Deep Inspiratory Breath-Hold Radiation for Left-Sided Breast Cancer using Novel Frame-based Tactile Feedback.

A frame providing tactile feedback for the reproducibility of deep inspiratory breath-hold (DIBH) is described. The frame, fitted across the patient, comprises a horizontal bar, parallel to the patient's long axis, and holds a graduated pointer perpendicular to it. The pointer provides individualized tactile feedback for reproducibility of DIBH. Within the pointer is a movable pencil, bearing a 5 mm coloured strip which becomes visible only during DIBH, and acts as a visual cue to the therapist. The average variation in separation in the planning and pretreatment cone-beam computed tomography of 10 patients was 2 mm (confidence interval 1.95-2.05). Frame-based tactile feedback is a novel, reproducible technique for DIBH.

Pubic Osteolysis in an Elderly Masquerading as Malignancy: A Case Report and Review of Literature.

INTRODUCTION: A rapidly progressive destructive lesion characterizes pubic osteolysis (PO) in the pubic bone due to an inadequate fracture healing response. It may be seen in pelvic insufficiency fractures (IF) secondary to radiation therapy (RT) of pelvic malignancies, occurring even in the absence of significant trauma. Such a radiological picture may distract the clinician towards a malignant etiology and may affect the management. CASE REPORT: A 79- year- old female, known case of carcinoma of the urinary bladder, underwent contrast-enhanced computed tomography (CT) (CECT) of the abdomen and pelvis as a routine follow- up and was found to have an osteolytic lesion in the right pubic bone, suggesting a malignant pathology. CT- guided biopsy did not reveal any malignant or infective etiology. The patient showed recovery with conservative management. CONCLUSION: Osteolytic lesions of the pubic bone can often occur following radiation for pelvic malignancies. It occurs due to impaired fracture reparative response by a bone afflicted by radiation therapy RT. It can be managed effectively with conservative analgesics, bisphosphonates, calcium, and Vitamin D supplementation. The radiographic picture can imitate malignant or infective lesions and provoke invasive testing for confirmation. The clinicians need to be conscious of this clinical entity to initiate proper treatment and avoid unnecessary investigations.

The Hippocampus: A New Organ at Risk for Postoperative Radiation Therapy for Bucco-alveolar Cancer? A Dosimetric and Biological Analysis.

PURPOSE: A significant proportion of patients with bucco-alveolar cancer are long-term survivors, warranting attention to survivorship issues. Decline in neurocognitive function after cranial irradiation for brain tumors correlates with a hippocampal maximum dose (Dmax) of more than 16 Gy, minimum dose (Dmin) of more than 9 Gy, and dose to 40% of the hippocampal volume (D40%) exceeding 7.3 Gy in 2-Gy equivalent dose (EQD2), respectively. We analyzed the utility of sparing the hippocampus in postoperative radiation therapy (PORT) for patients with bucco-alveolar cancer, given the proximity of target volumes to the hippocampus, by virtue of inclusion of the infratemporal fossa. METHODS AND MATERIALS: We instituted hippocampal sparing for patients with bucco-alveolar cancer receiving PORT in March 2018. Ten prior and 10 subsequent consecutive patients with pathologically staged I-IVA cancers of the buccal mucosa, alveolus, and retromolar trigone formed the control group (no hippocampal sparing) and the study group (hippocampal sparing), respectively. The brain and temporal lobes were prescribed dose constraints in both groups. Patients received doses of 60 to 66 Gy at 2 Gy per fraction using the image-guided intensity modulated radiation therapy / volumetric modulated arc therapy technique. Treatment plans were evaluated for (1) hippocampal dosimetric parameters, (2) planning target volume dosimetry and plan-quality indices, and (3) biological indices of equivalent uniform dose (EUD) and normal-tissue complication probability (NTCP) for impaired neurocognitive function. RESULTS: Hippocampal sparing significantly reduced the hippocampal DmaxEQD2, DmeanEQD2, and D40%EQD2 from 27 Gy to 10.9 Gy (P = .002), 14.3 Gy to 6.4 Gy (P = .002), and 15.5 Gy to 6.6 Gy (P = .005), respectively, with comparable plan-quality indices. The radiobiologically robust endpoints of ipsilateral hippocampal EUD (P = .005) and NTCP (P = .01) were statistically significantly improved. CONCLUSIONS: Meaningful dosimetric benefit, corroborated with radiobiological indices, was observed with hippocampal sparing. The feasibility and benefit of hippocampal sparing supports our view that the hippocampus should be incorporated as an organ at risk and attention should be given to neurocognitive function in patients with bucco-alveolar cancer who are receiving PORT.

Metachronous solitary plasmacytoma.

Solitary plasmacytoma is a rare disorder comprising 5%-10% of all plasma cell neoplasms. Progression to multiple myeloma is the most common pattern of relapse. Appearance of new lesions without any systemic disease is the most unusual pattern of relapse seen in <2% cases. We present a case of a 46-year-old female who presented with features of third and seventh cranial nerve palsy, diagnosed with solitary plasmacytoma, with no evidence of any systemic disease. As per standard recommendations, the patient received radiotherapy to the local site. The patient developed relapse twice, at three sites, during the follow-up period. Investigations revealed no evidence of any systemic disease. In view of repeat relapses, the patient was started on immune modulatory agent. Two and half years after the last radiotherapy, the patient is symptom free with no evidence of any new lesion.

Daily online localization using implanted fiducial markers and its impact on planning target volume for carcinoma prostate.

BACKGROUND: Aim of the study was to assess prostate motion on daily basis with respect to setup and to compare the shifts based on bony anatomy and gold fiducial markers. MATERIALS AND METHODS: Gold fiducial markers were inserted in prostate under U/S guidance and daily portal images were taken and compared with digitally reconstructed images, both using bony landmarks and fiducial markers as reference. A dose of 2 MU was given for two orthogonal images daily. The mean and standard deviation of displacement using gold seeds and bone were calculated. Systematic and random errors were generated. The planning target volume (PTV) was calculated using the Van Herk formula. RESULTS: A total of 180 portal images from 10 patients were studied. The mean displacement along x, y and z axes was 1.67 mm, 3.58 mm, and 1.76 mm using fiducial markers and 2.12 mm, 3.47 mm, and 2.09 mm using bony landmarks, respectively. The mean internal organ motion was 1.23 mm (+1.45), 3.11 mm (+2.69 mm); and 1.87 mm (+1.67 mm) along x, y and z axes, respectively. The PTV to account for prostate motion if daily matching was not done was 4.64 mm, 10.41 mm and 4.40 mm along lateral, superoinferior, and anteroposterior directions, respectively. If bony landmarks were used for daily matching, margins of 3.61 mm, 7.31 mm, and 4.72 mm in lateral, superoinferior, and anteroposterior directions should be added to the clinical target volume. CONCLUSION: Daily alignment using gold fiducial markers is an effective method of localizing prostate displacement. It provides the option of reducing margins, thus limiting normal tissue toxicity and allowing the possibility of dose escalation for better long-term control.