single-channel vaginal cylinder for vaginal cancer treatments with high-dose-rate brachytherapy

PurposeTo compare the three-dimensional (3D) image (CT/MR)-based planning with a multichannel vaginal cylinder (MVC) to a single-channel vaginal cylinder (SVC) for the treatment of vaginal cancer.Methods and MaterialsA total of 20 consecutive patients were treated with 3D CT/MR image-based high-dose-rate (HDR) brachytherapy using an MVC. All patients received external beam radiation therapy before HDR brachytherapy. A brachytherapy dose of 20–25 Gy of more than five fractions was delivered to clinical target volume (CTV). Retrospectively, treatment plans for all patients were generated using the central channel only to mimic an SVC applicator. The SVC plans were optimized to match CTV coverage with MVC plans. Dose homogeneity index as well as bladder, rectum, sigmoid, and urethral doses were compared.ResultsThe mean D₉₀ for CTV was 74.2 Gy (range: 48.8–84.1 Gy). The mean (±standard deviation) of dose homogeneity index for MVC vs. SVC was 0.49 (±0.19) and 0.52 (±0.23), respectively (p = 0.09). Mean bladder 0.1, 1, and 2 cc doses for MVC vs. SVC were 69 vs. 71.2 Gy (p = 0.35), 61.4 vs. 63.8 Gy (p = 0.1), and 59.5 vs. 60.9 Gy (p = 0.31), respectively. Similarly, mean rectum 0.1, 1, and 2 cc doses for MVC vs. SVC were 67.2 vs. 75.4 Gy (p = 0.005), 60.0 vs. 65.6 Gy (p = 0.008), and 57.3 vs. 62.0 Gy (p = 0.015), respectively, and mean sigmoid doses were 56.3 vs. 60.5 Gy (p = 0.10), 50.9 vs. 53.1 Gy (p = 0.09), and 49.1 vs. 50.7 Gy (p = 0.10), respectively.ConclusionThe 3D CT-/MR-based plan with MVC may provide better dose distribution in the management of certain clinical situations of vaginal cancer requiring intracavitary brachytherapy, especially in minimizing potential late rectal complications.