PurposeThis study was initiated to prove feasibility of hydrogel application in recto-vaginal space in intracavitary brachytherapy (ICBT) of cervical cancer in order to reduce rectal toxicity.Material and methodsIn a case of stage IIB cervical cancer, after external beam radiotherapy (EBRT), we planned ICBT 7 Gy × 3 fractions. In 1st fraction (Plan 1), due to narrow separation between rectum and cervix (0.18 cm), only 5 Gy was delivered at point A (with high-risk clinical target volume [HR-CTV] D90 5.94 Gy, intermediate risk clinical target volume [IR-CTV] D90 4.54 Gy, rectum D2cc 5.72 Gy, bladder D2cc 5.52 Gy, and sigmoid colon 5.82 Gy). In 2nd fraction (Plan 2), interstitial brachytherapy (ISBT) was attempted. For the prescription of 5 Gy, we get dose levels almost similar to the 1st insertion: HR-CTV D90 (6.7 Gy), IR-CTV D90 (3.06 Gy), bladder D2cc (5.7 Gy), rectum D2cc (4.8 Gy), sigmoid colon D2cc (1.3 Gy) (separation = 0.23 cm). During 3rd fraction (Plan 3), prior doing interstitial insertion, we instilled 50 cc of hydroxypropyl methylcellulose (Viscomet®) up to the tip of recto-vaginal septum. A repeat computed tomography (CT) scan was done 4 hours after Plan 3 treatment and it was re-planned (Plan 4) to find out migration of hydrogel if any and its dosimetric impact.Results9 Gy was delivered to point A with a separation of 1.1 cm in Plan 3 (with HR-CTV D90 16.4 Gy, IR-CTV D90 11.3 Gy, rectum D2cc 3.6 Gy, bladder D2cc 6.9 Gy, and sigmoid colon 2.2 Gy). We achieved an optimum cumulative EQD2 dose (HR-CTV D90 98.4 Gy, IR-CTV D90 76.1 Gy, rectum D2cc 67.7 Gy, bladder D2cc 73.2 Gy, and sigmoid colon 59.3 Gy). Hydrogel volume was decreased in Plan 4 without a major dosimetric changes.ConclusionsHydrogel instillation is a useful tool for recto-vaginal separation during cervical cancer brachytherapy. It increases therapeutic ratio without any adverse event.

Introduction: The aim of the study is to evaluate the clinical efficacy of Triple-D scoring system versus Quadruple-D scoring system for assessing stone-free rate (SFR) in individuals with renal stones measuring 1–2 cm in diameter after extracorporeal shock wave lithotripsy (ESWL). Materials and Methods: The study was conducted on 120 patients who presented to a tertiary care center in eastern India. Systemic random sampling technique was applied with a sampling interval of 2. Triple-D scoring system comprising of three computed tomography based metrics – stone dimension (volume), stone density (Hounsfield unit), and skin-to-stone distance (SSD) was done before ESWL. Stone location was included as an additional parameter to formulate Quadruple-D scoring system where an extra score was given for stones in the non-lower polar region. Stone-free status was assessed by plain abdominal radiography 3 weeks after ESWL. Results: In the study population, stone dimension, stone density, and stone location were positive predictors of SFR after ESWL whereas age, sex, and body mass index of the patients, laterality of the stone and SSD were not. The area under the curve of Triple-D and Quadruple-D scoring systems were 0.598 and 0.674. Conclusion: Triple-D scoring system has been successfully validated as the SFR showed a parallel increase with every positive component. The Quadruple-D scoring system with a simple addition of stone location can further facilitate the validation of Triple-D scoring by increasing SFR, keeping the calculation simple and easy to use. These findings support the incorporation of Quadruple-D scoring system over Triple-D scoring system.

PurposeDuring intracavitary brachytherapy (ICBT) for cervical cancer, the choice of applicator system remains rather arbitrary. However, as the applicator geometry may play an important role in dose distribution, thereby improving the therapeutic ratio, this study was conducted to compare the Manchester-style and Fletcher-style applicator systems.Material and methodsAfter completion of EBRT, 22 patients with cervical cancer (stage IIA-IIIB) underwent intracavitary brachytherapy. Two different types of applicators: Manchester-style and Fletcher-style were used for each patient for alternate insertions. The purpose was to compare the dose distribution obtained when two different applicators were applied to the same patient. CT based computerized treatment planning was done and dose was prescribed to point A. After optimization, height, width and thickness of the 100% isodose curve, as well as the 100% isodose volume were noted. Dose received by the urinary bladder and rectum were noted.ResultsThe 100% isodose volume and its maximum width were significantly greater (P value < 0.0001 in both occasions) when Manchester-style applicator was used. However, the dose received by 0.1 cc, 1.0 cc and 2.0 cc of the urinary bladder were all significantly greater (P value < 0.0001) with the Manchester-style applicator. No significant difference was found in rectal doses.ConclusionsThe larger 100% isodose volume, as well as the greater width achieved with the use of Manchester-style applicator can be helpful in circumstances where the tumour is large in size. However, this must be balanced against the increased dose received by the urinary bladder.