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N R Datta

Publications and source records attributed to N R Datta.

At least 37 records · Page 2Linked to original sources
PubMed1998

A non-randomized comparison of two radiotherapy protocols in inoperable squamous cell carcinoma of the oesophagus.

We report an audit of two different telebrachytherapy schedules in inoperable carcinoma of the oesophagus. Between October 1990 and December 1996, 108 patients with a Karnofsky performance status > or = 50 were selected from our database on the basis of intention to treat by telebrachytherapy. Teletherapy in the low dose group L (55 patients) consisted of 35 Gy in 15 fractions over 3 weeks, while that in the high dose group H (53 patients) consisted of 50 Gy in 25 fractions over 5 weeks. The choice of teletherapy dose was based on physician preference. The high dose rate intraluminal radiotherapy that followed 2 weeks later was identical in both groups and consisted of two applications of 6 Gy, a week apart. The pretreatment disease characteristics of the patients in both arms were similar. Relief of dysphagia was obtained in 49% of the patients in group L and in 75% of those in group H (chi2: P = 0.004). The median dysphagia-free interval was 0 and 7 months in groups L and H respectively (log-rank: P = 0.06), while the median overall survival was identical at 8 months (log-rank: P = 0.21) for both groups. The probability of survival at 1, 2 and 5 years was 34.8% versus 35.8%, 14.5% versus 13.9% and 0% versus 10% for groups L and H respectively. Morbidity in the form of ulcers, strictures and fistulae were observed in 9%, 7% and 5% of patients in group L compared with 8%, 8% and 13% in groups H respectively. This audit suggests that the protocol used in group H, when compared with group L, results in a greater proportion of patients being rendered dysphagia free, with a statistical trend towards a greater sustainment of dysphagia relief on follow-up.

Aged↗
PubMed1998

Partial transmission block for optimization of anterior supraclavicular-posterior axillary boost in the radiation therapy of carcinoma breast.

Radiation therapy of breast often involves an anterior supraclavicular-axillary (SC-AX) portal to irradiate the supraclavicular and axillary contents. However, the fall-off of the dose in this region leads to an inhomogeneity that could result either during the use of a single anterior SC-AX field or even with the concomitant use of a posterior axillary boost. An attempt has been made to circumvent this inhomogeneity by the use of a partial transmission block that could be placed in the anterior SC-AX portal corresponding to the posterior axillary boost field. The details of the quantum of partial transmission block to be used for different axillary separations and the reference depths of the dose prescription has been evaluated and presented.

Axilla↗
PubMed1997

Midline shield for radiation therapy of carcinoma of the uterine cervix: should it be "midline" or "individualized".

This study attempts to evaluate the advantage of individualized midline shield (IMLS) constructed on the basis of uterine geometry and applicator position in terms of the dosimetric consequences to points A-right (AR) and left (AL) as compared to standard midline shield (SMLS) in radiation therapy of carcinoma cervix. Twenty consecutive patients of carcinoma cervix (Stage I, II and III) were treated by external beam radiotherapy (EBRT) (50 Gy/5 weeks/25 fractions) and high-dose rate intracavitary brachytherapy (24 Gy/4 weeks/4 fractions) prescribed at point A. At the completion of 40 Gy by EBRT (phase I), IMLS (5 cm wide) at isocenter was fabricated on the basis of uterine geometry as ascertained by a dummy intracavitary application. The remaining 10 Gy of EBRT was delivered using IMLS (phase II) to effectively minimize and optimize the dose to point A. The dose profiles of IMLS were compared against the corresponding dose profile of a 5 cm SMLS and were found to be dependent on the positional variation of AR and AL with respect to the midline. With IMLS, the dose to AR and AL for the 10 Gy of phase II varied between 21.7-38.87% (30.01 +/- 4.87) and 22.42-35.72% (28.12 +/- 3.79) respectively. However with SMLS, the AR and AL doses would have ranged from 22.03% to 77.26% (34.55 +/- 15.94) for AR and from 20.59% to 96.2% (46.93 +/- 28.15) for AL leading to considerable inhomogeneity. Thus, in protocols incorporating midline shield for radiotherapy of carcinoma cervix, IMLS in place of SMLS could be preferred for achieving a definitive and homogeneous dose to the points AR and AL.

Brachytherapy↗
PubMed1996

Spatial information on dose distribution using multisectional dose-volume histograms.

Dose-volume histograms are useful tools to summarize the information on the dose profiles resulting within a target volume. However, the spatial relationships of the hot and the cold spots are blunted in the dose-volume histograms. This study tries to circumvent this problem using multisectional dose-volume histograms and highlight the utility of these in the optimization of a radiation therapy plan.

Brachytherapy↗
PubMed1996

Feasibility of non-cisplatin-based induction chemotherapy and concurrent chemoradiotherapy in advanced head and neck cancer.

The purpose of the present study was to determine the safety and efficacy of induction chemotherapy followed by concomitant chemoradiotherapy. Thirty-eight patients were randomised to receive induction chemotherapy, consisting of cyclophosphamide and methotrexate followed by concomitant 5-fluorouracil and irradiation (study group) or irradiation alone (control group). There were non-significant differences in the initial tumor clearance rates in the two groups. Median disease-free survival (in complete responders) was 17 months (6-60+) vs 11 months (5-60+) (p = 0.407) and overall survival 11 months (1-60+) vs 14 months (2-60+) (p = 0.428) in the study and control groups respectively. Acute morbidity and deaths during intervention were higher in the study group (p = 0.007). This study suggests that induction along with concomitant chemoradiotherapy is too toxic for routine use and also fails to provide a survival benefit.

Adult↗
PubMed1995

Urinary tract infection in patients of gynecological malignancies undergoing external pelvic radiotherapy.

A total of 216 midstream urine (MSU) samples from 36 patients with gynecological malignancies undergoing external pelvic radiotherapy (RT) were studied periodically every week for any evidence of urinary tract infection (UTI). UTI was detected in 33.3% patients of whom 8.3% had infection at the onset of RT and the rest developed UTI during the course of therapy. All three patients who had UTI at the onset of RT underwent cystoscopy as a part of routine pretreatment workup. A higher preponderance of UTI was observed in patients of stage III carcinoma cervix (33.3%) compared to stage II (16.7%) during the course of RT. Half of the patients with UTI had repeated episodes of infection despite appropriate antibiotic treatment. The study emphasizes the importance of conducting periodic MSU examination in patients with gynecological malignancies during RT and its treatment with appropriate antibiotics to minimize the risks of further injury to the already susceptible uroepithelium following radiotherapy.

Adult↗
PubMed1995

Multisectional planning for external beam radiotherapy: a "poor person's" alternative to three-dimensional treatment planning.

Recent technical advances in the field of computers have led to the use of three-dimensional dose computation for optimizing a radiation therapy plan. However, in centers which lack such a state-of-the-art technology, one could explore the use of multisectional planning to obtain information about the dose profiles all along the target volume. This article highlights the utility of multisectional planning as an alternative to three-dimensional treatment planning systems for external beam radiation therapy.

Esophageal Neoplasms↗
PubMed1993

Actinomycosis mimicking carcinoma of the maxillary sinus.

Human actinomycosis may pose a diagnostic problem at times and is often mistaken for a neoplasm. A thirty-five year old male was clinically diagnosed as a case of carcinoma of the right maxillary sinus on the basis of history, clinical presentation and radiologic findings. Tissue biopsy was negative for malignancy on three consecutive occasions. Microscopic examination showed bits of granulation tissue and fragments of filamentous structures. On microbiological examination, Actinomyces israelii was isolated and fungus culture was negative. Long term Penicillin treatment caused disappearance of all signs and symptoms. The report highlights the importance of bearing in mind the fact that certain rare, chronic, suppurative granulomatous infections, like actinomycosis, may mimic malignancy.

Actinomycosis, Cervicofacial↗
PubMed1991

Giant cell tumour of the petrous bone.

Giant cell tumours (GCT) are rare in the skull bones. In the cranium the sphenoid bone is the most common site. The petrous bone is a very uncommon location for such tumours. The chance location of GCT at the base of the skull makes total surgery difficult and hazardous. A case of GCT of the petrous bone is presented. The clinical course in the patient and role of primary radiotherapy in GCT in such an unusual site is discussed.

Adult↗
PubMed1990

Evaluation of electron beam irradiation technique in Indian breast carcinoma patients.

A technique for post-mastectomy irradiation in breast cancer patients is described. The chest wall and internal mammary nodes are irradiated with single, anterior electron beam. The axillary and supraclavicular nodal regions are treated with parallel opposed telecobalt beams. A total of 124 patients have been subjected to this procedure. All, except five, completed the treatment. Desquamation, dry as well as wet, was of universal occurrence in electron irradiated zones. The follow up period is 2-26 months with a median of 12 months. Out of the 106 followed up patients, two developed local recurrence while distant metastases were observed in 13 patients.

Adult↗
PubMedDate not supplied

Head and neck cancers: results of thermoradiotherapy versus radiotherapy.

Sixty-five patients were included in a randomized clinical study to evaluate the efficacy of local hyperthermia as a concomitant agent to radiotherapy in the treatment of carcinoma of the head and neck region. Local hyperthermia at 42-43 degrees C was generated by a 27 x 12 MHz radiofrequency diathermy unit and was used before radiotherapy in 33 patients; the remaining 32 patients were subjected to radiotherapy alone. The response in patients with early lesions (Stage I and II) was similar for both the groups, while in patients with advanced disease (Stage III and IV) a significantly better tumour control was obtained by the use of the combined treatment.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Variations in clinical estimates of tumor volume regression parameters and time factor during external radiotherapy in cancer cervix: does it mimic the linear-quadratic model of cell survival?

BACKGROUND: Tumor regression parameters and time factor during external radiotherapy (EXTRT) are of paramount importance. AIMS: To quantify the parameters of tumor regression and time factor during EXTRT in cancer cervix. SETTINGS AND DESIGN: Patients, treated solely with radiotherapy and enrolled for other prospective studies having weekly tumor regressions recorded were considered. MATERIALS AND METHODS: Seventy-seven patients received 50 Gy of EXTRT followed by intracavitary brachytherapy. Loco-regional regressions were assessed clinically and regression fraction (RF) was represented as RF=c + a 1D + a 2 D2 sub - a 3T, with c, D and T as constant, cumulative EXTRT dose and treatment time respectively. STATISTICAL ANALYSIS USED: Step wise linear regression was performed for RF. Scatter plots were fitted using linear-quadratic fit. RESULTS: Coefficients of parameters D, D2 sub and T were computed for various dose intervals, namely 0--20 Gy, 0--30 Gy, 0--40 Gy and 0--50 Gy. At 0--20 Gy and 0--30 Gy, only the coefficient of D2 was significant (P 2 sub and T turned significant (P 2 sub and T showed significance, leading to an estimate of 26 Gy for a1/a2 and 0.96 Gy/day for a3/a1. CONCLUSIONS: As with alpha/beta and gamma/alpha of post-irradiation cell survival curves, a1/a2 and a3/a1 represents the cumulative effect of various radiobiological factors influencing clinical regression of tumor during the course of EXTRT. The dynamic changes in the coefficients of D, D2 sub and T, indicate their relative importance during various phases of EXTRT.

Adenocarcinoma↗
PubMedDate not supplied

Summated chemotherapy dose-intensity versus loco-regional response in locally advanced breast cancer: its possible implications.

BACKGROUND: Summated dose-intensity (SDI) of chemotherapy regimen could influence the outcome in malignancies. AIMS: To evaluate the implication of SDI and identify key drugs for loco-regional response in locally advanced breast cancer (LABC). SETTINGS AND DESIGN: This retrospective study was based on audit of records of LABC patients who had received neoadjuvant chemotherapy (NACT). MATERIAL AND METHODS: Actual unit dose-intensity (UDI) of each drug and corresponding SDI of every doxorubicin (n=116 cycles) or non-doxorubicin (n=110 cycles) based NACT received by 42 patients of LABC were summated. Cumulative dose-intensity (CDI) for individual drugs and cumulative SDI (CSDI) for the entire course of NACT were estimated and correlated with quantum of primary tumor, axillary and supraclavicular nodal responses. STATISTICAL ANALYSIS USED: Two-sided chi-square, t-test, step-wise regression was used. RESULTS: Dose-response curve between CSDI and corresponding responses for both primary and lymph nodes were sigmoid in shape for both doxorubicin or non-doxorubicin based NACT. Curves were best fitted using a cubic fit for all patients (r2 = 0.82, 0.84 and 0.93 for primary tumor, axillary and supraclavicular lymph nodes respectively). CSDI emerged as an important prognosticators for both primary (P<0.001) and nodal (P<0.001) responses. Individually, CDI of 5-fluorouracil for primary (P<0.001), CDIs of doxorubicin (P<0.001) and methotrexate (P=0.006) for axillary nodes and CDI of cyclophosphamide (P=0.001) for supraclavicular nodes were significant. CONCLUSIONS: Loco-regional responses in LABC are dependent on CSDI of NACT regimen. Drugs for high-dose intensification protocols could be identified and chosen based on the impact of CDI of individual drugs in NACT.

Adult↗
PubMedDate not supplied

Tumor regression dynamics with external radiotherapy in cancer cervix and its implications.

BACKGROUND: To study the external radiotherapy (EXTRT) regression patterns in cancer of the cervix. AIMS: Evaluate EXTRT tumor regression doses (TRD) for 50% (TRD50), 80% response (TRD80), normalized dose response gradient (g50) and slope (slope50) with clinical outcome. SETTINGS AND DESIGN: Patients, treated solely with radiotherapy and enrolled for other prospective studies having weekly tumor regressions recorded were considered. MATERIAL AND METHODS: Seventy-seven patients received 50Gy of EXTRT at 2 Gy/fraction followed by 18Gy of high-dose rate intracavitary brachytherapy at 6 Gy/fraction. Loco-regional regressions were assessed clinically at weekly intervals during EXTRT to generate EXTRT dose-response curves. STATISTICAL ANALYSIS USED: Student's t test, logistic regression, Kaplan Meier and Cox's proportional hazard model. Scatter plots were fitted using cubic fit. RESULTS: Age (P=0.052) and absence or presence of gross residual tumor (AGRT and PGRT respectively) following EXTRT (P<0.001) were the only determinants for complete response (CR) at 1 month following completion of radiotherapy. EXTRT tumor regression sigmoid curves obtained for various patient characteristics differed only for those with AGRT and PGRT with differences in TRD50, (P<0.001); TRD80 (P<0.001) and slope50 (P=0.001). Response status to EXTRT was a prognosticator for loco-regional disease free survival (LDFS) (AGRT vs. PGRT; P=0.046). On multivariate analysis, both TRD50 and TRD80 emerged as significant predictors for tumor status at end of EXTRT while TRD80 was the sole determinant of LDFS. CONCLUSION: Extent of tumor regression to EXTRT is an important predictor for treatment outcome in cancer cervix as evident from TRD50 and TRD80 values of EXTRT tumor regression curves.

Adult↗
PubMedDate not supplied

Early occurrence of acute myeloid leukemia following adjuvant radiotherapy and higher cumulative dose of cyclophosphamide in carcinoma breast.

We report a case of cancer breast developing acute myeloid leukemia (AML) within a relatively short interval of two and a half years of her primary treatment. This could be attributed to post operative radiotherapy and a higher cumulative dose of cyclophosphamide (14.4 gm) which had to be given as a part of her combination chemotherapy regimen, initially as adjuvant and then later as salvage chemotherapy. The successful salvage therapy for secondary AML instituted in this case is also discussed.

Antineoplastic Agents, Alkylating↗