Intrauterine Brachytherapy Research Articles

PO31 Presentation Time: 10:30 AM: Dosimetric Evaluation of Normal Tissue Sparing in MRI Guided Adaptive Brachytherapy with Replan at Each Treatment Fraction in Cervix HDR Brachytherapy

<h3>Purpose</h3> Evaluate target and organ at risk (OAR) dosimetric benefit with replan at each treatment fraction in MRI guided adaptive brachytherapy (MRIGABT) for cervix cancer. <h3>Materials and Methods</h3> Radiotherapy treatment planning MRI (RTPMRI) were acquired before each brachytherapy fraction (1-4), in 10 patients treated with intrauterine brachytherapy (IUB) using the Venezia^TM applicator. Each patient had 2 IUB applicator insertions and received 28 Gy/4# following EBRT 25 Gy/25# (EMBRACE II protocol)¹. A replan based on anatomy on MRI acquired on day 2 (D2) of each IUB applicator insertion was planned and delivered (D2-replan). Total target and OAR dose was compared to conventional treatment where the treatment plan on day 1 of IUB applicator insertion is also delivered on day 2 (no replan). Total biologically equivalent doses for EBRT and brachytherapy were calculated in 2 Gy equivalents using the EQD2 equation and reported as total dose (Gy). <h3>Results</h3> Forty RTPMRI and IUB HDR treatment plans were analysed in 10 patients. The mean (±SD) total dose (EBRT + HRCTV 90) received for D2-replan and D2-no replan was 91.9 Gy (±2.3) and 90.5 Gy (±2.8). There was no statistically significant difference in target and OAR dose between D2-replan and no replan. But in individual patients there were clinically significant differences. No OAR dose constraints were exceeded with D2-replan, OAR dose constraints were exceeded in 5-20% of fractions when there was no replan (rectum 8/40#, sigmoid 2/40#, bowel 2/40# and bladder 2/40#). <h3>Conclusions</h3> Daily MRIGABT replan at each treatment fraction results in improved HRCTV dose and reduced OAR dose in some patients. With a replan, we saw consistent HRCTV D90 of >87 Gy, which is significantly associated with better disease control^2,3 especially in asymmetrical tumours. The additional resources required will not benefit all patients and selection criteria for patients who will benefit is required.

Clinical Outcomes Following Definitive 3D Image-Guided HDR Intracavitary Brachytherapy for Medically Inoperable Endometrial Cancer

<h3>Purpose/Objective(s)</h3> Endometrial cancer (EC) is the most common gynecologic malignancy in the U.S. Brachytherapy alone or in combination with external beam radiation therapy (EBRT) is considered an alternative definitive treatment for women who are not surgical candidates, though limited data exists for outcomes with modern 3D image-guided brachytherapy. As the U.S. population ages and rates of obesity and other comorbidities rise, more women may require definitive radiation therapy. In this study, we report outcomes for a large cohort of patients treated with intrauterine brachytherapy with 3D CT-guided planning. <h3>Materials/Methods</h3> Retrospective review identified 59 women with EC who received high dose rate (HDR) intrauterine brachytherapy with dual or triple tandem applicators with definitive intent, alone or in combination with EBRT, between 2009-2020. All patients underwent endometrial biopsy and 92% had pretreatment diagnostic CT and/or MRI imaging. 3D CT-guided brachytherapy planning was done using planning software. Local failure-free survival (LFFS), disease-free (DFS), and overall survival (OS) estimates were calculated by Kaplan-Meier method. Median follow-up was 44 months (interquartile range [IQR], 17-88). <h3>Results</h3> Median patient age was 68 years (range, 37-87). Patients had atypical complex hyperplasia (15%), or clinical stage I (76%), II (5%), or III (3%) EC. Patients were ineligible for surgery due to medical comorbidities, including obesity (97% of patients), pulmonary disease (36%), cardiovascular disease (41%), renal disease (9%), or complicated prior surgical history (9%). Median BMI was 45.7 kg/m² (range, 17.2-79.7), and 64% of patients met criteria for severe obesity (≥40 kg/m²). Brachytherapy dose delivered ranged from 8.5Gy in 1 fraction to 36.5Gy in 5 fractions. Among patients receiving brachytherapy alone, 83% were treated with 34Gy in 4 fractions. 20% of patients underwent EBRT immediately prior to or following brachytherapy and received lower doses of brachytherapy. Median coverage of the uterus CTV V100 = 92% (range, 65%-99%). 5-year LFFS, DFS, and OS rates were 91%, 82%, and 75%, respectively. Median time to any failure was 15 months (IQR, 10-26). Among 59 patients, 4 failed locally, 3 failed in the peritoneum, and 2 failed both locoregionally and distally. Two of 4 patients who failed locally were successfully salvaged with surgery. Five patients died of EC. Ten patients (17%) had perforation of the uterus with applicator placement. Antibiotics were not given prophylactically and no patients developed bacterial peritonitis or other infectious complication. There was no correlation between perforation of the uterus at the time of brachytherapy and peritoneal spread of EC. <h3>Conclusion</h3> Outcomes following definitive 3D image-guided brachytherapy were excellent, with 5-year LFFS of 91% and 5-year DFS of 82%. Patients rarely died of EC. Our data supports the use of 3D brachytherapy as definitive therapy for patients who are not candidates for surgery.

Gynecological intrauterine brachytherapy training for radiation therapists: The development and implementation of a training program

PURPOSEGynecological brachytherapy (GynBT) is an important part of gynecological cancer management. At Olivia Newton-John Cancer Wellness & Research Centre (ONJCWRC), Melbourne, Australia, radiation therapists (RTs) are integral to the MRI adaptive GynBT program workflow. However, there is limited GynBT training available for RTs in Australia. A GynBT training program has been developed at ONJCWRC to meet this need and support RTs in becoming competent, proficient and confident in the various roles in GynBT. This is a preliminary report on the development and implementation of a credentialing program, providing a structured approach to GynBT training of RTs. METHODS AND MATERIALSA credentialing program was designed with modules and competency assessments to ensure efficiency and proficiency of RTs in the GynBT workflow. The program includes theoretical modules in anatomy, international GynBT guidelines, radiation safety and local protocols; and practical modules in equipment, ultrasound for GynBT, operating theatre procedures, MRI, contouring, applicator reconstruction, planning, quality assurance and treatment delivery. Learning strategies include self-directed learning, tutorials, practical sessions, and third-party courses. The program concludes with an exit examination assessing major competencies. RESULTSThe program was implemented in April 2018 with three RTs completing the program and passing the exit examination on first attempt. On post-program survey, the RTs felt the program was comprehensive, helping to build their confidence, and proficiency in GynBT. CONCLUSIONSA GynBT RT credentialing program was successfully developed and implemented to improve the quality of training at ONJCWRC. This program is mandatory for RTs joining the GynBT team. This program can provide a framework for implementation of GynBT training in other centers.

MO-0297 Atlas based auto-segmentation in the delineation of rectum and bladder in intrauterine brachytherapy

MO-0297 Atlas based auto-segmentation in the delineation of rectum and bladder in intrauterine brachytherapy

Brachytherapy in Belgium in 2018. A national survey of the brachytherapy study group of the Belgian SocieTy for Radiotherapy and Oncology (BeSTRO)

PurposeTo explore the current practices patterns and evaluate the actual brachytherapy (BT) resources in Belgium. Material and methodsIn 2019, the Brachytherapy Study Group proposed to conduct a survey on behalf of the Belgian SocieTy of Radiation Oncology (BeSTRO) in order to identify current BT practice patterns. An electronic questionnaire was sent to all primary radiotherapy centers in Belgium. This questionnaire was based on the questionnaire that was used by the Italian Association of Radiation Oncology (AIRO) in 2016, asking for: (a) General information on the Radiation Oncology Centre; (b) BT equipment and human resources; (c) BT procedures; (d) BT assessment (number of patients treated annually, treated sites, and different modalities of treatments). ResultsAll 24 radiation oncology centers (100% response rate) answered the questionnaire and gave also information on the performance of brachytherapy in their (eventual) satellite centers. Eighteen (18) BT afterloader units were installed and operational in 2018. Thirteen centers mentioned a prostate seed implant program, one center a prostate and eye plaque program and one center only an eye plaque program. Less than 50% of centers have the infrastructure to offer the full-range of BT in their own department. In 2018, 1486 patients received a BT-treatment, 28% of them were treated by prostate seed implant, 8% were treated by eye-(seed) BT and 64% by high dose rate (HDR)/pulsed dose rate (PDR) BT. Forty-five percent of HDR/PDR patients were treated by vaginal dome BT, 22% by intra-uterine BT, 11% by skin BT, 10% by breast BT (almost exclusively in one centre), 8% for benign pathology (keloid) and the remaining 4% were treated for prostate (as a boost or as salvage in one centre), anal, penile, lung or oesophageal cancer. ConclusionsBelgian radiotherapy departments often perform BT only in a (highly) selected group of pathologies, resulting in a limited number of patients treated by this technique despite the sufficient availability of BT equipment. Modern indications are often not covered, hence patients do not have regular access to recognized treatment options, possibly leading to inferior oncological outcome. BeSTRO will use the results of this survey to stimulate improvements in training, awareness, education, implementation, collaboration and cooperation in the field of brachytherapy.

High-volume providers and brachytherapy practice: A Medicare provider utilization and payment analysis

PurposeBrachytherapy is an important component of the treatment of gynecologic and prostate cancers, with data supporting its impact on clinical outcomes. Prior data have suggested that brachytherapy tends to be focused at high-volume centers. Medicare reimbursement data can provide an understanding of the distribution of brachytherapy cases among billing providers. The objective of this study is to quantify the distribution of brachytherapy cases and high volume providers. Methods and MaterialsThe Medicare Physician and Other Supplier Public Use File was queried for individual physicians who had performed brachytherapy for more than 10 patients with gynecologic or prostate cancer in the years 2012–2015. Aggregate data were also queried. Trends were identified, and basic summary statistics were tabulated. ResultsDuring the study period, there was an increase in vaginal brachytherapy (3328 unique cases in 2012–4308 in 2015) but a decrease in intrauterine implants, such as tandem placements (1522 in 2012–1307 in 2015) and prostate brachytherapy (8860 in 2012–6527 in 2015). High-volume providers treating more than 10 patients represented a disproportionate number of patients treated, particularly with intra-uterine brachytherapy, representing no more than 1.2% of the active providers in a given year but up to 11.1% of intra-uterine brachytherapy cases. ConclusionsAmong Medicare claims, a small number of providers accounted for a significant proportion of gynecologic and prostate brachytherapy cases, particularly in the case of intrauterine implants. The vast majority of brachytherapy providers perform limited cases in this population. Efforts toward improving access to intrauterine implants in Medicare patients should be a national priority.

EP-2232: Feasibility of dose escalation with individualised bladder filling for intrauterine brachytherapy

EP-2232: Feasibility of dose escalation with individualised bladder filling for intrauterine brachytherapy

Presence of Pelvic Ascites Significantly Decreases Sigmoid and Small Bowel Dose in Simulated Intrauterine Brachytherapy: Making the Case for Hydrodissection

Presence of Pelvic Ascites Significantly Decreases Sigmoid and Small Bowel Dose in Simulated Intrauterine Brachytherapy: Making the Case for Hydrodissection

Cisplatin and Gemcitabine Combined with Highly Conformal External Beam Radiation Therapy in the Treatment of Cervical Cancer Patients Result in Low Toxicity and Promising Outcome

Cisplatin and gemcitabine combined with conventional radiation therapy in treatment of cervical cancer patients results in favorable outcome but excess toxicity. The purpose of this study was to determine toxicity profile of dual chemotherapy and highly conformal radiation therapy. 17 patients with cervical carcinoma FIGO stage IB2 – IIIB were treated with curative intent between 2011 and 2015. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Patients with 18FDG-PET/CT positive lymph nodes (n = 15; 83.3 %) received a simultaneous integrated boost to a total dose of 62 Gy. Chemotherapy prescription goals were: concomitant during 5 weeks of external beam radiation therapy (EBRT) 40mg/m2 cisplatin and 125mg/m2 gemcitabine, followed by adjuvant chemotherapy from week 10 (2 cycles 50mg/m2 cisplatin and 1000mg/m2 gemcitabine). EBRT was followed by 3 to 4 fractions (6 Gy) of 3D-HDR intrauterine brachytherapy. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0). Hematologic toxicity occurred mainly in form of grade 2 anemia in 10 patients (59%) while neutropenia grade 3 was reported in only 1 patient (6%). Other hematologic toxicities higher than grade 2 did not occur. One patient (6%) developed acute grade 3 diarrhea. Other gastrointestinal toxicities were not reported, neither were any other toxicities of acute or chronic nature higher than grade 2. The number of patients receiving complete chemotherapy regime declined gradually during course of therapy. From week 2 to week 5 gemcitabine was omitted in 4 (24%),7 (41%), 8 (47%),12 (71%) and cisplatin in 2 (12%),3 (18%),1 (6%),7 (41%) patients respectively. Adjuvant cycles of chemotherapy were omitted in 8 patients (47%). During median follow-up time of 20 months (5 to 63 months) 6 (35%) patients developed disease relapse, 5 (29%) of them in form of systemic disease. In contrast to previous findings cisplatin and gemcitabine in combination with highly conformal radiotherapy has a low toxicity profile. Further studies are necessary to determine optimal dose and efficiency of the proposed therapy concept.

Dose escalated intensity modulated radiotherapy in the treatment of cervical cancer.

PurposeStandard dose of external beam radiotherapy seems to be insufficient for satisfactory control of loco-regionally advanced cervical cancer. Aim of our study is to evaluate the outcome as well as early and chronic toxicities in patients with loco-regionally advanced cervical cancer, treated with dose escalated intensity modulated radiotherapy (IMRT) combined with cisplatin chemotherapy.Material and methodsThirty-nine patients with cervical carcinoma FIGO stage IB2 – IVA were treated with curative intent between 2006 and 2010. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors < 4 cm in diameter (n = 6; 15.4 %) received an external beam radiotherapy (EBRT) boost of 5.4 Gy, primary tumors > 4 cm in diameter (n = 33; 84.6 %) received an EBRT boost of 9 Gy. Patients with positive lymph nodes detected with 18FDG-PET/CT (n = 22; 56.4 %) received a boost to a total dose of 59.4 - 64.8 Gy. The para-aortic region was included in the radiation volume in 8 (20.5 %) patients and in 5 (12.8 %) patients the para-aortic macroscopic lymph nodes received an EBRT boost. IMRT was followed with a 3D planned high dose rate intrauterine brachytherapy given to 36 (92.3 %) patients with a total dose ranging between 15–18 Gy in three fractions (single fraction: 4–6.5 Gy). Patients without contraindications (n = 31/79.5 %) received concomitantly a cisplatin-based chemotherapy (40 mg/kg) weekly. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0).ResultsMean overall survival for the entire cohort was 61.1 months (±3.5 months). Mean disease free survival was 47.2 months (±4.9 months) and loco-regional disease free survival was 55.2 months (±4.4 months). 65 % of patients developed radiotherapy associated acute toxicities grade 1, ca. 30 % developed toxicities grade 2 and just two (5.2 %) patients developed grade 3 toxicities, one acute diarrhea and one acute cystitis. 16 % of patients had chronic toxicities grade 1, 9 % grade 2 and one patient (2.6 %) toxicities grade 3 in the form of vaginal dryness.ConclusionDose escalated IMRT appears to have a satisfactory outcome with regards to mean overall survival, disease free and loco-regional disease free survival, whereas the treatment-related toxicities remain reasonably low.

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.

The evolving practice of intrauterine cervix brachytherapy in Canada: A medical physics perspective

To determine the current equipment, technology, and treatment planning methods used in Canadian cancer centers for intrauterine cervix brachytherapy. A questionnaire was developed to survey medical physicists in Canada regarding technical aspects of intrauterine cervix brachytherapy. A response was obtained from one physicist at each radiotherapy facility in Canada. A total of 32 of the 41 Canadian radiotherapy facilities perform intrauterine brachytherapy. Most (88%) use high-dose-rate brachytherapy. Images used for treatment planning are two-dimensional (2D) X-rays (63%), CT (66%), MRI (13%), and cone beam CT (9%). Patients are moved to another room to obtain images at 66% of the centers. Dose is prescribed to a volume at 28% of centers, and dose-volume histogram information is used in evaluating dose to the organs at risk (47%) and target (31%). Manual optimization was the most common optimization method (81%). A total of 69% of the institutions made significant changes within the past 5 years, and 66% plan major changes within the next 2 years. Intrauterine brachytherapy treatment for cervical cancer is rapidly evolving in Canada, with centers moving toward 3D image-based methods. Often these imaging modalities are not located in the brachytherapy room, so studies on immobilization and verification would be useful. Access to MRI is increasing, but remains low, correlating with a low adoption of volume-based parameters for evaluating target coverage. National treatment guidelines would be useful for centers making the transition from 2D to 3D methods and for encouraging access to MRI.

Novel Intrauterine Brachytherapy Device Allows Precise Targeting of Tissues at Risk While Simultaneously Minimizing Normal Tissue Dose

Novel Intrauterine Brachytherapy Device Allows Precise Targeting of Tissues at Risk While Simultaneously Minimizing Normal Tissue Dose

Optimization of Pulsed Dose Rate Intra-uterine Brachytherapy for Cervix Cancer: A Comparison of Target Volume Doses

Optimization of Pulsed Dose Rate Intra-uterine Brachytherapy for Cervix Cancer: A Comparison of Target Volume Doses

Axillary radiotherapy as adjuvant treatment in sentinel node positive breast cancer patients

Purpose: A phase II trial was designed to evaluate the toxicity and outcome of patients with locally advanced cervix cancer treated with accelerated hyperfractionated radiotherapy (AHFX).Methods and Materials: In this prospective trial, AHFX doses of 1.25 Gy were administered twice daily at least 6 hours apart to a total pelvic dose of 57.5 Gy. A booster dose was then administered via either low-dose rate brachytherapy or external beam therapy to a smaller volume. All patients were accrued and treated at Peter MacCallum Cancer Institute (PMCI) between 1986 until April 1991.Results: Sixty-one eligible patients were enrolled in this protocol; 2 (3.2%) had Stage IIB; 42 (68.9%) had Stage III; 8 (13.1%) had Stage IV and 9 (14.8%) had recurrent cervical cancer. Fifty-two patients (85%) completed the planned external beam without a treatment break. Thirty patients had acute toxicity that required regular medication. One patient died of acute treatment related toxicity. Fifty-five patients received booster therapy: 45 with intrauterine brachytherapy, 6 with interstitial brachtherapy, and 4 with external beam. The median follow-up of surviving patients was 6 years. Overall 5-year survival is 27% and 5-year relapse free survival is 36%. Nineteen patients died with pelvic disease and the actuarial local control rate was 66%. There were 8 severe late complications observed in 7 patients. Seven required surgical intervention (an actuarial rate of 27%). Five patients also required total hip replacement.Conclusions: The local control rate was favorable compared with other series that have used standard fractionation, although overall survival remained similar. The severe late complication rate was high for this protocol and higher than similar protocols reported in the literature.

Image-based intracavitary brachytherapy in the treatment of inoperable uterine cancer: Individual dose specification at specific anatomical sites

Purpose With advances in imaging studies, dose specification for uterine cancer can be defined at specific anatomical sites such as the myometrium or the serosal surface rather than at arbitrary points or milligram-hours. This report presents our experience with image-based brachytherapy for inoperable uterine cancer. Methods and materials Eight patients with organ-confined uterine cancer (2 Stage I GI, 3 Stage I G2, 3 Stage I G3) underwent definitive radiation therapy because of poor medical condition. All the patients underwent a CT or MRI scan of the pelvis before intracavitary application. Based on the size of the uterine cavity, a single-channel intrauterine applicator was selected for a small uterus, and a multiple-channel intrauterine applicator was used for a large uterus. A CT ( n=5) or MRI ( n=3) scan of the pelvis was performed with the applicator in place in addition to orthogonal pelvic films. Individualized dose specification was 75 Gy to the midmyometrium and limited to 50 Gy to the serosal surface of the uterus based on imaging information. Results Four patients with Stage I G1–2 disease had intracavitary brachytherapy alone. Four patients with Stage I G2–3 disease were treated with a combination of external pelvic radiation and intracavitary brachytherapy. Six patients had low-dose-rate brachytherapy, and 2 patients had high-dose-rate brachytherapy. Five patients had single-channel intrauterine brachytherapy, and 3 patients had multiple-channel brachytherapy. Based on the measurements of the uterine wall thickness by the imaging studies, the dose specification was prescribed to 1.5 cm lateral to the central axis of the uterus in 4 patients, 2.0 cm in 3 patients, and 2.5 cm in 1 patient. The medium followup time after radiation treatment was 38 months. Six patients are alive without evidence of disease, and 2 patients died of other causes. All patients had local control without major side effects. Conclusions Image-based brachytherapy based on individualized dose specification at specific anatomical sites can be done easily and provides excellent local control for inoperable uterine cancer.

A phase III randomized study of misonidazole plus radiation vs. radiation alone for cervix cancer

Background and purpose A randomized-controlled study of radical radiotherapy for cervical cancer with or without the hypoxic sensitizer, misonidazole was conducted from 1981 to 1984 to investigate its therapeutic benefit. Patients and methods Seventy-three patients were accrued from the Princess Margaret Hospital, and St John Regional Cancer Centre and randomized to either misonidazole (MISO, n=39) or placebo (P, n=34) in addition to radiotherapy. MISO was given orally each day 4 h prior to external beam radiation treatment (45 Gy to midplane in 20 daily fractions) at a dose of 0.45 g/m 2, as well as during intra-uterine brachytherapy (40 Gy). Results The 10-year overall survival (OS) for the entire group was 46%, and the disease-free survival (DFS) was 39%. The 10-year OS for patients in the MISO arm was 45%, compared to 49% for the P arm ( P=0.89). The corresponding DFS figures were 36 and 43%, respectively, ( P=0.6). Ten patients (14%) developed severe late complications (grade 3 or 4). The 10-year serious late complication rate was 14% for MISO and 12% for P ( P=0.51). Conclusions Misonidazole failed to improve the outcome of patients with cervix cancer treated with radiotherapy.

Definition of vaginal doses in intrauterine high–dose-rate brachytherapy

Purpose The aim of this study was to evaluate dosimetric aspects of high–dose-rate (HDR) intrauterine brachytherapy applications and to discuss a possible definition of vaginal points for dose reporting. Methods and materials HDR brachytherapy was performed using a “Fletcher-like” applicator. Doses to the vaginal mucosa were assessed using 2 sets of points for each ovoid. Fifty treated patients were chosen for the analysis. Repeatability and reproducibility were analyzed. Total doses for the whole treatment at the vaginal points were calculated for each patient. The average dose for both ovoids was determined and the ratio of this dose to the dose at point “A” was calculated. The correlation between delivered doses and vaginal complications was tested statistically. Results Repeatability and reproducibility were found to be less than 1% compared with patient-to-patient variations (> 99%) for all points. The number of fractions and the number of patients in which the middle ovoid point was “representative” were calculated for the lateral and upper surfaces, respectively. The calculated vaginal-average to point “A” dose ratio was found to be 175% and 130% for the 20 and 25 mm ovoids, respectively. A correlation between delivered doses and the rate of complications was not found. Conclusions The proposed method has been validated and allows calculations of vaginal doses. The vaginal-to-point “A” dose ratios allow a fast estimation of the vaginal dose for 20 and 25mm ovoids. The doses delivered to our patients were below vaginal tolerance.

Phase I clinical trial of parenteral hydroxyurea in combination with pelvic and para-aortic external radiation and brachytherapy for patients with advanced squamous cell cancer of the uterine cervix

Purpose : Oral hydroxyurea (HU) is a potent radiation sensitizer, but in vitro studies have suggested that prolonged exposure to HU by way of continuous parenteral infusion would enhance clinical efficacy. The objective of this study was to determine the maximal tolerated dose and identify the toxicities of continuous infusion HU in combination with pelvic and para-aortic external beam radiotherapy (RT) and intrauterine brachytherapy in patients with locally advanced carcinoma of the uterine cervix. Methods : This Phase I study of concomitant RT was designed with an escalating dose schedule of HU administered by continuous infusion. HU was administered parenterally as a continuous infusion, 5 d/wk, during the first 21 days of external radiation, during the final 5 days of external beam RT, followed by another 5-day infusion schedule bracketing the single fraction of brachytherapy. The maximal tolerated dose was defined as the highest dose level at which 3 of 3 or 5 of 6 patients could be treated without dose-limiting toxicity. Results : At dose level 1 (0.25 mg/m 2/min), 0 of 4 patients experienced Grade 4 toxicities and 2 patients experienced Grade 3 hematologic toxicities that were not considered dose-limiting. One of the first 4 patients at level 2 (0.375 mg/m 2/min) had Grade 3 diarrhea, but the 3 subsequent patients tolerated the dose. At level 3 (0.5 mg/m 2/min), 4 of 5 patients failed to complete therapy without a >7-day interruption in HU. Conclusions : The maximal tolerated dose of parenteral HU was 0.375 mg/m 2/min when administered with concomitant RT. The most common toxicities were hematologic. A new trial, incorporating concurrent cisplatin, HU, and RT is planned.

Intra-uterine brachytherapy: educational needs for nurses undertaking direct patient care

Intra-uterine brachytherapy: educational needs for nurses undertaking direct patient care