The role of interstitial brachytherapy in the management of primary radiation therapy for uterine cervical cancer

Design approach and benefits of the 3D-printed vaginal individualized applicator (VIA)

PURPOSE

Interstitial gynecologic brachytherapy necessitates precise needle placement, requiring time and expertise. We aimed to simplify interstitial procedures and facilitate optimal needle distribution with individualized vaginal templates to guide interstitial needles.

MATERIALS/METHODS

We developed the 3D-printed vaginal individualized applicator (VIA), a cylindrical template containing individualized internal channels that guide interstitial needles to cover the tumor extent. Eight patients underwent VIA only interstitial implants (VIA only), and five intact cervical cases were treated using tandem and customized VIA (VIA + T). Procedure length, number of needles utilized and dosimetric measures were evaluated.

RESULTS

VIA was successfully designed and used clinically for 24 procedures (8 VIA only, 16 VIA + T). Average procedure needle insertion time reduced from 80.9 min for traditional interstitial to 42.9 min for VIA only, approximately 47% shorter with a similar mean high risk CTV volume (28.3 cc VIA only vs. 32.4 cc) and excellent dosimetry with average CTV V100% (94.3% and 94.4%). VIA + T was particularly useful in patients with small vaginal canals and large tumor size. For the five VIA + T patients average tumor size was 68.0cc (range 26.6-143.5 cc). VIA + T procedures were approximately 20% shorter than hybrid procedures with other applicators with mean length of 20.1 min and an average of 6.8 needles (range 3-12).

CONCLUSION

Our novel 3D-printed VIA facilitates gynecologic interstitial brachytherapy by simplifying needle placement, reducing procedure time, and maintaining excellent dosimetry. VIA can be customized for various clinical scenarios, particularly beneficial for large tumors or small vaginal canals.

Retrospective analysis of local recurrence pattern by computed tomography image-guided intracavitary and interstitial brachytherapy for locally advanced cervical cancer in a single Japanese institution

PURPOSE

The purpose of this study was to investigate the treatment results with focus on local control (LC) by computed tomography (CT)-guided intracavity brachytherapy and interstitial brachytherapy (ICBT/ISBT) for locally advanced cervical cancer (LACC).

METHODS AND MATERIALS

Patients with LACC undergoing ICBT/ISBT at least once in our institution between January 2017 and June 2019 were analyzed retrospectively. The primary endpoint was local control (LC), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and late toxicities. Differences between patient subgroups for prognostic factors in LC, PFS, and OS were analyzed using the log-rank test. The recurrence patterns of LC were also investigated.

RESULTS

Forty-four patients were included in the present study. The median high-risk clinical target volume (HR-CTV) at the initial brachytherapy was 48.2 cc. The median total dose of HR-CTV D90 (EQD2) was 70.7 Gy. The median followup period was 39.4 months. The 3-year LC, PFS and OS rates in all patients were 88.2%, 56.6%, and 65.4% (95% CI 50.3-78.0%), respectively. Corpus invasion and large HR-CTV (70 cc or more) were significant prognostic factors in LC, PFS, and OS. Marginal recurrences at the fundus of the uterus were detected in 3 of 5 patients in whom local recurrence was observed. Late toxicities of Grade 3 or higher were detected in 3 patients (6.8%).

CONCLUSIONS

Favorable LC was achieved by performing CT-guided ICBT/ISBT for LACC. The brachytherapy strategy for patients with corpus invasion or large HR-CTV may need to be reconsidered.

The MRI-guided two adaptive brachytherapy fractions versus one adaptive brachytherapy fraction in one application for the cervical cancer: a retrospective study

PURPOSE

This study retrospectively compared the clinical and toxicity outcomes for the cervical cancer of the MRI-guided two adaptive brachytherapy (IGABT) fractions versus one IGABT fraction in one application.

METHODS

One hundred and twenty patients with cervical cancer received external beam radiotherapy combined with or without concurrent chemotherapy, which was followed by the IGABT. The IGABT in 63 patients had one IGABT in each application (Arm 1), while in the other 57 patients, at least one treatment was two continuous IGABT every other day in one application (Arm 2). Clinical outcomes including overall survival (OS), cancer specific survival (CSS), progression free survival (PFS), local control (LC) were analyzed. Brachytherapy-related toxicities were evaluated, which included pain, dizziness, nausea/vomiting, fever/infection, blood loss during the removal of applicator and needles, the deep venous thrombosis, and other acute toxicities. The Common Terminology Criteria for Adverse Events (CTC-AE 5.0) was used to evaluate the incidence and severity of toxicities of the urinary system, lower digestive system, and reproduction system. Kaplan-Meier and the Log-rank test were used to analyze the clinical outcomes.

RESULTS

The median follow-up time of the patients in Arm 1 and Arm 2 was 23.5 and 12.0 months, respectively. The overall treatment time was significantly shorter in Arm 2 than Arm 1 (60 vs. 64 d; P = 0.017). The OS, CSS, PFS, and LC in Arm1 and Arm 2 was 77.8% vs. 86.0% (P = 0.632), 77.8% vs. 87.7% (P = 0.821), 68.3% vs. 70.2% (P = 0.207), and 92.1% vs. 94.7% (P = 0.583), respectively. The highest NRS of the pain during brachytherapy waiting period (2.22 ± 1.84 vs. 3.02 ± 1.65; P < 0.001) and at the time of the removal of the applicator (4.69 ± 1.49 vs. 5.30 ± 1.18; P < 0.001) in the patients who received one hybrid intracavitary and interstitial brachytherapy (IC/ISBT) in one application and two continuous IC/ISBT every other day in one application were significantly different. So far four patients with grade 3 late toxicities have been reported.

CONCLUSIONS

The findings of this study demonstrated that the two continuous IGABT every other day in one application is a logistically applicable, safe, and effective treatment strategy that could shorten the overall treatment time and reduce the medical cost, comparing with the one IGABT in one application.

Opioid consumption and pain in patients with gynecological cancer who underwent spinal anesthesia vs. general anesthesia for interstitial brachytherapy

AIMS

Interstitial brachytherapy (ISBT) is an effective option for delivering conformal high dose radiation to the target volume with better organ-at risk sparing but is thought to be more invasive and painful than other methods. This study investigated pain levels and opioid consumption in patients who received spinal anesthesia (SA) or general anesthesia (GA) for their ISBT.

MATERIALS AND METHODS

Patients that underwent ISBT from April 2014 to September 2018 were analyzed from a prospective institutional database. The most prevalent malignancies were cervical (45%), recurrent endometrial (27%) and vaginal (20%) cancers. Baseline patient characteristics, radiation treatment details, anesthesia records, and inpatient charts were obtained. Opioid consumption was quantified as oral morphine equivalent per day (OMEq/day) from implantation until removal. Pain score levels were collected by using an 11-point scoring system.

RESULTS

Ninety nine patients received GA and 40 patients received SA as their anesthesia for ISBT. During their first admission, 76 patients (55%) required intravenous opioids. Patients receiving SA had significantly lower mean pain scores on the morning of their procedure 6 (Interquartile range [IQR] 2-8) vs. 0 (IQR: 0-1); p < 0.001]. Pain did not significantly differ between cohorts at any other time. During the first admission, SA patients had a lower median opioid usage of 23 (IQR: 9-47) mg/day compared to GA patients at 38 (IQR: 21-71) mg/day (p = 0.011). No difference in opioid consumption was seen during subsequent admissions.

CONCLUSIONS

In patients undergoing ISBT, SA provides better immediate pain control post insertion compared to GA. Patients who received SA used lower amounts of opioids during their first ISBT insertion.

An Asian multi-national multi-institutional retrospective study comparing intracavitary versus the hybrid of intracavitary and interstitial brachytherapy for locally advanced uterine cervical carcinoma

This study is an international multi-institutional retrospective study comparing the clinical outcomes between intracavitary brachytherapy (ICBT) and the hybrid of intracavitary and interstitial brachytherapy (HBT) for locally advanced cervical cancer patients treated with definitive radiation therapy. Locally advanced cervical cancer, the initial size of which is larger than 4 cm and treated by concurrent chemoradiotherapy and image-guided adaptive brachytherapy, were eligible for this retrospective study. Patients who received HBT at least once were included in the HBT group, and patients who received only ICBT were included in the ICBT group. Anonymized data from 469 patients from 13 institutions in Japan, one from Korea and one from Thailand, were analyzed. Two hundred eighty and 189 patients were included in the ICBT group and the HBT group, respectively. Patients in the HBT group had more advanced stage, non-Scc histopathology, a higher rate of uterine body involvement, larger tumor at diagnosis, larger tumor before brachytherapy and a lower tumor reduction ratio. With a median follow-up of 51.3 months (2.1-139.9 months), 4-y local control (LC), progression-free survival (PFS) and overall survival (OS) for the entire patient population were 88.2%, 64.2% and 83%, respectively. The HBT group received a higher HR-CTV D90 than that of the ICBT group (68.8 Gy vs 65.6 Gy, P = 0.001). In multivariate analysis, the non-Scc histological subtype, HR-CTV D95 ≤ 60 Gy, reduction ratio ≤ 29% and total treatment time (TTT) ≥ 9 weeks were identified as the independent adverse prognostic factors for LC. Regarding LC, no difference was found between ICBT and HBT (4-y LC 89.3% vs 86.8%, P = 0.314). After adjustment for confounding factors by propensity score matching, no advantage of applying HBT was demonstrated regarding LC, PFS, or OS. Despite the fact that HBT patients had more adverse clinical factors than ICBT patients, HBT delivered a higher dose to HR-CTV and resulted in comparable LC.

Large volume was associated with increased risk of acute non-hematologic adverse events in the hybrid of intracavitary and interstitial brachytherapy for locally advanced uterine cervical cancer: preliminary results of prospective phase I/II clinical trial

OBJECTIVE

This is the preliminary results of a multi-center prospective clinical trial evaluating the feasibility of the hybrid of intracavitary and interstitial brachytherapy for locally advanced cervical cancer.

METHODS

Patients with FIGO stage IB2, IIA2, IIB, IIIA, IIIB and IVA uterine cervical cancer pretreatment width of which was ≥5 cm measured by MRI were eligible. Protocol therapy consisted of 30-30.6 Gy in 15-17 fractions of whole pelvic radiotherapy concurrent with weekly CDDP, followed by 24 Gy in 4 fractions of hybrid of intracavitary and interstitial and pelvic radiotherapy with central shield up to 50-50.4 Gy in 25-28 fractions. The primary endpoint of phase I part was that the rate of grade ≥ 3 acute non-hematologic adverse events related to hybrid of intracavitary and interstitial would be <10%.

RESULTS

Between October 2015 and October 2019, 74 patients underwent primary registration, with 52 patients eventually proceeding to the secondary registration. The median pretreatment tumor width was 5.7 cm, and FIGO Stages were IB2 10, IIA2 2, IIB 20 and IIIB 20, respectively. The median high-risk clinical target volume D90 was 72.0 Gy (54.8-86.6 Gy, EQD2), rectum D2cc was 53.7 Gy (29.3-80.3 Gy) and bladder D2cc was 69.8 Gy (38.9-84.8 Gy). The rate of grade ≥ 3 non-hematologic adverse events related to hybrid of intracavitary and interstitial was 1.9% (1/52), and 17.3% (9/52) of patients experienced non-hematologic adverse events related to hybrid of intracavitary and interstitial of any grade. In multivariate analysis, high-risk clinical target volume ≥ 35 ml was associated with an increased risk of any grade of acute non-hematologic adverse events related to hybrid of intracavitary and interstitial (P = 0.036).

CONCLUSION

The feasibility and reproducibility of hybrid of intracavitary and interstitial were demonstrated from a multi-center prospective clinical trial.

3D-Image-Guided Multi-Catheter Interstitial Brachytherapy for Bulky and High-Risk Stage IIB-IVB Cervical Cancer

Simple Summary

The prognosis of locally advanced cervical cancer still remains poor. Recently, image-guided brachytherapy ameliorated local control and pelvic control in these patients. Additionally, concurrent chemoradiotherapy with interstitial brachytherapy (ISBT) demonstrated more favorable outcomes than that with intracavity brachytherapy. The purpose of our study was to evaluate the efficacy and safety of CT-MRI-guided multi-catheter ISBT for bulky (≥4 cm) and high-risk stage IIB-IVB cervical cancer. Total of 18 patients with squamous cell carcinoma received concurrent chemoradiotherapy with ISBT were assessed. Four (22.2%), seven (38.9%), and seven (38.9%) patients were diagnosed with stage II, III, and IV cervical cancer, respectively. The four-year local control, pelvic control, disease-free survival, and overall survival rates were 100%, 100%, 81.6%, and 87.8%, respectively. Although three (16.7%) patients experienced grade 3 late adverse events, no one had procedure-related complications. CT-MRI-guided multi-catheter ISBT could be a promising treatment strategy for locally advanced cervical cancer.

Abstract

This study aimed to evaluate the efficacy and safety of computed tomography-magnetic resonance imaging (CT-MRI)-guided multi-catheter interstitial brachytherapy for patients with bulky (≥4 cm) and high-risk, stage IIB–IVB advanced cervical cancer. Eighteen patients who underwent concurrent chemoradiotherapy with multi-catheter interstitial brachytherapy between September 2014 and August 2020 were enrolled. The prescribed dose of external beam radiotherapy was 45–50.4 Gy, and the brachytherapy high-dose-rate aim was 25–30 Gy per 5 fractions. The endpoints were four-year local and pelvic control rates, four-year disease-free and overall survival rates, and the adverse events rate. The median follow-up period was 48.4 months (9.1–87.5 months). Fifteen patients received concurrent cisplatin therapy (40 mg/m², q1week). Four (22.2%), seven (38.9%), and seven (38.9%) patients had stage II, III, and IV cervical cancer, respectively. Pelvic and para-aortic lymph node metastases were observed in 11 (61.1%) and 2 (11.1%) patients, respectively. The median pre-treatment volume was 87.5 cm³. The four-year local control, pelvic control, disease-free survival, and overall survival rates were 100%, 100%, 81.6%, and 87.8%, respectively. Three (16.7%) patients experienced grade 3 adverse events, and none experienced grade 4–5 adverse events. CT-MRI-guided multi-catheter interstitial brachytherapy could be a promising treatment strategy for locally advanced cervical cancer.

High-Dose-Rate Interstitial Brachytherapy for Deeply Situated Gynecologic Tumors Guided by Combination of Transrectal and Transabdominal Ultrasonography: A Technical Note

Background and Purpose

High-dose-rate interstitial brachytherapy (HDR-ISBT) is recommended to obtain a better local tumor control for uterine cancer patients in specific situations such as bulky lesions, an extension to the lateral parametrium, or tumors with irregular shapes. Our group uses real-time transrectal ultrasonography (TRUS) to guide freehand interstitial needle insertion. Occasionally, target tumors locate deeper beyond the rectum and cannot be visualized by TRUS. CT can guide needles to deeply located tumors, but in such cases, repeated image obtainment is required to achieve ideal needle localization. In this report, we present nine cases of patients who underwent HDR-ISBT for deeply situated tumors guided by a combination of transrectal and transabdominal ultrasonography (TR/TA-US).

Material and Methods

Nine uterine cancer patients whose tumors were located deeper than the reach of TRUS and underwent HDR-ISBT guided by TR/TA-US were presented. All nine cases had no distal organ metastasis and underwent external beam radiation therapy (EBRT) to the pelvic region for 45–50.4 Gy in 25–28 fractions followed by boost HDR-ISBT for deeply situated tumors guided by TR/TA-US.

Results

There were seven cervical cancer and two endometrial cancer patients: six with extensive uterine corpus invasion, one cervical cancer with massive pelvic lymph node metastasis, one cervical cancer with postoperative pelvic recurrence, and one with left ovarian direct tumor invasion. The median follow-up period was 15 months (range 3–28 months). The average clinical target volume at the time of first HDR-ISBT was 131 ml (range 44–335 ml). The linear distance from the vaginal entrance to the deepest part of the tumor at first time brachytherapy of nine cases was 14.0 (9.0–17.0) cm. HDR-ISBT dose fractionation was 24–30 Gy in four or five fractions. Seven out of nine cases had no local recurrence in the follow-up period. One had local in-field recurrence 25 months after HDR-ISBT. Another case with carcinosarcoma could not obtain local control and underwent salvage hysterectomy for a residual uterine tumor 11 months after HDR-ISBT. Four cases had extra-field recurrence in lymph nodes or distant organs.

Conclusions

In brachytherapy for gynecologic malignancies, deeply situated tumors located out of reach of TRUS may obtain favorable local control by HDR-ISBT guided with TR/TA-US.

The Preliminary Results of 3-Dimensional Printed Individual Template Assisted 192Ir High-Dose Rate Interstitial Brachytherapy for Central Recurrent Gynecologic Cancer

Objective:

To evaluate the feasibility and safety of high dose rate interstitial brachytherapy (HDR-IB) assisted with 3-dimensional printing individual template (3D-PIT) for central pelvic recurrent gynecologic cancer (CR-GYN).

Methods:

Totally 32 patients diagnosed with CR-GYN received iridium-192(192Ir) HDR-IB assisted with 3D-PIT that was classified in 2 types(Type I: transvaginal template/ applicator, and Type II: transvaginal combined transperineal template). The prescribed dose to gross tumor volume (GTV) was 10-36 Gy in 2-6 fractions. We rely on a few dosimetric parameters for quality control. The short-term efficacy was evaluated by RECIST v1.1, and the adverse event was evaluated by CTCAE V4.0.

Results:

The median V100, D100 and D90 of per fraction among all the patients were 88.9%±9.8%, 3.45Gy±0.54 Gy, and 5.79Gy±0.32 Gy, respectively. Dosimetric comparison between preplan and treatment plan of 20/32 patients with Type II 3D-PIT showed no significant difference in GTV volume, V100, D100, D90, conformation index (CI) and homogeneity index (HI). No severe treatment complications occurred. Grade 3 or 4 late toxicities (fistula) were observed in 3 patients (9%). The local response rate (complete remission, CR + partial remission, PR) was 84.4% (27/32) 1 month after completion of treatment. The median time to progression (TTP) was 15.4 months (95% CI 11.3- 19.6 months), 1-year local control (LC) rate were 51.7%.

Conclusions:

HDR-IB assisted by 3D-PIT was a reliable modality for CR-GYN due to the clinical feasibility and accepted complications.

Transvaginal artificial ascites infusion as a spacer in gynecological brachytherapy: a novel technique

This is a first paper to report on artificial ascites infusion via vaginal wall for pelvic interstitial brachytherapy. Artificial ascites is commonly used for treating liver tumors, with radiofrequency ablation and percutaneous artificial ascites infusion through the abdominal wall for pelvic brachytherapy has been previously reported by our group. However, the trans-abdominal needle approach under ultrasound guidance is unreliable due to poor visualization resulting in fluid injection into the abdominal wall or mesenterium and the rate of successful artificial ascites infusion was low. Target tumor of the vaginal cuff brachytherapy is usually adjacent to the intestine, and transvaginal artificial ascites infusion under trans-rectal ultrasonography is considered as a rational and simpler method to create a space between target volume and organs at risk, such as intestines or sigmoid colon, by increased visualization of the needle compared to trans-abdominal approach. Here, we report a practical experience of transvaginal artificial ascites infusion.

Three-dimensional image-guided combined intracavitary and interstitial high-dose-rate brachytherapy in cervical cancer: A systematic review

PURPOSE

To evaluate the local control and toxicities of three-dimensional image-guided combined intracavitary and interstitial (IC/IS) high-dose-rate brachytherapy (BT) in cervical cancer through a systematic review.

METHODS AND MATERIALS

A systematic review of relevant studies was performed through the PubMed, Web of Science, and Cochrane Library databases through May 10, 2020. Articles reporting on IC/IS technology, volumetric doses to high-risk clinical target volume (HR-CTV) and organs at risk (OARs), tumor control and/or treatment-related side effects were identified. The key information, including the type of applicator, implantation technology, characteristics of implantation, volumetric doses, tumor control, and/or treatment-related side effects, was extracted. A probit model analysis between HR-CTV D90 and tumor local control was performed.

RESULTS

Twelve studies encompassing 520 patients were included in the probit model between HR-CTV D90 and the local control rate. The probit model showed a significant relationship between the HR-CTV D90 value and the local control probability, p = 0.003. The prescribed dose of 85 Gy_EQD2,10 would in theory warrant an 87.4% (95% confidence interval 82.5%-90.5%) local control rate.

CONCLUSION

IC/IS BT is an appropriate method to achieve a high therapeutic ratio for tumors with large volumes or poor responses after external irradiation in cervical cancer. The probit model showed that the dose escalation of HR-CTV D90 was helpful to improve the local tumor control rate.

Configuration analysis of the injection position and shape of the gel spacer in gynecologic brachytherapy

PURPOSE

In this single-institution retrospective study, configuration analysis was performed to determine the optimal location and volume of hyaluronic acid gel spacer injection into the rectovaginal or vesicovaginal septum for effective dose reduction (DR) to the organs at risk (OARs), the rectum and bladder.

METHODS AND MATERIALS

70 and 50 intracavitary brachytherapy treatment plans used only vaginal cylinders with gel spacers for the rectal and bladder sides, respectively, whereas 28 did not use spacers. Correlation analysis was performed between the geometrical parameters and injection position of the gel spacers and the 2-cm³ covering doses of the OARs for each treatment.

RESULTS

A higher DR was predicted for hyaluronic acid gel spacer injection within ±5 mm and ±2.5 mm in the lateral-medial direction from the midpoint on the rectal and bladder sides, and ±10 mm in the cranial-caudal direction from the midpoint on the rectal side. There were correlations between 2-cm³ covering doses and the gel spacer parameters: the volume on the rectal (p = 0.02) and bladder (p = 0.04) sides; the craniocaudal length on the rectal side (p << 0.05); and ventrodorsad thickness on each OAR (p << 0.05) sides. There was no significant difference in the DR between a volume of ∼10 cm³ and that of a higher volume (p >> 0.05).

CONCLUSIONS

A gel spacer volume of ∼10 cm³ provides sufficient OAR DR if its gravity point is on the midpoint between the cylinder applicator and OAR, and its craniocaudal length covers the active length of the cylinder applicator.

Interstitial high-dose-rate brachytherapy using cobalt-60 source for cervical cancer: dosimetric and clinical outcomes from a single institute

PURPOSE

To record and report dosimetric and clinical outcomes of interstitial brachytherapy using cobalt-60 (60Co) source in cervical cancer.

MATERIAL AND METHODS

Seventy patients who underwent external beam radiotherapy with dose of 45 Gy in 25 fractions, followed by interstitial brachytherapy (ISBT) 6.5 Gy × 4 fractions were included into this study. The ISBT applicators were inserted under combined spinal and epidural anesthesia. Computed tomography (CT) simulation was performed and axial CT images were transferred to treatment planning system. High-risk clinical target volume (CTVHR) and organs at risks (OARs) were contoured. Four fractions of 6.5 Gy were prescribed to CTVHR using inverse planning technique. Patients were followed-up for 3 years. Dosimetric parameters and clinical outcomes were recorded and compared with available literature.

RESULTS

Seventy patients with FIGO stage IIB-IVA were included in the study. The median EQD2 of 2 cm3 of bladder, rectum, sigmoid and D90 CTVHR were 70 Gy (53-75 Gy), 64 Gy (51-71 Gy), 48 Gy (44-72 Gy), and 77 Gy (70-86 Gy), and dose homogeneity index (DHI), dose non-uniformity ratio (DNR), coverage index (CI), overdose volume index (OI), and conformal index (COIN) were 0.58 (0.39-0.78), 0.42 (0.22-0.61), 0.87 (0.59-0.97), 0.19 (0.09-0.30) and 0.74 (0.52-0.85), respectively. Local control rate at 2 years was 87.14%. Eight patients had local recurrence and one patient had lung metastasis. Also, two patients with local recurrence had recto-vaginal fistula. Two patients had grade 2 proctitis (2.8%) and one patient developed grade 3 proctitis (1.4%). There was no grade 2 or higher bladder toxicity.

CONCLUSIONS

The dosimetric parameters, local control and toxicities of high-dose-rate interstitial brachytherapy in cervical cancer patients treated by 60Co radioactive source are similar, compared to available literature using iridium-192 (192Ir) source.

Modern development of high-dose-rate brachytherapy

Brachytherapy is an invasive therapy with placement of radiation source into or near the tumor. The difference between planning target volume and clinical target volume is minimal, and the dose out of the tumor reduces rapidly due to the inverse-square law. High-dose-rate brachytherapy enables three-dimensional image guidance, and currently, tumor dose as well as doses of the surrounding normal structures can be evaluated accurately. High-dose-rate brachytherapy is the utmost precision radiation therapy even surpassing carbon ion therapy. Biological disadvantages of high-dose rate have been overcome by the fractional irradiation. High-dose-rate brachytherapy is indispensable in the definitive radiation therapy of cervical cancer. Also in prostate cancer and breast cancer, high-dose-rate brachytherapy plays a significant role. Brachytherapy requires techniques and skills of radiation oncologists at the time of invasive placement of the radiation source into the tumor area. Education of young radiation oncologists is most urgent and important.

A case report of a patient with bulky uterine cervical neoplasm who achieved complete response with "intentional internal high-dose policy" high-dose-rate interstitial brachytherapy

RATIONALE

Gynecological high-dose-rate (HDR) brachytherapy has progressed for years, but it remains difficult for bulky tumors to be controlled locally. Dose limitations to organs at risk (OARs) are invariably obstacles in increasing the prescription dose. Additionally, it is controversial that the excessive hyperdose sleeve, the volume receiving a dose equal to or greater than twice the reference dose, should be eliminated in gynecological HDR brachytherapy. On the other hand, the technique of simultaneous integrated protection was reported for large hepatocellular carcinoma treatment, and similarly, internal high-dose brachytherapy could be used for treating bulky cervical carcinoma.

PATIENT CONCERNS

A 54-year-old female had irregular genital bleeding and lost 13 kg in one year.

DIAGNOSIS

She was diagnosed with T3bN1M0 cervical cancer in another hospital. The transverse diameter of the primary tumor was 10.5 cm.

INTERVENTIONS

The whole pelvis and para-aortic lymph node were irradiated with a total of 50 Gy in 25 fractions, but the size of the tumor showed only a slight decrease to 8.9 cm. After external beam radiotherapy, first-time high-dose-rate interstitial brachytherapy (HDR-ISBT) was administered without "intentional internal high-dose (IIHD) policy," the technique of high-dose administration to only the inside of the tumor. Considering the rectum dose limitation, in the additional 2 times of brachytherapy, "IIHD policy" HDR-ISBT was applied. In the second and third HDR-ISBT, the percentage of the volume exposed to 200% of the prescribed dose for high-risk clinical target volume increased by 241% and 204% compared with the first HDR-ISBT, while the doses to OARs were not significantly higher than those of the first-time HDR-ISBT.

OUTCOMES

Complete response was obtained, and no recurrence findings and side effects caused by HDR-ISBT have been detected for 2 years and 9 months.

LESSONS

To our knowledge, this is the first report of IIHD HDR-ISBT for bulky cervical cancer. This technique can be the solution for treating bulky cervical cancer.

Image-guided interstitial brachytherapy boost for nasopharyngeal carcinoma: technical aspects

Nasopharyngeal cancer generally responds well to concurrent chemoradiotherapy (CCRT). However, there is a small group of patients who respond poorly to CCRT, and experience local residual tumor or local relapse. Although several attempts have been performed to such a group of patients including re-irradiation with external beam radiation therapy (EBRT) or salvage surgery, clinical results remain unsatisfactory. Intracavitary brachytherapy (ICBT) boost after CCRT with EBRT has been explored, however, its efficacy is limited to those with superficial residual tumors. For those residual tumors thickness with more than 5 mm, interstitial brachytherapy (ISBT) boost would be an appropriate modality of choice. Here, we describe technical aspects of the high-dose-rate interstitial brachytherapy (HDR-ISBT) boost for nasopharyngeal cancer (NPC) patients who responded poorly to the CCRT with EBRT.

Dose-effect response in image-guided adaptive brachytherapy for cervical cancer: A systematic review and meta-regression analysis

PURPOSE

This study aimed to integrate and update the dose-effect relationship between volumetric dose and local control for cervical cancer brachytherapy.

METHODS AND MATERIALS

We identified studies that reported high-risk clinical target volume (HR-CTV) D₉₀ and local control probability by searching PubMed, Web of Science, and the Cochrane Library databases through Oct 27, 2019. The regression analyses were performed using a probit model between HR-CTV D₉₀, D₁₀₀, intermediate-risk clinical target volume (IR-CTV) D₉₀, and dose to Point A vs. local control probability. Subgroup analyses were performed according to stratification: time of local control, income level of the country or region, stage of cancer, pathology, mean volume of HR-CTV, dose rate, image modality, concurrent chemoradiotherapy proportion, interstitial proportion, and mean overall treatment time.

RESULTS

Thirty-three studies encompassing 2893 patients were included. The probit model showed a significant relationship between the HR-CTV D₉₀ value and the local control probability, p < 0.0001. The D₉₀ corresponding to a probability of 90% local control was 83.7 Gy_EQD2,10 (80.6-87.8 Gy_EQD2,10). Of the 33 studies included in our analysis, eight studies, including 1172 patients, reported the IR-CTV D₉₀ value, ranging from 59.1 Gy_EQD2,10 to 72.3 Gy_EQD2,10. The probit model also showed a significant relationship between the IR-CTV D₉₀ value and the local control probability, p = 0.0464. The 60 Gy_EQD2,10 for IR-CTV D₉₀ corresponded to an 86.1% local control probability (82.0%-89.8%).

CONCLUSIONS

A significant dependence of local control on HR-CTV D₉₀ and IR-CTV D₉₀ was found. A tumor control probability of >90% can be expected at doses >84 Gy_EQD2,10 and 69 Gy_EQD2,10, respectively, based on an updated meta-regression analysis.

Hyaluronic acid gel injection in rectovaginal septum reduced incidence of rectal bleeding in brachytherapy for gynecological malignancies

PURPOSE

The purpose of this study was to report our initial clinical results of hyaluronic acid gel injection (HGI) in the rectovaginal septum (RVS) to reduce the incidence of rectal bleeding in vaginal brachytherapy for gynecologic malignancies.

METHODS AND MATERIALS

Since 2008, CT based image-guided adaptive brachytherapy (IGABT) was initiated, and since 2015, HGI in the RVS was introduced in our institution. Vaginal cylinder with or without tandem or additional interstitial needles were applied for patients with gynecologic malignancies. Rectum dosimetric parameters and incidence of late rectum bleeding were compared between patients with and without HGI in the RVS.

RESULTS

Between May 2008 and October 2017, 83 patients with gynecologic malignancies were treated with IGABT involving vaginal cylinder. Eleven patients who were treated for palliative intention were excluded, and 72 patients were subjected to the analysis. Of the total 72 patients 46 were with uterine cervical cancer, 19 uterine corpus cancer, five vaginal cancer, one vulvar cancer, and one ovarian cancer. Fifteen and 57 patients were irradiated with and without HGI in the RVS, respectively. With a median follow-up period of 57.7 (4.7-123.1) months, 30 (41.7%) patients suffered from radiation-related rectal bleeding. Patients with HGI in the RVS had a statistically significant lower incidence of rectal bleeding compared with those without it (13.3% vs. 49.1%, p = 0.01).

CONCLUSIONS

HGI in the RVS reduced the incidence of late rectal bleeding for patients with gynecologic malignancies treated by vaginal cylinder and was not associated with HGI-procedure-related adverse events.

Image-guided high-dose-rate interstitial brachytherapy for recurrent rectal cancer after salvage surgery: a case report

Treatment options for patients with recurrent rectal cancer in pelvis represent a significant challenge because the balance of efficiency and toxicity needs to be pursued. This case report illustrates a treatment effect of image-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for locally relapsed rectal cancer after salvage surgery. A 61-year-old male who underwent laparoscopic high anterior resection (LAP-HAR) with D3 lymph node dissection as a primary treatment for rectal cancer (pT3N0M0, well-differentiated adenocarcinoma) had relapsed locally 8 months after initial surgery, for which he underwent salvage abdominal perineal resection (APR), followed by adjuvant 8 cycles of XELOX (capecitabine and oxaliplatin) chemotherapy. He developed pelvic recurrence 1 year after the second surgery. Image-guided HDR-ISBT was performed (30 Gy/5 fractions/3 days) followed by external beam radiation therapy with 39.6 Gy in 22 fractions. There were no severe complications related to salvage radiotherapy. CEA was decreased from 24.5 ng/ml to 0.7 ng/ml, 4 months after the salvage radiotherapy. Complete response was noted on follow-up MRIs done on 2, 5, 8, and 14 months after the treatment. Hence, HDR-ISBT appears to be effective for locally recurrent rectal cancer even after salvage surgery.

Hyaluronate gel injection for rectum dose reduction in gynecologic high-dose-rate brachytherapy: initial Japanese experience

Perirectal hyaluronate gel injection (HGI) appears to be a promising technique for healthy tissue dose sparing in pelvic radiotherapy. In this analysis, we report our initial experience of HGI in gynecologic brachytherapy, focusing on its safety and effectiveness for dose reduction to the rectum. Between July 2013 and May 2014, 36 patients received HGI for primary/salvage gynecologic brachytherapy. Dosimetric effect analysis was based on pre- and post-HGI computed tomography dataset registration with corresponding dose-volume histogram evaluation. The maximum dose to the most exposed 0.1 cm3 (D0.1cm3) and 2.0 cm3 (D2.0cm3) were used as index values for rectum and bladder dose evaluation. The dose indexes for target volume (TV) coverage were TV D90/V100. In all cases, HGI was well tolerated, with no acute or late adverse events documented at a median follow-up of 220 days (range, 18-1046 days). Rectum D2.0cm3 and D0.1cm3 were significantly decreased by HGI (P < 0.001 and P = 0.003, respectively), with no significant impact on dosimetric parameters of bladder and TV coverage. Factors correlating negatively with the dosimetric effect of HGI were an increasing number of interstitial catheters (P = 0.003) as well as Lcranial100% (P = 0.014) and Lcranial80% (P = 0.001) [i.e. the length from the anal verge to the most cranial point at which the 100% and 80% isodose lines, respectively, crossed the rectum]. The concept of HGI for gynecologic brachytherapy is plausible, and our initial experience indicates it to be an effective technique for rectal dose reduction in radiotherapy of intrapelvic tumours.

A hybrid technique of intracavitary and interstitial brachytherapy for locally advanced cervical cancer: initial outcomes of a single-institute experience

BACKGROUND

Locally advanced uterine cervical cancer (LAUCC) with lateral tumor extension may not always be covered adequately by conventional intracavitary brachytherapy (ICBT). Hybrid intracavitary and interstitial brachytherapy (HBT) seems to be an effective alternative by improving anatomy-oriented dose optimisation. The purpose of this study was to report initial clinical result for LAUCC treated by HBT.

METHODS

Between January 2012 and November 2015, 42 patients with LAUCC (T1b2-4a) were treated with primary radiation therapy including HBT. Patients with distant metastasis other than para-aortic lymph node spread were excluded from this study. A retrospective analysis was performed for toxicity evaluation and oncological outcome calculation.

RESULTS

Median follow-up was 23.2 months (range 13.2-71.4). Two-year overall survival, progression free survival, and local control rate were 81.6, 54.4, and 80.2%, respectively. Seven patients experienced local recurrence (16.6%). Of those, five were confined to the uterus and two at the parametria. Late adverse events ≥ grade 3 were seen in 3 patients.

CONCLUSIONS

HBT can generate favorable local control in tumors which cannot be adequately covered by ICBT.

Survival outcomes of patients with cervical cancer and accompanying hydronephrosis: A systematic review of the literature

Hydronephrosis is a sign of advanced stage disease in patients with cervical cancer. Its presence is believed to negatively affect the survival of patients. To date, however, consensus in this field is still lacking. The purpose of the present systematic review is to gather the available data and to provide directions for future research in the field. We systematically searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRA and Google Scholar databases from inception till June 2018. Overall, 22 studies were included in the present systematic review that evaluated outcomes from 8521 patients with cervical cancer. The findings of our systematic review support that hydronephrosis negatively affects the overall survival of cervical cancer patients. Specifically, the reported 5- year OS hazards ratio for hydronephrosis ranged between 1.34 and 3.74. Outcomes concerning the disease-free survival of these patients were, however, less discrete. None of the included studies reported whether the decreased survival of patients with hydronephrosis was attributed to complications of obstructive uropathy such as uremia and sepsis. Thus, it remains, to date, unclear whether placement of ureteral stents or percutaneous nephrostomy may actually benefit these patients. More studies are needed to evaluate the actual impact of hydronephrosis on survival rates at the various stages of cervical cancer and to help establish consensus regarding the optimal mode of management of these patients.

Artificial ascites for organs at risk sparing in intrapelvic brachytherapy: a case report of recurrent uterine cervical carcinoma adjacent to the bowel

Artificial ascites has been reported as an effective technique to reduce the risk of thermal injury in radiofrequency ablation of liver tumors by increasing the distance of collateral organs located next to the ablated sites. In this case report we share our experience with artificial ascites in an attempt to reduce the toxicity of collateral adjacent organs in the setting of re-irradiation for recurrent cervical cancer. A 52-year-old female who developed local recurrence after definitive radiation therapy was treated with interstitial re-irradiation by means of image-guided, (single-implant/multi fraction) high-dose-rate brachytherapy. Because the sigmoid colon was in close proximity to the recurrent tumor lesion, artificial ascites was generated before each treatment fraction by percutaneous injection of a defined amount of saline solution through the abdominal wall to create additional space between the two volumes. Artificial ascites showed a dosimetric improvement by reducing the sigmoid colon D_0.1cc per fraction from 286 cGy before to 189 cGy after saline injection. No severe complication was associated with the injection procedure.

Meeting report, “First Indian national conference on cervical cancer management - expert recommendations and identification of barriers to implementation”

Objective

In India, cervical cancer accounts for almost 14% of all female cancer cases. Although poverty continues to cast a wide net over the Indian subcontinent, the preceding three decades have borne witness to improvements in nutrition and sanitation for many citizens. However, due to an absence of a national immunization program to cover human papillomavirus (HPV) vaccination and lack of accessible cervical cancer screening, the disease is characterized by late detection, lack of access to affordable and quality health care, and high mortality rates. Treatment of cervical cancer is stage-specific and depends on the patient’s age, desire to preserve fertility, overall health, the clinician’s expertise, and accessibility to resources. There is a paucity of uniform treatment protocols for various stages of cervical cancer in India. Considering all these parameters, a need to optimize treatment paradigms for the Indian population emerged.

Methods/materials

Three expert panel meetings were held in different regions of India from 2016 to 2017. They were comprised of 15 experts from across the country, and included surgical oncologists, radiation oncologists, and medical oncologists. The panel members reviewed the literature from both national and global sources, discussed their clinical experience and local practices and evaluated current therapeutic options and management gaps for women diagnosed with cervical cancer.

Results

This article summarizes the expert opinion from these meetings. It discusses the available resources and highlights the current therapeutic options available for different cervical cancer stages: early stage disease, locally advanced tumors, recurrent/persistent/metastatic cancer. An Indian consensus governing treatment options emerged, including guidelines for use of the only approved targeted therapy in this disease, the anti-angiogenesis drug, bevacizumab.

Conclusions

The panel concluded that given the availability of state-of-the-art imaging modalities, surgical devices, radiotherapeutics, and novel agents in several population-dense urban centers, a uniform, multi-disciplinary treatment approach across patient care centers is ideal but not realistic due to cost and a paucity of third party payors for most Indian citizens. Preventative strategies including visual inspection with acetic acid to screen for precursor lesions (i.e., cervical intraepithelial neoplasia) with immediate referral for cervical cryotherapy and possible large-scale roll-out of the HPV vaccine in the near future can be expected to reduce mortality rates significantly in this country.

Image-guided interstitial high-dose-rate brachytherapy for locally recurrent uterine cervical cancer: A single-institution study

PURPOSE

The aim of this study was to investigate the efficacy and safety of image-guided high-dose-rate (HDR) interstitial brachytherapy (ISBT) for reirradiation of locally recurrent uterine cervical cancer.

METHODS AND MATERIALS

Between 2008 and 2015, patients receiving reirradiation using HDR-ISBT for local gross recurrence of uterine cervical cancer after definitive or postoperative radiotherapy were analyzed retrospectively. The prescription doses per fraction ranged 2.5-6.0 Gy, whereas the cumulative equivalent doses in 2 Gy fractions ranged 48.6-82.5 Gy. The effects of prognostic factors on the local control (LC), progression-free survival, and overall survival were analyzed, and late toxicity data were evaluated.

RESULTS

Eighteen patients were included in the analysis, with a median followup of 18.1 months. A tumor response was obtained in all patients, with radiological and pathological complete remission seen in 12 (66.7%) patients. The 2-year LC, progression-free survival, and overall survival rates for all patients were 51.3%, 20.0%, and 60.8%, respectively. The hemoglobin level and maximum tumor diameter were shown to be statistically significant prognostic factors for LC (p = 0.028 and 0.009, respectively). Late ≥ Grade 2 adverse events were observed in 5 patients (27.8%).

CONCLUSIONS

Image-guided HDR-ISBT for the reirradiation of locally recurrent uterine cervical cancer may play an important role for local tumor control in a subgroup of patients. However, the treatment indication must be weighed against the risk of higher-grade late toxicity.

Locally advanced squamous cell cervical cancer in a patient with septate uterus

A 33-year-old premenopausal multiparous woman with the history of septate uterus was referred to the hospital with menorrhagia and inter-menstrual bleeding occurring for the last 6 months. Work-up revealed a stage IIB cervical cancer. The patient underwent curative chemo/radiotherapy. The patient’s septate uterus presented several difficulties during application. Brachytherapy was applied using standard computed tomography-compatible tandem and ovoids. The high-risk clinical target volume (HR-CTV), intermediate risk CTV, and organs at risk were contoured according to the Groupe Européen de Curiethérapie – European Society for Radiology and Oncology (GEC-ESTRO) guidelines. Treatment was performed via 3-dimensional high-dose-rate technique with ¹⁹²Ir, with brachytherapy dose of 28 Gy in 4 fractions/7 Gy each, prescribed to the HR-CTV. Treatment was well tolerated with manageable acute toxicities. To the best of our knowledge, the current case is the second case of septate uterus with locally advanced cervical carcinoma. Due to the lack of guidelines about brachytherapy applications in patients with uterine anomaly and owing to the anatomical anomaly, brachytherapy application is challenging in this patients population.

Optimal perioperative anesthesia management for gynecologic interstitial brachytherapy

Purpose

To propose an optimal perioperative pain management clinical care pathway for interstitial brachytherapy for gynecologic cancer based on our interdepartmental experience.

Material and methods

We conducted a retrospective review of 23 women who underwent 32 interstitial brachytherapy procedures for gynecological cancers, analyzing patient demographics, type of anesthetic, medications, postoperative pain scores, adverse events, and delays in discharge. We measured the association of postoperative nausea and/or vomiting (PONV) with hydromorphone use, and postoperative pain scores and total narcotic administration with type of anesthesia.

Results

In 91% of patients postoperative pain was managed with an epidural infusion plus, as needed (PRN), IV or patient controlled analgesia (PCA) narcotics. The most common postoperative adverse event was PONV (53%), followed by delirium (22%). Hospital discharge was delayed, at least by one night, in 26% of patients. Use of a basal rate on the PCA was associated with all cases of delayed discharge from over-sedation and PONV. The use of 5 mg or more of intravenous (IV) hydromorphone during the first 24-hours postoperatively was associated with PONV (p = 0.01). Use of a basal PCA was associated with delirium (p = 0.03). Postoperative pain scores were not significantly associated with the type of anesthesia.

Conclusions

Interstitial gynecologic brachytherapy requires a multidisciplinary effort for optimal perioperative management. Our study outlines the appropriate preoperative, intraoperative, and postoperative anesthesia clinical care pathway. Decreased narcotic use during hospitalization and utilization of a patient-directed infusion may decrease side effects and allow for a more efficient hospital discharge.

Novel anesthetic technique for combined intracavitary and interstitial brachytherapy for cervix cancer in an outpatient setting

Purpose

To determine the feasibility and safety of outpatient combined intracavitary and interstitial brachytherapy for cervix cancer with sedation and local anesthesia.

Material and methods

We included patients diagnosed with non-metastatic cervix cancer and have completed brachytherapy between December 2015 and December 2016. Moderate to deep sedation was achieved using intravenous midazolam, propofol, fentanyl, and oxycodone. Local anesthesia was achieved with 2% lignocaine gel and a paracervical block containing a mixture of 1% ropivacaine, 2% lignocaine, and 1 : 1,000 adrenaline. Ceftriaxone and ondansetron were given prophylactically. Physiologic monitoring was performed throughout and pain scores were recorded using the Numeric Rating Scale. Follow-up was conducted at 8 weeks from the last fraction of brachytherapy. The feasibility and safety endpoints were a post-anesthesia discharge score (PADS) of 9 or above, and no grade 3 or above adverse events, respectively.

Results

A total of thirty-five brachytherapy insertions were carried out on nine patients. The median age of the patients was 56 years (range, 40-65). Eight patients had American Society of Anesthesiologists’ physical status of I or II, and one had a status of III. The mean duration of the insertion was 39 minutes (standard deviation [SD] = 14), during which no adverse events occurred. There was no significant nausea or vomiting post-sedation. The median pain scores post-insertion and during recovery were 0 (range, 0-6) and 0 (range, 0-7), respectively. At discharge, all patients had pain scores of 0 and maximum PADS of 10. The mean time to discharge was 4.1 hours (SD = 0.95). There were no brachytherapy-related admissions or complications.

Conclusions

Outpatient combined intracavitary and interstitial brachytherapy for cervix cancer with sedation and local anesthesia is feasible and safe. This could potentially lead to significant cost savings.

A method to incorporate interstitial components into the TPS gynecologic rigid applicator library

PURPOSE

T2 magnetic resonance imaging (MRI) is recommended as the imaging modality for image-guided brachytherapy. In locally advanced cervical carcinoma, combined endocavitary and interstitial applicators are appropriate (Vienna or Utrecht). To cover extensive disease, Template Benidorm (TB) was developed. Treatment planning system applicator libraries are currently unavailable for the Utrecht applicator or the TB. The purpose of this work is to develop an applicator library for both applicators.

MATERIAL AND METHODS

The library developed in this work has been used in the Oncentra Brachytherapy TPS, version 4.3.0, which has a brachytherapy module that includes a library of rigid applicators. To add the needles of the Utrecht applicator and to model the TB, we used FreeCAD and MeshLab. The reconstruction process was based on the points that the rigid section and the interstitial part have in common. This, together with the free length, allowed us to ascertain the position of the tip.

RESULTS

In case of the Utrecht applicator, one of the sources of uncertainty in the reconstruction was determining the distance of the tip of needle from the ovoid. In case of the TB, the large number of needles involved made their identification time consuming. The developed library resolved both issues.

CONCLUSIONS

The developed library for the Utrecht and TB is feasible and efficient improving accuracy. It allows all the required treatment planning to proceed using just a T2 MRI sequence. The additional use of specific free available software applications makes it possible to add this information to the already existing library of the Oncentra Brachytherapy TPS. Specific details not included on this manuscript will be available under request. This library is also currently being implemented also into the Sagiplan v 2.0 TPS.