Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience.

PURPOSE: The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution. METHODS AND MATERIALS: Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method. RESULTS: Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm3 (IQR 25-48 cm3). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula. CONCLUSIONS: Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

Regional Control and Chemoradiotherapy Dose Response for Clinically Involved Lymph Nodes in Patients with Locally Advanced Endometrial Cancers Who are Not Candidates for Upfront Surgical Staging Extrafascial Hysterectomy.

AIMS: There are limited data in endometrial cancer for nodal control and appropriate treatment volume for non-surgically resected nodes treated with chemoradiotherapy (CRT) for patients who are not candidates for upfront extrafascial hysterectomy. MATERIALS AND METHODS: Patients (n = 105) with clinical stage ≥ II endometrial cancer who were not candidates for upfront extrafascial hysterectomy treated with preoperative CRT were retrospectively reviewed. CRT included pelvic nodes to the common iliac for node-negative disease and para-aortic nodes to the renal vessel for any node-positive disease. Involved nodes most commonly received a boost of 55 Gy in 25 fractions ± additional 4-6 Gy sequential boost for nodes >2 cm. RESULTS: Of the included 95 patients, 55 patients were node positive, with a total of 300 positive nodes. At a median follow-up of 25 months (interquartile range 9-46), the 3-year regional control was 91%. The 3-year involved nodal control rate was 96%. Involved nodal control was significantly higher in type I histology, nodes <2 cm and by radiation dose (75% for <55 Gy, 98% for 55 Gy in 25 fractions and 89% for >55 Gy, P = 0.03). The 3-year para-aortic failure rate for node negative patients treated with pelvis-only CRT was significantly higher with positron emission tomography/computed tomography (PET/CT) versus computed tomography (CT)-based staging (0% versus 20%). CONCLUSION: This is the largest study examining regional control rates of involved lymph nodes with CRT for patients who were not candidates for upfront extrafascial hysterectomy. Nodal failure was low following CRT and dose ≥55 Gy in 25 fractions seems to be adequate for involved nodes.

Is the risk of substantial LVSI in stage I endometrial cancer similar to PORTEC in the North American population? - A single-institution study.

OBJECTIVES: A pooled analysis of PORTEC-1 & 2 identified substantial lymphovascular space invasion (LVSI) in 4.8% of patients, which predicted for pelvic recurrence, distant metastasis, and overall survival. Our institution implemented the PORTEC three-tier system of LVSI reporting (absent, focal, or substantial). We aimed to quantify the incidence of substantial LVSI in a North American population and to correlate extent of LVSI with lymph node (LN) involvement. METHODS: A retrospective review was conducted on patients with clinically uterine-confined, endometrioid type endometrial cancer who underwent surgical staging and were found to have pT1a-b disease. Binary logistic regression was used to assess predictors of LN involvement (defined as ITC, micrometastases, or macrometastases). RESULTS: In total, 438 patients with pT1a-b disease were identified. In the overall cohort and in the subset meeting PORTEC-1 inclusion criteria (n = 195), no LVSI was present in 67.4% and 50.8%; focal LVSI was present in 16.7% and 24.1%; and substantial LVSI was present in 16.0% and 25.1%, respectively. Among patients who underwent surgical LN assessment (79.2%, n = 347), LNs were involved in 3.3% without LVSI, 7.5% with focal LVSI (OR 2.4), and 15.2% with substantial LVSI (OR 5.3) (p = .005), with a similar trend in the PORTEC-1 cohort. Extent of LVSI correlated with disease burden in LN metastases. CONCLUSION: Our incidence of substantial LVSI was three to five times higher than reported by PORTEC and correlated with LN involvement. This questions the reproducibility of the three-tier LVSI reporting system and emphasizes the need for multi-institutional data outside PORTEC for confirmation of our findings.

Human papillomavirus infection mediates response and outcome of vulvar squamous cell carcinomas treated with radiation therapy.

PURPOSE: Human papillomavirus (HPV) is implicated as a causative factor in vulvar squamous cell carcinoma (VSCC). This study evaluates if p16-positivity, a surrogate for HPV, predicts for better response rates to chemoradiation therapy and survival. MATERIALS AND METHODS: We conducted a retrospective chart review of women treated with neoadjuvant or definitive chemoradiation (CRT) therapy from 2000 to 2016 for VSCC. p16 stain-positivity was defined as diffuse strong "block" immunoreactivity within invasive tumor. RESULTS: Seventy-three women with median follow-up of 13.4 months were analyzed. Thirty-three (45.2%) had p16+ tumors. Median age was 73 years (range: 37-89); with p16+ tumors, the median age was 60 years vs 73 years for women with p16- tumors (p < 0.001). The distribution of tumor size and stage by p16-status were similar. The complete clinical response (cCR) rate for p16+ tumors was 63.6% vs 35.0% for p16- tumors (p = 0.014). The pathologic complete response (pCR) rate for women treated neoadjuvantly was 53.8% vs 31.4% for p16+ vs p16-, respectively (p = 0.067). The combined complete response (cCR orpCR [CCR]) rate was 63.6% for p16+ and 30.0% for p16- (p = 0.004). Two-year vulvar control (VC) for women with p16+ tumors was 75.5% vs. 49.5% for p16- (p = 0.008). In women with p16+ tumors who achieved CCR, 2-year VC was 92.3% vs 52.1% for CIR (p = 0.009). For p16- tumors, 2-year VC was 67.3% vs 41.1% for CCR and CIR (p = 0.072). No woman with a p16+ tumor developed distant metastases vs. 7 with p16- tumor (p = 0.013). OS was not statistically different between p16+ cohorts, but was improved for p16- patients with CR vs CIR, 72.9% vs 18.8% (p = 0.026). CONCLUSIONS: p16-positive tumors appear to have better clinical and pathologic response rates and clinical outcomes.