Background and purpose Vaginal stenosis (VS) after pelvic radiotherapy can impair long-term quality of life. We prospectively assessed adherence and efficacy of VD use as the primary and secondary objectives, respectively. Material and methods Women with gastrointestinal (n=63) and gynecologic (n=46) cancers self-reported use and VD size in monthly diaries for 12 months after radiotherapy. Adherence was measured as actual VD use out of recommended times over 12 months (3×/week × 52 weeks = 156). Results Among 109 participants, aged 28–81 years (median, 58 years), mean percent adherence over 12 months was 42% (95% confidence interval [CI], 36%–48%). Adherence was highest in the first quarter (56%), but fell to 25% by the fourth. Disease type, treatment sequence, and chemotherapy were predictors of adherence (all P<.05). Eighty-two percent maintained pre-RT VD size at 12 months; of 49% with decrease in VD size at 1 month post-RT, 71% returned to pre-RT VD size at 12 months. Disease type, younger age, and increased adherence at 6 months were associated with maintaining or returning to pre-RT size at 12 months (all P≤.05). Conclusions VD use is effective in minimizing VS, but adherence at 12 months was poor. Studies evaluating methods of improving adherence and determining the optimal frequency and duration of use are needed.

646 Background: Pelvic radiotherapy with concurrent 5-fluorouracil based chemotherapy (chemoradiation) is a component of standard therapy for patients with T3/T4 or node-positive rectal cancer. Chemoradiation can be associated with significant acute gastrointestinal toxicity. This study sought to retrospectively compare patient and clinician reports of acute symptoms experienced by rectal cancer patients receiving chemoradiation. Methods: The charts of 199 rectal cancer patients who received chemoradiation from 11/06 to 2/11 were reviewed. Clinicians assessed toxicity weekly using Common Terminology for Clinical Adverse Event (CTCAE) version 3.0. Patient-reported outcomes (PROs) were collected weekly, in clinic, beginning 9/09 using the 7-item Bowel Problems Scale. 197 patients had at least one clinician assessment or PRO and were eligible for this study. Patient and clinician assessments were compared among a subgroup of 65 patients (paired group) who had at least one patient and clinician assessment on the same date using descriptive statistics. Agreement between patient and clinician assessments was evaluated by Cohen’s kappa coefficient. Results: Characteristics were well-balanced between all rectal patients and the paired group, with the exception of the use of intensity modulated radiotherapy (IMRT). IMRT has been used increasingly over time, and IMRT was therefore used in a larger proportion of the paired group versus all patients (77% vs. 51%, respectively). Diarrhea and proctitis were reported more often by patients than clinicians throughout treatment. Uncorrected agreement for diarrhea and proctitis was 82% and 72%, respectively. Corrected for chance, Cohen’s kappa was .64 for diarrhea, indicating moderate agreement, and .22 for proctitis, indicating only slight agreement. Conclusions: Our findings suggest a discrepancy between clinician and patient symptom reports. Further study is warranted to discern potential benefits of including PROs in prospective studies, and to find whether PROs can help clinicians set patient expectations, and/or enhance communication for optimal symptom management.

Purpose Although vaginal stenosis (VS) is a recognized toxicity in women who receive pelvic radiation therapy (RT), the relationship between RT dose and the volume and extent of toxicity has not been analyzed. We modeled this relationship to identify predictors of VS. Methods and Materials We evaluated 54 women, aged 29 to 78 years, who underwent pelvic RT for rectal or anal cancer during 2008 to 2011 and were enrolled in a prospective study evaluating vaginal dilator use. Maximum dilator size was measured before RT (baseline) and 1 month and 12 months after RT. Dilator use was initiated at 1 month. The difference (D) in dilator size before and after RT was recorded. Those with D ≤−1 were classified as having VS (n = 35); those with D ≥0 were classified as having no VS (n = 19 at 1 month). Dose-volume parameters were extracted, and the generalized equivalent uniform dose (gEUD) was used to build a predictive model. Results The mean vaginal doses were 50.0 Gy and 36.8 Gy for anal and rectal cancer patients, respectively. One month after RT, a gEUD model using a wide range of a values suggests that sparing of vaginal volume to a low dose may be important. When gEUD (a = −1) was <35 Gy and the mean vaginal dose was <43 Gy, severe VS was reduced (P = .02). A 1-year analysis suggests increasingly negative D values with increasing mean dose. However, patients with compliance <40% were more likely to have toxicity. Conclusions Vaginal stenosis is influenced by multiple RT dose-volume characteristics. Mean dose and gEUD constraints together may reduce the risk of severe VS.

Acute GI toxicity during definitive CRT for anal cancer was most significant during weeks 4-5, while rectal bleeding improved during treatment. Discrepancies in patient- and clinician-reported symptoms demonstrate the potential for patient-reported outcomes to be useful tools for anal cancer clinical assessments.