D. D'Souza

Adjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation for advanced endometrial cancer

OBJECTIVEnTo evaluate recurrence and survival associated with adjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation for advanced endometrial cancer.nnnMETHODnThis is a prospective cohort study of women with Stage III and IV endometrial cancer treated at a single institution between April 2002 and July 2006. Adjuvant therapy consisted of 4 cycles of intravenous paclitaxel (175 mg/m(2)) and carboplatin (350 mg/m(2)) every 3 weeks, followed by external beam radiotherapy (RT) to the pelvis (45 Gy), then another 2 cycles of chemotherapy. Para-aortic RT and/or HDR vault brachytherapy were added at the discretion of the treating physician. Toxicity of this protocol was previously reported. Primary endpoints for this study were disease-free and overall survival rates.nnnRESULTSnForty-three patients with a median age of 64 years (46-83 years) were evaluated. The majority had Stage IIIC disease (63%), and the most common histology was serous carcinoma (49%). Six cycles of combination chemotherapy were completed in 81%, and all patients completed pelvic RT. Median follow-up was 30 months (9-71 months). Twenty-one patients (49%) recurred at a median of 17 months (7-62 months). There were only 3 local recurrences, including 2 in the pelvis and 1 in the vagina/vulva. Median disease-free survival (DFS) was 50 months and median overall survival (OS) has not been reached. Three year DFS and OS rates were 53% and 68%, respectively.nnnCONCLUSIONnAdjuvant carboplatin and paclitaxel chemotherapy interposed with involved field radiation is associated with a low rate of local recurrence and favorable survival for advanced endometrial cancer.

Optimization of high-dose-rate cervix brachytherapy applicator placement: The benefits of intraoperative ultrasound guidance

PURPOSEnTo promote efficient workflow for image-guided high-dose-rate (HDR) brachytherapy (BT) for cervix cancer by implementing intraoperative ultrasound (US) guidance for placement and optimization of intrauterine applicators. We sought to establish this as part of routine radiation oncology practice without radiology consultation.nnnMETHODS AND MATERIALSnThirty-five consecutive insertions were performed in 21 women between July 2006 and March 2007. Cervical dilation, tandem selection and insertion were guided by transabdominal US. Final tandem position following vaginal applicator insertion was also confirmed by US. Computed tomography (CT) imaging was used for treatment planning and to assess perforation and applicator suitability for each patient anatomy.nnnRESULTSnIntrauterine tandem insertion was successfully guided by US in the majority of procedures (34/35). CT imaging confirmed accurate placement within the uterine canal in each case, compared with a historic institutional perforation rate of 10%. Visualizing patient anatomy during insertion altered the selection of tandem length and angle in 49% of cases, resulting in improved applicator matching to anatomy. Average insertion time significantly decreased from 34 to 26 minutes (p=0.01). Requests for assistance from gynecologic surgical oncology declined from 38% to 5.7% of procedures.nnnCONCLUSIONSnIntraoperative US guidance for cervix BT has been successfully implemented with staff and equipment from radiation oncology. Using US during every insertion has led to improved applicator selection and placement while decreasing procedure time and reducing out of department consultations. These changes have eliminated repeat insertions due to unfavorable applicator placement (as revealed on postoperative CT), thus improving department efficiency and quality of patient care.

A Phase II Trial of Arc-Based Hypofractionated Intensity-Modulated Radiotherapy in Localized Prostate Cancer

PURPOSEnTo evaluate acute and late genitourinary (GU) and gastrointestinal (GI) toxicity and biochemical control of hypofractionated, image-guided (fiducial markers or ultrasound guidance), simplified intensity-modulated arc therapy for localized prostate cancer.nnnMETHODS AND MATERIALSnThis Phase II prospective clinical trial for T1a-2cNXM0 prostate cancer enrolled 66 patients who received 63.2 Gy in 20 fractions over 4 weeks. Fiducial markers were used for image guidance in 30 patients and daily ultrasound for the remainder. Toxicity was scored according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.nnnRESULTSnMedian follow-up was 36 months. Acute Phase Grade 2 and 3 toxicity was 34% and 9% for GU vs. 25% and 10% for GI symptoms. One Grade 4 acute GI toxicity occurred in a patient with unrecognized Crohns disease. Late Grade 2 and 3 toxicity for GU was 14% and 5%, and GI toxicity was 25% and 3%. One late GI Grade 4 toxicity was observed in a patient with significant comorbidities (anticoagulation, vascular disease). Acute GI toxicity ≥ Grade 2 was shown to be a predictor for late toxicity Grade ≥ 2 (p < 0.001). The biochemical disease-free survival at 3 years was 95%.nnnCONCLUSIONSnHypofractionated simplified intensity-modulated arc therapy radiotherapy given as 63.2 Gy in 20 fractions demonstrated promising biochemical control rates; however, higher rates of acute Grade 3 GU and GI toxicity and higher late Grade 2 GU and GI toxicity were noted. Ongoing randomized controlled trials should ultimately clarify issues regarding patient selection and the true rate of severe toxicity that can be directly attributed to hypofractionated radiotherapy.

Evaluating the Impact of a Canadian National Anatomy and Radiology Contouring Boot Camp for Radiation Oncology Residents

BACKGROUNDnRadiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course (boot camp) designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach.nnnMETHODSnThe anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing.nnnRESULTSnTwenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, P<.001). Across all contoured structures, there was a 0.20 median improvement in students average Dice score (P<.001). For individual structures, significant Dice improvements occurred in 10 structures. Residents self-reported an improved ability to contour OARs and interpret radiographs in all anatomic sites, 92% of students found the MDT format effective for their learning, and 93% found the boot camp more effective than educational sessions at their own institutions. All of the residents (100%) would recommend this course to others.nnnCONCLUSIONSnThe ARC boot camp is an effective intervention for improving radiation oncology residents knowledge and understanding of anatomy and radiology in addition to enhancing their confidence and accuracy in contouring.

Three-dimensional-guided perineal-based interstitial brachytherapy in cervical cancer: A systematic review of technique, local control and toxicities

OBJECTIVEnTo evaluate local control and toxicities of perineal-based interstitial brachytherapy (P-ISBT) in cervical cancers treated with three-dimensional (3D) image-based planning through a systematic review. The secondary objective of this review is to summarize the implant and dosimetric techniques in 3D P-ISBT.nnnMETHODSnSystematic review of the literature using the PRISMA guideline was conducted through a search of Medline, EMBASE and Cochrane databases. This search resulted in 19 relevant manuscripts. Selected studies evaluated the role of perineal ISBT in cervical tumours treated using 3D planning. Eleven of nineteen manuscripts contained sufficient information for LC and toxicity calculations. Data were extracted by at least two investigators.nnnRESULTSnA total of 672 cervical cancer patients were treated with P-ISBT and planned with 3D image-based planning. Clinical outcomes could be identified for 392 patients and 60% were staged IIIB or higher. Most patients received 45-50.4Gy EBRT to the pelvis followed by a P-ISBT boost with a range of dose between 28 and 48Gy EQD2Gy. Overall LC was 79% (310/392) with a median follow-up ranging from 14 to 55months. Almost half of the patients (48%) had a median follow-up ≥35months. Patients treated to a lower tumour EQD2Gy total dose had inferior LC. Procedure-related complications were rare (7 infections and 7 episodes of bleeding) and limited. Combined late gastro-intestinal, genitourinary and vaginal grade 3 and 4 toxicity was 12.1%.nnnCONCLUSIONnPromising LC rates were found in patients with cervical cancers treated with perineal ISBT with 3D image-based planning. In this systematic review, 60% had stage IIIB disease or higher and yet a LC rate of 79% was found. LC seemed to correlate with the dose delivered to the tumour, while toxicity rates were similar to other cervical cancer series using 3D image-based brachytherapy. Perineal ISBT with 3D planning seems to be an effective and safe treatment for large advanced cervical tumours and may be a reasonable alternative to the increasingly more standard and modern intracavitary/interstitial (IC/IS) approaches such as the Vienna applicator.

Radiation Therapy Quality of Care Indicators for Locally Advanced Cervical Cancer: A Consensus Guideline

PURPOSEnRadiation therapy plays an important curative role for patients with locally advanced cervical cancer (LACC). There are no standards to define best practice. The purpose of this study was to develop a suite of radiation therapy key quality-of-care indicators (KQIs) for the curative management of LACC based on expert consensus.nnnMETHODS AND MATERIALSnA modified Delphi method was used after identifying candidate KQIs. Round 1 involved surveying all Canadian gynecology radiation oncologists. The current and anticipated future (5 years) importance and current achievability of each KQI was ranked. Round 2 consisted of a facilitated face-to-face meeting with a smaller expert panel to discuss, revise, and develop consensus on the KQIs.nnnRESULTSnThe literature review identified 83 candidate KQIs. Survey response was 71%. Round 2 yielded a final suite of 40 KQIs in the following categories: pretreatment assessment, external beam radiation therapy, brachytherapy, follow-up, and expertise/workload. A prominent theme was the importance of having KQIs to measure the current state, evolution, and future uptake of magnetic resonance-guided brachytherapy.nnnCONCLUSIONSnTo our knowledge, this is the first study establishing radiation therapy KQIs in LACC based on expert consensus. These KQIs should be used to guide programmatic direction and resource allocation to assure consistent and optimal patient care.

Assessment and improvement of radiation oncology trainee contouring ability utilizing consensus-based penalty metrics

The objective of this study was to develop and assess the feasibility of utilizing consensus‐based penalty metrics for the purpose of critical structure and organ at risk (OAR) contouring quality assurance and improvement.

The Utility of Penile Bulb Contouring to Localise the Prostate Apex as Compared to Urethrography

PURPOSEnHigh-precision radiotherapy relies on accurate anatomic localisation. Urethrography is often used to localise the prostatic apex. However, urethrography is an invasive localisation procedure and may introduce a systemic error. The penile bulb (PB) is contoured to minimise the risk of erectile dysfunction. The purpose of this study is to assess the value of using the PB, as an alternative to urethrography, to localise the prostate.nnnMETHODS AND MATERIALSnThe PB was localised on 10 patients treated with simplified intensity-modulated arc radiotherapy at computed tomography simulation during treatment weeks 1 and 7. All patients underwent placement of fiducial markers. Urethrography was used only at simulation. Distances from the superior PB contour to the inferior prostate contour, the apex fiducial marker, and to the inferior prostate contour were obtained as well. The PB was contoured by two observers independently. Agreement coefficients and analysis of variance were used to assess reliability between rates and consistency of measurements over time.nnnRESULTSnThe PB-apex distance was greater than or equal to the urethrogram-apex distance in 24/30 (80%) measurements, and the median difference was 3xa0mm and was consistent between raters. The greatest variation in PB-IM distance between weeks was 6xa0mm, the median was 3xa0mm, and the agreements of measurements between weeks for raters 1 and 2 were 0.79 and 0.69, respectively. These differences were not statistically different and were consistent with the computed tomography slice thickness.nnnCONCLUSIONSnThe PB can be used to identify the prostate apex and can be reliably contoured between observers. Measurements are consistent between patients and through the duration of treatment. The PB distance measurements support studies indicating that urethrography causes a shift of the prostate superiorly. The distance from the PB to prostate apex remains stable during treatment for individual patients but varies between patients.

Characterizing the impact of adaptive planning on image-guided perineal interstitial brachytherapy for gynecologic malignancies

PURPOSEnTo determine the dosimetric impact of organ and implant motion/deformation in the context of adaptive planning in image-guided gynecologic brachytherapy using a 3-fraction transperineal approach.nnnMETHODS AND MATERIALSnTwenty-six patients were analyzed. Each patient was treated with three fractions given over a 24-h period using a single insertion. A planning CT scan (±MRI) was acquired before the first fraction. A verification scan was taken within 1 h following the second fraction. A single plan was delivered for Fractions 1 and 2 with an adaptive plan delivered for Fraction 3. Two evaluation frameworks were established. Framework 1 investigated the effects of motion/deformation from both implant and organs. Framework 2 investigated the impact of implant motion/deformation alone. Differences in high-risk clinical target volume (HRCTV) D90%, V100%, and bladder/rectum D2cc were assessed.nnnRESULTSnFrom implant to verification, the HRCTV D90% and V100% decreased significantly (5.0%, p < 0.01; 3.1%, p < 0.01) and rectal D2cc was significantly higher (12.2%, pxa0= 0.02). Adaptive planning recouped these changes. Implant changes resulted in a reduction in HRCTV dose and coverage, but no significant effect was seen in the bladder or rectum.nnnCONCLUSIONSnAdaptive planning represents an important aspect of perineal-based interstitial image-guided brachytherapy given in three fractions; its absence would result in plan degradation.

Oral Scientific SessionRadiation Therapy Quality of Care Indicators for Locally Advanced Cervical Cancer: A Consensus Guideline

Purpose: Radiotherapy plays an important curative role for patients with locally advanced cervical cancer (LACC). There are no standards to define best practice. The purpose of this study was to develop a suite of radiotherapy key quality of care indicators (KQIs) for the curative management of LACC based on expert consensus. Methods: A modified Delphi method was used after identifying candidate KQIs. Round 1 involved surveying all Canadian GYN radiation oncologists. The current and anticipated future (5 years) importance and current achievability of each KQI was ranked. Round 2 consisted of a facilitated face-to-face meeting with a smaller expert panel to discuss, revise and develop consensus on the KQIs. Results: The literature review identified 83 candidate KQIs. Survey response was 71%. Round 2 yielded a final suite of 40 KQIs in the following categories: Pre-treatment assessment, External beam radiotherapy, Brachytherapy, Follow-up and Expertise/Workload. A prominent theme was the importance of having KQIs to measure the current state, evolution and future uptake of MRguided brachytherapy. Conclusions: To our knowledge this is the first study establishing radiotherapy KQIs in LACC based on expert consensus. These KQIs should be used to guide programmatic direction and resource allocation to assure consistent and optimal patient care. AC C EP TE D M AN U SC R IP T ACCEPTED MANUSCRIPT