Advanced imaging modalities have identified mesorectal nodal metastasis as a risk in locally advanced cervical cancer. Although controversial, recent contouring guidelines for IMRT recommend inclusion of mesorectum in high-risk patients. This study is to evaluate how much rectum and mesorectum receives the prescription dose for conventional 3D conformal RT (3D-CRT) and IMRT. Twenty previously irradiated intact cervical cancer were identified (Stage I: 10, Stage II: 4, Stage III: 6). The planning target volume was constructed by adding 2.0 cm margin to the gross tumor and uterus, 1.5 cm to the vagina, and 0.7 cm to the common, external and internal iliac, obturators and pre-sacral pelvic lymph nodes. The mesorectum was comprised of the portion of the rectum extending from the caudal aspect to where the sigmoid could be first visualized in the axial plane on CT scan. For 3D-CRT planning, a 4-field box was designed with appropriate dosimetric margin and the plan normalized such that 88-93% of the PTV received the prescription dose. For IMRT, a seven-field plan was optimized for conformity only and normalized so that the 100% of the dose matched the same volume covered in the 3D-CRT plan. The beam energy was 15 MV and the prescription dose was 45Gy. Rectum and mesorectum dose-volume histograms were compared between 3D-CRT and IMRT. The mean mesorectal and rectal volumes were 117cm3 (60.6 - 237 cm3) and 71cm3 (33 – 163 cm3) respectively. The mean volume of rectum receiving at least 95% of the prescription was 93.0 % (79.9 – 100%) and 82.2% (44.9 – 99.9%) for 3D-CRT and IMRT, respectively. The mean volume of mesorectum receiving at least 95% of the prescription was 90.7% (78.6 – 99.7%) and 78.8% (48.2 – 99.4%) for 3D-CRT and IMRT, respectively. Larger rectum volumes were observed to have a larger volume covered by prescription dose as a trend with either modality. When treating with either conventional 3D or IMRT, the mean rectal volume receive most of the prescription dose. Therefore, it is likely that inclusion of entire mesorectum within target volume would be tolerated and can be considered for patients with high-risk for mesorectal nodal metastasis.

The Accreditation Council For Graduate Medical Education (ACGME) requires that radiation oncology residents complete a minimum number of cases by the time of completion and provides a web-based case log system in which residents may enter each case to document their participation. Since 2009, our department has used an electronic whiteboard (WB) built with Oracle Apex to track all treatment courses through planning while automatically assigning each case to the appropriate resident. Ideally, the numbers of ACGME logged cases should match the WB log. Because of the significance of case logs to both the individual residents and to the department for all procedurally based fields, we investigated the observed discrepancy and trends of self-reported and automatic case logs over time through all years of training (PGY2-5). Logged resident data was retrieved from the ACGME and WB logs dating from the implementation of WB in 2009. A total of 25 residents’ ACGME and WB logs were reviewed and analyzed for each academic year running from July 1st to June 30th. Only residents with completed academic years were included. After the data were gathered, trends and differences among logs were observed per resident per year of training and a ratio was calculated between cases logged in the ACGME and cases assigned per WB. Temporal trends were observed for residents with multiple logged academic years. There was a total of 10,969 cases in the ACGME log and 9,935 in the WB. Of 25 residents, 18 were eligible for full analysis with more than 1 complete year of logged cases. An improvement in the accuracy of logging was observed from PGY2 to PGY3 in 8/15 (53.3%). A similar improvement was observed in 8/14 (53.3%) from PGY3 to PGY4 and 7/14 (50%) from PGY4 to PGY5. Analyzing the residents' results in aggregate, though, more accurate logging was seen among PGY-2 residents (average ratio of 1.09) in comparison to PGY3 (1.36). Other observations noted was that of all the residents, the PGY2s showed higher rates of under-logging cases (9/17: 52.94%), and PGY3s showed the highest rate in over-logging cases (12/16: 75%). The number of cases logged was noted to decrease as academic level increased. A trend of improved accuracy in logging cases was observed as residents progressed through training, even while the total number of annual cases decreased. Among the possibilities that may explain some of the discrepancies found among logs were resident failure to log all cases, not logging the simulation date as the date of procedure in the ACGME log, inaccurate resident assignment within the WB especially when on-call, and no WB logging of some cases. Further investigation is ongoing.

Conventional radiation fields for gynecologic malignancies include the primary tumor and regional lymph nodes in the pelvis. However, the mesorectum is not routinely assessed and usually is avoided to limit treatment related toxicities. There is a previous case report about mesorectal lymph node metastases (MRNM) in gynecologic cancers, but to the best of our knowledge there is no reported data evaluating the incidence of MRNM in this population. We would like to report our initial findings on MRNM incidence in cervical and vaginal cancer. A total of 31 patients sequentially evaluated for radiotherapy of cervical or vaginal cancer within the last year were reviewed. Three diagnostic radiologists retrospectively assessed all available pre-treatment imaging for positive nodal involvement in the pelvis, including the mesorectum. Pelvic nodal metastasis was defined as ≥ 1 cm, MRNM as ≥ 0.5 cm for CT and MRI scans. PET / CT scans generally were considered positive with SUV max > 2.5. The relationship of MRNM incidence with primary site, FIGO stage, other lymphatic involvement, and histology were evaluated. Of the 31 patients, 25 cervical (Stage IB2: 5; Stage II: 8; Stage III: 10; Stage IV: 2) and 6 vaginal (Stage I: 1; Stage II: 4; Stage III: 1) cases were evaluated. Eighteen pre-treatment PET/CT, 15 CT and 5 MRI scans were reviewed. Nineteen (61%) patients had positive pelvic nodal metastasis. Four of the 31 patients were positive for MRNM, which constitutes 12.9% of all the reviewed patients and 21% of patients with other pelvic nodal involvement. Of the patients with MRNM, two had cervical cancer (both stage III) and two had vaginal cancer (one stage II and one stage III). All patients with MRNM had squamous histology and had presence of pelvic node involvement. The incidence of MRNM was 12.9% of all reviewed patients and 21.0% of all patients with pelvic lymphatic involvement. More advanced disease and pelvic lymph node involvement are associated with MRNM. Further investigation is ongoing.