Standard Postoperative Radiation Therapy Research Articles

MET-05 Clinical investigation of treatment results and recurrence patterns of metastatic brain tumors from the viewpoint of postoperative irradiation

While whole brain radiation therapy (WBRT) had been the standard postoperative radiation therapy for metastatic brain tumors for long time, recently local radiation therapy (LRT) has be become to be a new standard due to the accumulation of clinical evidences. Treatment results and pattern of recurrence were retrospectively analyzed from view point of postoperative radiotherapy. In this study, totally 69 patients were included and they were divided into WBRT group or LRT group. We analyzed the number of lesions, treated era, overall survival after diagnosis of metastasis (OS), recurrence free survival after RT (RFS), and patterns of recurrences. The subjects consisted of 37males and 32 females and average age was 61.7 years old. There were 49 cases in the WBRT group and 20 cases in the LRT group. While all cases before November 2017 had WBRT performed, LRT was adopted mainly in cases with a small number of metastases since December 2017. Although there was a difference in the observation period between the two groups, OS tended to be longer in the LRT group (P=0.08), while RFS tended to be shorter in the LRT group (P=0.08). Radiological recurrence after RT was observed in 7 cases in both groups, and in WBRT group, all cases were local recurrence, whereas in LRT group, all cases were new lesions or disseminated recurrence. Although there are biases such as the difference in observation period between the two groups and the tendency to adopt WBRT in cases with a large number of metastases, there is a possibility that postoperative LRT is not inferior to WBRT, especially for cases with a small number of metastases. However, we have experienced some cases of disseminated recurrence, and so it is necessary to consider the resection fashion such as whether en-bloc resection or piece meal resection when selecting postoperative RT.

Patterns of Failure After Adjuvant Stereotactic Body Radiation Therapy for Pancreatic Cancer With Close or Positive Margins

PurposeThere is no consensus on treatment volumes for adjuvant stereotactic body radiation therapy (SBRT) for pancreatic cancer. Herein, we report patterns of failure after pancreatic SBRT for close/positive margins, which may inform target volume design. Methods and MaterialsAn institutional review board-approved retrospective review of patients with pancreatic adenocarcinoma treated with adjuvant SBRT for close/positive margins from 2009 to 2018 was conducted. Patterns of failure were defined as local (LF) within the tumor bed, regional (RF) within lymph nodes or anastomoses, or distant (DF). The cumulative incidence of locoregional failure was calculated using the cumulative incidence function accounting for the competing risk of death. LFs were mapped to the planning target volume (PTV) and classified as in-field (completely within the PTV), marginal (partially within the PTV), or out-of-field (completely outside the PTV). The location of LFs was compared with the Radiation Therapy Oncology Group 0848 contouring atlas to determine whether standard postoperative radiation therapy volumes would have included the LF. ResultsSeventy-six patients were treated with adjuvant SBRT for close (51.3%) or positive (48.7%) margins. Most (81.6%) received 36 Gy in 3 fractions, with a median PTV volume of 17.8 cc (interquartile range, 12.1-25.6). With a median follow-up of 17.0 months (interquartile range, 7.3-28.4), crude rates of first isolated LF, isolated RF, and DF +/– LF or RF were 9.2%, 6.6%, and 56.6%, respectively. Two-year cumulative incidences of LF, RF, locoregional failure, and DF were 34.9%, 30.8%, 49.2%, and 60.4%, respectively. Of 28 reviewable LFs, 21.4% were in-field while the remainder were completely outside (60.7%) or partially outside (17.9%) the PTV. Most LFs (92.9%) would have been encompassed by the Radiation Therapy Oncology Group consensus target volumes. ConclusionsAfter adjuvant pancreatic SBRT for close/positive margins, the majority of LFs were outside the PTV but within contemporary target volumes for conventional radiation therapy.

Nelfinavir treatment of adenoid cystic carcinoma: A case report

Adenoid cystic carcinoma (ACC) accounts for about 1% of all head and neck cancers and most commonly arises from the major and minor salivary glands, but may also develop in other sites.1 Complete resection with negative margins, the recommended surgical treatment, is commonly compromised by extensive perineural spread. Anatomic constraints such as extension to or through the skull base may also preclude meaningful resection, in which case the standard postoperative radiation therapy may serve as primary therapy instead. Despite displaying an indolent behavior, ACC is highly lethal. Disease-free survival at 5 years is around 50% and decreases to 30% to 40% at 15 years.2,3 Management options for recurrence are usually limited by the location and extent of the cancer (which is often metastatic), precluding further surgery or reirradation. Systemic treatment has been limited to toxic chemotherapy regimens with low efficacy. As a result, management of recurrent disease warrants further investigation.

Efficacy of postoperative radiation therapy for recurrent squamous cell carcinoma of the head and neck

Postoperative radiation therapy (RT) following surgical resection is often the recommended treatment for recurrent squamous cell carcinoma (SCC) of the head and neck. Despite common use, there are few published series evaluating such a management approach. We evaluated the efficacy of postoperative RT in 31 patients with recurrent SCC of the head and neck treated between 1981 and 1993. None of the patients had prior RT. All had complete resection of recurrent gross disease and no distant metastases. Maximum postoperative RT doses ranged from 59.4-70 Gy (median = 66 Gy). The 5-year disease-specific survival (DSS) and local control (LC) rate for all patients were 32 and 46%, respectively. Several prognostic factors were analyzed including site and stage of original primary tumor, disease-free interval, site of recurrence, status of surgical margins, and dose. Only site of recurrence significantly influenced both DSS and LC. Patients whose recurrence was limited to previously undissected tissue had 5-year DSS and local control rates of 60 and 74%, respectively, as compared to 19 and 29%, respectively, for patients whose recurrence was within previously dissected tissue (p = 0.05). Patients with recurrent SCC of the head and neck treated with standard postoperative RT following surgical resection do relatively well if the recurrence is within previously undissected tissue (i.e., nodal only); however, patients whose recurrence is within previously dissected tissue do poorly. Every effort to prevent locoregional disease recurrence at the time of primary therapy should be emphasized.

Adjuvant immunotherapy with interleukin 2 and lymphokine-activated killer cells after noncurative resection of primary lung cancer

A randomized controlled study of immunotherapy with interleukin 2 (IL-2) and lymphokine-activated killer (LAK) cells was conducted in 105 patients after noncurative resection of primary lung cancer. Half the patients received only the standard postoperative radiation therapy or chemotherapy (control group). The other half received immunotherapy with IL-2 and LAK cells in addition to the standard therapy (immunotherapy group). The primary endpoint was survival. The 7-year survival rate was greater in the immunotherapy group than in the control group (39.1% vs. 12.7%, P < 0.01). Among patients with squamous cell carcinoma, there was no statistical difference in outcome. In contrast, the 7-year survival rate among patients with adenocarcinoma in the control group was only 5.2% but for those in the immunotherapy group it was 38.9% ( P < 0.05). If resection was noncurative because of pulmonary metastasis, residual cancer or incomplete resection of lymph nodes, then immunotherapy was effective. If resection was noncurative because of residual cancer in the chest wall or diaphragm, or because of carcinomatous pleuritis or pleural dissemination, then there was no statistical difference in survival between the control group and the immunotherapy group.

Mitomycin C as an adjunct to postoperative radiation therapy in squamous cell carcinoma of the head and neck: Results from two randomized clinical trials

Purpose : This study was undertaken to assess the benefit of mitomycin C as an adjunct to postoperative radiation therapy in patients with operable squamous cell carcinoma of the head and neck. Methods and Materials : Between May 1980 and May 1991, 182 patients have been enrolled in two consecutive randomized clinical trials testing mitomycin C as an adjunct to radiation therapy in squamous cell carcinoma of the head and neck. In both trials, patients were stratified by stage, disease site and intent of therapy. This subset analysis includes 113 patients entered into these two randomized trials treated with surgery and postoperative radiation therapy. In the first trial, patients were randomized to receive standard postoperative radiation therapy alone compared with postoperative radiation therapy with concomitant mitomycin C. In the second trial, patients were randomized to postoperative radiation therapy or postoperative radiation therapy with concomitant mitomycin C plus dicoumarol. Results : As of November 1991, the 113 patients treated with surgery and postoperative radiation therapy in both trials had a median follow-up of 93 months. There have been a total of 12 local recurrences in the radiation therapy alone arm compared to 0 local recurrences in the radiation therapy/mitomycin C arm. There were eight regional recurrences in the radiation therapy alone arm compared with five regional recurrences in the mitomycin C arm. Patients in the mitomycin C arm experienced a superior 5-year actuarial local regional control rate (87% vs. 67%, p < .015) and a statistically significant disease-free survival benefit (67% vs. 44%, p < .03). Overall survival difference between the two arms (56% vs. 41%) has not reached statistical significance. Conclusions : We conclude from these prospectively designed randomized clinical trials that in patients with operable head and neck cancer treated with surgery and postoperative radiation therapy, concomitant administration of mitomycin C with radiation therapy will result in a statistically significant disease-free survival and local regional control benefit. We are currently investigating the value of other bioreductive alkylating agents as adjuncts to radiation therapy in patients with squamous cell carcinoma of the head and neck.