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2.
IARC Sci Publ ; (162): 101-6, 2011.
Article in English | MEDLINE | ID: mdl-21675411

ABSTRACT

The rural cancer registry of Barshi, Paranda and Bhum, was the first of its kind in India and was established in 1987. Registration of cases is carried out entirely by active methods. Data on survival from 15 cancer sites or types registered during 1993-2000 are reported in this study. Follow-up has been carried out predominantly by active methods, with median follow-up time ranging between 2-49 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 73-98%; death certificates only (DCOs) comprised 0-2%; 98-100% of total registered cases were included for survival analysis. Complete follow-up at five years ranged between 96-100% for different cancers. The 5-year age-standardized relative survival rates for selected cancers were non-melanoma skin (86%), penis (63%), breast (61%), cervix (32%), mouth (23%), hypopharynx (11%) and oesophagus (4%). The 5-year relative survival by age group did not display any particular pattern. Five-year relative survival trend between 1988-1992 and 1993-2000 showed a marked decrease for cancers of the tongue, hypopharynx, stomach, rectum, larynx, lung and penis; but a notable increase for breast and non-Hodgkin lymphoma.


Subject(s)
Neoplasms/mortality , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Follow-Up Studies , Humans , India/epidemiology , Infant , Infant, Newborn , Male , Middle Aged , Registries , Time Factors
3.
Clin Oncol (R Coll Radiol) ; 21(4): 285-93, 2009 May.
Article in English | MEDLINE | ID: mdl-19249195

ABSTRACT

With more than 1 million new cases each year, female breast cancer is the second most common cancer in the world and the most common cancer among women. Breast cancer involves a multimodality treatment and a co-ordinated approach from various specialties. Breast-conserving therapy (BCT) is increasingly being integrated into the management of breast cancer. The obvious advantages of BCT are equivalent local and distant control rates as compared with mastectomy and the preservation of the breast. However, the key to a successful BCT is achieving a cosmetic outcome that is acceptable to the patient and the physician. Cosmesis in breast cancer is the end result of a range of factors that fall under the broad heads of surgery, radiotherapy, chemotherapy and hormonal treatment. All of these modalities can play a role in compromising breast cosmesis. This overview discusses the factors that are critical in affecting the final cosmetic outcome in patients with BCT.


Subject(s)
Breast Neoplasms/surgery , Mammaplasty , Mastectomy, Segmental , Female , Humans , Treatment Outcome
4.
Clin Oncol (R Coll Radiol) ; 20(8): 613-8, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18585015

ABSTRACT

AIM: To evaluate the prognostic factors and treatment outcome of children with non-Hodgkin's lymphoma (NHL) of Waldeyer's ring treated at a single institution. MATERIALS AND METHODS: Thirty-two children with NHL of Waldeyer's ring treated at our institute between January 1990 and December 2001 were included in this analysis. The median age at presentation was 14 years, and most of the patients (87%) were boys. The most common histological subtype was diffuse large B-cell lymphoma (75%), 25% patients had stage I and 75% had stage II disease. Treatment comprised a combination of chemotherapy and radiotherapy in most of the patients (75%). Among these patients, 71% received a radiotherapy dose of > or = 45 Gy. RESULTS: After a median follow-up of 45 months, the 5-year disease-free and overall survival rates were 76.5 and 83.2%, respectively. Age > 10 years (P = 0.032), bulky tumours (P = 0.001) and the presence of B-symptoms (P = 0.004) had a negative influence on disease-free survival. Patients treated with a combination of chemotherapy and radiotherapy had a better outcome than patients treated with chemotherapy alone (disease-free survival: 87.1% vs 56.2%, P = 0.056). The complete response (P = 0.003), disease-free survival (P = 0.001) and overall survival (P = 0.001) rates were significantly better for patients receiving a radiotherapy dose > or = 45 Gy. CONCLUSION: The age at diagnosis, the size of the tumour, and the presence of B-symptoms significantly influenced the outcome of children with NHL of Waldeyer's ring in this study. A combined modality treatment, comprising chemotherapy and radiotherapy, resulted in a satisfactory outcome in patients with this rare neoplasm.


Subject(s)
Lymphoma, Non-Hodgkin/drug therapy , Lymphoma, Non-Hodgkin/radiotherapy , Adolescent , Age Factors , Child , Combined Modality Therapy , Disease-Free Survival , Female , Humans , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/radiotherapy , Lymphoma, Non-Hodgkin/pathology , Male , Prognosis , Radiotherapy Dosage , Survival Analysis
5.
Oral Oncol ; 44(10): 986-93, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18329324

ABSTRACT

Intraoral (oral cavity and oropharynx) adenoid cystic carcinomas are uncommon cancers characterized by slow evolution, protracted clinical course, multiple and/or delayed recurrences, and late distant metastases. The molecular biology behind this enigmatic disease remains poorly characterized. To analyze and correlate prognostic factors with outcome in intraoral adenoid cystic carcinoma. Medical records of 76 patients with intraoral adenoid cystic carcinoma treated with definitive loco-regional therapy at the institute between 1992 and 2004 were retrospectively reviewed and analyzed.Majority (85.5%) of the patients had advanced stage disease. Seventy-four patients underwent surgery, of which 51 (68.9%) received adjuvant radiotherapy. The median dose of radiation was 56 Gy (range 44-66 Gy). Two patients with medical co-morbidities received radical radiotherapy. Perineural invasion, margin positivity and nodal positivity were present in 24 (32.4%); 27 (36.4%); and 15 (19.7%) patients, respectively. Ten (13.1%) patients developed local recurrence and 6 (7.8%) distant metastases. With a median follow-up of 20 months (range 1-137 months), the 5-year Kaplan-Meier estimates of local control and disease-free survival were 57.9% and 47.1%, respectively. On uni-variate analysis, perineural invasion (p=0.003), oropharyngeal primary (p=0.033), and advanced T-stage (p=0.047) were associated with increased local recurrences. Perineural invasion (p=0.05) and primary site (p=0.042) also predicted disease-free survival. On multivariate analysis, both perineural invasion and primary site retained significance for local control (p=0.007, p=0.011) and disease-free survival (p=0.018, p=0.014), respectively. Intraoral adenoid cystic carcinoma is an uncommon disease with an enigmatic clinical course. Perineural invasion, site of primary, and T-stage significantly impact upon local control and disease-free survival. The role of adjuvant radiotherapy remains controversial. Larger prospective studies with mature follow-up are needed to define the optimal treatment of intraoral adenoid cystic carcinoma.


Subject(s)
Carcinoma, Adenoid Cystic/pathology , Carcinoma, Squamous Cell/pathology , Mouth Neoplasms/pathology , Adult , Carcinoma, Adenoid Cystic/radiotherapy , Carcinoma, Adenoid Cystic/surgery , Carcinoma, Squamous Cell/radiotherapy , Carcinoma, Squamous Cell/surgery , Disease-Free Survival , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Mouth Neoplasms/radiotherapy , Mouth Neoplasms/surgery , Neoplasm Recurrence, Local , Prognosis , Retrospective Studies , Treatment Outcome , Young Adult
6.
Br J Radiol ; 81(966): 485-9, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18283070

ABSTRACT

The purpose of the study was to evaluate the localization of the internal mammary lymph node chain (IMC) using CT scan data acquired after intraoperative placement of a catheter into the internal mammary vessel (IMV). CT data sets comprising 58 suitable patients with breast carcinoma undergoing placement of a catheter into the IMV during breast conservative surgery were evaluated for the study. CT was performed with a radio-opaque dummy wire placed into the IMC catheter. The following measurements were recorded in the second, third and the fourth intercostal spaces: anteroposterior distance from skin to the IMC catheter; transverse distance from mid-sternum to the IMC catheter; and anteroposterior distance from the skin to the heart. Finally, the IMC angle was determined. At the second intercostal space, the mean anteroposterior distance (range) was 29.0 mm (14.6-48.6 mm) and mean transverse distance was 26.1 mm (18.2-36.3 mm). The corresponding mean values for the third space were 32.5 mm (20.0-45.6 mm) and 24.1 mm (17.8-39.7 mm) and for the fourth intercostal space were 31.6 mm (21.1-45.6 mm) and 24.3 mm (15.6-34.3 mm), respectively. The mean skin to heart distance was 36.2 mm on the left side and 47.8 mm on the right side (p < 0.001). The mean IMC angle was 40.3 degrees (95% confidence interval: 25-55.6). There appears to be a wide variation in the depth and location of the IMC, as recorded by CT measurements of the catheter in the IMV, demonstrating the need for individual planning. The IMC nodal area is likely to be out of the tangential portals employed in conventional practice.


Subject(s)
Breast Neoplasms/radiotherapy , Lymph Nodes/diagnostic imaging , Mammography/methods , Tomography, X-Ray Computed/methods , Brachytherapy/methods , Catheterization/methods , Female , Humans , Lymphatic Metastasis/diagnostic imaging , Postoperative Care/methods , Radiography, Interventional
7.
J Med Phys ; 33(1): 3-8, 2008 Jan.
Article in English | MEDLINE | ID: mdl-20041045

ABSTRACT

The purpose is to compare CT-based dosimetry with International Commission on Radiation Units and Measurements (ICRU 38) bladder and rectum reference points in patients of carcinoma of uterine cervix treated with intracavitary brachytherapy (ICA). Twenty-two consecutive patients were evaluated. Orthogonal radiographs and CT images were acquired and transferred to PLATO planning system. Bladder and rectal reference points were identified according to ICRU 38 recommendations. Dosimetry was carried out based on Manchester system. Patient treatment was done using (192)Iridium high dose rate (HDR) remote after-loading machine based on the conventional radiograph-based dosimetry. ICRU rectal and bladder point doses from the radiograph plans were compared with D(2), dose received by 2 cm(3) of the organ receiving maximum dose from CT plan. V(2), volume of organ receiving dose more than the ICRU reference point, was evaluated. The mean (+/-standard deviation) volume of rectum and bladder was 60 (+/-28) cm(3) and 138 (+/-41) cm(3) respectively. The mean reference volume in radiograph and CT plan was 105 (+/-7) cm(3) and 107 (+/-7) cm(3) respectively. It was found that 6 (+/-4) cm(3) of rectum and 16 (+/-10) cm(3) of bladder received dose more than the prescription dose. V(2) of rectum and bladder was 7 (+/-1.7) cm(3) and 20.8 (+/-6) cm(3) respectively. Mean D(2) of rectum and bladder was found to be 1.11 (+/-0.2) and 1.56 (+/-0.6) times the mean ICRU reference points respectively. This dosimteric study suggests that comparison of orthogonal X-ray-based and CT-based HDR ICA planning is feasible. ICRU rectal point dose correlates well with maximum rectal dose, while ICRU bladder point underestimates the maximum bladder dose.

8.
Cancer Causes Control ; 19(2): 147-53, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17992576

ABSTRACT

OBJECTIVE: To study the cancer pattern among HIV positive cancer cases. METHOD: The study group included patients registered in the HIV Cancer clinic at the Tata Memorial Hospital (TMH), Mumbai, which is the largest tertiary referral cancer center in India. We used the gender and age-specific proportions of each cancer site of the year 2002 that was recorded in the Hospital Cancer Registry to estimate an expected number of various cancer sites among HIV positive cancer patients during the period 2001-2005. The observed number of site-specific cancer cases was divided by the expected number to obtain proportional incidence ratio (PIR). RESULTS: No case of Kaposi's sarcoma was observed. Increased proportion of non-Hodgkin's lymphoma (NHL) was observed (PIR in males = 17.1, 95%CI 13.33-21.84, females = 10.3, 95%CI 6.10-17.41). In males, PIR was increased for anal cancer (PIR = 10.3, 95%CI 4.30-24.83), Hodgkin's disease, testicular cancer, colon cancer, and few head and neck cancer sites. Among females, the PIRs for cervical cancer (PIR = 4.1, 95%CI 2.90-5.75), vaginal cancer (PIR = 7.7, 95%CI 2.48-23.85), and anal cancer (PIR = 6.5, 95%CI 0.91-45.88) were increased. CONCLUSIONS: The absence of Kaposi's sarcoma and increased PIRs for certain non-AIDS defining cancers among HIV infected cancer cases indicates a different spectrum of HIV associated malignancies in this region. The raised PIR for cervical cancer emphasizes the urgent need for screening programs for cervical cancer among HIV infected individuals in India.


Subject(s)
HIV Infections , Neoplasms/epidemiology , Registries , Adolescent , Adult , Child , Child, Preschool , Female , HIV Infections/complications , HIV Infections/epidemiology , Humans , Incidence , India/epidemiology , Infant , Male , Middle Aged , Neoplasms/complications
9.
Clin Oncol (R Coll Radiol) ; 19(8): 596-603, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17706403

ABSTRACT

AIMS: To study the influence of various factors affecting cosmetic outcome and late sequelae in a large cohort of women treated with breast-conserving therapy. MATERIALS AND METHODS: Between 1980 and 2000, 1022 pathological stage I/II breast cancer patients underwent breast-conserving therapy. On the basis of the type of tumour bed boost they received after whole breast radiotherapy, these women were assigned to three groups: (A) low dose rate (LDR) brachytherapy of 15-20 Gy (n=383); (B) high dose rate (HDR) brachytherapy of 10 Gy (optimised) in a single fraction (n=153); (C) electron beam 15 Gy/six fractions (n=460). Systemic adjuvant therapy was given to 757 women, of whom 570 received adjuvant chemotherapy. RESULTS: Cosmesis at the last follow-up was good or excellent in 77% of women. Post-radiation worsening of cosmesis was observed in 11.5% of women and was similar in the three boost groups. Moderate to severe late breast sequelae were observed in 22% of women in group B, which was significantly higher than the 12% in group A (P=0.002) and 9% in group C (P=0.0001). The actuarial 5-year local control rate was 91% and was 90, 92 and 93% in groups A, B and C, respectively. Tumour size (P=0.049) and adjuvant chemotherapy (P=0.04) were the significant factors affecting cosmetic outcome on univariate analysis. On multivariate analysis, adjuvant chemotherapy was the only factor leading to worsening in the cosmetic outcome, with P=0.03 (hazard ratio 1.65 [95% confidence interval 1.05-2.59]). CONCLUSION: The type of tumour bed boost did not have a significant effect on the worsening of cosmetic outcome. However, there were significantly more late breast sequelae in women treated with single fraction HDR implants. Chemotherapy had an adverse effect on the cosmetic outcome, but the late breast sequelae and local control rates were comparable.


Subject(s)
Breast Neoplasms/surgery , Chemotherapy, Adjuvant , Mastectomy, Segmental , Treatment Outcome , Adolescent , Adult , Aged , Antineoplastic Agents/therapeutic use , Brachytherapy , Breast Neoplasms/drug therapy , Breast Neoplasms/radiotherapy , Female , Humans , Middle Aged , Prospective Studies , Survival , Tamoxifen/therapeutic use , Time Factors
10.
Australas Phys Eng Sci Med ; 30(2): 127-34, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17682402

ABSTRACT

A new model of the telecobalt unit (TCU), Theratron Equinox-80, (MDS Nordion, Canada) equipped with a single 60 degree motorized wedge (MW), four universal wedges (UW) for 15 degrees, 30 degrees, 45 degrees and 60 degrees have been evaluated. MW was commissioned in Eclipse (Varian, Palo Alto, USA) 3D treatment planning system (TPS). The profiles and central axis depth doses (CADD) were measured with Wellhofer blue water phantom for MW and the measured data was commissioned in Eclipse. These profiles and CADD for MW were compared with UW in a homogeneous phantom generated in Eclipse for various field sizes. The dose was also calculated in the same phantom at 10 cm depth. For the particular MW angle and the respective open and MW beam weights, the dose was measured for a field size of 10 cm x 10 cm in a MEDTEC water phantom at 10 cm depth with a 0.13 cc thimble ion chamber (Scanditronix Wellhofer, Uppsala, Sweden) and a NE electrometer (Nuclear Enterprises, UK). Measured dose with ion chamber was compared with the TPS calculated dose. MW angle verification was also done on the Equinox for four angles (15 degrees, 30 degrees, 45 degrees and 60 degrees). The variation in measured and calculated dose at 10 cm depth was within 2%. The measured and the calculated wedge angles were in good agreement within 2 degrees. The motorized wedges were successfully commissioned in Eclipse for four wedge angles.


Subject(s)
Cobalt , Phantoms, Imaging , Radiotherapy Planning, Computer-Assisted/instrumentation , Radiotherapy Dosage , Time Factors
12.
J Med Phys ; 32(4): 150-5, 2007 Oct.
Article in English | MEDLINE | ID: mdl-21224924

ABSTRACT

Integrated PET/CT has emerged as an integral component of oncology management because of its unique potential of providing both functional and morphological images in a single imaging session. In this work, performance of the 'bismuth germinate (BGO) crystal'-based PET of a newly installed Discovery ST PET/CT was evaluated in 2D and 3D mode for whole-body scanning using National Electrical Manufacturers Association (NEMA) NU 2-2001 protocol and the recommended phantoms. During the entire measurements, the system operates with an energy window of 375-650 keV and 11.7 ns coincidence time window. The set of tests performed were spatial resolution, sensitivity, scatter fraction (SF) and counting rate performance. The average transaxial and axial spatial resolution measured as full width at half maximum (FWHM) of the point spread function at 1 cm (and 10 cm) off-axis was 0.632 (0.691) and 0.491 (0.653) cm in 2D and 0.646 (0.682) and 0.54 (0.601) cm in 3D respectively. The average sensitivity for the two radial positions (R = 0 cm and R = 10 cm) was 2.56 (2.63) cps/kBq in 2D and 11.85 (12.14) cps/kBq in 3D. The average scatter fraction was 19.79% in 2D and 46.19% in 3D. The peak noise equivalent counting rate (NECR) evaluated with single random subtraction was 89.41 kcps at 49 kBq/cc in 2D and 60 kcps at 12 kBq/cc in 3D acquisition mode. The NECR with delayed random subtraction was 61.47 kcps at 40.67 kBq/cc in 2D and 45.57 kcps at 16.45 kBq/cc in 3D. The performance of the PET scanner was satisfactory within the manufacturer-specified limits. The test result of PET shows excellent system sensitivity with relatively uniform resolution throughout the FOV, making this scanner highly suitable for whole-body studies.

14.
Br J Radiol ; 79(945): 766-73, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16940376

ABSTRACT

This study was designed to evaluate interfraction and intrafraction breast movement and to study the effect of respiratory training on respiratory indices. Five patients were immobilized in supine position in a vacuum bag and three-dimensional set up errors, respiratory movement of the breast during normal and deep breathing, tidal volume and breath hold time were recorded. All patients underwent respiratory training and all the respiratory indices were re-evaluated at the end of training. Cumulative maximum movement error (CMME) was calculated by adding directional maximum set up error and maximum post training movement during normal breathing. The mean set up deviation was 1.3 mm (SD +/- 0.5 mm), 1.3 mm (SD +/- 0.3 mm) and 4.4 mm (SD +/- 2.6 mm) in the mediolateral, superoinferior and anteroposterior dimensions. Pre-training mean of the maximum marker movement during normal breathing was 1.07 mm, 1.94 mm and 1.86 mm in the mediolateral, superoinferior and anteroposterior dimensions. During deep breathing these values were 2 mm, 5.5 mm and 4.8 mm. While respiratory training had negligible effect on breast movement during normal breathing, it resulted in a modest reduction during deep breathing (p = 0.2). The mean CMME recorded for these patients was 3.4 mm, 4.5 mm and 7.1 mm in the mediolateral, superoinferior and anteroposterior dimension. Respiratory training also resulted in an increase in breath hold time from a mean of 31 s to 44 s (p = 0.04) and tidal volume from a mean of 560 cm(3) to 1160 cm(3) (p = 0.04). With patients immobilized in the vacuum bag the CMMEs are relatively less. Individualized directional margins may aid in reduction of planning target volume (PTV).


Subject(s)
Brachytherapy/standards , Breast Neoplasms/radiotherapy , Breast/physiology , Movement , Respiration , Brachytherapy/methods , Female , Humans , Patient Education as Topic
15.
Clin Oncol (R Coll Radiol) ; 18(5): 383-9, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16817329

ABSTRACT

AIMS: Head and neck squamous cell carcinoma (HNSCC) continues to be a leading cancer in developing countries. Definitive radiation therapy either primary or as postoperative adjuvant is offered to most patients. We aimed to identify prognostic and therapeutic factors that affect locoregional control and survival in patients undergoing radical radiotherapy for head and neck squamous cell cancers. MATERIALS AND METHODS: A retrospective analysis of 568 previously untreated patients with squamous head and neck cancers, who received radical radiotherapy between 1990 and 1996, using local control, locoregional control and disease-free survival (DFS) as outcome measures. RESULTS: With a median follow-up of 18 months for living patients, the 5-year local control, locoregional control and DFS for all 568 patients were 53%, 45% and 41%, respectively, for all stages combined. The 5-year local control, locoregional control and DFS as per the American Joint Committee on Cancer stage grouping were 78%, 70% and 70%; 64%, 59% and 57%; 51%, 42% and 37%; and 40%, 27% and 22% from stages I to IV, respectively, with highly significant P values. Patients receiving higher doses (> or = 66 Gy) had a significantly better outcome compared with lower doses. The 5-year local control (59% vs 48%, P = 0.0015), locoregional control (47% vs 41%; P = 0.0043) and DFS (44% vs 37%; P = 0.0099) were significantly better in patients receiving > or = 66 Gy. Site of primary also affected outcome significantly, with oral cavity lesions faring badly. CONCLUSION: Tumour stage remains the most important factor affecting outcome in radical radiotherapy of HNSCC. A definite dose-response relationship exists with higher total doses, leading to better local control, locoregional control and DFS in all stages. Site of primary affects outcome too, with laryngeal primaries doing well and oral cavity cancers faring the worst.


Subject(s)
Carcinoma, Squamous Cell/radiotherapy , Head and Neck Neoplasms/radiotherapy , Radiotherapy, Conformal/methods , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/pathology , Female , Head and Neck Neoplasms/pathology , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Retrospective Studies , Survival Rate , Treatment Outcome
16.
Br J Radiol ; 79(940): 331-5, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16585727

ABSTRACT

The increase in the number of monitor units in sliding window intensity-modulated radiotherapy, compared with conventional techniques for the same target dose, may lead to an increase in peripheral dose (PD). PD from a linear accelerator was measured for 6 MV X-ray using 0.6 cm3 ionization chamber inserted at 5 cm depth into a 35 cm x 35 cm x 105 cm plastic water phantom. Measurements were made for field sizes of 6 cm x 6 cm, 10 cm x 10 cm and 14 cm x 14 cm, shaped in both static and dynamic multileaf collimation (DMLC) mode, employing strip fields of fixed width 0.5 cm, 1.0 cm, 1.5 cm, and 2.0 cm, respectively. The effect of collimator rotation and depth of measurement on peripheral dose was investigated for 10 cm x 10 cm field. Dynamic fields require 2 to 14 times the number of monitor units than does a static open field for the same dose at the isocentre, depending on strip field width and field size. Peripheral dose resulting from dynamic fields manifests two distinct regions showing a crest and trough within 30 cm from the field edge and a steady exponential fall beyond 30 cm. All dynamic fields were found to deliver a higher PD compared with the corresponding static open fields, being highest for smallest strip field width and largest field size; also, the percentage increase observed was highest at the largest out-of-field distance. For 6 cm x 6 cm field, dynamic fields with 0.5 cm and 2 cm strip field width deliver PDs 8 and 2 times higher than that of the static open field. The corresponding factors for 14 cm x 14 cm field were 15 and 6, respectively. The factors by which PD for DMLC fields increase, relative to jaws-shaped static fields for out-of-field distance beyond 30 cm, are almost the same as the corresponding increases in the number of monitor units. Reductions of 20% and 40% in PD were observed when the measurements were done at a depth of 10 cm and 15 cm, respectively. When the multileaf collimator executes in-plane (collimator 90 degrees) motion, peripheral dose decreases by as much as a factor of 3 compared with cross-plane data. The knowledge of PD from DMLC field is necessary to estimate the increase in whole-body dose and the likelihood of radiation induced secondary malignancy.


Subject(s)
Radiotherapy Planning, Computer-Assisted , Radiotherapy, High-Energy/methods , Radiotherapy, Intensity-Modulated/methods , Humans , Phantoms, Imaging , Radiation Protection , Radiotherapy Dosage , Radiotherapy, High-Energy/instrumentation , Radiotherapy, Intensity-Modulated/instrumentation , Scattering, Radiation
17.
Expert Rev Anticancer Ther ; 6(3): 405-17, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16503857

ABSTRACT

Head and neck cancer management has undergone several paradigm shifts for several relevant reasons. From the dismal experience with the use of radiotherapy as the sole modality in the treatment of this group of patients with advanced disease, radiotherapy has been evaluated as an adjuvant for the same group of patients who had undergone successful surgery. Although there is no level 1 evidence to support postoperative adjuvant radiation, several studies have demonstrated that adjuvant radiotherapy reduces the local failures and, thereby, improves survival. Predictors of recurrence after surgical resection are: positive margins of resection; extranodal spread in involved nodes; perineural invasion; and presence of two or more involved regional lymph nodes. Realization of the advantages of a combination of chemotherapy with radiotherapy has had a major impact on the management of these cancers. There is emerging evidence for the use of adjuvant concurrent chemoradiotherapy in the group with high-risk features. Multiple organ conservation strategies in the management of locally advanced head and neck cancers have evolved over the years. However, the meta-analyses of impact of chemotherapy in various settings reveal that concomitant chemoradiotherapy is superior to any of the other regimens. Increasing use of computed tomography, magnetic resonance imaging and positron emission tomography scan images has resulted in better visualization of target volumes and critical structures. Delineation of these structures is of paramount importance and has resulted in a profound change in conformal treatment planning. Better understanding of the physical aspects of delivery of radiotherapy and the advent of modern treatment planning systems have led to the development of conformal techniques. Although the benefit of these techniques on survival have yet to be demonstrated, there is evidence to suggest that they reduce treatment-related toxicities significantly and facilitate dose escalation. Increased knowledge of radiobiology has led to the development of various altered fractionation regimens in the management of locally advanced head and neck cancers. Discovery of cell-cycle kinetics and signal transduction pathways has led to the unearthing of several potential targets for targeted therapy. The epidermal growth factor receptor gene has emerged as the most promising target. The role of biological radiation response modifiers is evolving. All of these approaches to improve the therapeutic gain would be incomplete without evaluating their effect on the quality of life of these patients.


Subject(s)
Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/radiotherapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Cycle , Combined Modality Therapy , Head and Neck Neoplasms/surgery , Humans , Kinetics , Neoplasm Recurrence, Local , Prognosis , Radiotherapy, Adjuvant , Risk Factors , Signal Transduction , Survival
18.
J Surg Oncol ; 93(1): 56-61, 2006 Jan 01.
Article in English | MEDLINE | ID: mdl-16353188

ABSTRACT

BACKGROUND: The management of patients with a small pharyngolaryngeal cancer (T1 and T2) with large nodal metastases is a subject of debate. We present data on the feasibility and outcome of treating these patients with surgery for the nodal metastases followed by definitive radiotherapy. METHODS: Prospective study of 59 patients of small pharyngolaryngeal primary squamous carcinomas with operable (N2/N3) nodal metastasis treated with neck dissection followed by radiotherapy. RESULTS: Complete nodal clearance was achieved in 54 (90%). The mean nodal size was 4 cm and extranodal extension was seen in 88% of patients in the study group. There were no significant postoperative complications. Median interval between surgery and radiotherapy was 23 days. Forty-nine patients (83%) started their RT within 6 weeks of surgery. With a median follow-up of 25 months, the disease free and overall survival was 54% and 60% (5 years). CONCLUSION: The management of patients with a radiocurable pharyngolaryngeal primary with large nodes by this approach is a feasible option with adequate control and survival.


Subject(s)
Carcinoma, Squamous Cell/radiotherapy , Laryngeal Neoplasms/radiotherapy , Lymph Nodes/pathology , Lymphatic Irradiation , Neck Dissection , Pharyngeal Neoplasms/radiotherapy , Adult , Aged , Carcinoma, Squamous Cell/secondary , Carcinoma, Squamous Cell/surgery , Combined Modality Therapy , Disease-Free Survival , Feasibility Studies , Female , Humans , Laryngeal Neoplasms/pathology , Laryngeal Neoplasms/surgery , Lymphatic Metastasis , Male , Middle Aged , Neck , Neoplasm Staging , Pharyngeal Neoplasms/pathology , Pharyngeal Neoplasms/surgery , Prospective Studies , Treatment Outcome
19.
Int J Surg ; 4(2): 106-14, 2006.
Article in English | MEDLINE | ID: mdl-17462324

ABSTRACT

INTRODUCTION: In absence of randomized evidence to support safety of conservative surgery (BCT) in locally advanced breast cancer (LABC), we analyzed a cohort of 664 women with LABC treated during January 1998 to December 2002 at Tata Memorial Hospital, Mumbai, India. MATERIALS AND METHODS: All were treated with a multimodality regimen comprising of neoadjuvant chemotherapy (NACT) followed by surgery (modified radical mastectomy or BCT) and adjuvant radiotherapy and hormone therapy. The outcome was evaluated to assess safety of BCT. RESULTS: 71% (469/664) women responded to NACT (22% clinical CR and 49% PR) and 28.3% (188/664) underwent BCT. Positive lumpectomy margins were reported in 8.5%, with gross presence of tumor at the margins in 2.3% requiring a revision surgery. At a median follow-up of 30months, local relapse rate was 8% after BCT and 10.7% after mastectomy. The 3-year local DFS was better post-conservation than after mastectomy (87% vs 78%, P=0.02). The disease-free survival (DFS) was also superior after BCT, 72% vs 52% (P<0.001) at 3years and 62% vs 37% (P<0.001) at 5years respectively. On multivariate analysis, presence of lymphatic vascular emboli (LVE) was the major significant predictor of local recurrence (P<0.001, HR 2.52, 95% CI 1.52-4.18). DFS was better after BCT [(P<0.001, HR 2.0 (95% CI 1.38-2.91)]; shorter DFS was noted in LVE positive (HR 1.54, P=0.007) and larger residual disease after NACT (HR 1.13, P=0.001). CONCLUSION: BCT is technically feasible and safe post neo-adjuvant chemotherapy in women with LABC with no detriment in outcome.

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