Are active dwell positions always necessary in the ring/ovoids channel of the cervical applicator in the intracavitary-interstitial brachytherapy of cervical cancer?

Purpose: To compare dosimetric parameters of brachytherapy (BT) treatment plans made with or without active source positions of the ring/ovoid (R/O) applicator in locally advanced cervical cancer patients. Material and methods: Sixty patients with cervical cancer without vaginal involvement were selected for the study, who received intra-cavitary/interstitial BT. For each patient, two plans with and without active source dwell positions in R/O were created, using the same dose-volume constraints. EQD2 total doses from external beam and BT of target volumes and organs at risk (OARs) between the competing plans were compared. Results: There was no significant difference in the dose of high-risk clinical target volume (HR-CTV) and gross tumor volume (GTV) between the plans with inactive vs. active R/O. The mean D98 of intermediate-risk clinical target volume (IR-CTV) was significantly lower with inactive R/O; however, the GEC-ESTRO (EMBRACE II study) and ABS criteria were fulfilled in 96% in both plans. There was no difference in dose homogeneity, but conformity of the plans with inactive R/O was higher. Doses to all OARs were significantly lower in plans without R/O activation. While all the plans without R/O activation fulfilled the recommended dose criteria for OARs, it was less achievable with R/O activation. Conclusions: Inactivation of R/O applicator results in similar dose coverage of the target volumes with lower doses to all OARs, as activation of R/O in cervix cancer patients when HR-CTV does not extend to R/O applicator. The use of active source positions in R/O shows worse performance regarding the fulfilment of the recommended criteria for OARs.

Dosimetric comparison of inverse optimisation methods versus forward optimisation in HDR brachytherapy of breast, cervical and prostate cancer.

OBJECTIVE: Dosimetric comparison of HIPO (hybrid inverse planning optimisation) and IPSA (inverse planning simulated annealing) inverse and forward optimisation (FO) methods in brachytherapy (BT) of breast, cervical and prostate cancer. METHODS: At our institute 38 breast, 47 cervical and 50 prostate cancer patients treated with image-guided interstitial high-dose-rate BT were selected. Treatment plans were created using HIPO and IPSA inverse optimisation methods as well as FO. The dose-volume parameters of different treatment plans were compared with Friedman ANOVA and the LSD post-hoc test. RESULTS: IPSA creates less dose coverage to the target volume than HIPO or FO: V100 was 91.7%, 91% and 91.9% for HIPO, IPSA and FO plans (p = 0.1784) in breast BT; 90.4%, 89.2% and 91% (p = 0.0045) in cervical BT; and 97.1%, 96.2% and 97.7% (p = 0.0005) in prostate BT, respectively. HIPO results in more conformal plans: COIN was 0.72, 0.71 and 0.69 (p = 0.0306) in breast BT; 0.6, 0.47 and 0.58 (p < 0.001) in cervical BT; and 0.8, 0.7 and 0.7 (p < 0.001) in prostate BT, respectively. In breast BT, dose to the skin and lung was smaller with HIPO and FO than with IPSA. In cervical BT, dose to the rectum, sigmoid and bowel was larger using IPSA than with HIPO or FO. In prostate BT, dose to the urethra was higher and the rectal dose was smaller using FO than with inverse methods. CONCLUSION: In interstitial breast and prostate BT, HIPO results in comparable dose-volume parameters to FO, but HIPO plans are more conformal. In cervical BT, HIPO produces dosimetrically acceptable plans only when more needles are used. The dosimetric quality of IPSA plans is suboptimal and results in unnecessary larger active lengths.

Comparative analysis of image-guided adaptive interstitial brachytherapy and intensity-modulated arc therapy versus conventional treatment techniques in cervical cancer using biological dose summation.

PURPOSE: To compare image-guided adaptive interstitial brachytherapy (BT) and intensity-modulated arc therapy (IMAT) with conventional treatment techniques in cervical cancer using an alternative biological dose summation method. MATERIAL AND METHODS: Initially, 21 interstitial BT and IMAT plans of patients with cervical cancer were included and additional plans were created (inverse optimized interstitial, optimized intracavitary, non-optimized intracavitary BT plans, and conformal external beam radiotherapy [EBRT]). The most exposed volume of critical organs in BT were identified manually on EBRT CT images. Biological total doses (EQD2) were calculated and compared between each combination of BT and EBRT plans. This method was compared with uniform dose conception (UDC) in IMAT and conformal EBRT plans. RESULTS: The D90 of high-risk CTV and D2 of bladder and sigmoid were different in BT techniques only: p = 0.0149, < 0.001, < 0.001, respectively. The most advantageous values were obtained in the interstitial treatment plans and inverse optimized interstitial plans did not differ dosimetrically from these, while optimized intracavitary plans resulted in worse dose-volume parameters, and the worst of all were intracavitary plans without optimization. The D2 of rectum was significantly lower with IMAT than with conformal EBRT plans (p = 0.037) and showed the same trend in BT plans as the other parameters (p < 0.001). The UDC dose summation method overestimated D2 of bladder, rectum, and sigmoid (p < 0.001 for all). CONCLUSIONS: Although optimization improves the quality of conventional BT plans, interstitial plans produce significantly higher dose coverage of high-risk clinical target volume (HR-CTV) and lower doses to organs at risk (OARs). IMAT plans decrease the dose to the rectum. UDC overestimates OARs doses.

[Survival of pediatric patients with Ewing sarcoma treated at Semmelweis University]. / A Semmelweis Egyetemen kezelt Ewing-szarkómás gyermekek kezelési eredményeinek vizsgálata.

The survival of children treated with Ewing sarcoma at Semmelweis University were investigated. Pediatric patients with Ewing sarcoma treated at Semmelweis University from 2001 through 2013 were analyzed in terms of overall survival and clinical factors (age, primary localization and extent of the tumor, time interval from primary complaints to diagnosis). For statistical analysis Kaplan-Meier estimated survival and log rank test were applied. Mean age and follow-up time of the 78 patients were 11.16 and 6.29 years, respectively. In 57% of patients time interval from primary symptoms to diagnosis was less than half year. In 53.8% of the patients the disease was metastatic at primary diagnosis (pulmonary only: 29.5%, any other: 24.3%). 5- and 10-year overall survival of patients were 68.1% and 60.4%, respectively. Among the analyzed factors, the presence of metastasis impaired 5-year overall survival significantly (88.5% for localized disease, 63.5% for pulmonary only and 40.9% for any other metastasis). The survival rate of pediatric patients with Ewing sarcoma treated at Semmelweis University is similar to the result in Western European countries.

[Dosimetric evaluation of intracavitary-interstitial image-guided adaptive brachytherapy of cervical cancer and comparison with conventional treatment techniques]. / Méhnyakdaganatok képvezérelt adaptív intersticiális-intrakavitális brahiterápiájának dozimetriai elemzése és a hagyományos kezelési technikákkal való összehasonlítása.

Our aim was the dosimetric evaluation of intracavitary-interstitial high-dose-rate image-guided adaptive cervix brachytherapy, implemented in Hungary. Between 2016 and 2018, 21 patients with cervical cancer were treated with overall 72 fractions. Graphical optimized treatment plans were compared to inverse optimized plans, 3D optimized plans (without needles) and conventional intracavitary 2D plans. Significant difference was found in almost all dose-volume parameters. The most advantageous values came from interstitial plans, inverse optimized plans did not differ dosimetrically from the treatment plans, while intracavitary optimized plans disposed of less appropriate dose-volume parameters, the least of all were intracavitary 2D plans. Needle number showed correlation with conformality, but inverse correlation with Dose Nonuniformity Ratio and D2cm3 of rectum. Volume of High Risk CTV correlated with D2cm3 of bladder, rectum and sigmoid. Although 3D optimization improved the quality of conventional 2D plans, interstitial plans resulted in even more homogeneous dose distribution and significantly lower doses to organs at risks.

[Clinical results of combined intracavitary-interstitial image-guided adaptive brachytherapy in locally advanced cervical cancer]. / Elõrehaladott méhnyakdaganatok képvezérelt adaptív kombinált intrakavitális-intersticiális brahiterápiájának bevezetése Magyarországon.

We present the early clinical results achieved with image-guided adaptive brachytherapy (IGABT) with combined intracavitary-interstitial (IC-IS) technique recently implemented in Hungary in the treatment of locally advanced cervical cancer (LACC). Twenty-one patients were treated with radio-chemotherapy (RCT) followed by combined IC-IS BT. At the end of the RCT we assessed the residual tumour with pelvic MRI. On CT images registered with the applicator in place we contoured the organs at risk and the high-risk clinical target volume, which included the whole cervix and the eventual residual tumour in the parametria. No grade 4 toxicity was noticed. At 11 months follow-up the local control rate was 92.3%, the pelvic control rate 86.5%, the distant metastasis free survival and the disease-free survival were 74%. The combined IC-IS treatment was well tolerated. Our clinical results are similar to those reported in the literature.

Pathologic complete remission after preoperative high-dose-rate brachytherapy in patients with operable cervical cancer: preliminary results of a prospective randomized multicenter study.

The role of preoperative intrauterine brachytherapy (BT) in the multidisciplinary treatment of early stage cervical carcinoma (ESCC) is controversial. In 2005, a prospective randomized multicenter study was initiated in Hungary in order to explore the potential advantages of preoperative high-dose-rate (HDR) BT. In this article we evaluate the efficiency of preoperative HDR BT by the rate of pathologic complete remission (pCR) in the first 185 patients enrolled in the study at the National Institute of Oncology and at the Uzsoki Municipal Cancer Center in collaboration with the 1st Department of Gynaecology and Obstetrics of Semmelweis University, Budapest, Hungary. In arm A, patients received 2x8Gy preoperative intracavitary HDR BT, while in arm B no preoperative treatment was given. In both arms patients underwent radical Wertheim (Piver III) hysterectomy. The pCR rate was 25.7% after preoperative HDR BT, while it was only 11.2% with surgery alone (p=0.03), in these cases the tumor was eliminated during the diagnostic excision or conisation. The rate of positive surgical margins was 1.5% after preoperative BT, while it was as high as 11.4% without preoperative RT (p=0.02). There was no significant difference in the local tumor control (LTC), distant metastases free survival (DMFS) and overall survival (OS) between the two arms. According to our preliminary results preoperative intracavitary HDR BT significantly increases the rate of pCR and decreases the rate of positive surgical margins in patients with ESCC. Longer follow-up is required to establish the possible impact of pCR on the ultimate LTC and OS.

[Complete pathologic remission after preoperative high-dose brachytherapy in patients with operable cervical cancer: preliminary results of a prospective randomized study]. / Patológiai komplett remisszió preoperatív, nagy dózisteljesítményû brachyterápiát követoen operábilis méhnyakdaganatos betegeknél: egy prospektív, randomizált vizsgálat elozetes eredményei.

The purpose of the study was a preliminary evaluation of the efficacy of preoperative intracavitary high-dose-rate brachytherapy (HDR BT) in sterilization of the specimen of operable cervical cancer patients enrolled into a prospective, randomized study. Between 2005 and 2010, 100 operable cervical cancer patients of FIGO stage I/A2 (n=4), I/B1 (n=51), I/B2 (n=19), IIA (n=17), and proximal II/B (n=9) were randomized in two arms: in arm "A" (n=50) allocated treatment was 2x8 Gy preoperative intracavitary HDR BT followed by radical surgery, in arm "B" (n= 50) no preoperative treatment was given before the planned radical Wertheim hysterectomy. The rates of pathologic complete remission (pCR) were compared using the Fisher-exact test. In arm "A" 41 patients (82%), in arm "B" 42 patients (84%) underwent radical hysterectomy. The rate of pCR after preoperative BT was 26.8% (11/41), while in the control group the specimen was free of tumor in 7.1% (3/42; p=0.0204). Preoperative HDR BT for cervical cancer patients significantly increases the rate of pathologically tumor-free specimens. Longer follow-up is needed to evaluate the impact of pCR on local tumor control and survival. Our preliminary results support further enrollment of patients into our randomized clinical trial.