Trans-rectal ultrasound-guided hybrid intra-cavitary and interstitial brachytherapy in carcinoma cervix: A feasibility study from a tertiary cancer center in India.

Purpose: To report the feasibility of performing hybrid intra-cavitary and interstitial (IC/IS) brachytherapy in patients with carcinoma cervix under trans-rectal ultrasound (TRUS) guidance. Material and methods: All patients who received an external beam radiotherapy (EBRT) dose of 50 Gy in 25 fractions with weekly chemotherapy, followed by a brachytherapy boost (21 Gy in 3 fractions) were prospectively included for analysis. IC/IS brachytherapy was performed using Fletcher style tandem and ovoid applicator with interstitial component under TRUS guidance. Parameters of implant quality analyzed included ability to insert tandem, ratio of needles loaded to the number of needles inserted, and incidence of uterine or organ at risk (OARs) perforation. Dosimetric parameters evaluated were dose to point A*, TRAK, D90 high-risk clinical target volume (HR-CTV), and D2cc to OARs (bladder, rectum, and sigmoid). Width and thickness of the target was compared between TRUS (TRUSw and TRUSt) and MRI (MRIw and MRIt). Results: Twenty carcinoma cervix patients treated with IC/IS brachytherapy were included for analysis. The mean HR-CTV volume was 36 cc. The median number of needles used were 6 (range, 2-10 needles). None of the patients had uterine perforation. Two patients had bowel and bladder perforation. The mean D90 HR-CTV and D98 HR-CTV were 87.3 Gy and 82 Gy EQD2, respectively. The mean D2cc to the bladder, rectum, and sigmoid were 80 Gy, 70 Gy, and 64 Gy EQD2, respectively. The mean dose to point A* was 70.4 Gy EQD2. The mean TRAK was 0.40. The mean TRUSw (±SD) and MRIw (±SD) were 4.58 cm (±0.44) and 4.49 cm (±0.50), respectively. The mean TRUSt (±SD) and MRIt (±SD) were 2.7 cm (±0.59) and 2.62 cm (±0.59), respectively. On statistical analysis, there was a significant correlation between TRUSw and MRIw (r = 0.93), and TRUSt and MRIt (r = 0.98). Conclusions: TRUS-guided IC/IS brachytherapy is feasible and provides adequate coverage of the target, with acceptable doses to OARs.

Dosimetric Impact of Air Pockets in the Vaginal Cuff Brachytherapy Using Model-based Dose Calculation Algorithm.

Background: Endometrial cancer is the most common disease of the female reproductive system. Vaginal cuff brachytherapy (VCB) has intrinsic advantages compared to external beam therapy when treated with radiation. A single-channel cylinder is a standard applicator in VCB. The present study aims to estimate a change in the dose to vaginal mucosa due to air pockets between the cylinder and vaginal mucosa by calculating with the Acuros BV algorithm and comparing it to the Task Group 43 (TG-43) algorithm. Materials and Methods: Patients who presented with air packets were included retrospectively. For each patient, three plans were created: the first plan used TG-43, the second plan used dose recalculation with Acuros BV, and the third plan was generated by re-optimization by Acuros BV. On the same axial computed tomography image, the point doses at the cylinder's surface and the displaced mucosa were recorded and the ratios were then estimated. Results: The average volume of air pockets was 0.08 cc (range of 0.01-0.3 cc), and 84% of air pockets displaced the vaginal mucosa by ≥0.2 cm. The average ratios of dose were 0.77 ± 0.09 (1 standard deviation [SD]) and 0.78 ± 0.09 (1 SD) for TG-43 and Acuros BV algorithms, respectively. Due to the air pocket, mucosa received a reduced dose by an average of 22.72% and an average of 23.29% for TG-43 and Acuros BV, respectively. The maximum displacement of mucosa and the ratio of doses were negatively correlated for both. In the Optimized Acuros BV plan, total dwell time increased by 1.8% but no considerable change in the dose ratios. Conclusion: The calculated dose of mucous membrane forced out of the cylinder surface by air pockets by the Acuros BV algorithm was nonsignificantly different from TG-43. Therefore, even in the presence of air pockets, the TG-43 algorithm for calculating the VCB dose is appropriate.

Mucoepidermoid Carcinoma of the Salivary Gland: Long Term Outcomes from a Tertiary Cancer Center in India.

To analyze the patterns of failure and factors affecting recurrence and overall survival in mucoepidermoid carcinoma of the salivary gland. The hospital records were retrospectively analyzed from October 2010 to January 2016. Patients diagnosed as mucoepidermoid carcinoma of the salivary gland were eligible for analysis. All patients received surgery as the primary treatment modality with or without post operative radiotherapy. Statistical analysis for factors affecting recurrence was done by cox regression analysis and p value less than 0.05 was considered significant. A total of 116 patients were diagnosed to have malignant salivary gland tumors of which 69 were mucoepidermoid carcinomas (69.5%). The median age was 43 years (8-75 years). Majority of the tumors occurred in major salivary glands gland (77%). 51% patients were females. Most common stage was stage II (36%) followed by stage I (27.5%), stage IV (20.3%) and stage III (16%). High grade carcinomas comprised 34.8%, intermediate grade 30.4% and low grade 34.8%. 36 patients (52.2%) received adjuvant radiotherapy (60 Gy in 30 fractions). At a median follow up of 42 months (8-70 months), 8 (11.6%) patients died (7 cancer related and 1 noncancer related). The locoregional recurrence rate was 4.3% whereas the distant metastasis rate was 11.6%. Most common site of distant metastasis was lung. The mean disease free survival time was 61.4 months and the mean overall survival was 62 months. On univariate analysis, age < 50 years, node positive, presence of PNI, high grade, presence of LVI and local recurrence were significant factors for distant metastasis (p < 0.05). On multivariate analysis, high grade, presence of LVI and local recurrence were significant factors for distant metastasis (p < 0.05). Mucoepidermoid carcinomas of salivary gland have good long term local control and overall survival. Majority of the recurrences are distant metastasis. High grade, LVI and local recurrence are significant risk factors for distant relapse.

Comparison of dose delivered to vagina using two different intracavitary brachytherapy applicators for carcinoma cervix.

PURPOSE: The aim of the study was to compare the dose to vaginal points between two intracavitary applicators used for HDR brachytherapy in Carcinoma Cervix METHODS AND MATERIALS: Patients reporting to our center for Carcinoma cervix intracavitary brachytherapy were randomly allocated to treatment with either Manchester or Fletcher Suit Delclos (FSD) applicator. All patients received an EBRT dose of 50 Gy in 25 fractions along with weekly Cisplatin (40 mg/m2). Brachytherapy was administered using CT based planning. All patients received a dose of 7 Gy to Point A one week apart for a total of three fractions. For vaginal dose reporting, the PIBS points (PIBS, PIBS+1, PIBS+2, PIBS-1, PIBS-2) and dose to vagina at the level of ovoids was compared between the two applicators RESULTS: A total of 30 Carcinoma cervix patients were randomly allocated to receive intracavitary brachytherapy with either Manchester or FSD applicator. The mean vaginal reference length for patients treated with Manchester applicator was 4.3 and for patients treated with FSD applicator was 4.4. On analyzing dose to different vaginal points, patients treated with Manchester applicator received significantly higher mean and median doses to all PIBS points (except PIBS-2 cm) as compared to FSD applicator. On analyzing dose to the upper vagina at the level of the ovoids, the Manchester applicator delivered higher antero-posterior doses as compared to FSD applicator. CONCLUSIONS: Manchester applicator gives higher dose to the vagina as compared to FSD applicator for intracavitary brachytherapy in Carcinoma Cervix. The choice of using a particular applicator depends on the residual disease at the time of brachytherapy and patient anatomy.

Long term outcomes of Carcinoma Buccal Mucosa treated with High Dose Rate Interstitial Brachytherapy.

PURPOSE: To analyze the long-term local control, overall survival and toxicity in Carcinoma Buccal Mucosa patients treated with interstitial brachytherapy. METHODS AND MATERIALS: This analysis included patients diagnosed as Carcinoma Buccal Mucosa on biopsy and treated with radical brachytherapy or External Beam Radiotherapy (EBRT) followed by brachytherapy boost. All patients received High dose rate (HDR) interstitial brachytherapy. The total dose was 35 Gy in ten fractions for brachytherapy alone. Patients who received EBRT (50-54 Gy) were boosted by brachytherapy to a dose of 18-24 Gy in 6-8 fractions. All patients were treated using CT based planning. RESULTS: Between 2007 to 2017, a total of 24 patients of Carcinoma Buccal Mucosa received HDR interstitial brachytherapy either alone or as a boost. Majority of the patients were tobacco chewers (80%). 17(71%) patients were clinical stage T2N0M0 and 7(29%) were clinically T1N0M0. At a median follow up of 7 years (3-12 years), the local control rate was 100% in stage I and 88% in stage II. The 5 year overall survival rate was 80%. Two patients developed nodal recurrence and one patient developed distant metastasis within two years of treatment. Tumor size and brachytherapy technique (radical vs. boost) did not impact local control or overall survival (p > 0.05). Majority of the acute toxicities were Grade 1 and 2. One patient developed osteoradionecrosis of the mandible. CONCLUSIONS: Interstitial brachytherapy in early-stage Buccal Mucosa cancer either alone or as a boost provides excellent long term local control and overall survival. The acute and late toxicities are acceptable with majority of the patients presenting with Grade 1 or 2 toxicity.

Dosimetric predictors of acute bone marrow toxicity in carcinoma cervix - experience from a tertiary cancer centre in India.

BACKGROUND: The objective of this study was To determine the dose volume parameters predicting acute haematological toxicity in carcinoma cervix patients undergoing concurrent chemoradiotherapy. MATERIALS AND METHODS: All patients that presented to the hospital between Jan 2019 and Dec 2019 were prospectively analyzed. Patients diagnosed to have Carcinoma Cervix and planned for concurrent chemoradiation by volumetric modulated arc therapy (VMAT) were included for analysis. Patients were assessed at baseline and every week during treatment for acute haematological toxicities. Dose volume parameters from treatment plans were correlated with RTOG grade of haematological toxicities. RESULTS: A total of 34 patients diagnosed to have squamous cell carcinoma of cervix were treated by radical radiotherapy by VMAT technique and concurrent chemotherapy. The most common stage of presentation was stage IIB (61.7%). 29 patients (85.2%) completed five cycles of weekly cisplatin. Statistical analysis for sensitivity and specificity of dosimetric parameters was performed using receiver operating characteristic (ROC) curve. The probability of developing bone marrow toxicity was analyzed using T test. Mean dose to bone marrow exceeding 28.5 Gy was significantly associated with bone marrow toxicity (sensitivity - 82.4%, specificity - 70.6%). On analyzing dose volume parameters, volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy (V20, V30 and V40) more than 71.75%, and 49.75% and 22.85%, respectively, was significantly associated with bone marrow toxicity. CONCLUSIONS: Our study concludes that mean dose to bone marrow exceeding 28.5 Gy has high sensitivity and specificity for predicting bone marrow toxicity in patients receiving IMRT. Volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy significantly correlated with acute haematological toxicity.

Development of an indigenous low-cost multichannel cylinder applicator for vaginal tumors.

PURPOSE: The purpose of this study was to report our experience regarding the development of a low-cost multichannel vaginal cylinder applicator for superficial and recurrent vaginal tumors. METHODS AND MATERIALS: The applicator mold was created by applying heated wax sheets in layers around a plastic tube. Interstitial stainless-steel needles were placed at equal distance around the mold surface to create multiple channels for treatment. Two plans were created using CT images for a patient with a recurrent tumor over the posterior vaginal wall for comparing single-channel and multichannel cylinder dosimetry. The doses received by the target (high risk clinical target volume) and organs at risk (OARs) were computed using dose-volume histograms. RESULTS: There was no significant difference in terms of the prescribed dose delivered to high risk clinical target volume between the two plans. The volume of the target receiving 150 and 200 percent (V150 and V200) dose was higher in the multichannel cylinder plan than the single-channel cylinder plan. In terms of doses to the OARs, there was no significant difference between the rectum doses (D2cc rectum). There was a significant reduction in the dose to the bladder (D2cc bladder), urethra (D0.1cc urethra), and uninvolved vagina (D2cc uninvolved vagina). CONCLUSIONS: Multichannel vaginal cylinders reduce doses to the OARs as compared with the single-channel vaginal cylinder in superficial vaginal lesions limited to the wall of the vagina. Their use is limited by the cost of the applicator. Our low-cost multichannel vaginal cylinder can be used as a reliable alternative in such situations.

Outcomes of freehand interstitial brachytherapy in advanced gynecologic malignancies.

PURPOSE: The purpose of the study is to present the first results of freehand interstitial brachytherapy (ISBT) used to treat patients with carcinoma of the cervix and the vagina. METHODS AND MATERIALS: Patients diagnosed with carcinoma of the cervix or carcinoma of the vagina who were not suitable for intracavitary brachytherapy were treated with freehand ISBT. The implant was performed transperineally using C arm or transrectal ultrasound guidance. Patients received an external beam radiotherapy dose of 50 Gy in 25 fractions. The dose delivered by high-dose-rate ISBT was 18 Gy in three fractions, 6 Gy per fraction, 6 h apart. The brachytherapy dose volume parameters were analyzed after CT-based planning using GEC ESTRO image-guided brachytherapy-based guidelines. RESULTS: From June 2018 till November 2018, 14 patients were treated with freehand ISBT. The mean dose received by 90% of the high-risk clinical target volume (D90) was 82 Gy EQD210 for patients with carcinoma of the cervix and 80 Gy EQD210 for patients with carcinoma of the vagina. The mean dose received by 2 cc volume of the bladder and rectum was 80 Gy EQD23 and 70 Gy EQD23 for patients with carcinoma of the cervix and 75 Gy EQD23 and 72 Gy EQD23 for patients with carcinoma of the vagina, respectively. The mean dose received by 2 cc of the sigmoid was 65 Gy EQD23 for cervical carcinoma and 58 Gy EQD23 for vaginal carcinoma, respectively. At a median followup of 14 months, 2 patients developed local recurrence. Two patients developed Grade 2 gastro intestinal toxicity, and 1 patient developed Grade 2 genitourinary toxicity. None of the patients developed Grade 3 or 4 toxicities. CONCLUSION: A freehand interstitial implant is feasible in resource limited settings and provides acceptable local control with minimal acute toxicity.

Evaluation and Validation of IBA I'MatriXX Array for Patient-Specific Quality Assurance of TomoTherapy®.

TomoTherapy® is a modern radiation treatment technique in which intensity-modulated radiation therapy (IMRT) is delivered in helical fashion. A two-dimensional (2D) array which has been existing for IMRT patient-specific quality assurance (PSQA) verifications for many years is I'MatriXX. Our objectives were to validate this I'MatriXX and to evaluate it for different patient sites and fractionation schedules of TomoTherapy treatment. Twenty-five plans were created with virtual target for different possible pitch values and field widths for validation. Gamma index criteria of 3%/2% dose differences and 3/2 mm distance to agreement were used. QA plans of 26 different treatment sites and different fractionation schedules were used. Results indicated that the matrix response is independent of field width, pitch, and modulation factor of TomoTherapy with 3%, 3 mm criteria. High passing rate ranging from 99.7% to 90.7% was observed for selected patient plans. We found that I'MatriXX 2D array can be utilized for easy and quick TomoTherapy PSQA.

Carcinoma vulva patterns of recurrence and treatment outcomes: A single-institution experience.

AIM: The aim of this study was to evaluate the patterns of recurrence and outcomes in patients with vulvar cancer treated with surgery, with or without postoperative radiotherapy (RT) or RT alone. MATERIALS AND METHODS: The hospital records were retrospectively analyzed from February 2007 to May 2016. All patients that had biopsy-proven carcinoma vulva were included for analysis. Surgery was done by simple or radical vulvectomy with or without lymph node dissection. Radical RT dose was 60 Gy (photons alone or with electron boost). Adjuvant RT was administered in case of node positivity or positive margins. RESULTS: A total of 76 patients were diagnosed as squamous cell carcinoma of vulva. The median age was 59 years. About 59 patients were treated by surgery and 17 patients were treated by radical RT. The most common stage was IB. Adjuvant RT was administered in 10 patients. About 13 patients (22%) underwent inguinal lymphadenectomy. At a median follow-up of 35 months, 49 patients (64.4%) were alive, 27 died, and 6 patients were lost to follow-up. Locoregional recurrence rate was 24.5% in radical surgery group, 12% in surgery plus adjuvant RT group, and 47% in radical RT group. Distant metastasis rate was 4%. The progression-free survival at 3 years was 45.3% and 35.5% in the surgery group and radical RT group, respectively. CONCLUSION: Surgery resulted in favorable local control rates in early-stage carcinoma vulva. Adjuvant RT is indicated in case of nodal positivity or positive margins. Radical RT can be considered as an alternative in patients with comorbidities.

High-dose-rate interstitial brachytherapy in oral cancer-Its impact on quality of life.

PURPOSE: The aim of the study was to assess the impact of high-dose-rate (HDR) interstitial brachytherapy on quality of life (QOL) in oral cancer. METHODS AND MATERIALS: Thirty-two patients of oral cancer treated at our institute from January 2010 to December 2014 with radical radiotherapy (external beam radiotherapy + brachytherapy) were included for analysis; 30 patients received external beam radiotherapy (50-54 Gy) and HDR brachytherapy boost (18-24.5 Gy); 2 patients received radical HDR brachytherapy (31.5 Gy). Quality of life (QOL) was assessed by Telugu, Hindi, and English versions of EORTC Quality of Life Core-30 and EORTC Quality of Life Head and Neck Module (QLQ H&N35) before treatment, at 3 months, 6 months, 1 year, and 2 years after treatment. RESULTS: Of the 32 patients, 2 patients died and 1 patient progressed on followup; 2 patients were re-irradiation cases. On excluding these cases, 27 patients were available for analysis. The followup duration was 6-55 months. At the time of analysis, 91% (29) patients were disease free, 3% (1) progressed, and 6% (2) died. At the end of 2 years, none of the QLQ-C30 functional scores fell below the baseline. Pain, swallowing, sensory, speech, social contact, and social eating worsened at 3 months but improved over 2 years (p < 0.001). Sexuality and financial status showed delayed improvement (p < 0.001). Among the head and neck parameters, dry mouth and sticky saliva were significant determinants of QOL with delayed improvement (p < 0.001). The impact of age, sex, and tumor stage and on QOL was analyzed. Women reported a poorer QOL for physical and emotional parameters, social eating, weight loss, and fatigue. Tumor stage significantly affected QOL, with early stages showing a better QOL. CONCLUSIONS: Almost all patients regained normal function after treatment and reported an excellent QOL at 2 years. However, tumor stage significantly affected the QOL.