Dosimetric evaluation of an ipsilateral intensity modulated radiotherapy beam arrangement for parotid malignancies.

BACKGROUND: We conducted a dosimetric comparison of an ipsilateral beam arrangement for intensity modulated radiotherapy (IMRT) with off-axis beams. PATIENTS AND METHODS: Six patients who received post-operative radiotherapy (RT) for parotid malignancies were used in this dosimetric study. Four treatment plans were created for each CT data set (24 plans): 1) ipsilateral 4-field off-axis IMRT (4fld-OA), 2) conventional wedge pair (WP), 3) 7 field co-planar IMRT (7fld), and 4) ipsilateral co-planar 4-field quartet IMRT (4fld-CP). Dose, volume statistics for the planning target volumes (PTVs) and planning risk volumes (PRVs) were compared for the four treatment techniques. RESULTS: Wedge pair plans inadequately covered the deep aspect of the PTV. The 7-field IMRT plans delivered the largest low dose volumes to normal tissues. Mean dose to the contralateral parotid was highest for 7 field IMRT. Mean dose to the contralateral submandibular gland was highest for 7 field IMRT and WP. 7 field IMRT plans had the highest dose to the oral cavity. The mean doses to the brainstem, spinal cord, ipsilateral temporal lobe, cerrebellum and ipsilateral cochlea were similar among the four techniques. CONCLUSIONS: For postoperative treatment of the parotid bed, 4-field ipsilateral IMRT techniques provided excellent coverage while maximally sparing the contralateral parotid gland and submandibular gland.

Patient-reported quality of life during definitive and postprostatectomy image-guided radiation therapy for prostate cancer.

PURPOSE: The importance of patient-reported outcomes is well-recognized. Long-term patient-reported symptoms have been described for individuals who completed radiation therapy (RT) for prostate cancer. However, the trajectory of symptom development during the course of treatment has not been well-described in patients receiving modern, image-guided RT. METHODS AND MATERIALS: Quality-of-life data were prospectively collected for 111 prostate cancer patients undergoing RT using the validated Prostate Cancer Symptom Indices, which assessed 5 urinary obstructive/irritative and 6 bowel symptoms. Patients who received definitive RT (N = 73) and postprostatectomy RT (N = 38) were analyzed separately. The frequency and severity of symptoms over multiple time points are reported. RESULTS: An increasing number of patients had clinically meaningful urinary and bowel symptoms over the course of RT. A greater proportion of patients undergoing definitive RT reported clinically meaningful urinary symptoms at the end of RT compared with baseline in terms of flow (33% vs 19%) and frequency (39% vs 18%). Individuals receiving postprostatectomy radiation also reported an increase in symptoms including frequency (29% vs 3%) and nocturia (50% vs 21%). Clinically meaningful bowel symptoms were less commonly reported. Patients receiving definitive RT reported an increase in diarrhea (9% vs 4%) and urgency (12% vs 6%) at the completion of RT compared with baseline. Both bowel and urinary symptoms approached their baseline levels by the time of first follow-up after treatment completion. The majority of patients who had clinically meaningful urinary or bowel symptoms during RT did not have them at 2 years or beyond, and development of new symptoms in the long term was uncommon. CONCLUSIONS: There is a modest increase in urinary and bowel symptoms over the course of treatment for individuals receiving definitive and postprostatectomy image-guided RT. These data can help inform both providers and patients regarding the trajectory of symptoms and allow for reasonable expectations regarding toxicity under treatment.

Incidence of subclinical nodal disease at the time of salvage surgery for locally recurrent head and neck cancer initially treated with definitive radiation therapy.

OBJECTIVES/HYPOTHESIS: To estimate the incidence of subclinical nodal disease at the time of isolated local recurrence (LR) after chemoradiotherapy for an initially staged N0 head and neck squamous cell carcinoma. METHODS: We retrospectively reviewed 44 patients who underwent salvage surgery with or without elective neck dissection (END) for an isolated LR between 1997 and 2010. The incidence of subclinical nodal disease was determined from the pathology reports and from clinical neck failures. RESULTS: Thirty patients received END. The overall incidence of subclinical nodal disease in patients with dissected necks was 10% (3/30 patients). The rate of regional control for the 14 observed necks was 100%. Three-year local control and overall survival rates for the END and non-END cohorts were 71% versus 73% (P=0.80) and 55% versus 64%, respectively (P=0.40). CONCLUSIONS: The risk of subclinical nodal disease is low for patients with an isolated LR after chemoradiotherapy.

Challenges scoring radiation pneumonitis in patients irradiated for lung cancer.

BACKGROUND AND PURPOSE: To quantify uncertainties in scoring radiation pneumonitis. MATERIALS AND METHODS: Records of 434 patients irradiated for lung cancer from 2000 to 2010 were retrospectively reviewed; IRB-approved study. From these, 121 received ≥ 60 Gy for non-small cell lung cancer (NSCLC) with ≥ 6 months follow-up. Patients where the physicians were uncertain of the diagnosis due to confounding factors were deemed "hard to score". Subgroups were defined based on lung dosimetric parameters, and frequencies in different subgroups were compared via Fisher's exact test. RESULTS: 21/121 of patients were considered to have pneumonitis; median follow 17 months. Of these, 10/21 were "hard to score"; reasons including acute COPD exacerbation, infection, and tumor progression. "Hard to score" pneumonitis was slightly more common in patients with a COPD history (15%) vs. without COPD (4%) (p=0.05); and with a pre-RT FEV1<1.7 L (16%) vs. ≥1.7 L (4%) (p=0.09). Rates of "unambiguous" pneumonitis trended to be non-significantly slightly higher in patients higher mean lung doses, V5, and V30. CONCLUSION: Radiation pneumonitis occurred in 17% of patients undergoing RT for NSCLC; with diagnostic uncertainty in 48% of these. Poor pre-RT pulmonary function increases the rate of "hard to score" pneumonitis. Dosimetric parameters are slightly better related to "unambiguous" than "hard to score" pneumonitis, as expected.

Compressive optic neuropathy due to orbital metastasis of a sacral chordoma: case report.

A 44-year-old man presented with unilateral proptosis and progressively deteriorating vision of his left eye over a 2-week period. He had a history of recurrent sacral chordoma for 1 year that had previously been treated with combined surgical excision, chemotherapy, and radiation therapy. MRI showed compression of the optic nerve by an orbital mass that proved to be an orbital metastasis of his sacral chordoma. The tumor mass was excised subtotally, and adjuvant orbital radiation therapy was administered.