Gregory M. Richards

Acute toxicity of high-dose-rate intracavitary brachytherapy with the MammoSite applicator in patients with early-stage breast cancer.

Background: Intracavitary brachytherapy with the MammoSite applicator as the sole radiation treatment in breast-conserving therapy is an option for women with early-stage breast cancer; we evaluated the acute toxicities associated with this treatment method.Methods: Thirty-one patients with 32 stage I or II breast carcinomas underwent breast-conserving therapy, which included lumpectomy with negative margins, sentinel node biopsy, or axillary dissection, followed by brachytherapy with the MammoSite applicator. Acute radiation skin complications were graded on the day of radiotherapy completion and at weeks 2, 4, 6, and 12 after radiation treatment. Cosmesis was graded on the Harvard Scale at all follow-ups.Results: The median follow-up was 11 months (range, 4–15 months). Twenty-seven of the 31 patients were treated with the device as the sole method of radiotherapy. No acute toxicities occurred during the 5 days of treatment. Nineteen patients (68%) had no to mild acute skin reactions, and 25% developed bright erythema and patchy moist desquamation. Two patients (7%) developed confluent moist desquamation within the first 4 weeks (grade 3); this healed by week 12. All skin reactions were localized to the area overlying the balloon. Sixteen percent (5 of 32) of all breasts with implants developed infection. Cosmesis was good to excellent in 86% of cases.Conclusions: Most acute skin toxicities were mild. Our infection rate was higher than in prior studies that used interstitial brachytherapy. Cosmesis was good to excellent in most patients. Breast brachytherapy with the MammoSite catheter was well tolerated; further investigations of breast brachytherapy with this system are warranted.

Comprehensive IMRT Plus Weekly Cisplatin for Advanced Head and Neck Cancer: The University of Wisconsin Experience

We retrospectively examined the treatment efficacy and toxicity profile of intensity‐modulated radiotherapy (IMRT) plus concurrent weekly cisplatin chemotherapy in patients with locoregionally advanced head and neck squamous cell carcinoma (HNSCC).

Planned postradiotherapy neck dissection : Rationale and clinical outcomes

Objectives: In this study, we examine pathology results and clinical outcome for patients with locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN) who present with advanced neck disease and undergo planned postradiotherapy neck dissection.

Reirradiation of large-volume recurrent glioma with pulsed reduced-dose-rate radiotherapy.

PURPOSE Pulsed reduced-dose-rate radiotherapy (PRDR) is a reirradiation technique that reduces the effective dose rate and increases the treatment time, allowing sublethal damage repair during irradiation. PATIENTS AND METHODS A total of 103 patients with recurrent glioma underwent reirradiation using PRDR (86 considered to have Grade 4 at PRDR). PRDR was delivered using a series of 0.2-Gy pulses at 3-min intervals, creating an apparent dose rate of 0.0667 Gy/min to a median dose of 50 Gy (range, 20-60) delivered in 1.8-2.0-Gy fractions. The mean treatment volume was 403.5±189.4 cm3 according to T2-weighted magnetic resonance imaging and a 2-cm margin. RESULTS For the initial or upgraded Grade 4 cohort (n=86), the median interval from the first irradiation to PRDR was 14 months. Patients undergoing PRDR within 14 months of the first irradiation (n=43) had a median survival of 21 weeks. Those treated ≥14 months after radiotherapy had a median survival of 28 weeks (n=43; p=0.004 and HR=1.82 with a 95% CI ranging from 1.25 to 3.10). These data compared favorably to historical data sets, because only 16% of the patients were treated at first relapse (with 46% treated at the second relapse, 32% at the third or fourth relapse, and 4% at the fourth or fifth relapse). The median survival since diagnosis and retreatment was 6.3 years and 11.4 months for low-grade, 4.1 years and 5.6 months for Grade 3, and 1.6 years and 5.1 months for Grade 4 tumors, respectively, according to the initial histologic findings. Multivariate analysis revealed age at the initial diagnosis, initial low-grade disease, and Karnofsky performance score of ≥80 to be significant predictors of survival after initiation of PRDR. CONCLUSION PRDR allowed for safe retreatment of larger volumes to high doses with palliative benefit.

Linear accelerator radiosurgery for trigeminal neuralgia.

OBJECTIVE: To report the clinical outcomes following treatment of trigeminal neuralgia with linear accelerator-based radiosurgery. METHODS: Twenty-eight patients with medication refractory idiopathic trigeminal neuralgia were treated with a single fraction of 80 Gy to the trigeminal nerve root. For treatment delivery, a 4-mm collimator and a 7-arc technique were delivered using a stereotactic floor stand system with an isocenter stability of 0.2 ± 0.1 mm to minimize dose to the brainstem. Treatment delivery time was approximately 55 minutes. RESULTS: With a median follow-up of 12 months (range, 1–40 mo), 57% of patients achieved complete pain relief and 75% (exact 95% confidence interval, 55 to 89%) had their pain reduced to 3 or less on a 10-point pain scale. Median time to pain relief was 1 month. Four patients did not respond to treatment. The actuarial mean time to pain recurrence in responders was 14 months, and the actuarial mean response duration in major to complete responders was 16 months. Women had significantly longer mean time to pain recurrence than men (16 versus 7 months; P = 0.05). Three patients reported new mild facial numbness after radiosurgery and one patient developed neurotrophic keratopathy. CONCLUSION: Linear accelerator-based radiosurgery for medication refractory trigeminal neuralgia provides effective pain relief with a low complication rate.

Motexafin gadolinium in the treatment of brain metastases

Motexafin gadolinium (MGd) is a novel, MRI-detectable, anticancer agent that enhances the cytotoxic potential of radiation therapy through several mechanisms, including depleting intracellular reducing metabolites that are necessary for repairing the oxidative damage induced by irradiation. It has tumor-specific uptake, normal tissue sparing, and tolerable and reversible toxicities in clinical trials. MGd’s use in conjunction with whole-brain radiation therapy (WBRT) has demonstrated an improvement in neurocognitive decline, neurologic progression, and quality of life in patients with brain metastases from NSCLC. Its use in conjunction with radiosurgery and whole brain radiation therapy in the setting of brain metastases is currently being studied, as is MGd with radiation and temozolomide in patients with glioblastoma multiforme. MGd is also being actively investigated as a single agent or in combination with chemotherapy or radiation therapy in other tumors, including pediatric brain tumors, NSCLC, lymphoma, renal cell carcinoma, and pancreatic and biliary tumors.

Motexafin gadolinium: a novel radiosensitizer for brain tumors

Despite advances in the field of oncology, progress for patients with brain metastases and most primary brain tumors has been slow. New efforts to enhance the therapeutic index of radiation therapy are under way, including the use of radiosensitizers. Motexafin gadolinium (Xcytrin®) is one such novel agent with several unique properties that enhance the cytotoxic potential of radiation therapy, as well as several chemotherapeutic agents, and possibly has independent cytotoxicity in certain lymphoid malignancies. Motexafin gadolinium is very well tolerated with tumor specific uptake. The rationale for the use of this drug as well as its current and future role as a radiation enhancer in the management of brain tumors is reviewed.

Motexafin gadolinium: a novel radiosensitizer for brain tumors.

For a variety of reasons, the management of brain tumors, both primary and metastatic, remains a considerable challenge. As most systemic therapies do not cross the BBB at therapeutic doses, radiation and surgery have played primary roles in the management of these diseases. Despite significant advances in surgical techniques and radiation delivery, outcomes for most adult brain tumors continue to be poor. In an effort to enhance the effects of radiation in the brain, a variety of radiation sensitizers, including motexafin gadolinium, have been investigated. In the following manuscript, we summarize motexafin gadolinium and its role in brain tumors.

SU-FF-T-67: Comparison of Linac Based Fractionated Stereotactic Radiotherapy and Tomotherapy for Treatment of Skull-Base Tumors

Purpose: To compare and evaluate Tomotherapy and linac based fractionated stereotactic radiotherapy (FSRT) techniques in the treatment of lesions located in the base of skull. Method and Materials: Five patients with skull-base tumors, originally planned for optical guided FSRT to prescribed doses of 50.4 to 54Gy were replanned using TomoTherapy treatment planning software. All original CT scans, MR-CT fusion defined contours for target and normal structures, and PTV margins were used for Tomotherapy planning. Linac based plans utilized one of the following FSRT planning techniques: non-coplanar or coplanar intensity modulated radiation therapy (IMRT), multiple non-coplanar conformal arcs, and non-coplanar conformal radiation therapy (CRT). These plans were used as the gold standard to which the Tomotherapy plans were compared. Results: Use of both linac based FSRT and helical tomotherapy generated highly conformal treatment plans. Criteria used for comparison included prescription isodose to target volume (PITV) ratios, inhomogeneity index (II), equivalent uniform dose (EUD) for PTVs, mean normalized total doses (NTDmean) for critical structures, and size of 10, 20, and 30Gy isodose volumes. Non-coplanar linac based plans exhibited a 23% to 50% decrease in PITV ratios, increased II, similar EUD, and generally comparable to improved NTDmean for critical structures when compared to helical tomotherapy, which are coplanar by nature. Use of non-coplanar field arrangements also resulted in a 14% to 72% reduction of these low dose isodose volumes when compared Tomotherapy. All criteria except for the II, which was much improved with Tomotherapy, were found to be similar when coplanar linac based plans were compared to helical tomotherapy plans. Conclusion: Results show a distinct advantage in using non-coplanar beam arrangements for treatment of skull-base tumors. In the case where disease spreads far inferiorly, limiting the ability to use non-coplanar arrangements, Tomotherapy can be used to generate a comparable treatment plan.