Dosimetric Comparison of Isodose Surface Volume and Total Reference Air Kerma (TRAK) based Volume in Cervical Cancer Brachytherapy.

OBJECTIVE: We aim to compare TRAK & TPS based isodose volumes in cervical cancer brachytherapy and assess the feasibility, accuracy and potential future implications of TRAK in this regard and as a newer emerging tool to assess treatment intensity in cervical cancer brachytherapy. METHODS: one hundred patients with histologically proven squamous cell carcinoma of cervix uteri were assessed for brachytherapy (after completion of external radiation) and prospectively enrolled for the study. 60 Gy, 75 Gy, and 85 Gy isodose volumes were obtained from the TPS (VTPS) for 50, 25 & 25 patients with Manchester, Fletcher & interstitial implant respectively, receiving various fractionation schedules by Ir192 HDR remote after-loading system. Using the formula Vpred=4965(TRAK/dref)3/2+170(TRAK/dref)-1.5 the TRAK based isodose surface volumes (Vpred) were derived. Reference doses (dref) were calculated based on accumulated EBRT and brachytherapy doses. The two sets of volume were compared with respect to applicator type, standard, and optimised plan. Surrogate point A dose was also correlated. RESULT: VTPS - Vpred were 5.24 ± 2.7%, all volumes being predicted within 10%. Correlation of TRAK vs VTPS60/ VTPS75/ VTPS85 showed R2 of 0.994, 0.987 and 0.971 respectively. There was no significant difference in predicted volumes with respect to applicator type. The surrogate point A showed mean volume and standard deviation of 7.44 ± 13.4%, 17.63 ± 16.38 and 3.5 ± 0.95 for Manchester optimised, Fletcher optimised and standard plans respectively. TRAK with point A (R2=0.5632), bladder (R2=0.2015) and rectal doses (R2=0.121) yielded no correlation. CONCLUSION: Volumes calculated by TRAK correlate with TPS obtained volumes significantly and the formula predicting isodose surface volumes within 10% accuracy for ICBT applications and not for pure interstitial implants. However, TRAK fails to correlate with surrogate point A, bladder and rectal doses hence has questionable utility as a marker for biological response & treatment intensity.

Nimotuzumab provides survival benefit to patients with inoperable advanced squamous cell carcinoma of the head and neck: a randomized, open-label, phase IIb, 5-year study in Indian patients.

OBJECTIVE: Overexpression of epidermal growth factor receptor (EGFR) in many cancers makes it an attractive therapeutic target. This study evaluated the clinical utility of nimotuzumab, a monoclonal anti-EGFR antibody, used concurrently with radiotherapy (RT) and chemoradiotherapy (CRT) in squamous cell carcinoma of the head and neck (SCCHN). METHODS: This open-label study randomized 92 treatment-naïve patients (1:1) with advanced SCCHN into chemoradiation (CRT ± nimotuzumab) or radiation (RT ± nimotuzumab) group by investigator's discretion; these were further randomized into CRT + nimotuzumab or CRT and RT + nimotuzumab or RT groups, respectively. Treatment included 6 cycles each of cisplatin (50 mg/week), nimotuzumab (200 mg/week), and RT (total dose, 60-66 Gy). Response (tumor size reduction) was assessed at Month 6 post-treatment and survival, at Month 60. RESULTS: Forty and 36 patients in the chemoradiation and radiation groups, respectively (intent-to-treat population) were evaluated. Overall response at Month 6 post-treatment was 100% with CRT + nimotuzumab, 70% with CRT, 76% with RT + nimotuzumab, and 37% with RT. At Month 60, overall survival was 57% with CRT + nimotuzumab, 26% with CRT (P = 0.03), 39% with RT + nimotuzumab, and 26% with RT (P > 0.05). Median overall survival was not reached for CRT + nimotuzumab; it was 21.94 months for CRT (P = 0.0078), 14.36 months for RT + nimotuzumab, and 12.78 months for RT (P = 0.45). Risk of death was 64% lower with CRT + nimotuzumab than with CRT (95%CI: 0.37, 1.56), and 24% lower with RT + nimotuzumab than with RT (95%CI: 0.16, 0.79). Thus nimotuzumab was safe and well tolerated with few mild to moderate self-limiting adverse events. CONCLUSION: Concurrent use of nimotuzumab with CRT/RT is safe and provides long-term survival benefit.

Strain improvement of thermotolerant Saccharomyces cerevisiae VS strain for better utilization of lignocellulosic substrates.

AIM: Pentose-utilizing yeast development by protoplast fusion and sequential mutations and ethanol fermentation using lignocellulosic substrate. METHODS AND RESULTS: Protoplasts of thermotolerant Saccharomyces cerevisiae and mesophilic, xylose-utilizing Candida shehatae were fused by electrofusion. The fusants were selected based on their growth at 42 degrees C and ability to utilize xylose. The selected best fusant was mutated sequentially and 3 mutant fusants obtained were tested for their stability. The mutant fusant CP11 was found to be stable and used for lignocellulosic fermentation. The Prosopis juliflora wood material was hydrolysed with 1% sulphuric acid initially for 18 h at room temperature and then for 20 min at 121 degrees C. The acid hydrolysate was separated and used for detoxification by ethyl acetate and overliming. The hard cellulosic fraction was hydrolysed with Aspergillus niger crude cellulase enzyme for 18 h at 50 degrees C. The substrate (15% w/v) yielded 84 g l(-1) sugars, representing 80% (w/w) hydrolysis of carbohydrate content present in the lignocellulosic material. The acid and enzyme hydrolysates were then equally mixed and used for fermentation with the developed fusant yeast (CP11). The fusant yeast gave an ethanol yield of 0.459 +/- 0.012 g g(-1), productivity of 0.67 +/- 0.015 g l(-1) h(-1) and fermentation efficiency of 90%. CONCLUSIONS: Protoplast fusion followed by sequential mutations method gave a stable and good performing fusant with maximum utilization of reducing sugars in the media. SIGNIFICANCE AND IMPACT OF THE STUDY: This new method could be applied to develop fusants for better biotechnological applications.

Lantana camara for fuel ethanol production using thermotolerant yeast.

AIM: Evaluation of Lantana camara's use as feedstock for fuel ethanol production. METHODS AND RESULTS: Lantana camara plant material was hydrolysed with 1% sulfuric acid for 18 h at room temperature, followed by heat treatment of 121 degrees C for 20 min. Hemicellulosic hydrolyzate was separated and used for detoxification by ethyl acetate and overliming. Cellulosic fraction was hydrolysed with Aspergillus niger crude cellulase enzyme for 18 h at 55 degrees C. Using 15% (dw/v) substrate 73 g l(-1) total reducing sugars were obtained to give 78.7% hydrolysis of carbohydrate content. Acid and enzyme hydrolyzates were mixed equally and used for fermentation with thermotolerant Saccharomyces cerevisiae (VS(3)). Yeast fermented L. camara hydrolyzate well with a fermentation efficiency of 83.7% to give an ethanol yield of 0.431 +/- 0.018 g ethanol pre g sugar and productivity of 0.5 +/- 0.021 g l(-1) h(-1). CONCLUSIONS: Even though inhibitors were present in L. camara hydrolyzate, maximum sugars were utilized by thermotolerant yeast. SIGNIFICANCE AND IMPACT OF THE STUDY: Use of L. camara for fuel ethanol production with improved strains and detoxification can be recommended.