Interfraction variations in doses at OARs during three-dimensional high dose rate brachytherapy planning of cervix cancer

Objective

The American Brachytherapy (BT) Society recommends that BT must be included as a component of the definitive radiation therapy for cervical carcinoma because recurrences and complications are decreased when BT is used in addition to external beam radiotherapy. The aim of this study is to quantify the interfraction dose variations (VARacts) during high dose rate (HDR) BT, the effect of variation in dose in terms of excess "unrecognized" dose to OAR and to conclude the reason of the variation in reference of applicator position/geometry versus deformation of the organ at risk (OAR) concerned.

Materials and Methods

Total 30 patients of carcinoma cervix, biopsy proven, between June 2018 and May 2019, were taken for the study. All patients were treated with external beam radiation therapy to a dose of 50 Gy in 25 fractions over 5 weeks, followed by three fractions of HDR intracavitary brachytherapy (ICBT) (7.5 Gy to point A in each fraction) by two-dimensional (2D) X-ray-based planning. Before treatment in the first and last fraction of BT, computed tomography (CT) scan was done for every patient. Then, a 3D-based planning was performed with CT images on our HDR Plus software with image sequence option. VARact was calculated. Rigid image registration of consecutive fraction images was used for quantification of the hypothetical variation in dose (VARhypo) arising exclusively due to changes in applicator placement and geometry.

Results

The mean contoured rectal volumes for the first and third fractions were 41.49 cc and 44.72 cc, respectively, while the respective volumes for bladder were 9.33 cc and 9.35 cc cm. These differences were statistically insignificant (P value: 0.263 and 0.919 for rectum and bladder, respectively). The mean equivalent dose in 2 Gy fraction (EQD2) bladder D2cc was 5.68 Gy and 5.79 Gy in the first and third fraction ICBT, respectively. The mean EQD2 for the rectal D2cc was 11.63 Gy and 12.85 Gy in the first and third fraction ICBT, respectively. None of the patients had an actual cumulative EQD2 more than 90 Gy for bladder, but 36.66% of the patients had a rectal dose exceeding the tolerance (75 Gy). Regression plots showed that VARhypo alone could predict about 42.2% of the VARact in the rectum and 19.2% of the VARact in the bladder. Thus, the remaining variation was due to the organ deformation-related dose variations between the two fractions.

Conclusions

There were no statistically significant variations in the volumes or doses of OAR between the two fractions. However, a significant proportion of patients may have a higher dose to the OAR in the third fraction in the absence of individualized planning. This increase is likely to be more detrimental where higher doses per fraction are used. Variations in OAR doses may be caused by organ deformation and/or changes in applicator placement/geometry.

Comparative study of concurrent conventional chemoradiotherapy versus hypofractionated chemoradiotherapy in newly diagnosed glioblastoma multiforme postoperative patients

Purpose

To assess the treatment response and toxicity profile among two groups of newly diagnosed glioblastoma multiforme (GBM) postoperative patients receiving conventional radiotherapy (RT) versus hypofractionated RT with concurrent temozolomide (TMZ) in both.

Materials and Methods

A total of 50 patients randomly allotted into two arms (25 in each). Dose received 60 Gy (2 Gy/#) in conventional fractionation RT versus 50 Gy (2.5 Gy/#) in hypofractionated RT with concurrent TMZ 75 mg/m2 orally daily in both arms, respectively. Follow-up was done at 1, 3, 6, and 12 months after completion of treatment to evaluate toxicities, treatment response, and progression-free survival (PFS).

Results

All patients were well tolerated with treatment; no major adverse effects were monitored in two arms. There was no statistical significant difference in treatment response, which was found 64% versus 60% in arm A and arm B, respectively, at 3 months of follow-up (P = 0.768). Toxicity profiles were also noted similar in both arms. The 6-month PFS was 84% and 80% in arm A and arm B, respectively (P = 0.71) and 12-month PFS was 60% and 52% in arm A and arm B, respectively (P = 0.69).

Conclusion

Among the patients followed, this study showed that hypofractionated RT regimen was not inferior to conventional RT regimen.

A plan comparison study between rapid arc and conventional intensity-modulated radiation treatment plans in nasopharyngeal carcinoma patients

Introduction

Head and neck cancers are one of the common malignancies in Indian population. It's entity, nasopharyngeal carcinoma is among the aggressive malignancies with its location and spread near very critical structures. Thus requires a highly conformal radiotherapy delivery techniques.

Purpose

The aim of the study is to dosimetrically evaluate and to compare Intensity modulated radiation therapy (IMRT) plans and RAPID ARC plans for irradiation of nasopharyngeal carcinoma.

Material and Method

A retrospective study is done on 10 nasopharyngeal carcinoma patients, who were treated with Radiotherapy at ATRCTRI Bikaner. Radiotherapy was delivered by IMRT technique (Total of 70 Gy in 33 fractions). Same patients are now planned on Rapid arc technique. Dosimetric comparison is done in terms of PTV coverage, OAR dose, conformity index, homogeneity index.

Result

PTV coverage is similar with both the plans. Homogeneity index is higher for IMRT plans 0.119+/- 0.020 compared to 0.104 +/- 0.018 for Rapid arc plans (statistically significant).The Rapid arc plans achieved slightly better conformity 1.018+/-0.09, whereas 1.105+/-0.12 for IMRT plans. Rapid arc achieved better results for OAR, statistically significant for Brainstem (54.4 +/-10.4 Gy for IMRT and 49.7+/-4.2 Gy for Rapid Arc, Lens (Left lens and Right lens received 10.55+/-5.8 Gy and 9.44+/-9.08 by IMRT and 6.12+/-6.1 Gy and 5.45+/-6.05 Gy for Rapid Arc), optic nerves (Right and Left optic nerve received 34.36 and 35.01 Gy for IMRT plans and 30.06 and 30.05 Gy for Rapid Arc plans. However the gains are statistically insignificant for spinal cord and vestibulocochlear nerve. No major difference found for Right and left parotid between both the arms.

Conclusions

Rapid Arc is better technique compared to IMRT for Nasopharyngeal carcinoma treatment, that provides better dose conformity, more homogeneous coverage and OAR sparing. However study is retrospective and has lesser patients, thus requires prospective study with more number of patients along with comparison of clinical outcome.

Comparative study of induction chemotherapy followed by chemoradiotherapy versus chemoradiotherapy alone in locally advanced head and neck cancer

Objective

Concurrent chemoradiotherapy (CTRT) is the standard treatment for patients with unresectable, nonmetastatic Locally advanced squamous cell cancer of head and neck (LASCCHN). The aim of this study to compare the efficacy and toxicity of induction chemotherapy (ICT) followed by CTRT versus standard CTRT alone in patients with LASCCHN.

Materials and Methods

Between January 2017 and September 2017, 100 patients with LASCCHN (Stage III and IV) were randomly assigned to two arms: 50 patients in each. Arm A treated by standard CTRT alone (a total 66 Gy in 33fr 2 Gy/# administered daily 5 days/week with 3 weekly inj. cisplatin 100 mg/m² divided in two days) and Arm B received two cycles of ICT (TPF - inj. paclitaxel 175 mg/m2 on day 1, cisplatin 100 mg/m2 divided in 2 days and inj. 5FU 1 gm/m2 iv d1 and d2 ) followed by same CTRT. Assessment was done weekly during RT and 1, 3, 6, 12, and 18 months posttreatment for treatment response, toxicities, and progression-free survival (PFS).

Results

Total response was observed 79.1% and 82.1% in Arm A and Arm B, respectively (P = 0.705) at 6-8 weeks after the completion of treatment. Acute toxicities were significantly higher in ICT arm. The 18 months PFS was 57% versus 55% in Arm A and Arm B, respectively (x² = 0.039, P = 0.8414).

Conclusion

Among the patients followed, this study failed to show benefit of ICT-CTRT over CTRT alone in patients of LASCCHN.

Hypofractionated radiotherapy versus conventional radiotherapy in early glottic cancer T1-2N0M0: A randomized study

Objective

Glottic cancer has an excellent probability of cure. The early glottic cancer is usually treated by radiotherapy with different fractionation schedules. The aim of this study was to compare conventional versus hypofractionated radiotherapy with respect to overall survival and disease-free survival.

Materials and Methods

A total of fifty patients with T1-2N0M0 glottic cancer with no previous treatment history were prospectively randomized into two arms. In Arm A (Study), patients received a total of 55 Gy in 20# at 2.75 Gy/#, 5 days a week. In Arm B (Control), patients received a total of 66 Gy in 33# at 2 Gy/#, 5 days a week. Disease response was evaluated by the WHO criteria at the end of treatment, then at 1, 2, and 3 months to complete their 6-month follow-up. Overall survival and disease-free survival were evaluated at 1, 2, and 3 years.

Results

Overall, 100% of patients in the study arm and 96% of patients in the control arm had complete response after 6 months. Overall survival rates at 1, 2, and 3 years were 96%, 96%, and 88%, respectively, in the study arm, while in the control arm, these values were 92%, 84%, and 80%, respectively, and the difference was not statistically significant (P > 0.05). Disease-free survival at 3 years was 88% in the study arm and 80% in the control arm.

Conclusion

The study suggests that hypofractionated regimen may be better in local control and symptomatic relief with the added advantage of shorter treatment time, which offers better patient compliance and advantageous in busy setups where there is heavy patient load.

A Comparative Study Of Concurrent Chemo-Radiotherapy With or Without Neoadjuvant Chemotherapy in Treatment of Locally Advanced Non Small Cell Lung Cancer

INTRODUCTION

The standard treatment for unresectable stage III non-small-cell lung cancer (NSCLC) is concurrent chemoradiotherapy. This study was undertaken to evaluate whether induction chemotherapy along with concurrent chemoradiotherapy would result in better tumor control, improved symptom control and any variation in toxicity as compared to concurrent chemoradiotherapy alone.

PATIENTS AND METHODS

Between February 2015 to September 2016, 25 patients each were randomized to control group, in which they received concurrent chemoradiotherapy with weekly cisplatin 40 mg/m2 intravenous, during chest radiotherapy of 66Gy in 33 fractions for 6.5 weeks, and study group, in which patients received three cycles of induction chemotherapy with Cisplatin 75 mg/m2and Paclitaxel 175 mg/m2administered every 21 days followed by identical chemoradiotherapy.

RESULTS

The two groups of patients (with induction vs. without induction chemotherapy) were similar in age, performance status, histology, grade, and stage. At 6thmonth follow-up, complete response was seen in 6 patients in control arm and 7 patients in study arm (?2 = 1.603, p = 0.205) and partial response was seen in 13 and 12 patients in control and study arms respectively (?2 = 1.932, p = 0.165). Symptom control of cough, hemoptysis, chest pain and dyspnoea were also similar in both groups.

DISCUSSION

In our study, no difference in treatment outcome with respect to the two groups was observed, which was similar to studies which have been conducted previously. Radiation is a good modality for symptom control of cough, hemoptysis, chest pain and dyspnoea. In toxicities, pneumonitis and hematological toxicity was slightly higher in study group even at 6th month follow up.

CONCLUSION

Slight increase in toxicity with no added benefit in locoregional tumor control and symptom regression, was seen in patients receiving induction chemotherapy followed by chemoradiotherapy. Concurrent chemoradiotherapy alone can thus be used as only modality of treatment in unresectable stage III NSCLC.

Long Term Arm and Shoulder Toxicities in Breast Cancer Patients Receiving Hypofractionated Radiation Therapy

   Aim: The purpose of this study is to evaluate the late toxicities in hypo fractionated radiation schedule in breast cancer patients with regional nodal irradiation (RNI), limited to axilla and supraclavicular regions. Late effects on arm and shoulder were noted as follows: skin edema (lymphedema), restricted shoulder movements (brachial plexus injury) and localised pain.Material and Methods: In this study we randomly enrolled 100 breast cancer post mastectomy cases in the year 2018. All cases were previously asymptomatic after surgery. They were prospectively treated with hypo fractionated local and regional nodal irradiation by 2.67 gray / fraction dose, total 15 fractions (total dose-40 gray). Evaluation was done at 12 months after completion of radiation therapy. Assessment was done by RTOG, LENT- SOMA scales. Results: Significant lymphedema was observed in 17 (17%) cases. Restricted arm mobility was seen in 14 (14%) of patients. Pain (moderate/severe) in arm and shoulder was most commonly seen, in 25 (25%) cases. Conclusions: As hypo fractionated regimes in breast cancer treatment have become new standard; its late term effects are significant and comparable to other conventional radiation therapy regimes. These studies need further and longer duration of evaluation.    

Neo-adjuvant chemotherapy followed by either continuous hyper-fractionated accelerated radiation therapy week-end less or conventional chemo-radiotherapy in locally advanced NSCLC-A randomised prospective single institute study

Context

Better locoregional control and increased overall survival by continuous hyper fractionated accelerated radiotherapy have been shown in unresectable nonsmall cell lung carcinoma (NSCLC). Dose escalation and neoadjuvant chemotherapy (NACT) along with continuous hyperfractionated accelerated radiotherapy week end-less (CHARTWEL) were also tried for improved survival. In this present study, we compared the results of NACT followed by CHARTWEL against NACT followed by conventional concurrent chemo-radiation therapy.

Aims

The aim of this study is to compare the locoregional control and toxicities in NSCLC Stage IIIA and B in both arms.

Settings and Design

Randomized, prospective single-institutional study with a study population comprising all locally advanced unresectable NSCLC patients enrolled in 2014 at our institute.

Subjects and Methods

All enrolled patients were randomized into two arms-CHARTWEL and concomitant chemo-radiotherapy (CCRT), after three weeks of the fourth cycle of NACT. In CHARTWEL arm 30 patients received two-dimensional radiotherapy (RT) 58.5 Gy/39 fr/2.5 weeks while in CCRT arm 30 received 66 Gy/33 fr/6.5 weeks. Disease response was evaluated at 6 months and toxicity assessment during and after treatment completion. Data were analyzed using tools such as percentage, mean, Chi-square test and P value. Chi-square and P value was calculated by statistical online software (http://quantpsy.org).

Results

28% of patients in study arm and 20% in control arm had complete response at 6 months after RT. Locoregional disease control was observed in 44% in study arm and 32% in control arm of patients. There was no statistical difference in grades of toxicities or overall survival (OS)/disease-free survival except persistent esophagitis Grade III seen in two patients of study arm.

Conclusions

Study suggests that CHARTWEL in combination with NACT is an effective strategy to treat patients with locally advanced lung cancer with the advantage of a smaller dose and shorter duration. Although large multivariate studies still needed.

Metronomic palliative chemotherapy in locally advanced, recurrent and metastatic head-and-neck cancer: A single-arm, retrospective study of a regional cancer center of North India (Asia)

Background

Head-and-neck cancer is the most common cancer in developing countries of Southeast Asia. Most of the patients present to the hospital in advanced stage and have a poor prognosis. This study aims to evaluate the efficacy and toxicity profile of oral metronomic chemotherapy (MCT) in the form of methotrexate and celecoxib in locally advanced, recurrent and metastatic head-and-neck cancers.

Materials and Methods

This was a single-arm retrospective observational study that included posttreatment patients with locally advanced, recurrent and metastatic disease in the year 2016 (January 1, to December 31, 2016). A total of 84 patients warranting palliative chemotherapy but not willing to take intravenous chemotherapy were included in the study. The oral MCT schedule consisted of oral celecoxib (200 mg twice daily) and oral methotrexate (15 mg/m²/week). Response evaluation was done using the Response Evaluation Criteria in Solid Tumors criteria version 1.1, and toxicity profile was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03. Descriptive statistics and Kaplan-Meier analysis were performed.

Results

Eighty-four patients, 68 males and 16 females, with a median age of 62 years (range: 35-80 years), were enrolled in the study to receive oral MCT. The Eastern Cooperative Oncology Group performance status was 0-1 in 62 patients and 2-3 in 22 patients. The primary sites of disease were buccal mucosa (18), tongue (22), tonsil (24), lower alveolus (7), hypopharynx (10), and soft palate (3). The best clinical response rate in post oral MCT was seen in the first 4 months (120 days). Objective response was observed in 67% of patients in the form of stable disease (56%) and partial response (11%). Disease progression was observed in 27% of patients. The median follow-up was 192 (6.4 months) days. The median estimated overall survival was 195 (6.5 months) days. The median estimated progression-free survival was 110 (3.6 months) days. Symptomatic relief with respect to pain was reported in about 75% of patients. Eighteen (21%) patients had Grade I-II mucosal reactions. Grade III-IV mucosal reactions were observed in five (6%) patients. Seventy-eight (93%) patients died at the end of the study at 1 year. Dose reduction was required in 15 (18%) patients.

Conclusion

Oral MCT using celecoxib and methotrexate is an effective, economical, and well-tolerated regimen with good pain control and low toxicity profile in patients with locally advanced, recurrent and metastatic head-and-neck cancer.

Acute treatment-related toxicity in elderly patients with good performance status compared to young patients in locally advanced esophageal carcinoma treated by definitive chemoradiation: A retrospective comparative study

Introduction

The benefit of definitive chemoradiotherapy (CRT) in elderly patients with locally advanced esophageal cancer is not well established. We perform a single institutional retrospective study of CRT in terms of toxicity in elderly patients (age more than 60 years) as compared with young cohort (age <60 years) in locally advanced nonmetastatic esophageal cancer.

Patients and Methods

A total 145 of patients, 79 in young age (Group A) and 66 patients of elder age (Group B) with Stage II and III squamous cell carcinoma of the esophagus with ECOG PS of 0-1, who had undergone definitive CRT at our institute from January 2015 to November 2018 were selected for this analysis. Chemotherapy was cisplatin (40 mg/m²) given concurrently on weekly basis with radiotherapy (RT). Total prescribed dose of RT was 50.4 Gy at the rate of 1.8 Gy per fraction. Median age was 40 years (25-60 years) and 65 years (60-75 years) in young and elderly group, respectively. Follow-up is done at median of 28 months (1-48 months) after treatment.

Results

Acute Grade 2-3 esophagitis was seen in 48.10% in young cohort, while it was 60.6% in older group. Grade 2-3 nausea and vomiting was seen in 32.91% in young age patients, while it was 45.5% in elder patients. No statistically significant difference is seen in acute treatment-related toxicity in young and elderly group.

Conclusion

Our conclusion is that patients with adequate functional status should not be excluded from curative CRT based on age alone.

Prospective randomized trial of standard antiemetic therapy with yoga versus standard antiemetic therapy alone for highly emetogenic chemotherapy-induced nausea and vomiting in South Asian population

Aim/Background

Chemotherapy-induced nausea and vomiting (CINV) is one of the most distressing side effects of highly emetogenic chemotherapy regimens. There have been continuous efforts in the direction to control CINV by many investigators.

Materials and Methods

Randomly selected patients were those receiving highly emetogenic chemotherapy regimen grouped into yoga and standard antiemetic therapy (n = 50) just before receiving chemotherapy and continued for the following days and other group (n = 50) received only the standard antiemetic agent. Both the groups were assessed, followed for acute and delayed onset of chemotherapy-induced and anticipatory nausea and vomiting using radiation therapy oncology group grading for the same. We also assessed the quality of life of the patient using the Functional Assessment of Cancer Therapy-General questionnaire.

Results

The median age group of the patients was 51 years with male:female ratio 2:1, The Eastern Cooperative Oncology Group (ECOG) performance status was 0/1 in 38% of the selected population, while ECOG 2 in 62% of the patients. In yoga arm, insignificant reduction in chemotherapy-induced nausea (90% vs. 78%, P = 0.35) and but significant reduction in vomiting (42% vs. 22%, P =0.01) was observed as compared to the standard antiemetics only arm. There was a significant reduction in Grade 2 and 3 nausea (84% vs. 38% P < 0.01) and vomiting (14% vs. 0% P < 0.01). Quality of life is also significantly improved in the yoga arm, especially in the ECOG 2 performance status.

Conclusions

This study concludes that yoga along with standard antiemetic medication should be a part of the management plan for the cancer patients receiving highly emetogenic chemotherapy.

Estimation of radiation-induced second cancer risk associated with the institutional field matching craniospinal irradiation technique: A comparative treatment planning study

Aim

To estimate and compare the lifetime attributable risk (LAR) of radiation-induced second cancer (SC) in pediatric medulloblastoma patients planned with institutional 3D conformal field matching method, gap junction method and Intensity Modulated Radiotherapy (IMRT).

Background

The epidemiological studies on childhood cancer survivors reported that long-term cancer survivors who received radiotherapy are at a significantly increased risk for the development of SC. Hence, the increased concern to predict the SC risk for long-term survivors.

Materials and methods

In addition to institutional field matching planning method, IMRT and gap junction methods were created for ten pediatric medulloblastoma patients. The risk estimates were made based on the site-specific cancer risk coefficient provided by the BEIR VII committee according to the organ equivalent dose for various critical organs. Also, plans were compared for target volume dose distribution and dose received by critical organs.

Results

When compared to the gap junction method, the IMRT and institutional field matching method were superior in normal tissue sparing and dose conformity. However, highly significant volume of low dose associated with IMRT was the main concern for the SC risk. The accumulated LAR for all the critical organs with 3D conformal gap junction and IMRT method was 23-25% while for the 3D conformal field matching method it was 21%.

Conclusion

The LAR associated with the institutional field matching technique was substantially lower. As this method is highly robust and easy to set up, it can be a better choice of a craniospinal irradiation technique where 3DCRT is the only choice of treatment.

Lung cancer screening - gaining consensus on next steps - proceedings of a closed workshop in the UK

Lung cancer is the most common cause of cancer death in the UK, and survival from the disease is persistently poor. Efforts to improve outcomes for patients have focused on ways of reducing late diagnosis of the disease, and access to optimal treatment. Research on lung cancer screening has so far provided some evidence of an impact on lung cancer mortality, but there is some debate about whether implementation of a national screening programme should await further trial data, principally that from the NELSON trial. The ongoing poor outcomes and the belief amongst some clinicians that there is sufficient evidence has prompted several local projects testing out lung screening in their communities, sometimes referred to as lung health checks or proactive approaches to high-risk individuals. Funding from NHS England has been forthcoming to support this. Acknowledging roll-out of such activities, which effectively constitute local lung screening in the absence of a NSC recommendation, it was timely to bring key national stakeholders together with academic and clinical experts, to agree a way forward. Cancer Research UK therefore convened a closed workshop in March 2018, involving national and international expertise. This paper outlines the proceedings, key discussion points, highlighted research gaps, and areas of consensus and next steps.

Accelerated hypofractionation (OCTA SHOT): Palliative radiation schedule in advanced head and neck carcinoma

BACKGROUND

Head and neck cancers are attributed to be the most common type of malignancy in the developing countries with most cases presenting in advanced stage. This pilot study was performed to evaluate the effect of an accelerated hypofractionated 4 days schedule (octa shot) in providing palliation to such advanced cases of head and neck cancer.

MATERIALS AND METHODS

Twenty-two patients with advanced (Stage VIB-IVB) squamous cell carcinoma of head and neck region were enrolled in the study. All these patients were planned for radiotherapy at Cobalt Unit with a fractionation schedule of 3.5 Gy/fraction, 2 fractions/day with 6 h interval between two fractions, for four days (28 Gy/8Fr/4 days). Patients were reviewed at 2 and 4 weeks to assess change in tumor size, any symptomatic relief, or toxicity. The tumor response, dermal, and mucosal toxicities were assessed using WHO criteria.

RESULTS

Median age of these 22 patients (17M male + 5F female) in the study was 59.8 years. After completion of radiotherapy, first response evaluation done at 15th day showed ≥50% objective response in 14 patients. At 1 month, this response increased to ≥75% in 16 patients and 50%-75% in three patients. None of the patients had disease progression. Improvement in symptoms was reported with respect to pain and dysphagia by patients subjectively. Only two patients reported Grade III mucositis; remaining patients had mucositis and dermatitis up to Grade II.

CONCLUSION

The study concludes that this "octa shot" is an effective palliative radiotherapy schedule. With a decreased duration of hospital stay, it is also favorable for outpatients.

Reduction of Dose to the Contralateral Breast by Superflab Use in Radiation Therapy for Mammary Carcinomas

Background: Radiation therapy is an integral part of multimodality treatment for locally advanced carcinoma of breast. Radiation doses to nearby critical normal structures like heart, lungs, and contralateral breast (CLB increases risk of second malignancies. In this study, we measured doses to the CLB and studied effects of a 1 cm thickness superflap. Materials and Methods: Fifty post-mastectomy carcinoma breast patients were included in the study.Radiation therapy of 50 Gy was planned in 25 fractions, 5 days a week, using the Eclipse Treatment Planning System version 8.9.15, with a pencil beam convolution algorithm and 6 MV photon beam. Plans were transferred to a linear accelerator (Varian 2300 CD) for execution of treatment. Twenty-four CaSO4 thermoluminescent dosimeter discs (TLDs) were used for dose measurement over the CLB. The dose was measured for each patient without a superflab for ten fractions and with for another ten fractions for subsequent comparison. Results: Mean doses/fractions received by the CLB with and without a superflab? were 3.78 ± 1.29 cGy and 7.82 ± 2.62 cGy, respectively, with total dosees of 94.69 ± 32.43 cGy (1.89% of prescribed dose) and 191.14 ± 65.62 cGy (3.82% of prescribed dose). The average reduction in mean dose with a 1 cm thick superflab was 46.57 ± 17.18%, in the range of 20 to 80% and statistically significant (p < 0.001). Conclusion: Superflab? is an effective method for dose reduction to CLB. It is an easy, convenient and low time consuming method. Elucidation of any role in reduction of 2nd malignancies in CLB now needs large studies with long follow-up.

Characterisation of Shiga toxin-producingEscherichia coli(STEC) isolated from seafood and beef

Shiga toxin-producing Escherichia coli (STEC) strains isolated in Mangalore, India, were characterised by bead-enzyme-linked immunosorbent assay (bead-ELISA), Vero cell cytotoxicity assay, PCR and colony hybridisation for the detection of stx1 and stx2 genes. Four strains from seafood, six from beef and one from a clinical case of bloody diarrhoea were positive for Shiga toxins Stx1 and Stx2 and also for stx1and stx2 genes. The seafood isolates produced either Stx2 alone or both Stx1 and Stx2, while the beef isolates produced Stx1 alone. The stx1 gene of all the beef STEC was found to be of recently reported stx1c type. All STEC strains and one non-STEC strain isolated from clam harboured EHEC-hlyA. Interestingly, though all STEC strains were negative for eae gene, two STEC strains isolated from seafood and one from a patient with bloody diarrhoea possessed STEC autoagglutinating adhesion (saa) gene, recently identified as a gene encoding a novel autoagglutinating adhesion.

Application of polymerase chain reaction for detection of Vibrio parahaemolyticus associated with tropical seafoods and coastal environment

AIMS

To study the incidence of Vibrio parahaemolyticus in seafoods, water and sediment by molecular techniques vs conventional microbiological methods.

METHODS AND RESULTS

Of 86 samples analysed, 28 recorded positive for V. parahaemolyticus by conventional microbiological method, while 53 were positive by the toxR-targeted PCR, performed directly on enrichment broth lysates. While one sample of molluscan shellfish was positive for tdh gene, trh gene was detected in three enrichment broths of molluscan shellfish.

CONCLUSIONS

Direct application of PCR to enrichment broths will be useful for the rapid and sensitive detection of potentially pathogenic strains of V. parahemolyticus in seafoods.

SIGNIFICANCE AND IMPACT OF THE STUDY

Vibrio parahaemolyticus is an important human pathogen responsible for food-borne gastroenteritis world-wide. As, both pathogenic and non-pathogenic strains of V. parahaemolyticus exist in the seafood, application of PCR specific for the virulence genes (tdh & trh) will help in detection of pathogenic strains of V. parahaemolyticus and consequently reduce the risk of food-borne illness.

Direct immunofluorescent studies of skin biopsies in pemphigus

Direct immunofluorescent studies of skin biopsies from 16 pemphigus vulgaris patients revealed immunoglobulin deposits in 12 (75%) cases with fluorescence at intercellular areas in epidermis. In 2 patients (12.5%) dermoepidermal junction also showed immunoglobulin deposits. IgG was the commonest type of immunoglobulin demonstrated in 12 out of 16 (75%) cases followed by IgM in 5 (31.25%) and IgA in 1 (6.25%) cases. Seven (43.75%) cases showed presence of IgG alone while IgM with IgG was found in 4 (25%) cases. One (6.25%) case showed deposition of IgG, IgM and IgA. The results indicated that demonstration of immunoglobulin in skin biopsies by direct immunofluorescent technique is quite a useful adjunct in diagnostic confirmation of pemphigus.

Osteoradionecrosis of mandible in patients treated with definitive radiotherapy for carcinomas of oral cavity and oropharynx. A retrospective study

A retrospective analysis of 1140 cases of cancer of oral cavity and oropharynx treated with definitive radiotherapy was carried out with regard to the incidence and precipitating factors of mandibular osteoradionecrosis. 14 cases developed osteoradionecrosis out of which 10 had spontaneous mandibular necrosis and 4 had dental extractions in the area where osteoradionecrosis developed. Amongst the 10 cases of spontaneous osteoradionecrosis, 8 patients received doses of 6500 cGy in 6 1/2 weeks or 7000 cGy in 7 weeks by megavoltage cobalt 60 teletherapy and the remaining two patients received the doses of 6000 cGy in 6 weeks. The aforesaid 4 patients of osteoradionecrosis in the area of dental extractions had received doses of only 6000 cGy in 6 weeks.