Radiation therapy oncology group gynecologic oncology working group: comprehensive results

Improvement of treatment plan quality with modified fixed field volumetric modulated arc therapy in cervical cancer

PURPOSE

This study aims to introduce modified fixed field volumetric modulated arc therapy (MF-VMAT) which manually opened the field size by fixing the jaws and comparing it to the typical planning technique, auto field volumetric modulated arc therapy (AF-VMAT) in cervical cancer treatment planning.

METHODS AND MATERIALS

Previously treated twenty-eight cervical cancer plans were retrospectively randomly selected and replanned in this study using two different planning techniques: AF-VMAT and MF-VMAT, resulting in a total of fifty-six treatment plans. In this study, we compared both planning techniques in three parts: (1) Organ at Risk (OARs) and whole-body dose, (2) Treatment plan efficiency, and (3) Treatment plan accuracy.

RESULTS

For OARs dose, bowel bag (p-value = 0.001), rectum (p-value = 0.002), and left femoral head (p-value = 0.001) and whole-body (p-value = 0.000) received a statistically significant dose reduction when using the MF-VMAT plan. Regarding plan efficiency, MF-VMAT exhibited a statistically significant increase in both number of monitor units (MUs) and control points (p-values = 0.000), while beam-on time, maximum leaf travel, average maximum leaf travel, and maximum leaf travel per gantry rotation were statistically significant decreased (p-values = 0.000). In terms of plan accuracy, the average gamma passing rate was higher in the MF-VMAT plan for both absolute dose (AD) (p-value = 0.001, 0.004) and relative dose (RD) (p-value = 0.000, 0.000) for 3%/3 and 3%/2 mm gamma criteria, respectively.

CONCLUSION

The MF-VMAT planning technique significantly reduces OAR doses and decreases the spread of low doses to normal tissues in cervical cancer patients. Additionally, this planning approach demonstrates efficient plans with lower beam-on time and reduced maximum leaf travel. Furthermore, it indicates higher plan accuracy through an increase in the average gamma passing rate compared to the AF-VMAT plan. Consequently, MF-VMAT offers an effective treatment planning technique for cervical cancer patients.

Half-beam volumetric-modulated arc therapy in adjuvant radiotherapy for gynecological cancers

PURPOSE

The purpose of this study is to introduce half-beam volumetric-modulated arc therapy (HVMAT), an innovative treatment planning technique from our work, for reducing dose to the organs at risk (OAR) during adjuvant radiotherapy for gynecological cancers.

METHODS AND MATERIALS

Seventy-two treatment plans of 36 patients with gynecological cancers receiving adjuvant radiotherapy were assessed. Among them, 36 plans were designed using HVMAT and paired with the other 36 traditional volumetric-modulated arc therapy (VMAT) plans for each patient. The main uniqueness of the HVMAT designs was that it consisted of two opposite-shielded half-beam fields rotated inversely in two coplanar arcs, collocating with the specially-devised avoidance structures to enhance the control of the OAR doses. The dose distributions in HVMAT and VMAT were evaluated and compared using the random effects model.

RESULTS

The ratios of OAR doses in HVMAT compared with VMAT showed a comprehensive OAR dose reduction when using HVMAT (V_20Gy : bladder, 0.92; rectum, 0.95; V_30Gy : bowel, 0.91; femoral heads, 0.66), except for the ilium (V_30Gy : 1.12). The overall mean difference for each OAR across V_40Gy , V_30Gy , V_20Gy , and bowel V_15Gy was statistically significant (almost all p < 0.001). In addition, HVMAT promoted a better conformity index, homogeneity index, D_2% , and V_107% of the planning target volume (all p < 0.001).

CONCLUSIONS

HVMAT is capable of generating deep double-concave dose distributions with the advantage of reducing dose to several OARs simultaneously. It is highly recommended for pelvic irradiation, especially for treating gynecological cancers in adjuvant radiotherapy.

Long-term outcomes of individualized management after sentinel lymph-node biopsy for vulvar cancer

BACKGROUND

The management for patients with vulvar cancer after sentinel lymph-node biopsy (SLNB) remains controversial. The aim of this study was to investigate the long-term outcomes of individualized management after SLNB for early stage vulvar cancer.

METHODS

The medical records of patients with vulvar cancer treated by surgery involving SLNB between 2004 and 2019 were retrospectively reviewed. During this period, the inguinofemoral lymphadenectomy (IL) were performed with individualized strategy, while the postoperative intensity-modulated radiotherapy was planned with a consistent policy.

RESULTS

We identified 138 patients with at least one sentinel node detected, of whom 64 underwent further IL while 74 had SLNB only. Nodal metastases (pN+) were confirmed in 22 patients with IL and 16 without. Radiotherapy was scheduled with the dose of 60-70 Gy for all pN+ patients and finally completed in 15 with IL and 15 without. The median follow-up time was 56 months (6-156 months). Recurrence was observed in 24 patients, of whom 10 were pN- at primary treatment. The 3-year overall survival (OS) was 97.2, 95.2, 68.3, and 71.8%; 3-year disease-free survival (DFS) was 94.5, 91.4, 60.2, and 59.2%, respectively, for patients with pN- and IL, pN- and SLNB, pN+ and IL, and pN+ and SLNB. Neither OS nor DFS showed significant difference between SLNB and IL in pN- (P = 0.564 for OS, P = 0.423 for DFS), or pN + patients (P = 0.920 for OS, P = 0.862 for DFS).

CONCLUSIONS

With appropriate adjuvant radiotherapy, SLNB alone provided similar long-term survival compared with IL for both patients with and without sentinel node metastasis.

Long-term outcomes of concomitant cisplatin plus radiotherapy versus radiotherapy alone in patients with stage IIIB squamous cervical cancer: A randomized controlled trial

OBJECTIVE

The present analysis determined the disease free survival (DFS) and overall survival (OS) at up to 14 years of follow-up in women who participated in our previous phase 3 randomized controlled clinical trial, in which women with stage IIIB squamous cervical cancer received either cisplatin plus RT or RT alone for treatment. The first study showed that the addition of cisplatin to RT offered a significant benefit in DFS, but not in OS.

METHODS

The present analysis examined DFS and OS in 146 women from the original cohort (72 patients in the CRT arm and 74 patients in the RT-only arm) with follow-up of up to 14 years.

RESULTS

Longer term follow-up showed that treatment with CRT offers a significant benefit in DFS and OS compared with treatment with RT only. Patients who received RT alone had significantly worse OS (HR, 1.88; 95% CI, 1.09-3.24) and DFS (HR, 1.82; 95% CI, 1.07-3.08) compared with patients who received CRT. The multivariate analyses also showed that the patients with baseline Karnofsky performance status (KPS) <90% showed significantly worse OS (HR, 3.11; 95% CI, 1.78-5.43), as did those with hemoglobin <10 mg/dL (HR, 4.32; 95% CI, 2.23-8.36). Patients with baseline KPS < 90% showed significantly worse DFS (HR, 2.83; 95% CI, 1.60-5.01), as did those with hemoglobin <10 mg/dL (HR, 4.16; 95% CI, 2.17-7.95).

CONCLUSIONS

For stage IIIB cervical cancer, treatment with CRT offers a significant benefit in DFS and OS compared with treatment with RT only.

Overexpression of the immediate early response 5 gene increases the radiosensitivity of HeLa cells

The effects of the immediate early response 5 (IER5) gene on the sensitivity of HeLa cells to radiation remain unclear. In the present study, stably transfected HeLa cells resulting in the knockdown or overexpression of IER5 were investigated. In addition, xenografts of normal, IER5-silenced and -overexpressed HeLa cells were injected into nude mice and examined. The results demonstrated that the radiosensitivity of the IER5-overexpressed HeLa cells was significantly increased compared with that of the normal and IER5-silenced cells. The upregulation of IER5 effectively decreased cell proliferation and IER5 silencing promoted cell proliferation compared with that in the normal HeLa cells. Following irradiation of the cells with IER5 knockdown, cell cycle was arrested at the G₂/M phase and an increase in the proportion of S phase cells was observed. By contrast, the overexpression of IER5 led to an increase in the proportion of G₁ phase cells. Furthermore, the upregulation of IER5 inhibited tumor growth in vivo. The present findings demonstrate that the IER5 gene affects the radiosensitivity of HeLa cells and serves an important role in cell proliferation, suggesting that this gene may be a potential radiotherapeutic target in cervical cancer.

The role of para-aortic nodal irradiation in cervical cancer

The current standard of care for locally advanced cervical cancer is whole pelvis and para-aortic radiation when indicated, delivered concomitantly with chemotherapy and brachytherapy. Para-aortic node involvement is a predictor of survival in locally advanced disease but presence of metastases is difficult to determine because the currently available imaging methods lack enough sensitivity to be able to detect accurately para-aortic metastases when surgical staging is not feasible. The objective of this review is to describe the current status of para-aortic lymph node irradiation in locally advanced cervical cancer. It includes analysis of the diagnostic imaging and surgical approaches for assessment of para-aortic lymph node dissemination, together with indications for radiotherapy and radiotherapeutic techniques.

Scoping Review and Meta-analysis of Hyperbaric Oxygen Therapy for Radiation-Induced Hemorrhagic Cystitis

PURPOSE OF REVIEW

To critically review and summarize existing literature assessing the effectiveness of hyperbaric oxygen therapy (HBOT) for the treatment of radiation-induced urologic injury.

RECENT FINDINGS

Though 5 of the included 13 studies were published in the last 2-3 years, the only randomized controlled study was performed in 2012. Recent studies have confirmed the safety and efficacy of HBOT as well as identified risk factors for success vs. failure of HBOT for hemorrhagic radiation cystitis (HRC). Of the 602 patients that received HBOT for HRC, 84% had a partial or complete resolution. In the 7 studies that utilized RTOG/EORTC, 75% of patients saw an improvement in hematuria of at least one grade (out of possible 5 total). Of the 499 patients with documented follow-up, 14% experienced recurrence, with a median time to recurrence of 10 months (6 to 16.5 months).