Use of ultrasound in image-guided high-dose-rate brachytherapy: enumerations and arguments.

Inherently, brachytherapy is the most conformal radiotherapeutic technique. As an aid to brachytherapy, ultrasonography (USG) serves as a portable, inexpensive, and simple to use method allowing for accurate, reproducible, and adaptive treatments. Some newer brachytherapy planning systems have incorporated USG as the sole imaging modality. Ultrasonography has been successfully used to place applicator and dose planning for prostate, cervix, and anal canal cancers. It can guide placement of brachytherapy catheters for all other sites like breast, skin, and head and neck cancers. Traditional USG has a few limitations, but recent advances such as 3-dimensional (3D) USG and contrast USG have enhanced its potential as a dependable guide in high-dose-rate image-guided brachytherapy (HDR-IGBT). The authors in this review have attempted to enumerate various aspects of USG in brachytherapy, highlighting its use across various sites.

Modulated Radiotherapy with Concurrent and Adjuvant Temozolomide for Anaplastic Gliomas: Indian Single-center Data.

OBJECTIVE: To evaluate early clinical outcome for anaplastic gliomas (AG) treated in the era of modulated radiotherapy (RT) and concurrent plus adjuvant temozolomide (TMZ) in an Indian setting. MATERIALS AND METHODS: Fifty-three patients with AGs treated with modulated RT and concurrent (95%) and adjuvant TMZ (90%) were analyzed. About 80% of patients had Karnofsky performance status (KPS) at least 90 with 30% seizure at presentation. Postoperative magnetic resonance imaging was available in 65% cases and RT dose was 60 Gy in 30 fractions. First posttreatment imaging was performed at 1 month and then at 3 and 6 months post-RT and then every 3 months. Kaplan-Meier analysis was used to estimate disease-free survival (DFS) and overall survival (OS), and analysis was done using SPSS version 18.0. RESULTS: With median follow-up of 25 months, 2-year DFS and OS were 75% and 88%. There were only 5% symptomatic central nerves system and 8% symptomatic hematological toxicities. At the 1st evaluation, 30.4% had complete response (CR), at 3 months 40%, and at 6 months 43%. At 6 months, only 4% had progressive disease. Forty-six patients were evaluable till the last follow-up with and 55% had stable to CR. On univariate analysis for DFS, KPS at presentation >90 (P = 0.001) and response at 6 months (P = 0.02) were significant and for OS KPS at presentation (P = 0.004) alone. CONCLUSION: Modulated RT with TMZ among Grade III glioma patients resulted in minimum treatment-related toxicities and encouraging survival. Molecular prognostic markers will determine most favorable groups in future.

Simple diagrammatic method to delineate male urethra in prostate cancer radiotherapy: an MRI based approach.

Stereotactic body radiotherapy (SBRT) is being increasingly utilized in the treatment of prostate cancer. With the advent of high-precision radiosurgery systems, it is possible to obtain dose distributions akin to high-dose rate brachytherapy with SBRT. However, urethral toxicity has a significant impact on the quality of life in patients with prostate cancer. Contouring the male urethra on a CT scan is difficult in the absence of an indwelling catheter. In this pictorial essay, we have used the MRI obtained for radiotherapy planning to aid in the delineation of the male urethra and have attempted to define guidelines for the same.

Quantification of coronary artery motion and internal risk volume from ECG gated radiotherapy planning scans.

BACKGROUND: Radiotherapy for carcinoma of breast and thoracic structures involves inadvertent radiation to heart and coronary arteries (CA). Coronary artery stenosis in high radiation dose segments has been documented. Cardiac and respiratory motion induced displacement of CA and internal risk volume (IRV) margin remains inadequately quantified. MATERIAL AND METHODS: Twenty cases of carcinoma breast, lung and lung metastasis were enrolled in this study. ECG gated intravenous contrast enhanced computed tomography (CECT) scans were performed in inspiratory breath hold (IBH) and expiratory breath hold (EBH). The images were segregated into inspiratory systole (IS), inspiratory diastole (ID), expiratory systole (ES) and expiratory diastole (ED) sets. Left anterior descending (LAD), limited segment of LAD close to chest wall (short LAD), right coronary artery (RCA), Left circumflex artery (LCX) and left ventricle (LV) were delineated in all four sets. Mean displacements in systole versus diastole and inspiration versus expiration were calculated in three co-ordinates [anterio-posterior (Z), left-right (X) and cranio-caudal (Y)]. RESULTS: Mean of displacement (mm) between systole and diastole (IS versus ID; and ES versus ED) in X, Y, Z co-ordinates were: LAD 3.0(±1.6), 2.8(±1.5), 3.6(±2.0); Short-LAD 3.0(±1.1), 0.8(±0.4), 2.4(±0.6); LV 2.4(±1.6), 1.7(±1), 5.0(±1.5); LCX 4.9(±1.6), 2.9(±1.3), 5.1(±1.9); RCA 6.6(±2.2), 3.6(±2.1), 5.9(±2.2). Mean displacement between inspiration and expiration (IS versus ES; and ID versus ED) in X, Y, Z axes were: LAD 3.3(±1.5), 8.0(±3.4), 3.8(±1.8); Short-LAD 2.7(±1), 12.2(±4.4), 3.3(±1.5); LV 2.9(±1.4), 9.8(±3.3), 4.7(±1.9); LCX 2.9(±.8), 9.7(±3.2), 6.2(±2.5); RCA 2.6(±1.3), 7.6(±2.5), 3.8(±1.7). CONCLUSION: Radial (RM), cranio-caudal margin (CC) of 7mm, 4mm in breath-hold radiotherapy whereas RM, CC of 7mm, 13mm respectively in free breath radiotherapy will cover the range of motions of CA, LV and can be recommended as IRV for these structures.

Clinical outcomes of adaptive radiotherapy in head and neck cancers.

OBJECTIVE: The present study evaluated the efficacy and toxicity of adaptive radiotherapy (RT) among patients with head and neck cancer. METHODS: 36 patients eligible for radical RT underwent RT planning scans and were planned for 54-Gy dose to both high-risk and low-risk target volumes in Phase I. All patients underwent a second (adaptive) scan during the fifth week of RT. Phase II plans for 16 Gy to high-risk planning target volume were developed on these mid-treatment scans. The primary end point was local response. Disease-free survival (DFS), overall survival (OS) and treatment-related morbidity were secondary end points. RESULTS: Median reductions in gross primary and nodal disease volumes on mid-treatment scans were 34% and 43.2%, respectively. 16 patients experienced grade 3 acute mucositis. No patient had grade 3 or above haematologic toxicity. Four patients developed local recurrences, all within the RT field. Median DFS and OS were 17.5 and 23.5 months, respectively. CONCLUSION: Adaptation to changes in the anatomic and tumour volume or shape may help tilt the balance towards more efficient dose delivery as well as better normal tissue sparing. ADVANCES IN KNOWLEDGE: This study supports the need for adaptive replanning for minimizing normal tissue toxicity without compromising local control and adds to the existing body of literature.

Simple diagrammatic approach to delineate duodenum on a radiotherapy planning CT scan.

In recent years, there has been increasing application of intensity-modulated radiotherapy and stereotactic body radiotherapy for the treatment of abdominal malignancies (stomach, pancreas, liver, spinal metastases). This warrants accurate delineation of organs at risk, especially the duodenum. The tortuous and curvy anatomy of duodenum often indistinguishable from adjoining organs is a practical challenge. Radiation Therapy Oncology Group (RTOG) has already published upper abdominal normal structure contouring guidelines to ease the delineation process. This pictorial essay following the RTOG guideline elaborates the step-by-step identification of the different parts of duodenum in relation to the adjoining important structures.

Analysis of intrafraction motion in CyberKnife-based stereotaxy using mask based immobilization and 6D-skull tracking†.

Purpose: Analysis of intrafraction motion in patients with intracranial targets treated with frameless, mask based stereotactic radiosurgery / radiotherapy using standard couch and 6D-skull tracking on CyberKnife. Materials and methods: Twenty-seven treatment datasets of fifteen patients were analyzed. For each sequential pair of images, the correction to the target position (position "offset") in six-degrees of motion was obtained. These offsets were used to calculate intrafraction shifts, and their statistical distribution. PTV margins were calculated, based on Van Herk formula. Results: The mean ± 1 SD intrafraction translationals were 0.27±0.61mm in left-right, 0.24±0.62mm in antero-posterior and 0.14±0.24mm in supero-inferior direction, and rotations were 0.13±0.21 degrees roll, 0.18±0.25 degrees pitch and 0.28±0.44 degrees yaw. Most intrafraction shifts were ≤ 1mm and 1 degree. Fourteen instances of intrafraction shifts exceeding the robotic correction threshold were noted. Calculated PTV margins were 1mm, 1mm and 0.4mm for for left-right, antero-posterior and supero-inferior directions, respectively. Conclusions: CyberKnife 6D-skull tracking with 1mm PTV margin effectively compensates for intrafraction motion. The occasional large intrafraction movements may assume significance for techniques not employing intrafraction motion management.

Chemoradiation in elderly patients with head and neck cancers: a single institution experience.

AIMS: To evaluate the efficacy and toxicity of concurrent chemoradiation in patients with head and neck cancers aged 65 and older. MATERIALS AND METHODS: Thirty-two elderly patients were treated with radical chemoradiation. Twenty-six (81.3%) out of thirty-two patients had stage III-IV disease. Twenty-nine (90.6%) patients received concurrent weekly cisplatin or carboplatin, 3 (9.4%) patients received concurrent cetuximab or nimotuzumab. Total dose of radiotherapy ranged from 66Gy to 70Gy. RESULTS: Twenty-nine patients (90.6%) completed at least 5cycles of concurrent chemotherapy. Twenty-four (77.6%) patients achieved complete response. Fourteen (45.2%) patients experienced grade 3 mucositis. None of our patients developed grade 3 or above hematological toxicity. Loco-regional control and overall survival at 2year were 71.6% and 88.9%, respectively. CONCLUSIONS: Chemoradiation in elderly patients with high precision radiotherapy is a feasible option.

Incidental radiation to axilla in early breast cancer treated with intensity modulated tangents and comparison with conventional and 3D conformal tangents.

PURPOSE: To analyze incidental radiation doses to minimally dissected axilla with Intensity modulated radiotherapy (IMRT), 3D conformal radiotherapy (3DCRT) and standard tangents (ST). METHODS & MATERIALS: We prospectively evaluated incidental radiation to axilla in fifty cases of early breast cancer treated with breast conservation surgery with sentinel node biopsy alone followed by whole breast irradiation with IMRT. Three plans were devised for each CT dataset, comprising ST, 3DCRT and IMRT tangents. Doses to axillary nodal levels I, II and III were evaluated for mean dose, V95, V90, V80 and V50. Comparisons were made using ANOVA. RESULTS: The mean doses delivered to axilla by the three techniques (IMRT, 3DCRT, ST) were: 78% (range 67-90, SD ± 5.2%), 80% (63-95, ±7.5%) and 87% (73-98, ±4.8%) for level I (IMRT vs ST; p = 0.037); 70% (46-89, ±12.4%), 72% (34-93, ±15.5%) and 65% (29-87, ±11.8%) for level II; and 51% (28-76, ±11.1%), 53% (19-86, ±13.7%) and 41% (6-72, ±10.6%) for level III, respectively. V90 values (volume receiving 90% of dose) for the three techniques were 49% (43-53, ±2.7%), 57% (51-65, ±3.1%) and 73% (65-80, ±3.4%) for level I (IMRT vs. ST; p = 0.029); 35% (26-42, ±4.7%), 41% (33-50, ±4.2%) and 25% (17-36, ±4.5%) for level II (IMRT vs ST; p = 0.068); and 15% (9-22, ±3.4%), 16% (10-24, ±3.7%) and 8 (5-12, ±3.1%) for level III (IMRT vs ST; p = 0.039), respectively. CONCLUSION: Axillary levels I and II (lower axilla) receive substantial amount of incidental radiation doses with all the three techniques; however, conformal techniques (IMRT, 3DCRT) deliver significantly lesser incidental radiation to lower axilla than ST technique.

Frame-based radiosurgery: Is it relevant in the era of IGRT?

PURPOSE: To assess the setup errors and intrafraction motion in patients treated with frame-based and frameless stereotactic radiosurgery (SRS). MATERIALS AND METHODS: Ten patients treated with frame-based and six patients treated with frameless radiosurgery were prospectively enrolled in the study. Leksell frame was used for frame-based and a customized uniframe orfit cast for frameless techniques. Cone beam computed tomography (CBCT) scans were taken immediately before and after each treatment to evaluate the positional accuracy and corrections applied with the use of hexapod couch for both groups. RESULTS: The mean translational shifts with frame-based SRS were 1.00 ± 0.30 mm in the lateral direction (X), 0.20 ± 1.20 mm in craniocaudal direction (Y) and -0.10 ± 0.31 mm in the anteroposterior direction (Z). The rotational shifts for frame-based treatments were as follows: roll 0.32 ± 0.70, pitch 0.44 ± 0.66 and yaw 0.20 ± 0.4. For frameless SRS, translational shifts were -0.40 ± 0.90, 1.10 ± 1.10, and 0.50 ± 1.30 mm in X, Y, and Z directions, respectively, and rotational shifts were -0.11 ± 0.78, 0.20 ± 0.44, and 0.29 ± 0.35 in roll, pitch, and yaw, respectively. Intrafraction shifts with frame-based SRS were: X = 0.60 ± 1.80 mm, Y = 0.20 ± 0.60 mm, and Z = 0.00 ± 0.05 mm; and rotational shifts were: roll 0.01 ± 0.27, pitch 0.06 ± 0.15, and yaw 0.01 ± 0.09. For frameless SRS, these were: X = 0.11 ± 0.20 mm, Y = 0.20 ± 0.40 mm, and Z = 0.20 ± 0.20 mm and rotational shifts were: roll 0.09 ± 0.23, pitch 0.00 ± 0.12, and yaw 0.00 ± 0.09. CONCLUSIONS: In our experience, set up accuracy of frameless SRS is as good as frame-based SRS. With availability of verification methods such as CBCT and hexapod couch, an accurate and precise treatment delivery is feasible with frameless techniques.

Molecular and circulatory expression of insulin growth factors in Indian females with advanced cervical cancer.

BACKGROUND: Recent studies have demonstrated an association between insulin growth factor (IGF) and insulin growth factor binding protein-3 (IGFBP-III) serum levels and increased risk for various cancers. However, little information is available on clinical implications of the IGF system in Indian patients with cervical cancer. This study explored associations by analyzing their expression profiles in cervical cancer cases. MATERIALS AND METHODS: Totals of 50 patients with advanced cervical cancer and 40 healthy controls were enrolled. Human papillomavirus (HPV) and cervical biopsy sample were obtained from all participating women. Circulatory levels were estimated by ELISA and the tissue expression was assessed using RT-PCR and Western blotting. RESULTS: Levels of IGF-I and II showed significant increase whereas IGFBP-III showed significant decline in all patients as compared to controls. Spearman correlation analysis between IGFs and HPV status showed significant correlations. CONCLUSIONS: We demonstrated elevated circulating levels and tissue expression of IGF-I and IGF-II in advancer cancer cervix patients, as compared with controls, with a converse trend being apparent for IGFBP-III. In future, associations of the IGF system and clinical outcome of cervical cancer patients in post treatment samples might point to significance in disease mapping as a prognostic marker after validation with a larger patient series.

Set-up uncertainties: online correction with X-ray volume imaging.

AIM: To determine interfractional three-dimensional set-up errors using X-ray volumetric imaging (XVI). MATERIALS AND METHODS: Between December 2007 and August 2009, 125 patients were taken up for image-guided radiotherapy using online XVI. After matching of reference and acquired volume view images, set-up errors in three translation directions were recorded and corrected online before treatment each day. Mean displacements, population systematic (Σ), and random (σ) errors were calculated and analyzed using SPSS (v16) software. Optimum clinical target volume (CTV) to planning target volume (PTV) margin was calculated using Van Herk's (2.5Σ + 0.7 σ) and Stroom's (2Σ + 0.7 σ) formula. RESULTS: Patients were grouped in 4 cohorts, namely brain, head and neck, thorax, and abdomen-pelvis. The mean vector displacement recorded were 0.18 cm, 0.15 cm, 0.36 cm, and 0.35 cm for brain, head and neck, thorax, and abdomen-pelvis, respectively. Analysis of individual mean set-up errors revealed good agreement with the proposed 0.3 cm isotropic margins for brain and 0.5 cm isotropic margins for head-neck. Similarly, 0.5 cm circumferential and 1 cm craniocaudal proposed margins were in agreement with thorax and abdomen-pelvic cases. CONCLUSION: The calculated mean displacements were well within CTV-PTV margin estimates of Van Herk (90% population coverage to minimum 95% prescribed dose) and Stroom (99% target volume coverage by 95% prescribed dose). Employing these individualized margins in a particular cohort ensure comparable target coverage as described in literature, which is further improved if XVI-aided set-up error detection and correction is used before treatment.

Synchronous malignant vagal paraganglioma with contralateral carotid body paraganglioma treated by radiation therapy.

Paragangliomas are rare tumors and very few cases of malignant vagal paraganglioma with synchronous carotid body paraganglioma have been reported. We report a case of a 20-year old male who presented with slow growing bilateral neck masses of eight years duration. He had symptoms of dysphagia to solids, occasional mouth breathing and hoarseness of voice. Fine needle aspiration cytology (FNAC) performed where he lived showed a sinus histiocytosis and he was administered anti-tubercular treatment for six months without any improvement in his symptoms. His physical examination revealed pulsatile, soft to firm, non-tender swellings over the anterolateral neck confined to the upper-mid jugulo-diagastric region on both sides. Direct laryngoscopy examination revealed a bulge on the posterior pharyngeal wall and another over the right lateral pharyngeal wall. Magnetic resonance imaging (MRI), 99mTc-labeled octreotide scan and angiography diagnosed the swellings as carotid body paraganglioma, stage III on the right side with left-sided vagal malignant paraganglioma. Surgery was ruled out as a high morbidity with additional risk to life was expected due to the highly vascular nature of the tumor. The patient was treated with radiation therapy by image guided radiation to a dose of 5040cGy in 28 fractions. At a follow-up at 16 months, the tumors have regressed bilaterally and the patient can take solids with ease.

Pulmonary metastasis from renal synovial sarcoma treated by stereotactic body radiotherapy: a case report and review of the literature.

Primary synovial sarcoma of kidney is an uncommon neoplasm, metastasizing most commonly to lung. Surgery and/or palliative chemotherapy for pulmonary metastases is commonly used to improve tumor control and survival. Stereotactic body radiotherapy (SBRT) is a relatively new approach to treat pulmonary metastasis, encouraged by the results of cranial and spinal stereotactic radiosurgery. The local control and toxicity profile of patients with pulmonary metastasis treated with SBRT are comparable to pulmonary metastatectomy. Furthermore, with advancement of imaging techniques, immobilization techniques, tumor-tracking techniques, and treatment planning and delivery system, SBRT can now be alternatively employed for the treatment of pulmonary metastasis as a comparable substitute to surgical resection.

Primitive neuroectodermal tumor of prostate.

Primitive neuroectodermal tumors (PNETs) are malignant proliferations of small, undifferentiated neuroectodermal cells occurring mainly in children and share the same reciprocal translocation between chromosomes 11 and 22 and the same patterns of biochemical and oncogene expression as osseus and extraosseus Ewing's sarcoma. Some PNETs occur in the brain, while others (the peripheral PNETs) occur in sites outside the brain, such as in the extremities, pelvis and the chest wall. They mostly originate in the chest, pelvis and retroperitoneum; in rare cases, occurrence in the head and neck area has also been seen. We present a rare case of primitive neuroectodermal tumor arising in the prostate gland in a 25-year-old male. To the best of our knowledge, this is the first documentation of a primary peripheral primitive neuroectodermal tumor in the prostate gland of any patient from India and rarely reported in English literature.